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DESIGN STANDARDS City of Auburn Engineering Division Public Works Department 25 West Main St. Auburn, WA 98001-4998 (253) 931-3010 FAX (253) 931-3053
City of Auburn Design Standards Table of Contents Chapter 1 – General Information Section: Page: 1.00 Preface 1-01 1.01 Contact Information 1-01 1.02 Reference Material 1-01 1.02.1 City
Reference Material 1-01 1.02.1.1 City of Auburn Construction Standards Manual 1-01 1.02.1.2 Engineering Handouts 1-02 1.02.1.2.1 Design Packets 1-02 1.02.1.2.2 General Handouts 1-02
1.02.1.2.3 Fee Related Handouts 1-02 1.02.1.2.4 Summaries 1-02 1.02.1.2.5 Technical Memos 1-02 1.02.2 Other Reference Material 1-03 1.03 Deviation from Standards 1-03 1.04 Contest of
City Engineer’s Decision 1-03 1.05 Changes to Standards 1-04 11/06/08 Design Standards Page i REF. H:\DEVELOPMENT\Manuals\Design Standards\TOC (11/08)
Chapter 2 – Plan Approval Process Section: Page: 2.00 Preface 2-01 2.01 Types of Plans 2-01 2.01.1 Grading Plans 2-01 2.01.2 Building Site Plans 2-01 2.01.3 Public Facility Extension
(FAC) Plans 2-02 2.01.4 Other Plans 2-02 2.02 Review and Approval Process 2-03 2.02.1 Submittals 2-03 2.02.2 City Review 2-04 2.02.3 Plan Approval 2-04 2.02.4 Project Close Out 2-05
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Chapter 3 – Plan Preparation Requirements Section: Page: 3.00 Preface 3-01 3.01 General Requirements 3-01 3.02 Plan Format 3-01 3.02.1 Grading Plans 3-01 3.02.2 Building Site Plans 3-02
3.02.3 Facility Extension (FAC) Plans 3-02 3.03 General Plan Requirements 3-02 3.03.1 Standard Plan Format 3-02 3.03.2 Drafting Standards 3-04 3.04 Plan Sheet Elements 3-04 3.04.1 Cover
Sheet 3-04 3.04.2 Temporary Erosion and Sediment Control (TESC) Plan Sheet 3-06 3.04.3 Grading Plan Sheet 3-07 3.04.4 Cross-Section Sheet 3-07 3.04.5 Detail Sheet 3-08 3.04.6 Grading
and Storm Drainage Plan Sheet 3-08 3.04.7 Utility Plan Sheet 3-09 3.04.7.1 Water 3-09 3.04.7.2 Sanitary Sewer 3-10 3.04.8 Utility Profile Sheet 3-10 3.04.8.1 Storm Drainage 3-10 3.04.8.2
Water 3-11 3.04.8.3 Sanitary Sewer 3-11 3.04.9 Public Street Plan and Profile Sheet 3-11 3.04.9.1 Plan View 3-11 3.04.9.2 Profile 3-12 3.04.9.3 Intersections 3-12 3.04.9.4 Typical Roadway
Sections 3-12 3.04.9.5 Striping and Signing 3-12 3.04.9.6 Signalization 3-12 3.04.9.7 Illumination 3-13 3.04.9.8 Streetscape 3-13 11/06/08 Design Standards Page iii REF. H:\DEVELOPMENT\Manuals\Design
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Chapter 3 – Plan Preparation Requirements (Cont.) Section: Page: 3.04.9.9 Other Features 3-13 3.04.10 Site Landscape Plan Sheet 3-13 3.04.11 Site Irrigation Plan Sheet 3-14 11/06/08
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Chapter 4 – Report Preparation Requirements Section: Page: 4.00 Preface 4-01 4.01 General Requirements 4-01 4.02 Report Types 4-01 4.02.1 Geo-Technical Reports 4-01 4.02.2 Storm Drainage
Reports 4-01 4.02.3 Other Reports. 4-02 4.03 Report Requirements 4-02 4.03.1 Geo-Technical Reports 4-02 4.03.2 Storm Drainage Reports 4-02 4.03.2.1 Background Computations for Sizing
Storm Drainage Facilities 4-04 4.03.2.2 Drainage Basin Report Summary 4-05 4.03.3 Other Reports 4-05 11/06/08 Design Standards Page v REF. H:\DEVELOPMENT\Manuals\Design Standards\TOC
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Chapter 5 – TESC, Clearing and Grading Section: Page: 5.00 Preface 5-01 5.01 TESC Design Criteria 5-01 5.01.1 Temporary Erosion and Sediment Control (TESC) 5-01 5.01.2 Temporary Detention
Systems 5-02 5.01.3 Temporary Retention Systems 5-02 5.01.4 Winterization Plan 5-03 5.02 Land Clearing 5-03 5.02.1 Purpose 5-03 5.02.2 Plan/Permit Requirements 5-04 5.02.3 General Requirements
5-04 5.03 Grading 5-04 5.03.1 Excavations 5-04 5.03.2 Fills 5-05 5.03.2.1 Preparation for Fill 5-05 5.03.2.2 Compaction 5-05 5.03.3 Slope Easement 5-05 5.04 Retaining Walls 5-06 5.04.1
Rockeries 5-06 5.04.1.1 Size 5-06 5.04.1.2 Material 5-06 5.04.1.3 Underdrains 5-06 5.04.2 Block Retaining Walls 5-06 5.04.2.1 Material 5-06 5.04.2.2 Underdrains 5-07 5.04.3 Reinforced
Concrete Walls 5-07 5.04.3.1 Material 5-07 5.04.3.2 Underdrains 5-07 5.04.4 Mechanically Stabilized Earth Walls (MSE Walls) 5-07 5.04.4.1 Material 5-07 5.04.4.2 Underdrains 5-07 5.05
Construction Sequence 5-07 5.05.1 Requirements 5-07 11/06/08 Design Standards Page vi REF. H:\DEVELOPMENT\Manuals\Design Standards\TOC (11/08)
Chapter 6 – Storm Drainage Section: Page: 6.00 Preface 6-01 6.01 General Requirements 6-01 6.02 Detention System Design Criteria 6-03 6.02.1 Detention Ponds 6-03 6.02.1.1 Purpose 6-03
6.02.1.2 Design 6-03 6.02.1.3 Dam Safety Requirements 6-04 6.02.2 Parking Lot Ponding 6-07 6.02.2.1 Purpose 6-07 6.02.2.2 Design 6-07 6.02.3 Detention Vaults 6-07 6.02.3.1 Purpose 6-07
6.02.3.2 Design 6-07 6.02.3.3 Detention Vault Inlet and Outlet Requirements 6-08 6.02.3.4 Detention Vault Access 6-08 6.03 Retention System Design Criteria 6-10 6.03.1 Purpose 6-10 6.03.2
Design 6-10 6.03.3 Retention System Infiltration Rate Requirements 6-10 6.03.4 Retention System Infiltration Rate Analysis 6-11 6.04 Discharge Control Requirements 6-11 6.04.1 Purpose
6-11 6.04.2 Design 6-11 6.04.3 Discharge Control Structures 6-12 6.05 Storm Drainage Quality Treatment 6-13 6.05.1 Purpose 6-13 6.05.2 General Requirements 6-13 6.05.3 Wetponds 6-13
6.05.3.1 Design Criteria 6-13 6.05.4 Wetvaults 6-17 6.05.4.1 Design Criteria 6-17 6.05.5 Bioswales 6-19 6.05.5.1 Design Criteria 6-19 11/06/08 Design Standards Page vii REF. H:\DEVELOPMENT\Manuals\De
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Chapter 6 – Storm Drainage (Cont.) Section: Page: 6.05.6 Oil/Water Separators 6-20 6.05.6.1 Design Criteria 6-20 6.05.7 Emerging Technologies 6-20 6.05.7.1 Design Criteria 6-20 6.06
Landscaping for Storm Drainage Facilities 6-21 6.06.1 Purpose 6-21 6.06.2 Design 6-21 6.06.3 Suggested Plants 6-22 6.06.3.1 Tree Selection Guide for Storm Drainage Detention/Retention
Facilities 6-22 6.06.3.2 Shrub Selection Guide for Storm Drainage Detention/Retention Facilities. 6-23 6.06.3.3 Perennial Groundcover Selection Guide for Storm Drainage Detention/Retention
Facilities 6-23 6.06.3.4 Shrub Selection Guide for Storm Drainage Detention/Retention Facilities 6-24 6.06.3.5 Grass Seed Mixes for Detention/Retention Facilities 6-24 6.06.3.6 Bioswale
Landscaping 6-25 6.06.3.6.1 Bioswale Grass Seed Mixes 6-25 6.06.3.6.2 Bioswale Suggested Plants 6-25 6.07 Storm Drainage Conveyance Systems 6-26 6.07.1 Purpose 6-26 6.07.2 Design 6-26
6.07.3 Public Street Drainage System Requirements 6-27 6.08 Stormwater Pollution Prevention Plan 6-27 6.08.1 Purpose 6-27 6.08.2 Stormwater Pollution Prevention Plan General Requirements
6-28 6.09 Public Storm Utility Easements 6-28 6.10 Material Requirements for Storm Drainage Systems 6-29 6.10.1 Storm Sewer Pipes 6-29 6.10.2 Storm Sewer Structures 6-29 11/06/08 Design
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Chapter 7 – Water Facilities Section: Page: 7.00 Preface 7-01 7.01 Design Criteria 7-01 7.01.1 Water Mains 7-01 7.01.1.1 Water Main Sizing 7-01 7.01.1.2 Water Main Location 7-02 7.01.1.3
Water Main Fittings 7-02 7.01.2 Water Services 7-03 7.01.2.1 Domestic Services 7-03 7.01.2.2 Other Services 7-04 7.01.3 Water Valves 7-04 7.01.3.1 Water Valve Sizing 7-04 7.01.3.2 Water
Valve Location 7-04 7.01.4 Pressure Reducing Stations 7-05 7.01.5 Fire Systems 7-05 7.01.5.1 Fire Hydrant Assemblies 7-05 7.01.5.2 Fire Sprinkler Systems 7-05 7.01.5.3 Fire Flows 7-06
7.01.5.4 Fire Department and Hydrant Access 7-07 7.02 Public Water Utility Easements 7-07 7.03 Material Requirements for Water Systems 7-07 11/06/08 Design Standards Page ix REF. H:\DEVELOPMENT\Manua
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Chapter 8 – Sanitary Sewer Facilities Section: Page: 8.00 Preface 8-01 8.01 Design Criteria 8-01 8.01.1 Sanitary Sewer Mains 8-01 8.01.1.1 Sanitary Sewer Main Sizing 8-01 8.01.1.2 Sanitary
Sewer Main Location 8-02 8.01.2 Sanitary Sewer Manholes 8-02 8.01.2.1 Sanitary Sewer Manhole Type and Size 8-02 8.01.2.2 Sanitary Sewer Manhole Locations 8-03 8.01.2.3 Sanitary Sewer
Manhole Parameters 8-03 8.01.3 Side Sewers 8-04 8.01.3.1 Side Sewer Parameters 8-04 8.01.4 Sanitary Sewer Cleanouts 8-04 8.01.5 Fats, Oils, and Grease, (FOG) and Sand/Grit Interceptors
8-05 8.01.6 Sanitary Sewer Pumps 8-06 8.02 Public Sanitary Sewer Utility Easements 8-06 8.03 Material Requirements for Sanitary Sewer Systems 8-06 8.03.1 Sanitary Sewer Pipes 8-06 8.03.2
Sanitary Sewer Structures 8-07 11/06/08 Design Standards Page x REF. H:\DEVELOPMENT\Manuals\Design Standards\TOC (11/08)
Chapter 9 – Utilities Section: Page: 9.00 Preface 9-01 9.01 Design Criteria 9-01 9.01.1 Private Utilities Located Within City Right-of-Way 9-01 9.01.1.1 Private Utilities Located Underground
9-01 9.01.1.2 Private Utilities Located Aboveground 9-01 9.01.2 Public and Private Utilities Located Underground Within City Right-of-Way 9-02 9.01.2.1 Perpendicular Trenching in Asphalt
Pavement 9-02 9.01.2.2 Longitudinal Trenching in Asphalt Pavement 9-03 9.01.2.3 Trenching in Concrete Pavement 9-03 9.01.2.4 Trenching in Other Right-of-Way Surfaces 9-03 11/06/08 Design
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Chapter 10 – Streets Section: Page: 10.00 Preface 10-01 10.01 Street Classifications 10-01 10.01.1 Arterials 10-01 10.01.1.1 Principal Arterial 10-02 10.01.1.2 Minor Arterial 10-02 10.01.2
Collectors 10-02 10.01.2.1 Residential Collector 10-02 10.01.2.2 Non-Residential Collector 10-02 10.01.2.3 Rural Collector 10-02 10.01.3 Local Streets 10-03 10.01.3.1 Local Residential
10-03 10.01.3.2 Local Non-Residential 10-03 10.01.3.3 Rural Residential 10-03 10.01.3.4 Private Street 10-03 10.01.4 Alleys 10-04 10.01.5 Private Access Roads (Shared Driveways) 10-04
10.01.6 Half-Streets 10-05 10.02 Street Design Requirements 10-07 10.02.1 Table 10-1 10-07 10.02.2 Street Geometry 10-08 10.02.2.1 Minimum Horizontal Curve Radius 10-08 10.02.2.2 Degree
of Horizontal Curvature 10-08 10.02.2.3 Tangents Between Reverse Curves 10-08 10.02.2.4 Superelevations 10-08 10.02.2.5 Vertical Grades 10-08 10.02.2.5.1 Vertical Curves 10-08 10.02.2.6
Cross Slopes 10-09 10.02.3 Right-of-Way 10-09 10.02.4 Roadway Width (Travel Way) 10-09 10.02.4.1 Inside Through Lanes and Curb Lanes 10-09 10.02.4.2 Center Turn Lanes 10-09 10.02.4.3
Other Lanes 10-09 11/06/08 Design Standards Page xii REF. H:\DEVELOPMENT\Manuals\Design Standards\TOC (11/08)
Chapter 10 – Streets (Cont.) Section: Page: 10.02.4.4 Road Edge 10-10 10.02.5 Street Layout 10-10 10.02.5.1 Residential Streets 10-10 10.02.5.2 Cul-de-sacs 10-10 10.02.5.2.1 Temporary
Cul-de-sacs 10-11 10.02.5.2.2 Permanent Cul-de-sacs 10-11 10.02.5.3 Traffic Volumes 10-11 10.03 Sight Distance 10-11 10.03.1 Sight Distance Categories 10-11 10.03.1.1 Stopping Sight
Distance 10-11 10.03.1.2 Decision Sight Distance 10-12 10.03.1.3 Passing Sight Distance 10-12 10.03.1.4 Intersection Sight Distance 10-12 10.03.2 Sight Distance Design 10-12 10.03.3
Table 10-2 10-13 10.03.4 Figure 10-1 10-14 10.03.5 Figure 10-2 10-15 10.04 Street Access Points 10-16 10.04.1 Public Street Intersections 10-16 10.04.1.1 Intersection Spacing 10-16 10.04.1.2
Horizontal Approach Angle 10-16 10.04.1.3 Curb and Right-of-Way Radius 10-16 10.04.1.4 Landing Approach 10-16 10.04.1.5 Street Crowns 10-16 10.04.2 Private Street Intersections 10-16
10.04.3 Table 10-3 10-17 10.04.4 Driveways 10-18 10.04.4.1 Driveway Locations 10-18 10.04.4.1.1 Functional Intersection Boundary 10-18 10.04.4.1.2 Table 10-4 10-19 10.04.4.1.3 Figure
10-3 10-19 10.04.4.1.4 Figure 10-4 10-20 11/06/08 Design Standards Page xiii REF. H:\DEVELOPMENT\Manuals\Design Standards\TOC (11/08)
Chapter 10 – Streets (Cont.) Section: Page: 10.04.4.2 Driveway Layout 10-21 10.04.4.3 Driveway Alignment (Horizontal & Vertical) 10-21 10.04.4.4 Driveway Widths 10-21 10.04.4.4.1 Residential
10-21 10.04.4.4.2 Commercial/Industrial 10-21 10.04.4.5 Restricted Access Driveways 10-22 10.05 Sidewalks 10-22 10.05.1 Width 10-22 10.05.2 Thickness 10-22 10.05.3 Meandering Sidewalks
10-23 10.05.4 ADA Access 10-23 10.06 Bikeways 10-23 10.07 Pavement Design 10-24 10.07.1 Design Requirements 10-24 10.07.1.1 Street Classification 10-24 10.07.1.2 Street Subgrade 10-24
10.07.1.3 Street Pavement Sections 10-25 10.07.2 Pavement Section Design Chart 10-26 10.07.3 Requirements for Engineered Pavement Sections 10-26 10.07.3.1 Traffic Requirements 10-26
10.07.3.2 Pavement Minimums 10-27 10.07.3.3 Soils Classifications 10-27 10.07.3.3.1 Poor Soils 10-27 10.07.3.3.2 Medium Soils 10-27 10.07.3.3.3 Good Soils 10-27 10.07.3.3.4 Excellent
Soils 10-27 10.07.3.3.5 Unified Soils Classification Symbols 10-28 10.07.3.4 Report Submittal 10-28 10.07.4 Materials Specifications 10-28 10.07.4.1 Gravel Base 10-28 10.07.4.2 Crushed
Rock 10-28 10.07.4.3 Asphalt Concrete Pavement 10-29 11/06/08 Design Standards Page xiv REF. H:\DEVELOPMENT\Manuals\Design Standards\TOC (11/08)
Chapter 10 – Streets (Cont.) Section: Page: 10.08 Landscaping 10-29 10.08.1 General Landscaping Requirements 10-29 10.08.2 Landscape Strip Components 10-29 10.08.3 Landscape Strip Dimensions
10-29 10.08.4 Plant Layers 10-29 10.08.5 Trees 10-30 10.08.5.1 Placement and Spacing 10-30 10.08.5.2 Tree Canopy Shape 10-31 10.08.5.2.1 V-Shaped Trees 10-31 10.08.5.2.2 Pyramidal Trees
10-31 10.08.5.2.3 Round Trees 10-31 10.08.5.2.4 Oval Trees 10-31 10.08.5.2.5 Columnar Trees 10-31 10.08.5.3 Root Direction Devices 10-31 10.08.5.4 Tree Planting Wells and Grates 10-31
10.08.6 Plant Selection 10-32 10.08.7 Plant Selection Table 10-33 10.08.8 Planting Methods and Maintenance 10-34 10.08.9 Establishment Period 10-34 10.08.10 Deviations from the Landscaping
Strip Standards 10-34 10.09 Mailboxes 10-35 10.09.1 Mailbox Locations 10-35 10.09.2 Mailbox Installation 10-35 10.10 Illumination 10-35 10.10.1 General 10-35 10.10.2 Design 10-35 10.10.3
Table 10-6 Lighting Schedule 10-36 10.10.4 Light Standard Foundations 10-36 10.10.5 Service Cabinet 10-36 10.10.6 Service Cabinet Foundations 10-36 10.10.7 Conduit 10-37 10.10.8 Junction
Boxes 10-37 10.10.9 Light Standards 10-37 10.10.10 Light Standard Handholes 10-36 11/06/08 Design Standards Page xv REF. H:\DEVELOPMENT\Manuals\Design Standards\TOC (11/08)
Chapter 10 – Streets (Cont.) Section: Page: 10.10.11 Photoelectric Controls 10-37 10.10.12 Luminaires 10-37 10.11 Survey Monuments 10-38 10.12 Guardrail 10-38 10.13 Bollards 10-39 10.14
Transit Stops 10-39 10.14.1 Bus Pullout Requirements 10-39 10.14.2 Locations for Bus Pullouts 10-39 10.14.3 Design of Bus Pullouts 10-38 10.15 Traffic Control Devices 10-40 10.15.1 Pavement
Markings 10-40 10.15.1.1 Crosswalks 10-40 10.15.1.2 Left-turn Channelization 10-40 10.15.1.3 Left-turn Lane at End of Two-way Left-turn Lane 10-40 10.15.1.4 Lane Division 10-40 10.15.1.5
Painted Islands 10-40 10.15.1.6 Two-way Left-turn Lanes 10-40 10.15.1.7 C-Curb 10-41 10.15.2 Signing 10-41 10.15.3 Construction Area Traffic Control 10-41 10.16 Roadway Barricades 10-41
10.17 Traffic Impact Analysis 10-42 11/06/08 Design Standards Page xvi REF. H:\DEVELOPMENT\Manuals\Design Standards\TOC (11/08)
11/06/08 Design Standards Page xvii REF. H:\DEVELOPMENT\Manuals\Design Standards\TOC (11/08) Chapter 11 – Site Design Section: Page: 11.00 Preface 11-01 11.01 Zoning Code Requirements
11-01 11.01.1 Building Setbacks and Lot Orientation Requirements 11-01 11.01.2 Landscaping 11-01 11.01.3 On-Site Parking Requirements 11-02 11.02 Land Use Approvals 11-02 11.02.1 Subdivisions
11-02 11.02.2 Planned Unit Developments 11-02 11.02.3 Gated Communities 11-02 Chapter 12 – City Telecommunication Utility Section: Page: 12.00 Preface 12-01 12.01 Design Criteria 12-01
12.01.1 Conduits 12-01 12.01.2 Splice Vaults and Pull Boxes 12-01
Chapter 1 -General Information 1.00 Preface The City of Auburn has adopted this Design Standards manual to encourage the standardization of design elements for consistency and to assure
that public safety needs are met. This manual contains engineering standards for use by professional civil engineers when designing facilities within the City of Auburn. The information
contained in this manual cannot provide for all situations and conditions that may be encountered. Specific provisions contained within this manual may not be appropriate for all locations
and existing conditions. These standards are intended to assist, but not substitute for, competent work by professional civil engineers. The design requirements contained within this
manual do not set legal standards of care, but provide guidance for possible engineering treatment under some circumstances. This chapter contains general information on this manual
and the City of Auburn. 1.01 Contact Information Public Works Department Fire Department City Hall (2nd Floor East Wing) North Fire Station 25 West Main Street 1101 "D" Street NE Auburn,
Washington 98001-4998 Auburn, Washington 98002-4016 Phone: (253) 931-3010 Phone: (253) 931-3060 Fax: (253) 931-3053 Fax: (253) 931-3055 Building Division Planning Department City Hall
(2nd Floor West Wing) City Hall (2nd Floor West Wing) 25 West Main Street 25 West Main Street Auburn, Washington 98001-4998 Auburn, Washington 98001-4998 Phone: (253) 931-3020 Phone:
(253) 931-3090 Fax: (253) 804-3114 Fax: (253) 804-3114 1.02 Reference Material 1.02.1 City Reference Material The reference material referred to herein may be obtained from the City
of Auburn Public Works Department: 1.02.1.1 City of Auburn Construction Standards Manual The Construction Standards manual sets forth the standards used during the construction of all
civil projects within the City’s jurisdiction including the extension of public water, sanitary sewer, storm drainage, and transportation facilities by private developers. The manual
is comprised of two sections. Section I contains the City’s Standard Specifications and Section II contains the City’s Standard Details. The Standard Specifications are a supplement
to, and a modification of, the “Washington State Department of Transportation (WSDOT/APWA) Standard Specifications for Road, Bridge and Municipal Construction,” latest edition. The Standard
Details are 8/9/2004 Design Standards Page 1-01 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 1 (8-04)
comprised of the City’s construction and design detail drawings for grading, water, sanitary sewer, storm drainage, and street work within the City that are supplemented by the “Washington
State Department of Transportation (WSDOT) Standard Plans for Road, Bridge and Municipal Construction.” 1.02.1.2 Engineering Handouts The following Handouts are currently available from
the Public Works Department to aid the public in planning and constructing development projects within the City of Auburn. Contact the Public Works Department for the most current list
available. 1.02.1.2.1 Design Packets These handouts contain checklists for developing a civil plan set for submittal, and updating approved civil plans after construction has been completed:
A. Plan Submittal Packet. B. Record Construction Document Packet. 1.02.1.2.2 General Handouts These handouts contain information describing various City permit, plan or project requirements:
A. Handout of T.E.S.C. Requirements for Small Sites. B. Handout for Residential Footing Drain Construction. C. Handout to Aid in the Design of Accessible Parking Spaces. D. Handout for
Cross-Referencing Standard Details. E. Handout on Accessing City Streets. 1.02.1.2.3 Fee Related Handouts These handouts contain information explaining some City development fees: A.
Handout on Transportation Impact Fees. B. Handout on School Impact Fees. C. Handout on Utility Connection Fees. 1.02.1.2.4 Summaries These handouts give a brief description of City policies
and requirements: A. Developer Public Facility Extension Process Summary. B. Summary of Street, Utility, and Site Work Requirements. C. Summary of Half-Street Requirements. D. Summary
of Bonding Requirements. 1.02.1.2.5 Technical Memos These handouts contain information that is subject to change or is too specific to be included in this manual: A. Technical Memo on
Small Site Water Quality Treatment Measures. B. Technical Memo on Backflow Prevention. C. Technical Memo on Stormwater Pump Requirements. 8/9/2004 Design Standards Page 1-02 REF. H:\DEVELOPMENT\Manua
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1.02.2 Other Reference Material The following publications should be used as additional reference material for design applications not covered by the City’s publications: A. Washington
State Department of Transportation (WSDOT) “Standard Specifications for Street, Bridge and Municipal Construction” as amended by the City’s Construction Standards Section I. These will
be referred to in City publications as the "WSDOT Standard Specifications." B. Washington State Department of Transportation (WSDOT) “Design Standards” (latest edition). C. American
Association of State Highway and Transportation Officials’ (AASHTO) “A Policy on Geometric Design of Highways and Streets” (latest edition). D. Department of Ecology’s (DOE) “Stormwater
Management Manual for Western Washington” (latest edition). E. State of Washington Department of Ecology’s “Criteria for Sewage Works Design” (latest edition). F. State of Washington
Department of Health (DOH) “Design Standards for Group A Public Water Systems” (latest edition). G. American Water Works Association (AWWA) Standard Specifications (latest edition).
H. King County’s “Surface Water Design Manual” (latest edition). I. “IES Lighting Handbook” (Illuminating Engineering Society of North America) (latest edition). 1.03 Deviation from
Standards The design standards contained herein should be used when designing a development project within the City of Auburn. In special cases, City standards may not best address a
particular engineering application. In these instances, a design deviation from the City’s standards may be requested from the City Engineer. All such requests shall include applicable
engineering justification for the deviation. Deviation requests and supporting justification must be sealed by a licensed professional civil engineer. The City Engineer will evaluate
the request and notify the applicant of his/her decision within fifteen (15) working days of the receipt of a complete deviation request. 1.04 Contest of City Engineer’s Decision Contest
of the City Engineer’s Engineer’s decision (Section 1.03) shall follow the following procedure: The applicant shall have fifteen (15) working days in which to submit a notice contesting
the decision of the City Engineer. The Public Works Director shall then have fifteen (15) working days in which to review the materials submitted and determine whether to uphold or modify
the City Engineer’s decision. If in the Public Works Director’s judgment the City Engineer’s decision should be amended in favor of resolving the protest, the Public Works Director shall
so direct the City Engineer. 8/9/2004 Design Standards Page 1-03 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 1 (8-04)
8/9/2004 Design Standards Page 1-04 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 1 (8-04) If the Public Works Director upholds the City Engineer’s decision, the Public Works
Director shall prepare a written staff paper detailing the rationale of the City Engineer’s decision and a finding of fact for submission to a hearing by the Public Works Committee of
the Auburn City Council. 1.05 Changes to Standards The City of Auburn’s Public Works Committee is authorized to make any additions, deletions, or modifications stated in these Standards.
(ACC 12.04.010)
Chapter 2 – Plan Approval Process 2.00 Preface This chapter contains standards and procedures that apply to the review and approval process for civil engineering plans. Development or
redevelopment of property within the City of Auburn, and/or within the limits of Auburn’s Utility Service Area, that require civil engineered plans to support a development action must
follow the processes outlined below. 2.01 Types of Plans This section contains information regarding the types of civil engineering plans submitted to the City. Specific plan requirements
are described in detail in Chapter 3. Civil engineering plans submitted to the City for review fall within the following four categories. 2.01.1 Grading Plans Grading plans are required
prior to the issuance of a Grading Permit and before commencement of construction in the following situations: A. Any application made for a Grading Permit that includes excavations
and/or fills exceeding one hundred cubic yards (100 yd3) of material. B. An application made for a Building Permit for all new non-residential developments and residential construction
of three units or more per lot. C. An application made for a Land Clearing Permit when the proposed work involves temporary roads and leveling of the site. D. An application made for
construction of a parking lot. E. An application made for a plat or a short plat that requires grading on the site resulting in the movement of over one hundred cubic yards (100 yd3)
of material. 2.01.2 Building Site Plans A Building Site Plan includes all civil site development requirements including site layout, site access, parking, utility service, and storm
drainage control. An approved Site Plan is required prior to the issuance of a Building Permit and before commencement of construction. Building Site Plans are required for the following
situations: A. A Building Site Plan along with a Grading Plan is required in association with a Building Permit application for all new non-residential developments and residential construction
of three (3) units or more per lot. B. Where an existing site is redeveloped such that new buildings and additions and/or alterations to existing buildings increase the assessed value
of the improvements on the property by greater than fifty percent (50%), and/or increase impervious area by more than five thousand square feet (5000 ft2) and/or alter site access requirements,
and/or connect to and impact City streets and utilities. 8/9/2004 Design Standards Page 2-01 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 2 (8-04)
C. The Change of Use of an existing site requires one or more of the following. 1. The installation of onsite parking resulting in the addition of over five thousand square feet (5000
ft2) of impervious area. 2. The alteration of the access to and from City streets including adding or removing driveways. 3. The installation of a new storm system to serve impervious
area of over five thousand square feet (5000 ft2) of impervious area. 4. The installation of code-required landscaping. (This will require the submittal of a landscape plan for review
and approval by the City of Auburn Planning Department). One example is the conversion of a residential property to a commercial use. The work covered by the Building Site Plan may include
the building and grading work; however, the applicant must make separate applications for a Building Permit and a Grading Permit. 2.01.3 Public Facility Extension (FAC) Plans An approved
Public Facilities Extension Plan (FAC Plan) is required prior to installing new or improving existing public sanitary sewer, water, storm drainage, and/or transportation facilities.
FAC Plans are required in the following situations: A. With a Building Site Plan when construction of the building requires the extension of a City water, sanitary sewer, or storm drainage
facility. B. With a Building Site Plan when construction of the building requires improvements to the street in front of the building. C. With a Grading Plan for public utility improvements
within Plat and Short Plats. D. For county projects where water and sanitary sewer mains within Auburn’s Utility Service Area are extended. Prior to preparing plans for submittal, the
applicant should obtain a “Developer Public Facility Extension Process Summary” from the City. This summary explains some of the basic requirements and steps of the FAC process. 2.01.4
Other Plans Some projects may also require other types of plans. The requirements for these additional plans will usually be addressed early in the submittal process. These plans could
include, but are not limited to, the following: A. Landscape plans. B. Land clearing plans. C. Irrigation plans. D. Wetland plans. 8/9/2004 Design Standards Page 2-02 REF. H:\DEVELOPMENT\Manuals\Desi
gn Standards\Chapter 2 (8-04)
2.02 Review and Approval Process 2.02.1 Submittals When submitting civil engineering plans to the City for review, the following steps should be taken to insure a complete submittal
and timely approval of civil engineering plans: A. Applicants are encouraged to meet with
City staff prior to plan submittal. (Pre-application information is available through Auburn Planning Department.) All plans and associated documents submitted to the City will be assigned
a permit number and receive a preliminary review to make sure that they adequately address the minimum requirements of a complete application. Any such plans and associated documents
not meeting these requirements will be returned to the applicant or his designee as unacceptable for review, with a written explanation of necessary corrections required prior to the
subsequent resubmission. B. Prior to preparing civil engineering plans for submittal, the applicant should obtain a Plan Submittal Packet from the City. This packet contains information
necessary necessary to prepare plans in conformance with City guidelines. The checklists within the Plan Submittal Packet shall be completed and submitted along with the civil engineering
plans. C. Civil Engineering plans and associated documents are to be submitted to the Building Division for processing by the City. D. After the receipt of a completed Facility Extension
(FAC) Application and FAC application fees, the City will make a preliminary review of the plans and supporting data to verify the scope of the proposed extension(s) and check for completeness
of the application. Once the City is satisfied with the completeness of the application and has verified the length of the extension(s), a letter will be sent requesting that the following
be submitted before any detailed FAC Plan review work will be performed: 1. An executed Facility Extension Agreement. 2. Forty percent (40%) of the total calculated Facility Extension
fee. (The remaining sixty percent (60%) will be due prior to construction.) E. The following number of documents and plans are required for a complete submittal: Plan sets Plan Submittal
Packet Stormwater Reports Geotechnical Reports Grading Plans 5 1 2 1 Building Site Plans 10 1 2 1 FAC Plans 10 1 2 1 F. All Plans submitted to the City shall be non-ammonia based prints.
G. All proposed public right-of-way dedications and easements not under the ownership of the applicant should be dedicated to the City prior to final plan approval. A title report will
be required to confirm property ownership. 8/9/2004 Design Standards Page 2-03 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 2 (8-04)
H. The following applicable information may be required along with the plan submittal: 1. Title report (required if right-of-way is being dedicated). 2. The final biologist report, including
the wetland mitigation plan when appropriate. 3. Traffic reports. 4. A copy of the final SEPA determination (for projects where the City isn’t the lead agency). 5. A copy of other applicable
applications (Short Plat, Plats, etc.). 6. Letter indicating how SEPA and/or other applicable application conditions have been accounted for in the development/plan process. I. All plans,
calculations, or reports submitted for review shall be stamped by a Washington State licensed professional civil engineer (PE). Mylar plans, calculations, and reports submitted for final
approval need to have the PE stamp signed and dated (sealed). J. Where the plan review process is running concurrent with other applications (SEPA, Plats, etc.), the above-referenced
information may not be available at time of plan submittal. In such instances, other required applications shall be provided prior to final plan approval. 2.02.2 City Review The City
will review plans and associated calculations and reports for conformance with City development requirements, standards, and policies. Red-line construction drawings, calculations, reports,
and written plan review comments will be returned to the applicant’s designated contact person for revisions. The applicant’s engineer shall revise construction drawings, calculations,
or reports to address City plan review comments. The revised drawings (the required number will be determined by the City) and associated calculations and reports along with the redline
comments shall be resubmitted to the City for additional review. 2.02.3 Plan Approval Once the plan review process is completed and all City review comments have been addressed, the
City will request that one copy of mylars be submitted for approval. A. Final reproducible plans shall be placed on a minimum 4-mil thick mylar and will be signed by the City Engineer
or his designate and shall remain on file with the City. (Note: No sticky back transparencies, no sepia mylars, and no Xerox mylars are accepted by the City.) Upon approval, the developer
will be required to check out these mylars from the City and make the required number (6 to 18 sets) of prints for the City, plus any required for themselves or the contractors, prior
to issuance of any construction permits. B. All applicable AutoCAD files shall be submitted to the City on a compact or floppy disk along with the mylars for integration into the City’s
Geographic Information System (GIS). For more information on AutoCAD file submittal, please obtain a copy of the City’s “Record Construction Document Packet.” 8/9/2004 Design Standards
Page 2-04 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 2 (8-04)
8/9/2004 Design Standards Page 2-05 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 2 (8-04) 2.02.4 Project Close Out The following is the basic process required for closing out
a project after construction has been completed: A. After completion of construction, the approved Mylars shall be checked out from the City. A copy of the “Record Construction Document
Packet” can be obtained from the City. This packet outlines the requirements to “as-built” the Mylars. B. All changes to the approved plan noted by the contractor and/or surveyor during
the construction process shall be clearly indicated on approved Mylar, preferably in red. The only exception will be in such instances when the changes are so drastic that they cannot
be clearly shown on the approved Mylar. In these cases, a new Mylar shall be printed with the changes shown, sealed by the engineer providing the record construction drawings, and included
with the approved Mylar as the as-built package. C. The “Record Drawing Certification” block on all sheets of the as-built Mylar shall be signed by the Engineer or Surveyor making the
corrections and the plan set returned to the City for verification by the City before the project will be accepted and closed out. D. A final storm drainage report/letter shall be submitted
to the City verifying that the storm facilities were installed as designed. The following documents shall also be completed for Facility Extension Projects prior to project close out.
A. All legal documents, including but not limited to a Bill of Sale and Utility Easements, shall be updated as need and executed. B. A “Developers Contribution Document” shall be obtained
from the City and completed. C. All Maintenance Bonds or Assignments of Funds for the one-year maintenance period shall be in place.
8/9/2004 Design Standards Page 3-01 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 3 (8-04) Chapter 3 -Plan Preparation Requirements 3.00 Preface This chapter describes how civil
engineering plans should be laid out to meet City requirements and provide a format that is easy to follow and understand. Civil engineering plans need to meet these basic standards
in order to move through the review process in an efficient manner. 3.01 General Requirements The following general requirements shall be taken into account when preparing civil engineering
plans for review and approval by the City: A. The general construction requirements for the City of Auburn shall be those contained in the “Washington State Department of Transportation
(WSDOT) Standard Specifications for Road, Bridge and Municipal Construction," current edition, except where supplemented or modified by the City in this manual or the City’s Construction
Standards manual. B. The civil engineering plans shall reference City Standard Specifications and Standard Details as necessary. The City’s Standard Specifications and Standard Details
are contained in the Construction Standards Manual, a copy of which shall be on-site during construction. C. All civil engineering plans and reports shall be prepared and sealed by a
Washington State licensed professional civil engineer. D. Property surveys shall be performed and sealed by a Washington State licensed professional land surveyor and be tied to the
current City datum (NAVD 88). A list of City Benchmarks is available upon request. E. All civil engineering plans and calculations shall be neat, uncluttered, legible, and in conformance
with the requirements herein. The City prefers that all plans be prepared utilizing AutoCAD software. F. Where applicable, shop drawings shall be submitted for review and approval prior
to construction. 3.02 Plan Format The City requires that plan sets be submitted in an order consistent with this section. Depending on the complexity or simplicity of the project, the
amount of detail and content required will be subject to change. 3.02.1 Grading Plans Grading plans shall consist of the following sheets: A. Cover sheet (See 3.04.1). B. Temporary Erosion
and Sediment Control (TESC)/Demo Sheet (Land Clearing when applicable) (See 3.04.2).
8/9/2004 Design Standards Page 3-02 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 3 (8-04) C. Grading Plan (See 3.04.3). D. Cross-Sections (See 3.04.4). E. Details (See 3.04.5).
3.02.2 Building Site Plans Building Site Plans shall consist of the following sheets: A. Cover Sheet (See 3.04.1). B. Temporary Erosion and Sediment Control (TESC)/Demo Sheet (Land Clearing
when applicable) (See 3.04.2). C. Storm Drainage and Grading Plan (See 3.04.6). D. Utility Plan (See 3.04.7). E. Cross-Sections (See 3.04.8). F. Details (See 3.04.5). G. Landscape Plan
(See 3.04.10). H. Irrigation Plan (See 3.04.11). If a separate associated grading plan has been submitted and approved, those areas covered under the grading plans will not need to be
readdressed in the building site plans. 3.02.3 Facility Extension (FAC) Plans These plans will be required whenever public streets, sanitary sewer, storm drainage, and/or water lines
are being extended or modified. The FAC portion of a plan set could consist of the following sheets: A. Cover Sheet (See 3.04.1). B. Temporary Erosion and Sediment Control (TESC)/Demo
Sheet (Land Clearing when applicable) (See 3.04.2). C. Utility Plan and Profiles (See 3.04.7 & 3.04.8). D. Street and/or Storm Plan and Profiles (See 3.04.8 & 3.04.9). E. Street Cross-Sections
and Additional Street Elements (See 3.04.9). F. Details (See 3.04.5). G. Street and/or Site Landscape Plans (See 3.04.10). FAC plans may also contain information normally associated
with either a grading or a building site plan. 3.03 General Plan Requirements 3.03.1 Standard Plan Format Applicable information in this section shall be shown on the plan set. A. Each
sheet of the plan set shall be stamped by a professional civil engineer licensed in the State of Washington. The stamp on the final Mylar, to be submitted for approval, shall be sealed.
B. North arrow and plan alignment shall be to the top, right, or left.
8/9/2004 Design Standards Page 3-03 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 3 (8-04) C. A title block shall be provided along the right-hand edge on each plan sheet. The
title block shall include the development title (in bold print), the name, address and phone number of the firm preparing the plan and the owner/developer, a revision block (showing
the date of the latest revision), page of pages numbering, and sheet title (e.g., road and storm drainage, grading, erosion/sedimentation control, water and sanitary sewer). D. Indicate
units of measurement for all slope callouts as either percent (%) or feet per foot (ft/ft). Do not mix units of measurement on a plan set. E. Provide all match lines with matched sheet
numbers (stationing). F. The street classification shall be provided under the street name on all plan views. G. A City of Auburn approval block (4"x2") shall be provided with the following
information in lower right corner of each plan sheet. Show project reference numbers (BLD for Building Permit, FAC for Public Facility Extension Plan, LND for Land Clearing Permit, STM
for Storm Permit and/or GRA for Grading/Erosion Control Permit) in the approval block area. PROJECT REF: THESE PLANS ARE APPROVED FOR CONFORMANCE WITH THE CITY OF AUBURN’S ENGINEERING
DIVISION REQUIREMENTS. APPROVED BY: DATE APPROVED: H. A sign-off block (4”x2”) shall be provided for Record Drawing certification and printed as follows on each plan sheet, located directly
to the left or directly above the approval block. RECORD DRAWING CERTIFICATION THESE DRAWINGS CONFORM TO THE CONTRACTOR’S CONSTRUCTION RECORDS. BY: DATE: TITLE/POSITION: CONFIRMED BY
CITY: DATE: The locations of the title blocks, approval blocks, and engineering stamp shall remain consistent throughout all the plan sheets.
8/9/2004 Design Standards Page 3-04 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 3 (8-04) 3.03.2 Drafting Standards Drafting requirements are as follows: A. Plan sheets shall
be printed on 24"x36" size paper. Approved plans shall be good quality, 4-mil thickness, Mylar or approved equal. No stick-on type material will be allowed. No Xerox, sepia, or toner-printed
Mylars are allowed. B. Lettering size shall be no smaller than one tenth (1/10) of an inch in height and shall be uppercase. Callouts and other information shall be printed horizontally
in most cases. C. Existing features shall be shown with dashed lines and/or half-toned (screened). D. Proposed features shall be shown with solid lines. The intent is to clearly distinguish
existing features from proposed improvements. E. Minimum scale shall be: 1. Site work: 1" = 40' horizontal. 2. Public facility work: 1" = 20' horizontal. Vertical scales should typically
be 1/10th the horizontal scale. For public facility work in areas with steep slopes, 1” = 5’ may be used in place of 1” = 2’. Use a scale that best utilizes paper space and gives the
best overall view of the site. F. Use APWA AutoCAD symbols in the legend to identify both existing and proposed improvements and utilities. 3.04 Plan Sheet Elements The following section
covers the basic elements that are required to be shown on the different plan sheets. While all plan sets will have a cover sheet, there are other sheets covered here that may or may
not be included in a particular projects plan set. 3.04.1 Cover Sheet The Title sheet(s) shall incorporate all the requirements listed in Section 3.02, plus the following applicable
items: A. A general scaled site plan covering an area approximately ten inches (10”) square. B. Vicinity map (approximate scale) with north arrow covering an area approximately five
inches (5”) square. C. Site address. D. Owner/Developer, address, contact, and phone number. E. Engineer/Surveyor/Architect, address, contact, and phone number. F. Elevations with City
datum ((NAVD 88) tied to City benchmarks with reference to the benchmarks’ numbers and locations indicated. G. The permit number in one-inch (1”) bold lettering shall be above the title
block (located on the right side of the sheet) on the cover sheet only. H. Sheet Index
1/21/2009 Design Standards Page 3-05 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 3 (8-04) I. Legend. J. Legal description including quarter section, section, township, and range.
K. Parcel numbers. L. Site zoning and adjacent zoning. M. Applicable plat name and lot numbers. N. Applicable site information including the number of parking spaces required and the
number of parking spaces provided. O. Type of building construction as defined by the adopted Building Code. P. Site access including adjacent driveways, roadways, and intersections
that may have an impact on the location and type of site access. Q. An overall site plan key map shall be shown if the plan set includes more than five (5) plan sheets, unless otherwise
directed by the city. R. The following nine (9) City of Auburn General Notes: 1. THIS DEVELOPMENT PROJECT SHALL CONFORM TO THE CITY OF AUBURN'S REQUIREMENTS AND BE IN ACCORDANCE WITH
THE APPROVED PLANS. ANY CHANGES FROM THE APPROVED PLAN WILL REQUIRE APPROVAL FROM THE OWNER, ENGINEER AND THE CITY. 2. ALL WORKMANSHIP AND MATERIALS SHALL CONFORM TO THE “WASHINGTON
STATE DEPARTMENT OF TRANSPORTATION (WSDOT) STANDARD SPECIFICATIONS FOR ROAD, BRIDGE, AND MUNICIPAL CONSTRUCTION” (2002 EDITION), EXCEPT WHERE SUPPLEMENTED OR MODIFIED BY THE CITY’S CONSTRUCTION
STANDARDS MANUAL. COPIES OF THE ABOVE DOCUMENTS SHALL BE AVAILABLE AT THE JOB SITE DURING CONSTRUCTION. 3. A PRE-CONSTRUCTION MEETING SHALL BE REQUIRED PRIOR TO THE START OF ALL CONSTRUCTION.
CONTACT THE PUBLIC WORKS DEPARTMENT AT 253-931-3010 TO SCHEDULE A MEETING. 4. LOCATIONS SHOWN FOR EXISTING UTILITIES ARE APPROXIMATE. THE CONTRACTOR IS CAUTIONED THAT OVERHEAD UTILITY
LINES MAY NOT BE SHOWN ON THE DRAWINGS. IT SHALL BE THE CONTRACTOR'S RESPONSIBILITY TO DETERMINE THE TRUE ELEVATIONS AND LOCATIONS OF ALL UNDERGROUND UTILITIES AND THE EXTENT OF ANY
HAZARD CREATED BY OVERHEAD UTILITY LINES. IDENTIFICATION, LOCATION MARKING AND RESPONSIBILITY FOR UNDERGROUND FACILITIES OR UTILITIES IS GOVERNED BY THE PROVISIONS OF CHAPTER 19.122
REVISED REVISED CODE OF WASHINGTON (RCW). PRIOR TO STARTING CONSTRUCTION, THE CONTRACTOR SHALL CALL ONE-CALL (1-800-424-5555) FOR UTILITY LOCATIONS (WATER, SANITARY SEWER, STORM SEWER,
GAS, POWER, TELEPHONE AND TELEVISION). 5. PRIOR TO THE START OF CONSTRUCTION A PROPOSED ROUTE AND SCHEDULE FOR HAULING MATERIAL TO THE SITE SHALL BE SUBMITTED TO THE CITY FOR APPROVAL.
IF THE CITY BELIEVES THAT THE PROPOSED HAUL ROUTE WILL ADVERSELY IMPACT THE STREET NETWORK, HAULING MAY BE LIMITED TO APPROPRIATE OFF-PEAK HOURS OR ALTERNATE ROUTES. 6. THE CONTRACTOR
SHALL BE RESPONSIBLE FOR PUBLIC SAFETY ON AND AROUND THIS PROJECT. PRIOR TO THE START OF WORK, ALL METHODS AND EQUIPMENT USED FOR TRAFFIC CONTROL AND STREET MAINTENANCE SHALL BE SUBMITTED
TO THE CITY FOR APPROVAL. CONTRACTORS AND THEIR SURETY SHALL BE LIABLE FOR INJURIES AND DAMAGES TO PERSONS OR PROPERTY SUFFERED BECAUSE OF CONTRACTORS OPERATIONS OR NEGLIGENCE CONNECTED
WITH THEM.
1/21/2009 Design Standards Page 3-06 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 3 (8-04) 7. ALL CONSTRUCTION SURVEYING FOR EXTENSIONS OF PUBLIC FACILITIES SHALL BE DONE UNDER
THE DIRECTION OF A WASHINGTON LICENSED LAND SURVEYOR OR A WASHINGTON LICENSED PROFESSIONAL CIVIL ENGINEER. 8. CERTIFIED DRAWINGS ARE REQUIRED PRIOR TO PROJECT ACCEPTANCE. REFER TO THE
CITY'S "RECORD CONSTRUCTION DOCUMENT" HANDOUT. 9. OTHER PERMITS REQUIRED INCLUDE____________________________________ S. Construction Sequence outlining a basic construction schedule.
See Section 5.05. 3.04.2 Temporary Erosion and Sediment Control (TESC) Plan Sheet TESC design shall be in accordance with Chapter 5 – Grading & Erosion Control, and include the following
applicable items: A. All existing site features and conditions shall be shown on this sheet including the existing topography. B. A phasing schedule for installing and removing TESC
measures, including the transition from the temporary storm drainage system to the permanent storm drainage system. C. A construction entrance to prevent tracking of sediments onto City
streets. See EROSION-01 for the City’s minimum requirement. Note that a wash pad and/or other mitigation may be required. D. Siltation control measures (i.e., siltation ponds, silt fences,
setbacks, hay bales, ditches, etc.) shall be provided as appropriate to protect adjacent properties. E. This sheet may also function as a demolition site plan and should indicate all
existing features and structures to be removed/demolished and those that will remain. F. Protection of downstream storm drainage conveyance facilities. G. Limits of clearing work. H.
Show existing trees six inches (6”) in diameter and larger for evergreens and four inches (4”) in diameter or larger for deciduous. Indicate if tree is to either be retained or removed.
Note that a land-clearing permit may be required. I. Provide temporary storm drainage retention or detention facilities including City of Auburn’s Standard Control Structure Detail No.
STORM-04. Include appropriate water surface (W.S.) elevations, seasonal high groundwater elevation, orifice sizes, design storms for the W.S. elevations, and release rates. J. Provide
site stabilization criteria including hydroseeding mixture and application rates. K. The following six (6) City of Auburn Grading and Erosion Control Notes: 1. WITHIN THE CITY OF AUBURN,
ALL REQUIRED SEDIMENTATION AND EROSION CONTROL FACILITIES INDICATED ON THE PLANS MUST BE CONSTRUCTED AND IN OPERATION PRIOR TO LAND CLEARING AND/OR OTHER CONSTRUCTION ACTIVITIES. THESE
FACILITIES SHALL BE MAINTAINED, AND UPGRADED IF NECESSARY, TO INSURE THAT SEDIMENT-LADEN WATER AND STORM DRAINAGE RUNOFF DOES NOT IMPACT THE ADJACENT PROPERTIES, NATURAL DRAINAGE WAYS,
OR THE EXISTING CITY STORM DRAINAGE SYSTEM. 2. THE SOURCES FOR ALL MATERIAL IMPORTED TO THE SITE SHALL BE APPROVED BY THE CITY. 3. THE STORM DRAINAGE DETENTION (RETENTION IF INFILTRATION
SYSTEM IS USED), SEDIMENTATION AND EROSION CONTROL FACILITIES DEPICTED ON THE APPROVED
8/9/2004 Design Standards Page 3-07 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 3 (8-04) DRAWINGS ARE INTENDED TO BE MINIMUM REQUIREMENTS TO MEET ANTICIPATED SITE CONDITIONS.
ADDITIONAL DRAINAGE AND EROSION CONTROL FACILITIES MAY BE REQUIRED AS SITUATIONS WARRANT DURING CONSTRUCTION. THE IMPLEMENTATION, MAINTENANCE, REPLACEMENT AND ADDITIONS TO THESE CONTROL
SYSTEMS SHALL BE THE RESPONSIBILITY OF THE PERMITTEE. 4. THE TEMPORARY EROSION CONTROL FACILITIES, INCLUDING ALL PERIMETER CONTROLS AND THE DETENTION (RETENTION IF INFILTRATION SYSTEM
IS USED) CONTROL PONDS, SHALL REMAIN IN PLACE UNTIL FINAL SITE CONSTRUCTION IS COMPLETED. AFTER CITY APPROVAL, THE CONTRACTOR WILL BE RESPONSIBLE FOR REMOVING ALL TEMPORARY FACILITIES.
5. THE CONTRACTOR WILL BE REQUIRED TO WATER THE SITE, AS NECESSARY, TO REDUCE DUST EMISSIONS AS A RESULT OF CONSTRUCTION ACTIVITY. THE CONTRACTOR SHALL ALSO SWEEP ALL AFFECTED PUBLIC
ROADS, AS NECESSARY, TO REMOVE MATERIAL DEPOSITED AS A RESULT OF PROJECT CONSTRUCTION ACTIVITY. 6. ALL AREAS OF ACTIVE EARTHWORK WHICH HAVE THE POTENTIAL FOR EROSION AND SEDIMENTATION
IMPACTS ON ADJACENT PROPERTIES, NATURAL DRAINAGE WAYS, OR THE EXISTING CITY STORM DRAINAGE SYSTEM MUST BE STABILIZED ACCORDING TO THE FOLLOWING SCHEDULE: FROM APRIL 1 TO SEPTEMBER 30,
AREAS AT FINAL GRADE AND THOSE THAT ARE SCHEDULED TO REMAIN UNWORKED FOR MORE THAN THIRTY DAYS SHALL BE STABILIZED WITHIN TEN DAYS. FROM OCTOBER 1 TO MARCH 31, EARTHWORK ACTIVITIES SHALL
BE CONDUCTED IN STAGES IN ORDER TO MINIMIZE SOIL EXPOSURE. EXPOSED SOILS WITH AN AREA GREATER THAN 5,000 SQUARE FEET THAT ARE SCHEDULED TO REMAIN UNWORKED FOR MORE THAN 24 HOURS AND
EXPOSED AREAS OF LESS THAN 5,000 SQUARE FEET THAT WILL REMAIN UNWORKED FOR MORE THAN SEVEN DAYS SHALL BE STABILIZED IMMEDIATELY. 3.04.3 Grading Plan Sheet The Grading design shall be
in accordance with Chapter 5 – Grading & Erosion Control, and include the following applicable items: A. Indicate approximate fill and/or excavation quantities in cubic yards. B. Show
the existing topography shaded back and overlaid by the proposed grades. C. Show existing and finished elevations and contours. Spot elevations may be required for relatively flat sites
to supplement the contour elevations as necessary to adequately reflect existing and finish grades. Provide spot elevations along property line and a minimum of thirty feet (30’) beyond
property line (at least fifty foot (50’) intervals). D. Show type of fill material and associated compaction requirements. E. Notes to protect and maintain erosion control facilities
during grading operations. Some projects may be able to combine the grading sheet with the erosion control and demo plan depending on the complexity of the project. 3.04.4 Cross-Section
Sheet The Cross-Section plan sheet(s) shall have the following applicable items: A. Cross-sections for fill and grading shall be shown through all properties to at least thirty feet
(30’) beyond the property lines. Adequate cross-sections shall be shown to represent the site. At a minimum this shall include one east-west and one north-south cross-section.
8/9/2004 Design Standards Page 3-08 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 3 (8-04) B. This sheet may also contain cross-sections for the temporary storm drainage pond.
C. The scale used for the site cross-sections on this sheet should match the scale on the other sheets. Some projects may be able to combine the cross-section sheet with the grading
sheet depending on the complexity of the project. 3.04.5 Detail Sheet The Detail sheet(s) shall have the following applicable items: A. Any detail that is specific to this project. B.
City Standard Details should not be shown on this sheet unless they need to be modified for a project specific application. C. Storm control manholes are normally shown on this sheet.
D. This sheet may also contain cross-sections for the temporary storm pond. City Standard Details should be called out on the applicable plan sheet using the detail number. 3.04.6 Grading
and Storm Drainage Plan Sheet Grading and Storm Drainage system design shall be in accordance with Chapter 5 – Grading & Erosion Control, and Chapter 6 – Storm Facilities, and include
the following applicable items: A. The layout of all the storm drainage pipes with the length, slope, and material type indicated in the labeling of the storm drainage pipes. Provide
arrows to indicate the direction of flow into the structures. B. Typical ditch section. C. Location of manholes and catch basins. Indicate type, stationing, offset, rim and invert elevations,
and number manholes and catch basins consecutively. D. Existing and proposed sanitary sewers and water mains (use ghost lines). Identify crossings and minimum distance between utilities.
E. Building downspouts or footing drain locations, inverts and connections to the storm drain system. F. For single-family home sites, indicate means for collection and discharge of
water from roof, foundation drains, and driveways. G. Provide arrows to indicate drainage direction in parking lots, roadway intersections and cul-de-sacs. H. Reference to the detail
and/or cross-section sheets for storm drainage detention or retention facilities such as the control discharge structure and pond crosssections. Indicate water surface elevations, allowable
discharge rates, and design storms. I. Show an emergency overflow to the public storm drainage system. J. Berm dimensions, material, and compaction requirements for ditches and detention
ponds where applicable. K. Indicate type of material and size of energy dissipaters (riprap, etc.). L. Provide details of the storm drainage water quality facility.
8/9/2004 Design Standards Page 3-09 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 3 (8-04) M. Limits of surface water ponding within parking lots. N. Trash racks as applicable.
O. Location and widths of easements. P. Location and type of pumps, if applicable. Q. Bioswale location, length, width, slopes, and cross-section. R. Planting and seeding requirements
with establishment procedure (construction sequence) for water quantity or quality systems. S. Finish floor elevations of all buildings. 3.04.7 Utility Plan Sheet The Utility sheet will
show the private connections to the public water and sanitary sewer systems and any required extensions of the public water and sanitary sewer systems. The Utility sheet(s) shall have
the following applicable items: 3.04.7.1 Water Water system design shall be in accordance with Chapter 7 – Water Facilities, and include the following items: A. Water pipe size, location,
and type of material. B. Details of connections to existing water mains. C. Valve size, locations and type. D. Fire hydrants locations. E. Air vac/blow-off locations. F. Pressure reducing
valve and associated vaults as required. G. Concrete blocking, mechanical, or restrained joint pipe support. H. Watermain, water meter, and fire hydrant easements. I. Meter and service
size and location. J. Irrigation meter size and location. K. Proposed irrigation line location, including backflow prevention and flow detection device. L. For buildings requiring fire
sprinklers, the following notes shall be shown on the plan: SPRINKLER SYSTEMS SHALL MEET THE FOLLOWING REQUIREMENTS:
1. FIRE LINE TO BE SIZED BY A FIRE PROTECTION ENGINEER. 2. BACKFLOW PROTECTION IS REQUIRED ON FIRE SPRINKLER LINES. 3. A SEPARATE DETAILED PLAN OF THE UNDERGROUND FIRE SPRINKLER LINE
SHALL BE APPROVED BY THE FIRE MARSHAL AND INSTALLED BY A WASHINGTON STATE CERTIFIED LEVEL “U” CONTRACTOR IN ACCORDANCE WITH WAC 212-80-010. A POST INDICATOR VALVE WILL BE INSTALLED ON
THE SPRINKLER LINE TO ISOLATE THE SYSTEM FROM THE CITY’S WATER SYSTEM WHEN REQUIRED FOR REPAIR.
8/9/2004 Design Standards Page 3-10 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 3 (8-04) 3.04.7.2 Sanitary Sewer Sanitary sewer system design shall be in accordance with Chapter
8 – Sanitary Sewer Facilities, and include the following items: A. Sanitary sewer pipe size, locations, type of material, and stationing. B. Location of manholes. Indicate type of manhole,
stationing, offset, rim and invert elevation, and number manholes consecutively. During the City review process, manhole numbers shall be assigned by the City to be incorporated into
the next submittal. C. The direction of sewage flow shall be indicated with an arrow at the manhole. Proposed sewer shall have solid arrowheads while existing pipe and manholes shall
be shown in ghost or screened lines with the arrowhead and manhole not filled. D. Drop manholes, if approved, are to be detailed on the plans. E. Stationing for side sewers from downstream
manholes. F. Connection of a side sewer to the City’s sanitary sewer pipe shall be indicated with a tee. G. Locations of sanitary sewer cleanouts. H. Locations of sanitary sewer easements.
I. Clearly define right-of-way and adjacent property lines. Parcel numbers for all lots adjacent to the improvements shall be indicated. J. Floor drains, drains from other covered areas
potentially subject to pollutants, and wash areas within parking lots shall be connected to the sanitary sewer through an approved oil/water separator. 3.04.8 Utility Profile Sheet The
Utility Profiles, when required, should be included on the associated utility plan sheet if at all possible. 3.04.8.1 Storm Drainage For complex private storm systems and all public
storm lines, a profile will be required. These profiles should include the following items where applicable: A. Public storm drainage located within the street right-of-way shall be
shown on the street profile. See Section 3.04.9.2 B. Public storm drainage located in an easement shall have separate profiles. C. Structure size, location, type, station, invert elevation,
type of lid or grate, and rim elevation. D. Pipe size, type of material, slope (ft/ft), and lineal footage. E. Utility crossings shall identify size and type of utilities involved. F.
Ditches where applicable, size, type and slope. G. Existing and finished grade along pipe centerline. H. Connections to existing structures.
8/9/2004 Design Standards Page 3-11 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 3 (8-04) 3.04.8.2 Water For complex on-site public water systems and all public water mains within
the street, a profile will be required. These profiles should include the following items where applicable: A. Water line located within the street right-of-way shall be shown on the
street profile. See Section 3.04.9.2. B. Water line profiles are not generally required for lines located in easements unless there are utility conflicts. C. Pipe size, type of material,
lineal footage, cover and stationing. D. Utility crossings shall identify size and type of utility involved. E. Existing and finished grade along pipe centerline. F. Connections to existing
mains and fittings. G. Label bends fittings and valves include blocking. 3.04.8.3 Sanitary Sewer A profile will be required for all public sanitary sewer mains. These profiles should
include the following items where applicable. A. Sanitary sewer located within the street right-of-way shall be shown on the street profile. See Section 3.04.9.2 C. Structure size, location,
type, station, invert elevations, type of lid, and rim elevation. D. Pipe size, type of material, slope (ft/ft), and lineal footage. E. Utility crossings shall identify size and type
of utility involved. F. Existing and finished grade along pipe centerline. G. Connections to existing structures. H. Side sewer locations and stationing. 3.04.9 Public Street Plan and
Profile Sheet Whenever a project includes construction within a public street excluding utility connections, both a plan and a profile shall be included in the plan set. The Public Street
Plan and Profile sheet(s), when required, shall have the following applicable items: 3.04.9.1 Plan View The plan view should include the following items where applicable: A. Plan views
shall be drawn at a 1" = 20' scale. B. Existing and proposed rights-of-way. C. Existing and proposed contours and elevations. D. Existing and proposed street names. E. Existing and proposed
centerline bearings. F. Existing and proposed signs and traffic control devices. G. Existing and proposed storm drainage systems.
8/9/2004 Design Standards Page 3-12 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 3 (8-04) H. Existing and proposed sewers and water mains (use ghost lines). Identify crossings
and minimum distances between utilities. I. Horizontal curves. J. Horizontal stationing. K. Location of curbs, sidewalks, wheelchair ramps, and driveways (by station). L. Locations of
monuments at all centerline intersections, cul-de-sacs, PCs, and PTs by station. M. Street luminaries, conduit for streetlights, traffic signals, and traffic signal loop detectors located
within the vicinity of the project. N. Mailbox types and locations. Submit to postmaster for approval. O. Address any horizontal utility conflicts in plan. P. Street landscaping, if
required. Q. Construction limits. R. Slope excavation and/or embankment limits. 3.04.9.2 Profile The profile should include the following items where applicable: A. Profiles shall be
drawn using 1" = 20' horizontal and 1" = 2' vertical scales. B. Existing and proposed centerline road road grade. C. Existing and proposed storm drainage systems. D. Existing and proposed
sewers and water mains (use ghost lines). Identify crossings and minimum distances between utilities. C. Finish grade elevations every fifty feet (50’) and every twenty-five feet (25’)
for vertical curves along design centerlines. D. Vertical curve information in profile section. E. Address vertical utility conflicts in profile. 3.04.9.3 Intersections Intersection
plans shall be twenty (20) scale drawings in conformance with Standard Detail TRAFFIC-13. 3.04.9.4 Typical Roadway Sections Typical roadway sections shall show pavement depths, widths
and materials, cross-slopes of pavement (%), centerline, dimensioned right-of-way lines, curb and gutter, ditches, embankment and excavation slopes (1:1), rockers, walls, etc. Typical
sections will be labeled within identified station ranges. 3.04.9.5 Striping and Signing Provide forty (40) scale plans per these Standards and MUTCD, including lane markers, pavement
markings, and signing. 3.04.9.6 Signalization Provide twenty (20) scale separate detailed signalization plan per City of Auburn Standards, including poles, bases, conduits, and traffic
loops.
1/21/2009 Design Standards Page 3-13 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 3 (8-04) 3.04.9.7 Illumination Provide forty (40) scale street lighting plans per these standards,
including information on luminaires, service cabinets, junction boxes, power source, conduits, and wire. 3.04.9.8 Streetscape Provide information on planting of the public landscape
strips along the street frontage. Information should include the following: 1. Type and size of trees. 2. Tree spacing. 3. Type of ground cover. 4. Root control/barrier. 5. Irrigation
if applicable. 3.04.9.9 Other Features Include locations of any other feature including mailboxes and bus stops. 3.04.10 Site Landscape Plan Sheet The site landscape sheets, when required,
shall have the following applicable items: A. Adjacent streets both public and private. B. Have boundaries and dimensions of site. C. The location of on-site buildings. D. The location
of on-site parking areas. E. The location and size of landscape areas. F. The location, species, and size of planting materials. G. The location of outdoor storage areas. H. The location
of significant trees. I. The following approval block: PROJECT REF: THESE PLAN SHEETS ARE APPROVED FOR CONFORMANCE WITH THE CITY OF AUBURN’S PLANNING DEPARTMENT REQUIREMENTS.. Approved
By: Date Approved:
8/9/2004 Design Standards Page 3-14 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 3 (8-04) 3.04.11 Site Irrigation Plan sheet The site irrigation sheets, when required, shall
have the following applicable items: A. The connection point to the City system. B. The size location, and type of the backflow prevention. C. The proposed layout of the irrigation system.
D. Be consistent with the site’s building and landscaping plans.
Chapter 4 – Report Preparation Requirements 4.00 Preface This chapter describes how technical engineering reports should be laid out to meet City requirements and provide a format that
is easy to follow and understand. Reports need to meet these basic standards in order to move through the review process in an efficient manner. 4.01 General Requirements The following
general requirements shall be met for all technical engineering reports being submitted for review and approval: A. All reports and calculations shall be prepared, stamped, signed, and
dated by a Washington State licensed professional civil engineer. B. All reports and calculations shall be neat, uncluttered, legible, and in conformance with the requirements herein.
C. All reports shall be bound with the civil engineers stamp clearly visible. D. Reports shall reference City Standards as necessary. 4.02 Report Types The following are basic types
of reports submitted as supporting project information. Depending on the complexity or simplicity of the project and its location, the amount of detail, and the number and types of reports
required will be subject to change. The examples given are the typical reports required for a standard project. 4.02.1 Geo-Technical Reports See Section 4.03.1 Geo-technical reports
shall contain the following information: A. Project summary. B. Geo-technical findings and recommendations. C. Pavement subgrade analysis and recommendations when project includes pavement
design. D. Vicinity map and site plan. E. Supporting data. 4.02.2 Storm Drainage Reports See Section 4.03.2 Storm drainage reports shall contain the following information: A. Project
summary. B. Storm design findings and recommendations. C. Storm design calculations. 8/9/2004 Design Standards Page 4-01 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 4 (8-04)
D. Vicinity map and site plan. E. Supporting data. 4.02.3 Other Reports Other reports could include the following: A. Traffic Reports. B. Wetland Delineation Reports. C. Downstream Analysis
Reports for Storm Systems. D. Sensitive Area Impact Reports. 4.03 Report Requirements 4.03.1 Geo-Technical Reports The geo-technical report format shall include the following applicable
items: A. Title page including project name and address. B. General information, which includes existing site conditions. C. Site history including any prior grading. D. Subsurface soil
information and conditions including groundwater elevations. E. Soil log information and locations of explorations. F. Soil characteristics including suitability for fill and compaction
requirements. G. Slope stability analysis. H. Seismic hazards. I. Site plan showing the topography and proposed structures and paving. J. Grading information including depth of cuts
and recommended slopes. K. Recommendations on temporary erosion and sediment control. L. Conclusions and recommendations for foundations. M. Appendix with test pit and boring logs. N.
Information on infiltration rates for use in designing retention ponds and infiltration trenches. O. California Bearing Ratio (CBR) information for pavement design. 4.03.2 Storm Drainage
Reports The storm drainage report format shall include the following applicable items: A. Title Page, including project name and address. B. Project Overview. The project overview must
include a general description of the proposed construction on the site. The overview shall also include descriptions of the pre-developed and post-developed conditions of the site, the
total area of the site, the area of the improvements, and the disposition of storm drainage runoff before and after development. 8/9/2004 Design Standards Page 4-02 REF. H:\DEVELOPMENT\Manuals\Design
Standards\Chapter 4 (8-04)
C. Off-Site Drainage Analysis Off-site drainage analysis shall include identification of the upstream tributary areas and a downstream analysis. D. Existing Site Hydrology (Part A) Discuss
assumptions and site parameters used in analyzing the existing site hydrology. The existing pre-developed condition is defined as a pre-fill or undisturbed condition of the existing
site. E. Developed Site Hydrology (Part B) Provide a narrative, mathematical and graphic presentation of the parameters selected, and values used for the developed site conditions. Include
acreage, runoff coefficients (CN), time of concentration (Tc), travel time (Tt), roadway layout, and all proposed drainage facilities as part of the narrative. F. Hydraulic Analysis
(Part C) Provide a brief discussion of the parameters required to calculate the size of conveyance systems including the following information: 1. Retention or detention facilities designed
using hydrographic analysis. 2. Basin summary. 3. Hydrograph summary. 4. Stage storage tables for retention/detention system. 5. Stage discharge tables for discharge structures. 6. Level
pool routing summary. 7. Apply the appropriate factor of safety to the pond sizing. 8. Route the 24-hour, 100-year post-development storm event through the retention/detention facility
to verify the performance standards. 9. Conveyance system designed using pipe network analysis. 10. Biofiltration system designed. G. Retention/Detention System Sizing (Part D) 1. Provide
an illustrative drawing of the retention/detention facility and its appurtenances. This drawing shall show basic measurements necessary to calculate the storage volumes available from
zero to the maximum head. Detention systems shall show all orifice/restrictor sizes, head relationships, and control structure/restrictor orientation to the detention facility. Retention
systems shall show the split flow manhole and the bioswale orientated to the retention facility. 2. Include all calculations, equations, references, storage/volume tables, graphs, and
other aides necessary to clearly show results and methodology used to determine the retention/detention facility volumes. 3. This section of the Storm Drainage Report should provide
a clear sequence of how the retention/detention facility size was determined and include the following information: a. Total acreage. b. Pervious acreage. c. Impervious acreage. d. Soil
log information indicating soil types and existing land characteristics. e. CN. 8/9/2004 Design Standards Page 4-03 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 4 (8-04)
f. The following precipitation information shall be included where applicable. i. Precipitation for 64% of the 2-year/24-Hr design storm event (bio-swales bypass only). ii. Precipitation
for 50% of the 2-year/24-Hr. design storm event, if applicable. iii. Precipitation for 2-year/24-Hr. design storm event. iv. Precipitation for 10-year/24-Hr. design storm event. v. Precipitation
for 25-year/24-Hr. design storm event. vi. Precipitation for 100-year/24-Hr. design storm event. g. Design storm(s) discharge and storage time(s). h. Seasonal high groundwater information.
i. Infiltration rate analysis (retention only). j. Topographical map showing site, overland flow line (Tc), slope, and drainage basins. k. Calculations. H. Conveyance System Analysis
and Design This section shall present the detailed analysis of any existing conveyance systems and the analysis and design of the proposed storm drainage collection and conveyance system
for the development. This information should be presented in a clear, concise manner that can be easily checked and verified. All pipes, culverts, catch basins, channels, swales, and
other storm drainage conveyance appurtenances must be clearly labeled and correspond directly to the engineering plans. I. Erosion/Sedimentation Control Design Erosion/Sedimentation
Control Design includes all hydrologic and hydraulic information used to analyze and size the erosion/sedimentation control (ESC) facilities shown in the engineering plans. Describe
the methodology and attach any graphics or drawings used to size the ESC facilities. J. Conclusions and Recommendations. 4.03.2.1 Background Computations for Sizing Storm Drainage Facilities
A. Depiction of the drainage area on a topographical map of approved scale and contour interval, with the acreage of site, development, and developmental coverage indicated. The Time
of Concentration (Tc) lines shall be shown, as well as the slope and any drainage basins. B. Indication of the existing peak flows of surface water currently entering and leaving the
subject property utilizing the appropriate design storm(s), if available. C. The pre-developed condition is defined as a pre-fill or undisturbed condition of the site. D. Subsurface
flows that will be intercepted and discharged downstream need to be accounted for in the overall storm drainage design. Downstream conditions will determine to what extent those flows
must be accounted for within the storm drainage design. E. Indication of the developed flow of storm drainage peak runoff, which will be generated utilizing the appropriate design storms
for the subject property. 8/9/2004 Design Standards Page 4-04 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 4 (8-04)
8/9/2004 Design Standards Page 4-05 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 4 (8-04) F. Capacity of downstream facilities, post and pre-development. G. Sufficient capacity
under design conditions of downstream facilities. H. Storm drainage facilities shall be designed to mitigate or address drainage rate, volume, and water quality impacts associated with
site development activities. 4.03.2.2 Drainage Basin Report Summary Summarize the following areas for the Storm Drainage Report: A. Pre-and post-developed basins. B. Time of concentration
calculations. C. Time of concentration topographical map (can be included in Appendix). D. Summary of pre-developed conditions with post-development requirements. E. Summary and justification
of runoff coefficients. 4.03.3 Other Reports Other reports may be required on a site-specific basis. The specific information required in these reports shall be determined during the
SEPA process or by the department requiring the report. These reports shall include the following basic items: A. Title page including project name and address. B. General information,
which includes existing site conditions. C. Site plan showing the topography and proposed structures and paving. D. Conclusions and recommendations. E. Appendix with collected field
information.
Chapter 5 – TESC, Clearing and Grading 5.00 Preface The design of temporary erosion and sediment control (TESC) clearing and grading plans shall conform to the requirements herein. Compliance
with these standards does not alleviate the design engineer from using sound professional engineering practices. The design criteria contained herein are the minimum acceptable under
standard conditions. Special conditions may require more stringent requirements that will be addressed during the plan review process. The purpose of these requirements is to provide
the design criteria necessary to preserve the City of Auburn’s water courses; minimize surface and ground water quality degradation; control sedimentation in creeks, streams, rivers,
ponds, lakes, and other water bodies; protect adjacent and downstream property owners from increased runoff rates which could cause erosion and flooding; and ensure the safety and stability
of City of Auburn’s roads and rights-of-way. 5.01 TESC Design Criteria 5.01.1 Temporary Erosion and Sediment Control (TESC) TESC design requirements shall meet design criteria requirements
of erosion control, storm retention, detention, and storm conveyance systems herein, including the following: A. TESC silt control and detention facilities shall be sized for runoff
volumes associated with graded sites. B. See Standard Drawing STORM-4 for grading/erosion discharge control structure. C. TESC Detention/Retention facilities for temporary control of
surface water shall include additional measures, such as sedimentation ponds and gravel filter berms, to protect downstream system or the infiltration area from silt. Continual maintenance,
including removal of silt, shall be performed as needed to keep the facility fully functioning until permanent facilities are in place. D. TESC retention facilities shall be sized for
runoff volumes associated with graded sites. A backup/reserve infiltration area shall be provided as necessary. Chapter 6 of this manual contains more detailed information on infiltration
rate design criteria. E. The TESC plan shall be designed to avoid creating adverse effects on public right-of-ways or adjacent properties. (See Standard Detail EROSION-08 and other reference
details) F. A 50' x 20' x 1’ minimum quarry spall construction entrance shall be required and maintained throughout the hauling operation for erosion control and to prevent sediment
tracking onto public streets. Additional measures may be required depending upon site conditions including the construction of a wash pad area and/or paving portions of the site where
construction has been completed. (See Standard Detail EROSION-01) 8/9/2004 Design Standards Page 5-01 REF. H\DEVELOPMENT\Design Standards\Chapter 5 (8-04)
G. Siltation control measures (i.e., silt fences, setbacks, ditches, etc.) shall be provided to protect any on-site sensitive area designated for preservation, public right-of-way and/or
adjacent properties. (See Standard Detail EROSION-08 and other referenced details) H. Measures, including but not limited to catch basin protection, shall be taken to prevent silt-laden
water from entering the City's public storm system and/or adjacent or downstream rivers, streams, and on-and off-site sensitive areas. (See Standard Details EROSION-03 & EROSION-04)
I. All exposed slopes shall be stabilized with an approved erosion control treatment. (See Section 5.03) J. No fill or cut slopes shall be steeper than two horizontal to one vertical
(2:1) unless in accordance with an accepted geotechnical report sealed by a Washington State licensed engineer. (See Section 5.03) K. A minimum horizontal setback of five feet (5') shall
be provided between the bottom of any fill placement and the top of the bank of any defined drainage channel. L. When filling a site, particular care should be taken to prevent impeding
the existing upstream surface drainage flow. M. Denuded areas and soil stockpiles must be stabilized according to the Erosion Control Notes. (See Section 3.04.2) All TESC measures regardless
of design and implementation must meet the latest Nephelometric Turbidity Units (NTU) test requirements. The City will conduct tests and if the applicable limits are not met, the project
will be halted until such time as it is brought into compliance. 5.01.2 Temporary Detention Systems A. Temporary storm drainage detention facilities used during the grading and erosion
control process shall be designed with a 1.2 safety factor applied to the post-development calculated pond design volume for the 25-year 24-hour postdevelopment storm event if overflow
is provided or a 1.5 safety factor for the 25-year 24-hour post-development storm event if overflow is not provided. A higher factor of safety may be required in areas of steep slope
and/and/or areas containing highly erodible soils. The detention shall be defined as the active storage available a minimum of one foot (1’) above the seasonal high ground water. B.
Temporary Detention Facilities shall discharge at the 2-year 24-hour predevelopment discharge rate. C. The temporary storm drainage facility shall be designed using an approved hydrograph
method. (See Section 6.00). D. Silt control measures shall be used, including but not limited to sedimentation ponds, gravel filter berms, silt fences, and hay bales. E. Temporary control
structures in association with TESC plans shall be shown on the plans and conform to the City of Auburn's Standard Detail No. STORM-04. They shall be installed on-site and maintained
during the construction period prior to connecting to the City storm system. 5.01.3 Temporary Retention Systems Temporary Retention Systems requirements are as follows: 8/9/2004 Design
Standards Page 5-02 REF. H\DEVELOPMENT\Design Standards\Chapter 5 (8-04)
A. Temporary storm water retention facilities used during the grading and erosion control process shall be designed with a 1.4 safety factor applied to the postdevelopment calculated
facility design volume for the 25-year 24-hour postdevelopment storm event if overflow is provided or a 1.7 safety factor applied to the 25-year 24-hour post-development storm event
if overflow is not provided. A higher factor of safety may be required in areas of steep slope and/or areas containing highly erodible soils. B. Flow of sediment-laden water shall be
diverted to a sediment trap for removal and collection of sediment prior to infiltration. C. The temporary infiltration area shall not be used as part of the permanent infiltration area.
D. The temporary storm drainage facility shall be designed using an approved hydrograph method. (See Section 6.00) 5.01.4 Winterization Plan Any project with exposed soil, or that will
be worked from October 1st to March 31st, shall prepare a Winterization Plan for review by the City. The plan shall at the minimum contain the following information: A. Purpose. B. Property
location. C. Property description. D. Contacts – including name, title, organization, and phone number of person or persons responsible for maintaining the project site. E. Temporary
Erosion and Sediment Control (TESC) plan. F. Inspection and monitoring schedule. G. Maintenance and repair responsibility. H. A stockpile of TESC materials and their location. I. An
Exhibit A – legal description. J. An Exhibit B – vicinity map. K. Inspection Report Form. L. BMP’s (Best Management Practices) to be employed (site specific). 5.02 Land Clearing 5.02.1
Purpose The following section establishes the requirements for land clearing. These requirements do not supercede nor are they intended to be inconsistent with any landscaping requirement
established by the Zoning Ordinance or other City action. A land clearing permit shall be required except for the following situations: A. Situations where the land clearing is included
in the grading or building permit. B. The removal of dead or diseased trees or ground cover. 8/9/2004 Design Standards Page 5-03 REF. H\DEVELOPMENT\Design Standards\Chapter 5 (8-04)
C. Clearing associated with agricultural uses, excluding timber cutting not otherwise exempted. D. Clearing of less than 20,000 square feet within an individual lot for the purpose of
constructing a single-family home or duplex provided construction starts within ninety days. A permit will be required if said clearing is proposed within fifty feet of any sensitive
areas. E. The removal of six (6) trees or less per acre per parcel on undeveloped and underdeveloped properties. F. The removal of trees and ground cover in emergency situations involving
immediate danger to life or property. G. Routine landscape maintenance and minor repair. Land Clearing permits will typically be required in situations where a significant amount of
trees and vegetation are proposed for removal in a manner that will not trigger the grading permit requirements. (See Section 2.01.1) 5.02.2 Plan/Permit Requirements The following information
shall be provided prior to the approval of a land clearing permit: A. A statement as to the purpose for clearing and the subsequent use of the property. B. The method of work including
details justifying how the work will be performed without triggering the requirements for a grading permit. C. A cover sheet and site plan (See Chapter 3) showing the vegetation to be
removed and the location and type of all existing
significant trees. D. If the clearing is to include the removal of ground cover, a TESC plan may be required. E. A plan showing existing trees six inches (6”) in diameter and larger
for evergreens and four inches (4”) in diameter or larger for deciduous. The plan shall indicate if a tree is to either be retained or removed. 5.02.3 General Requirements A. Clearing
shall not unreasonably create or contribute to erosion, landslides, flooding, siltation, or other pollution as determined by the City. B. Clearing shall contain reasonable provisions
for the preservation of natural features, vegetation, sensitive areas, and drainage courses. C. Clearing shall be conducted so as to expose the smallest area of soil for the least amount
of time. D. A licensed and bonded contractor shall perform the clearing of any tree that is within striking distance of a structure, overhead power/utility lines, public right-of-way,
roads or that has the potential to cause damage to other trees. E. A right-of-way use permit shall be required when the public right-of-way is used to clear, stockpile, or load products
and/or debris resulting from clearing. 5.03 Grading 5.03.1 Excavations 8/9/2004 Design Standards Page 5-04 REF. H\DEVELOPMENT\Design Standards\Chapter 5 (8-04)
A. Cut slopes shall generally be constructed no steeper than two horizontal to one vertical (2:1). The City may approve steeper slopes after a geotechnical analysis is performed justifying
a steeper slope. Upon City approval, a steeper slope may also be used in the following cases: a. A slope of one-and-a-half horizontal to one vertical (1.5:1) may be used if no structure
is to be supported, the slope is less than eight feet (8’) in height, and the slope can be adequately protected against erosion. b. A slope of one horizontal to one vertical (1:1) may
be used for cuts into stable bedrock. B. Cut slopes shall be stabilized by terracing, cat tracking, jute mat, grass sod, hydroseeding, or by other planting or surfacing materials acceptable
to the City. C. The City may also require geotechnical analysis for the following: a. Slopes with sub-surface or surface water flows. b. In areas of questionable soils conditions. c.
Where the length of the slope requires terracing. d. In other situations where slope stability could be in question. 5.03.2 Fills A. Fill slopes shall generally be constructed no steeper
than two horizontal to one vertical (2:1). The City may approve steeper slopes after a geotechnical analyses is performed justifying a steeper slope. Temporary fills for preloading of
building pads may use a slope one and one half horizontal to one vertical (1.5:1). B. Fill slopes shall be stabilized by terracing, cat tracking, jute mat, grass sod, hydroseeding, or
by other planting or surfacing materials acceptable to the City. C. The City may also require geotechnical analysis for the following: a. Slopes with surface water flows. b. In areas
of questionable soils conditions. c. Where the length of the slope requires terracing. d. In other situations where slope stability could be in question. 5.03.2.1 Preparation for Fill
Prior to any fill being placed, all vegetation, topsoil and other unsuitable material shall be removed unless dictated otherwise by the geotechnical engineer. Where fill is being placed
on existing slopes of greater than five horizontal to one vertical (5:1), a geotechnical analysis shall be performed. 5.03.2.2 Compaction Fill material shall be placed in lifts of no
more than twelve inches (12”) and compacted to ninety percent (90%) or greater of the maximum dry density as determined by ASTM D1557 Modified Proctor or as directed by the geotechnical
engineer. 5.03.3 Slope Easement Slope easements adjacent to the right-of-way for maintenance of cut or fill slopes and drainage facilities may be required. Easement shall be from the
catch point plus a minimum of five feet (5’), as determined by the City. 8/9/2004 Design Standards Page 5-05 REF. H\DEVELOPMENT\Design Standards\Chapter 5 (8-04)
5.04 Retaining Walls Retaining walls can vary with design and must be approved by the City. Retaining walls in locations where the possibility exists for pedestrians to walk near the
top edge of the wall may require protective fencing. Retaining walls with a vertical difference of three feet (3’) or greater along pedestrian corridors and areas where maintenance personnel
will be required to access will require a handrail for safety of pedestrian traffic. 5.04.1 Rockeries See Standard Detail GENERAL-04 Rockeries may be used for containment of cut slopes
or fill embankment up to a maximum height of eight feet (8’) as shown in the referenced Standard Detail GENERAL-04. Rockeries over four feet (4’) in height or in areas of questionable
soil stability will require an engineered design. The engineered design may include a soils investigation and report by a geotechnical engineer and structural calculations to support
the rockery design. 5.04.1.1 Size Size Categories include: Two-man rocks (200 -600 pounds) 18” -28” average diameter. Three-man rocks (600 -2000 pounds) 28” -36” average diameter. Four
man rocks (2001 -4000 pounds) 36” -48” average diameter. 5.04.1.2 Material The rock material shall be as rectangular as possible. No stone shall be used that does not extend through
the wall. The quarried rock shall be hard, sound, durable, and free from weathered portions, seams, cracks, and other defects. The rock density shall be a minimum of 160 pounds per cubic
foot, measured accordingly to WSDOT test method 107 (Bulk Specific Gravity -S.S.D. basis). 5.04.1.3 Underdrains Underdrains are required for all retaining walls over four feet (4’) in
height (i.e., concrete walls, MSE walls, soil nail walls, block retaining walls, etc.). A minimum six-inch (6”) diameter perforated or slotted drainpipe shall be placed in a shallow
excavated trench located along the inside edge of the keyway. The pipe shall be bedded on and surrounded by “Gravel Backfill for Drains” (WSDOT/APWA 9-03.12(4)) to a minimum height of
eighteen inches inches (18”) above the bottom of the pipe. A filter fabric shall surround the gravel backfill and shall have a minimum of one foot (1’) overlap along the top surface
of the gravel. The perforated pipe shall be connected to a storm drain system or to an acceptable outfall. 5.04.2 Block Retaining Walls Block retaining walls, (i.e., Keystone, Allan
Block, Ecology Block) may be used for containment of cut slopes or fill embankment. Block retaining walls over four feet (4’) in height or in areas of questionable soil stability will
require an engineered design. The engineered design may include a soils investigation and report by a geotechnical engineer and structural calculations to support the block wall design.
8/9/2004 Design Standards Page 5-06 REF. H\DEVELOPMENT\Design Standards\Chapter 5 (8-04)
5.04.2.1 Material Blocks used for retaining walls shall be in good condition and structurally sound; cracked and/or broken blocks should be returned to the manufacturer. Unless designed
as a gravity wall (ecology blocks), block walls over four feet (4’) in height shall employ geo-grid type material to increase the structural stability of the wall. 5.04.2.2 Underdrains
(See Section 5.01.4.3) 5.04.3 Reinforced Concrete Walls Reinforced concrete walls or cast-in-place concrete walls may be used for containment of cut slopes or fill embankment. Concrete
retaining walls over four feet (4’) in height or in areas of questionable soil stability will require an engineered design. The engineered design may include a soils investigation and
report by a geotechnical engineer and structural calculations to support the concrete wall design. 5.04.3.1 Material A minimum 3,000-psi structural reinforced concrete shall be used
in the design of concrete retaining walls. 5.04.3.2 Underdrains (See Section 5.01.4.3) 5.04.4 Mechanically Stabilized Earth Walls (MSE Walls) MSE walls may be used in conjunction with
other retaining walls or as a stand-alone application when constructing fill slopes. MSE walls will require an engineered design. The engineered design shall include a soils investigation
and report by a geotechnical engineer and structural calculations to support the MSE wall design. 5.04.4.1 Material MSE walls shall employ well-draining structural soil compacted to
the geotechnical engineer’s specifications. 5.04.4.2 Underdrains (See Section 5.01.4.3) 5.05 Construction Sequence 5.05.1 Requirements A construction sequence is intended to ensure that
the timing and installation of adequate storm drainage and erosion control measures are in place prior to activities that may cause erosion to occur. The following elements should be
included in a construction sequence: A. Attendance at a pre-construction meeting with City of Auburn officials. B. Establishment of clearing and grading limits. C. Construction of temporary
construction entrance. D. Construction of perimeter ditches, filter fabric fences, and other erosion control devices as shown. 8/9/2004 Design Standards Page 5-07 REF. H\DEVELOPMENT\Design
Standards\Chapter 5 (8-04)
8/9/2004 Design Standards Page 5-08 REF. H\DEVELOPMENT\Design Standards\Chapter 5 (8-04) E. Construction of storm drainage control (be specific) facilities including emergency overflow
as applicable. F. Construction of ditches and swales as necessary to direct all surface water to the storm drainage control (be specific) facilities as clearing and grading progress.
Prevention of uncontrolled surface water being allowed to leave the site at any time during the grading operations. G. Establishment of at what point grading activities can begin, which
is usually only after all drainage and erosion control measures are in place. H. For sites with a final development plan, the following shall also be addressed when applicable: 1. Installation
of on-site permanent storm drainage, sanitary sewer, and water facilities. 2. Site paving. 3. Indicate at what point building construction may begin. 4. A description of how to transition
from the temporary to permanent storm facilities. 5. The possibilities of any phased construction. 6. Any off-site public or private improvements including the general timing and duration.
7. The removal of all TESC measures at project completion upon City approval. I. The TESC plan sheet shall also include a construction sequence element which clearly identifies the timing
and methodology required to: 1. Contain areas of active earthwork to prevent uncontrolled discharge of storm drainage 2. Minimize erosion and the extent and time soils are exposed on-site.
3. Address seasonal variations in weather conditions (the period of greatest concern is October 1 through April 1). A separate winterization may be required. 4. Prevent tracking of sediment
onto City streets. 5. Protect permanent on-site and off-site storm drainage systems.
Chapter 6 -Storm Drainage 6.00 Preface The purpose of these requirements is to provide the design criteria necessary to help preserve the City of Auburn’s water courses; to minimize
surface and ground water quality degradation; to control the sedimentation in creeks, streams, rivers, ponds, lakes, and other water bodies; to protect adjacent and downstream property
owners from increased runoff rates which could cause erosion and flooding; to ensure the safety of City of Auburn’s roads and rights-of-way; and to decrease drainage-related damage to
both public and private property. Compliance with these standards does not alleviate the design engineer from using sound professional engineering practices. The design criteria contained
herein are the minimum acceptable under standard conditions. Special conditions may require more stringent requirements that will be addressed during the plan review process. The City’s
Comprehensive Drainage Plan establishes drainage basins and design parameters used to estimate future line hydraulic capacities. Anyone proposing to extend or modify the City’s storm
drainage system should contact the Public Works Department for information on line sizes and locations. Developer constructed public storm drainage improvements shall be installed by
means of a Facility Extension Agreement (FAC) between the developer and the City. The Public Works Department can provide information on this agreement as well as applicable permit and
connection fee estimates. 6.01 General Requirements The following general requirements shall be met in developing a storm drainage system: A. Storm drainage entering the subject property
shall be received at the naturally occurring locations, and storm drainage exiting the subject property shall be discharged as near as possible to the natural locations or to adjacent
public facilities with adequate energy dissipation within the subject property to mitigate downstream impacts. B. The design storm peak discharge from the subject property shall not
be increased by the proposed development. Retention or detention systems shall be utilized to accomplish this requirement. C. Storm drainage quantity and quality control measures are
required for new public street improvements. The construction of localized street improvements, such as adjacent half-street improvements, may be exempted from storm drainage quantity
and quality control measures depending upon the type and magnitude of the improvements. The City shall make the final determination if new public facilities are required based on the
amount of impervious area being constructed, downstream considerations, the availability of proposed or existing regional storm facilities, or other appropriate considerations. D. A
separate storm drainage detention or retention system is required for each commercial or industrial lot unless a combined storm drainage system is used for more than one lot. In such
cases, a private cross-drainage easement and maintenance agreement is required for each lot, unless cross-drainage requirements are set up as a condition of the recorded final plat.
Copies of the recorded 8/9/2004 Design Standards Page 6-01 REF. H\DEVELOPMENT\Design Standards\Chapter 6 (8-04)
easements or plat condition, including the storm water pollution and prevention plan must be provided to the City prior to civil plan approval. E. Detention or retention systems shall
be designed so that site drainage overflow, for the storm events in excess of the maximum design storm, can sheet flow across driveways into adjacent public streets or be discharged
to a public storm drainage facility prior to impacting on-site or adjacent properties, unless cross-drainage agreements have been secured. F. In general, the lowest on-site storage elevation
shall be higher than the hydraulic grade line of the receiving off-site storm drainage system. The hydraulic elevation of the receiving system shall be based on the 25-year 24-hour design
storm or as determined by the City, if a specific elevation is known. G. The finished floor elevation of buildings shall be a minimum of one foot (1’) above the maximum high water elevation
indicated in the detention or retention system design and a minimum of six inches (6”) above the overflow design elevation. Elevations shall be indicated on the plans. H. No individual
lot or development shall be allowed to drain uncontrolled storm drainage from more than six hundred square feet (600 SF) of impervious surface area across driveways into the public right-of-way.
I. The storm drainage detention or retention concepts for a project, including water quality measures, are subject to approval by the City prior to finalization of the project design.
J. In areas with soils that have high infiltration rates or are located within an aquifer protection area, liners or impermeable barriers may be required to be incorporated with storm
drainage system designs. K. All open detention and retention ponds shall be appropriately and aesthetically located, designed, and planted. Pre-approval of the design concept, including
landscaping, is required from the City for all proposed public ponds. Joint use facilities incorporating recreation or open space opportunities are encouraged. L. All storm facility
landscape planting and seeding plans shall be prepared and sealed by a Washington State licensed professional Landscape Architect or similar specialist approved by the City of Auburn.
M. The preferable method of conveyance for storm drainage is by a gravity system. Pump stations will be allowed only with pre-approval of the City. A technical memo on pump station design
is available upon request. N. All projects shall execute with the City a standard Stormwater Easement and Maintenance Agreement for the site’s private storm drainage facilities. The
easement shall be approved by the City and executed by the owner prior to the issuance of occupancy permits for the development. O. All non-single family roof and foundation drains shall
be directed into the site storm drainage detention or retention system or other discharge point as applicable. Piped conveyance systems shall be a minimum of six inches (6”) in diameter
and contain cleanouts as necessary. All piped conveyance lines shall be connected to the storm drainage detention or retention system at catch basins or other maintenance access points.
Piped conveyance lines from roof drains shall have a minimum of one percent (1%) slope and shall meet the materials requirements of Section 6.10. Runoff shall be discharged by one of
the following methods: 1. Discharged into an on-site infiltration system. 8/9/2004 Design Standards Page 6-02 REF. H\DEVELOPMENT\Design Standards\Chapter 6 (8-04)
2. Discharged into a private collection pipe that would be connected to a public drainage system at a catch basin. For new plat developments a series of private collection systems, each
serving as many lots as feasible, shall connect to the public system. Such systems shall be located within private drainage easements. 3. Alternative low impact development designs will
also be considered. P. Single-family home sites shall provide a means for collection and discharge of water from roof, foundation drains, and driveway. The storm drainage pipe shall
be 4” minimum diameter with a minimum one percent (1%) slope. Runoff shall be discharged by one of the following methods: 1. Discharged into an on-site infiltration system. 2. If soils
do not allow an on-site infiltration system, then discharge into a private collection pipe that would be connected to a public drainage system at a catch basin with pre-approval. Q.
For small sites with less than twenty thousand square feet (20,000 SF) of impervious area, some of the design criteria contained within this chapter may not be feasible. For such cases,
a technical memo on small site storm water treatment measures has been created and is available upon request. R. For re-developing properties, if the assessed valuation of the proposed
improvements is greater than fifty percent (50%) of the value of the existing structure, then the re-developed parcel is required to bring the existing storm drainage system into conformance
with current city storm drainage standards and regulations. Redeveloped projects in the designated “Downtown Plan Area” are not required to upgrade functional storm facilities to current
City standards when there is no change in the amount of impervious surface. S. The following minimum factors of safety should then be applied to determine the final design size of a
facility: 1. Detention systems with an overflow are not required to have an additional safety factor applied to the volume; however, a 1.3 safety factor applied to the volume shall be
used if no overflow is provided. 2. Retention systems with an overflow shall be designed with a minimum 1.2 safety factor applied to the volume; a 1.5 safety factor applied to the volume
shall be used if no overflow is provided. 6.02 Detention System Design Criteria 6.02.1 Detention Ponds 6.02.1.1 Purpose When soil conditions are determined to be unsatisfactory for infiltration,
a detention pond may be used for commercial, industrial, roadway, or residential projects when space is available for an aboveground detention facility. A design of a detention pond
may be modified into a wetpond to provide stormwater quality (See Section 6.05.3). 6.02.1.2 Design The following criteria shall be incorporated when designing detention ponds: A. Detention
ponds should be designed using rounded shapes and variations in slopes to provide a more natural and aesthetically pleasing facility. 8/9/2004 Design Standards Page 6-03 REF. H\DEVELOPMENT\Design
Standards\Chapter 6 (8-04)
B. The total maximum depth of the detention pond from the bottom to the emergency overflow water surface elevation shall be fifteen feet (15’). C. Where a portion of the pond is constructed
within a fill slope, an access road shall be provided adjacent to the detention pond along the entire length of the fill. D. The interior side slopes of the detention pond from the pond
bottom to the 10-year water surface elevation shall not be steeper than two horizontal to one vertical (2H:1V) for heights of five feet (5’) or less and three horizontal to one vertical
(3H:1V) for heights over five feet (5’). This area shall be planted with perennial ground cover. From above the 10-year water surface elevation to the top of the pond, the side slope
shall not be steeper than three horizontal to one vertical (3H:1V). A WSDOT type I black vinyl-coated 42-inch fence shall be provided in the center of a three-foot (3’) wide bench at
the 10-year storm elevation. E. For maintenance and aesthetic purposes, pond designs should minimize structural elements such as retaining walls. For ponds where retaining walls are
required, they should be limited to a maximum of three sides. F. An access road shall be provided to the pond. The access road shall be a minimum of fifteen feet (15’) wide. Turns in
the access road shall be designed using a minimum inside radius of thirty feet (30’) and a minimum outside radius of fifty feet (50’). On public ponds a ten-foot (10’) wide access ramp
shall extend down into all cells. On private ponds the access ramp is required on the inlet cell only if it can be demonstrated that adequate maintenance can be provided to subsequent
cells without road access. At no point shall the slope of the access ramp exceed seven horizontal to one vertical (7H:1V). Access shall be provided to the outlet control structure and
any additional significant drainage system components. G. Storm detention systems shall be designed such that storm drainage from public systems doesn’t discharge into areas of private
ownership or private maintenance responsibilities. H. A minimum freeboard of one foot (1’) shall be provided between the emergency overflow elevation and the top of the pond. I. The
edge of the detention facility shall be located a minimum of twenty feet (20’) from any structure, property line, and/or infiltration gallery. The detention facility shall be set back
a minimum of fifty feet (50’) from the top of any slope greater than fifteen percent (15%). Detention facilities built on or near steep slopes will require a geotechnical analysis and
report addressing the potential impacts on the slope. A geotechnical analysis and report must be prepared addressing the potential impact of the facility on a steep slope. 6.02.1.3 Dam
Safety Requirements Stormwater ponds that can impound ten acre-feet (435,600 ft3; 3.26 million gallons) or more may be subject to Washington State’s dam safety requirements. The Dam
Safety office of the Department of Ecology is available to provide written guidance and technical assistance to project owners and design engineers for help in understanding and addressing
dam safety requirements for specific projects. The Dam Safety office should be contacted early in the design process to aid in streamlining Dam Safety’s review and approval. The Dam
Safety office is located in the Ecology headquarters building in Lacey. 8/9/2004 Design Standards Page 6-04 REF. H\DEVELOPMENT\Design Standards\Chapter 6 (8-04)
8/9/2004 Design Standards Page 6-05 REF. H\DEVELOPMENT\Design Standards\Chapter 6 (8-04)
8/9/2004 Design Standards Page 6-06 REF. H\DEVELOPMENT\Design Standards\Chapter 6 (8-04)
6.02.2 Parking Lot Ponding 6.02.2.1 Purpose Parking lot ponding may be used for commercial projects when space is limited and unavailable for an above ground detention facility. 6.02.2.2
Design Parking lot ponding, upon the approval of the City Engineer, may be allowed within the following design limits: A. At no time shall parking lot emergency overflow elevation exceed
a depth of six inches (6”). B. The overflow elevation shall be a minimum of one foot (1’) below the finish floor elevation of adjacent buildings and adjacent properties, landscaping
and parking stalls. At no time shall parking lot ponding encroach on walking paths, sidewalks, or American Disabilities Act (A.D.A.) required parking stalls or adjacent A.D.A. access.
6.02.3 Detention Vaults 6.02.3.1 Purpose A detention vault may be used for commercial, industrial, or roadway projects when there are space limitations precluding the use of aboveground
storage options. Vaults are box-shaped underground storage facilities typically constructed with with reinforced concrete. The use of public vaults for residential development is discouraged.
A design of a detention vault may be modified into a wetvault to provide stormwater quality (See Section 6.05.4). 6.02.3.2 Design Detention vaults, upon the approval of the City, may
be allowed within the following design limits: A. The minimum interior depth of vaults shall be seven feet (7’). The maximum interior depth of vaults shall be fifteen feet (15’). B.
The maximum depth of a vault from finished ground surface to bottom of vault shall be twenty feet (20’). C. The detention vault bottom should slope at least five percent (5%) from each
side towards the center, forming a broad “v” to facilitate sediment removal. More than one “v” may be used to minimize vault depth. D. A public sanitary sewer manhole shall be located
within one hundred feet (100’) of all vault access points that can be used for decanting the vault prior to maintenance. E. Pumped outfalls are not allowed. F. A buoyancy analysis is
required demonstrating that the vault will not be impacted by ground water. G. Minimum three thousand (3,000) psi structural reinforced concrete shall be used for detention vaults. All
construction joints must be provided with water stops. H. All vaults shall meet structural stability requirements for the overburden support and HS-20 traffic loading. If the vault is
to be placed in a parking lot, 8/9/2004 Design Standards Page 6-07 REF. H\DEVELOPMENT\Design Standards\Chapter 6 (8-04)
then a higher loading may be required. Cast-in-place wall sections shall be designed as retaining walls. A Structural Engineer licensed in the State of Washington shall stamp all structural
designs. Vaults shall be placed on stable, well-consolidated native or compacted foundation material with suitable bedding material. Vaults shall not be allowed in fill slopes unless
analyzed in a geotechnical report for stability and construction purposes. 6.02.3.3 Detention Vault Inlet and Outlet Requirements The following criteria shall be used when designing
detention vault inlets and outlets: A. The number of inlets to the detention vault shall be limited to a maximum of three (3). B. The vault and the outlet pipe should be designed to
convey the postdeveloped 100-year design flow. C. The inlet to the detention vault shall be designed such that the flow velocity is reduced to three feet per second (3 fps) to eliminate
re-suspension of settled sediments. D. Outlet control structures shall be designed based on the requirements in Section 6.04. 6.02.3.4 Detention Vault Access Access must be provided
over the inlet pipe and outlet structure. The following guidelines for access shall be used: A. All underground detention facilities shall have a minimum of one (1) access cover with
ladder per fifty feet (50’) of length or width and at least one (1) access cover with ladder to the bottom of the vault or tanks per cell. Provide enough manholes to insure that an escape
route will be available to a worker within fifty feet (50’). B. Lockable grates instead of solid manhole covers are required to increase air contact with the water surface. Grates will
allow air contact with the water and minimize the possibility of stagnant conditions, which can result in oxygen depletion especially in warm weather. Vaults shall be designed with a
five-foot by ten-foot (5’x10’) grated access
hatch over the inlet and outlet pipes. Access hatches installed in drive isles and other paved areas subject to vehicular traffic shall be H-20 rated. If more than one “v” is provided
in the vault floor, access to each “v” must be provided at either end of the vault. C. Ladders and hand-holds shall be provided at all access points. D. Vaults must comply with the OSHA
confined space requirements, which includes clearly marking entrances to confined space areas. 8/9/2004 Design Standards Page 6-08 REF. H\DEVELOPMENT\Design Standards\Chapter 6 (8-04)
8/9/2004 Design Standards Page 6-09 REF. H\DEVELOPMENT\Design Standards\Chapter 6 (8-04)
6.03 Retention System Design Criteria 6.03.1 Purpose Retention systems may take the form of ponds, vaults, or perforated pipe/network. Retention systems may be used for commercial, industrial,
single-family, or roadway projects where on-site soils allow for infiltration of stormwater at acceptable rates. 6.03.2 Design The following criteria shall be incorporated when designing
retention systems: A. The City prefers retention (infiltration) for storm drainage quantity control when soil conditions are satisfactory for such application and water quality treatment
can be provided. The retention system shall be designed using any Santa Barbara Urban Hydrograph method of calculation. B. To support a retention system design, the City requires an
infiltration rate analysis and adequate soil log information for the location of the proposed retention facility to a minimum depth of three feet (3’) below the proposed effective bottom
of the facility. C. Overflow systems for retention systems shall be designed in such a a way as to discharge excess water during a major storm event to a public facility by sheet flow.
Sheet flowing across adjacent properties will not be allowed. D. For sites less than twenty thousand square feet (20,000 SF) of area, the retention facility may be designed using a 25-year
24-hour storm event if overflow is provided or the 100-year 24-hour storm event if no overflow is provided. E. The bottom of the retention facility shall be three feet (3’) minimum above
the seasonal high ground-water elevation. F. The system shall be located in natural soils and not in embankments. G. The maximum allowable void ratio for pipe trench rock shall be twenty-five
percent (25%), which includes a five percent (5%) siltation allowance. H. Catch basins shall be provided on each end of the infiltration system if the trench design method is utilized.
Access to these catch basins is required for maintenance and operation. I. Perforated pipes used in conjunction with infiltration systems shall be installed with the perforated holes
facing downward toward the bottom of the trench. J. Infiltration systems shall be located outside of parking and driving areas, unless otherwise approved by the City. K. In aquifer recharge
protection areas, additional water quality measures may be required. L. Infiltration trenches and galleries shall be designed such that no point in the facility is located more than
fifty feet (50’) from an access structure. 6.03.3 Retention System Infiltration Rate Requirements The infiltration rate for a Storm Drainage Retention System shall be based upon field
test results. The following minimum information shall apply to infiltration rate analysis that is required to support a retention system design: 8/9/2004 Design Standards Page 6-10 REF.
H\DEVELOPMENT\Design Standards\Chapter 6 (8-04)
A. A minimum of three (3) percolation tests shall be performed within the area proposed for an infiltration system. They are to be spaced uniformly throughout the area. If soil conditions
are highly variable, more tests may be required B. The minimum allowable percolation rate for an infiltration system is fifteen (15) minutes per inch and the maximum allowable rate is
two (2) minutes per inch. Infiltration rate design information shall be prepared and sealed by a licensed engineer or licensed geologist and submitted to the City along with the storm
drainage report. 6.03.4 Retention System Infiltration Rate Analysis Infiltration rate testing shall follow the general steps listed below: A. Preparation of the Test Hole: The diameter
of each test hole is six inches (6”) minimum diameter hole dug or bored to the proposed depth of the infiltration system. Carefully scratch the bottom and sides of the hole in order
to remove any smeared soil surfaces and to provide a natural soil interface into which water may percolate. Remove all loose material from the hole. Add two inches (2”) of coarse washed
sand or fine gravel to protect the bottom from scouring and sediment. B. Saturation and Swelling of the Soil: Fill the hole with clear water to a minimum depth of twelve inches (12”)
over the gravel. Keep at least six inches (6”) of water in the hole, by refilling if necessary, for at least four (4) hours (preferably overnight). If soil, other than loose sand, has
a dry appearance when the hole is initially dug, soil must be allowed to swell overnight prior to soaking period to permit it to approach the condition it will be in when system is in
operation. If soil was initially wet prior to saturation, proceed to the next paragraph. The saturation and swelling of well draining soils may not be required. C. Percolation Rate Measurement:
Immediately after saturating the soil and permitting it to swell, adjust the depth of water in the test hole to six inches (6”) over the gravel. From a fixed reference point, measure
the drop drop in water level over a thirty-minute period, refilling to six inches (6”) over the gravel if necessary. The drop in thirty-minutes is used to calculate the percolation rate
(time required in minutes for water to fall one inch (1”)). 6.04 Discharge Control Requirements 6.04.1 Purpose The purpose of a discharge control structure is to limit the runoff discharge
rate from a developed site to the pre-developed discharge rate. Discharge control devises are usually comprised of circular orifices and notched weirs. 6.04.2 Design The following criteria
shall be incorporated when designing discharge control facilities: A. The discharge rates for storm drainage detention systems shall be based upon the peak discharge rates (Q). The peak
discharge rates shall be equal to or less than the following criteria: 1. The 2-year 24-hour post-development storm event peak Q discharge rate shall be 50% of the 2-year 24-hour pre-development
storm event peak discharge rate. 8/9/2004 Design Standards Page 6-11 REF. H\DEVELOPMENT\Design Standards\Chapter 6 (8-04)
2. The 10-year 24-hour post-development storm event peak Q discharge rate shall match the 10-year 24-hour pre-development storm event peak Q discharge rate. 3. The 25-year 24-hour post-development
storm event peak Q discharge rate shall match the 25-year 24-hour pre-development storm event peak discharge rate. 4. The 100-year 24-hour post-development storm event peak Q discharge
rate shall match the 100-year 24-hour pre-development storm event peak discharge rate. B. When determining the pre-developed flows, the site shall be analyzed at its historic pre-developed
condition. For Auburn and surrounding vicinity this may either be a forested or pasture condition or a combination of the two. Typically developments on the hillsides and plateaus will
fall under the forested condition and those in the valleys will be the pasture condition. C. The hydraulic head of the discharge control structure shall be designed so that the orifice
at the bottom of the control structure shall be a minimum of one inch (1”) in diameter. D. The calculated orifice diameter size shall be rounded off to the nearest 1/16th inch increment.
6.04.3 Discharge Control Structures Discharge control structures shall conform to City of Auburn Standard details and meet the following requirements: A. Notched Weir Control Structures
1. Notched weir structure details shall be shown on the plans to scale and follow the requirements shown on standard detail STORM-01. 2. A baffle shall be provided on the notched weir
to provide oil/water separation. B. Orifice Control Structures 1. Orifice structure details shall be shown on plans to scale and follow the requirements shown on standard detail STORM-02.
2. The overflow/orifice assembly shall not impede access or maintenance and operation. C. Small Site Control Structures 1. Small site structure details shall be shown on plans to scale
and follow the requirements shown on standard detail STORM-03. 2. Small site water quality control structures will only be allowed for sites with under 2600 square feet of impervious
area excluding roof areas. 8/9/2004 Design Standards Page 6-12 REF. H\DEVELOPMENT\Design Standards\Chapter 6 (8-04)
6.05 Storm Drainage Quality Treatment 6.05.1 Purpose Storm drainage quality treatment measures are required to remove sediment and pollutants from storm runoff prior to discharging into
the downstream facilities. Storm drainage quality treatment may be achieved by a variety of different methods. These include, but are not limited to, wetponds, wetvaults, bioswales,
oil/water separators, and various emerging technologies. 6.05.2 General Requirements Storm Drainage Quality Treatment General Requirements are as follows: A. All systems shall, at a
minimum, provide water quality treatment for a volume of stormwater discharged during the 6-month 24-hour post-development storm event. For ease of calculation, this may be assumed to
be seventy-two percent (72%) of the 2-year 24-hour post development storm event. B. Storm drainage discharge requires quality control pre-treatment via an approved method prior to discharge
into downstream systems or groundwater. A technical memo is available upon request to address treatment options for small and/or developed parcels. The memo addresses alternative storm
drainage quality treatment best management practices (BMPs) that may be allowed on sites where the preferred treatment is not feasible. C. Water quality systems shall be designed for
simplicity and ease of maintenance. D. Treatment systems shall be designed such that storm drainage from public streets does not discharge into areas of private ownership or private
maintenance responsibility unless a hold-harmless and cross drainage agreement has been secured. 6.05.3 Wetponds A wetpond may be used for commercial, industrial, residential plats,
or roadway projects when space is available for aboveground treatment. The primary design factor that determines the removal efficiency of a wetpond is the volume of the wetpool. Larger
volumes in the wetpool create a higher potential for pollutant removal. Performance is also improved by avoiding dead zones like corners where little circulation occurs, using large
length-to-width ratios, dissipating energy at the inlet, and ensuring that flow rates are uniform to the extent possible and not increased between cells. Other design considerations
include those for safety, maintenance, and detention sizing. 6.05.3.1 Design Criteria The following criteria shall be incorporated when designing wetponds: A. The wetpool volume for
the wetpond shall be equal to or greater than the total developed volume of runoff from the 6-month 24-hour storm event. B. The surface area of the wetpond at the water quality design
water surface must be at least equal to one percent (1%) of the impervious area of the drainage basin. C. The wetpool portion of the pond shall be a minimum of three feet (3’) in depth
with an additional one-foot (1’) of sediment storage provided in the first cell. 8/9/2004 Design Standards Page 6-13 REF. H\DEVELOPMENT\Design Standards\Chapter 6 (8-04)
D. Wetponds should be designed as flow-through systems with the distance between the inlet and outlet maximized. A flow length-to-width ratio greater than 3:1 is recommended. E. Wetponds
shall be separated into two cells by a keyed gravel berm. The gravel berm shall rise from the pond bottom to an elevation between the 10-year and 25-year design stormwater surface elevation.
F. An access road shall be provided to the wetpond. The access road shall be a minimum of fifteen feet (15’) wide. Turns in the access road shall be designed using a minimum inside radius
of thirty feet (30’) and a minimum outside radius of fifty feet (50’). On public ponds a ten-foot (10’) wide access ramp shall extend down into all cells. On private ponds the access
ramp is required on the inlet cell only if it can be demonstrated that adequate maintenance can be provided to subsequent cells without road access. At no point shall the slope of the
access ramp exceed seven horizontal to one vertical (7H:1V). Access shall be provided to the outlet control structure and any additional significant drainage system components. G. Wetponds
shall be designed to eliminate the infiltration of untreated stormwater. H. For private wetponds, a minimum three-inch (3”) diameter power conduit shall be under grounded to the edge
of the pond for possible future installation of aerators. Aerators are required to be installed on public wetponds. Power provided to public ponds shall be independently metered. Specific
power and aeration requirements will be determined case by case during plan review and will be based upon the size and configuration of the wetpond. 8/9/2004 Design Standards Page 6-14
REF. H\DEVELOPMENT\Design Standards\Chapter 6 (8-04)
8/9/2004 Design Standards Page 6-15 REF. H\DEVELOPMENT\Design Standards\Chapter 6 (8-04)
8/9/2004 Design Standards Page 6-16 REF. H\DEVELOPMENT\Design Standards\Chapter 6 (8-04)
6.05.4 Wetvaults The use of wetvaults is limited to sites under one (1) acre (43,560 SF) of impervious area. As with wetponds, the primary design consideration that determines the removal
efficiency of a wetvault is the volume of the wetpool. Larger volumes in the wetpool create a higher potential for pollutant removal. Other impacts to the design factors include those
for safety, maintenance, and detention sizing. 6.05.4.1 Design Criteria The following criteria shall be incorporated when designing wetvaults: A. The wetpool volume for the wetvault
shall be equal to or greater than the total volume of runoff from the 6-month 24-hour storm event. B. The surface area of the wetvault at the water quality design water surface must
be at least equal to one percent (1%) of the impervious area of the drainage basin. C. The inlet and outlet should be designed to obtain the maximum flowpath. D. The sediment storage
in the first cell shall be an average of one-foot (1’) minimum. Because of the v-shaped bottom, the depth of sediment storage needed above the bottom of the side wall is roughly proportional
to vault width according to the schedule below: Vault Width 15' 20' 40' Sediment Depth (from bottom of side wall) 10" 9" 6" E. The wetpool portion of the vault shall be a minimum of
three feet (3’) in depth measured from the bottom of the sidewall. F. For wetvaults in which the surface area of the second cell is greater than 1,250 square feet, four percent (4%)
of the surface area over the second cell should be grated for ventilation. G. Vaults should be designed as flow-through systems with the distance between the inlet and outlet maximized
as much as possible. A flow length-to-width ratio greater than 3:1 is recommended. H. The vault shall be separated into two (2) cells by a wall. The wall shall extend from the vault
floor to the water quality design surface elevation. I. The two (2) cells of a detention vault should not be divided into additional subcells by internal walls. If internal structural
support is needed, it is preferred that column construction be used to support the vault lid rather than walls. 8/9/2004 Design Standards Page 6-17 REF. H\DEVELOPMENT\Design Standards\Chapter
6 (8-04)
8/9/2004 Design Standards Page 6-18 REF. H\DEVELOPMENT\Design Standards\Chapter 6 (8-04)
6.05.5 Bioswales Sites under twenty thousand square feet (20,000 SF) of impervious area may use bioswales, or larger sites when they are used to supplement other approved forms of storm
drainage quality treatment. 6.05.5.1 Design Criteria Bioswale design shall use the following criteria: A. Bioswales shall be at least one hundred feet (100’) in length. Swale lengths
shall be adjusted to achieve a minimum hydraulic residence time of nine (9) minutes for design storm flows. Roof runoff may bypass the bioswale. The bioswale may not be used for detention/retention
storage. In areas where the stormwater can infiltrate, liners or impermeable material will be required. B. Bioswales shall be sized to treat the volume of the 2-year 24-hour postdevelopment
design storm. Flows greater than the 2-year 24-hour postdevelopment storm must bypass the swale unless it can be shown that velocities will be less than one foot per second (1 fps) or
less. Sites of less than ten thousand square feet (10,000 SF) of impervious area are not required to by-pass flows. C. Bioswales shall be designed to be a minimum of one foot (1’) above
the seasonal high ground water elevation. D. Bioswales should be designed at a slope of two to four percent (2%-4%). A deviation for slopes less than two percent (2%) will be required
and must be planted with wetland vegetation. Sudden gradient drops may be provided to maintain a maximum of four percent (4%) slope so long as to not impede maintenance or introduce
erosion potential. E. Bioswales shall be designed using a Manning’s runoff coefficient “n” = 0.20. F. Side slopes shall be no steeper than three horizontal to one vertical (3H:1V) in
the treatment area. Side slopes above the treatment area shall be no steeper than two horizontal to one vertical (2H:1V). Vertical walls may be used on a maximum of three (3) sides,
provided proper access is provided for maintenance and safety issues. G. The design flow depth shall be three inches (3”) or less. H. Determine the required base width using Manning’s
Equation. A minimum of two feet (2’) in width is required for a one hundred foot (100’) bioswale. Maximum velocity during design flow shall not be greater than one foot per second (1
fps) for design storm flows. I. A minimum of ten feet (10’) shall be provided between the outside edge of the bioswale and any property line or obstruction that would impede maintenance.
Landscaping for storm drainage quality treatment facilities require irrigation to prevent plants and sod from dying during times of limited precipitation. When irrigation is not available
to water bioswales during construction, seeding or hydroseeding may be done only between March 1 and May 1 and between September 1 and October 15, unless other watering provisions are
established. 8/9/2004 Design Standards Page 6-19 REF. H\DEVELOPMENT\Design Standards\Chapter 6 (8-04)
J. Permanent level spreaders or other devises shall be used every fifty feet (50’) to redistribute the flows to avoid channeling in the bio-swale. Construction materials are limited
to concrete. 6.05.6 Oil/Water Separators Oil separation facilities are to be used in pre-treating storm drainage flows from fuel islands and wash pads where heavy concentrations of oil
may occur, and floor drains prior to discharging into the sanitary sewer system. Each installation must be designed for the specific oil component and flow rate receiving treatment.
6.05.6.1 Design Criteria The following criteria shall be used in the design of oil separation facilities: A. Wash pads intended for washing the exterior surfaces of vehicles shall drain
to a Type 2 Catch Basin with a down turned 90-degree elbow prior to discharge to the sanitary sewer. B. A forebay to collect floatable and the larger settleable solids. C. An afterbay
in which absorbent pillows or similar materials are placed. Used absorbent pillows shall be properly disposed of. D. An inspection T inside the first chamber at the inflow pipe and a
sample T at the outflow pipe. E. Access to the separator shall be maintained free for inspection at all times. F. A maximum of two hundred square foot (200 SF) area open to rainfall
may discharge to the separator. G. If a pump mechanism is required to convey the discharge from the site to the sanitary sewer system, the pump must be designed for discharge to a controlled
gravity outlet flow into the City system. H. The separator shall have a valve on the discharge pipe that can be closed during cleaning and in the event of a spill. I. All piping entering
and leaving the separator must be six inches (6”) minimum diameter. J. Access points in the top of the vault must be provided to allow a minimum twelve-inch (12”) diameter access for
observation and maintenance to all chambers of the separator. K. Access doors as applicable, should be galvanized spring-assisted diamond plate with a penta-head bolt-locking latch and
recessed lift handle. L. Doors must open a full one hundred and eighty degrees (180º). 6.05.7 Emerging Technologies The City may allow the use of emerging technologies for storm drainage
quality treatment with prior approval by the City. To date the City has approved the use of Vortechnics Systems, Stormceptors, and Stormwater Management Storm Filter Systems. As new
and approved technologies become available, the City will evaluate their use on a case-by-case basis. Consideration will be given to systems with a proven track record that have received
WSDOT and/or Department of Ecology approval. 6.05.7.1 Design Criteria 8/9/2004 Design Standards Page 6-20 REF. H\DEVELOPMENT\Design Standards\Chapter 6 (8-04)
At a minimum, emerging technology systems must provide the following: A. Provide storm drainage quality treatment for the volume of stormwater discharged during the 6-month 24-hour post-development
storm event. B. Provide storm drainage quality treatment for the maximum flow velocity from the 2-year 24-hour post-development storm event. C. Remove a minimum of eighty percent (80%)
of the total suspended solids (TSS) from the site stormwater. D. Designed, where applicable, to remove a minimum of fifty percent (50%) of all heavy metals, phosphorus, and/or oils from
the site stormwater. E. Allow for reasonable and practical maintenance and operation. 6.06 Landscaping for Storm Drainage Facilities 6.06.1 Purpose Public and private storm drainage
facilities should enhance natural appearances, protect significant cultural and natural resources, and be appropriate to the use of the site and the surrounding area. Landscaping shall
be designed to shield the storm drainage facilities and create a natural-appearing setting while not adversely impacting the function and maintenance of the storm drainage facilities.
A Landscape Plan with the Storm Drainage Site Plan is required for City review and approval. 6.06.2 Design The following criteria shall be incorporated when designing landscaping for
storm drainage facilities: A. Identify the type of landscaping and screening appropriate to the site taking into account zoning and proposed use. Landscaping and screening requirements
are described in Auburn City Code (ACC) Title 18. The purpose of each type is to reflect the level of landscaping and screening density needed to maintain compatibility with the character
of the neighborhood. B. An effort should be made to retain all significant trees on the site, evergreens six inches (6”) or greater in diameter, or any deciduous tree four inches (4”)
or greater as defined in ACC Title 18. Diameter measurements are taken at four feet (4’) above grade elevation. Authorization by the City is required for the removal of any significant
tree. C. Identify the soil type and hydrological regime of each portion of the storm drainage facility to determine appropriate site criteria for plant selection. D. Select tree and
shrub species from the Plant Selection Guide contained herein. Plant choices must reflect the functional and aesthetic needs of the site. Fall planting is recommended for the optimal
acclimation and survivability. An irrigation system will be required on public ponds to insure plant establishment. Irrigation systems may also be needed on private ponds if plantings
are done in the spring/summer or in times of limited precipitation, unless other watering provisions are established. E. Plant choices are not restricted to those listed in the Plant
Selection Guide, but plant selection must be based on ease of maintenance, appropriateness to the use of the site (commercial, residential, or industrial), and survivability. Plant 8/9/2004
Design Standards Page 6-21 REF. H\DEVELOPMENT\Design Standards\Chapter 6 (8-04)
selection should correspond with street tree requirements and neighborhood character as appropriate. Selections are to be approved by the City during the review process. NOTE: Plants
identified in the Guide are predominately native and reflect the soil conditions and water regimes of the area. F. Develop a Landscape Plan to scale identifying the location and species
of existing trees and the location and schedule of species, quantity, and size of all proposed trees, shrubs, and ground covers. Drawings should be scaled at 1”=10’ or 1”= 20’ to optimally
relay information on the plant location and placement. Construction specifications should indicate appropriate soil amendments where necessary and planting specifications as recommended
by the American Standards for Nursery Stock and the American National Standards Institute (ANSI). G. Excluding access points, a minimum ten feet (10’) width of Type-III landscaping in
accordance with Auburn City Code 18.50 shall be provided around the exterior length of the pond. This width may be reduced to five feet (5’) if the interior side slopes of the pond are
landscaped. H. No tree and shrub planting is allowed within pipeline easements, traveled surfaces, or over underground utilities. 6.06.3 Suggested Plants The following sections contain
the suggested trees and plants and grasses to be used in landscaping storm drainage facilities. The trees and plants listed are native to the region and should be chosen over non-native
species. The lists shown are not all-inclusive; additional trees and plants may be acceptable upon approval of the City. 6.06.3.1 Tree Selection Guide for Storm Drainage Detention/Retention
Facilities Suggested Trees Botanical Name Common Name Tolerates Wet to Saturated Soils Recommend Moderately Wet to Dry Soils Recommend Dry Soils Acer circinatum Vine Maple ♦ Alnus rubra
Red Alder ♦ Betula papyrifera Paper Birch ♦ Corylus cornuta Hazelnut ♦ Crataegus douglasii Black Hawthorn ♦ Fraxinus latifolia Oregon Ash ♦ Picea sitchensis Sitka Spruce ♦ Pinus contorta
Shore Pine ♦ Pinus monticula Western White Pine ♦ Populus tremuloides Quaking Aspen ♦ Prunus virginiana Choke Cherry ♦ Pseudotsuga menziesii Douglas Fir ♦ Salix lasiandra Pacific Willow
♦ Salix scouleriana Scouler Willow ♦ Salix sitchensis Sitka Willow ♦ Thuja pljcata Western Red Cedar ♦ Tsuga heterophylla Western Hemlock ♦ 8/9/2004 Design Standards Page 6-22 REF. H\DEVELOPMENT\Desi
gn Standards\Chapter 6 (8-04)
6.06.3.2 Shrub Selection Guide for Storm Drainage Detention/Retention Facilities Suggested Shrubs Botanical Name Common Name Tolerates Wet to Saturated Soils Recommend Moderately Wet
to Dry Soils Recommend Dry Soils Amelanchier alnifolia Serviceberry ♦ Cornus sericea Red Osier Dogwood ♦ Gaultheria shallon Salal ♦ Holidiscus discolor Ocean Spray ♦ Lonicera involucrata
Black Twinberry ♦ Mahonia aquifolium Tall Oregon Grape ♦ Mahonia repens Low Oregon Grape ♦ Oemleria cerasiformis Indian Plum ♦ Physocarpus capitatus Pacific Ninebark ♦ Ribes sanguineum
Red Flowering Currant ♦ Rosa nutkana Nootka Rose ♦ Rosa rugosa Rugosa Rose ♦ Rubus spectabilis Salmonberry ♦ Rubus spectabilis Thimbleberry ♦ Sambucus racemosa Red Elderberry ♦ Symphoricarpos
albus Snowberry ♦ Vaccinium ovatum Evergreen Huckleberry ♦ Vaccinium parviflorum Red Huckleberry ♦ 6.06.3.3 Perennial Groundcover Selection Guide for Storm Drainage Detention/Retention
Facilities Suggested Perennial Groundcover Botanical Name Common Name Tolerates Wet to Saturated Soils Recommend Moderately Wet to Dry Soils Recommend Dry Soils Athyrium filix-femina
Lady Fern ♦ Dicentra formosa Bleeding Heart ♦ Polystichum munitum Sword Fern ♦ 8/9/2004 Design Standards Page 6-23 REF. H\DEVELOPMENT\Design Standards\Chapter 6 (8-04)
6.06.3.4 Shrub Selection Guide for Storm Drainage Detention/Retention Facilities Suggested Aquatics/Emergent Wetland Plants Botanical Name Common Name Tolerates Open Water (3’ + Depth)
to Shallow Standing Water (<1’ Depth) Potamogeton natans Floating Pondweed ♦ Lotus conicalitatus Birdsfoot Trefoil ♦ Nymphaea odorata American Water Lily ♦ Lemna minor Common Duckweed
♦ Polygonum punctatum
Dotted Smartweed ♦ Polygonum amphibium Water Smartweed ♦ Oenanthe sarmentosa Water Parsley ♦ Alisma plantago-aquitica American Waterplantain ♦ Sparganium spp. Bur-reed ♦ Sagittaria spp.
Arrowhead ♦ Scirpus acutus Hardstem Bulrush ♦ Scirpus microcarpus Small-fruited Bulrush ♦ Carex obnupta Slough Sedge ♦ Carex languinosa Wooly Sedge ♦ Eleocharis spp. Spike Rush ♦ Carex
spp. Sedge ♦ Tolmiea menziesii Piggy back plant ♦ Hordcum brachyantherum Meadow Barley ♦ 6.06.3.5 Grass Seed Mixes for Detention/Retention Facilities Moisture Condition By Weight Species
Common Name Percent Very Moist Agrosotis tenuis Colonial Bentgrass 50 Festuca ruba Red Fescue 10 Alopocuris pratensis Meadow Foxtail Moist Festuca arundinacea Meadow Fescue 70 Agrosotis
tenuis Colonial Bentgrass 15 Alopecurus pratensis Meadow Foxtail 10 Trifoluim hybridum White Clover 5 Moist-Dry Agrosotis tenuis Colonial Bentgrass 10 Festuca ruba Red Fescue 40 Lolium
multiflorum Annual Ryegrass 40 Trifolium repens White Clover 10 Application rates: Hydroseed @60 lbs/acre Handseed @2 lbs/1000 square feet 8/9/2004 Design Standards Page 6-24 REF. H\DEVELOPMENT\Desig
n Standards\Chapter 6 (8-04)
6.06.3.6 Bioswale Landscaping 6.06.3.6.1 Bioswale Grass Seed Mixes GRASS SEED MIXES SUITABLE FOR BIOSWALES* Use for Slopes >2% Mix 1 Mix 2 75-80 percent Tall or Meadow Fescue 60-70 percent
Tall Fescue 10-15 percent Seaside/Colonial Bentgrass 10-15 percent Seaside/Colonial Bentgrass 5-10 percent Redtop 10-15 percent Meadow Foxtail 6-10 percent Alsike Clover 1-5 percent
Marshfield Big Trefoil 1-6 percent Redtop Note: All percentages are by weight. * Based on Briargreen, Inc. 6.06.3.6.2 Bioswale Suggested Plants FINELY TEXTURED PLANTS TOLERANT OF FREQUENT
SATURATED SOIL CONDITIONS OR STANDING WATER Use for Slopes <2% Common Name Scientific Name Spacing (on center) Shortawn Foxtail Alopecurus aequalis seed Water Foxtail Alopecurus geniculatus
seed Spike rush Eleocharis spp. 4 inches Slough sedge Cared obnupta 6 inches or seed Sawbeak sedge Carex stipata 6 inches Sedge Carex spp. 6 inches Western Mannagrass Glyceria occidentalis
seed Velvetgrass Holcus mollis seed Slender rush Oenanthe sarmentosa 6 inches Hardstem bulrush Scirpus acutus 6 inches Small-fruited bulrush Scripus microarpus 12 inches 8/9/2004 Design
Standards Page 6-25 REF. H\DEVELOPMENT\Design Standards\Chapter 6 (8-04)
6.07 Storm Drainage Conveyance Systems 6.07.1 Purpose Storm drainage conveyance systems are required to safely move stormwater downstream. The storm drainage conveyance system may take
the form of pipes, open ditch, or sheet flow. 6.07.2 Design The following criteria shall be incorporated when designing storm drainage conveyance systems: A. Storm drainage conveyance
systems shall be designed to convey the volume from the 100-year 24-hour post development storm event. B. A backwater analysis method shall be used for the analysis of both proposed
and existing systems to convey the post developed rate of runoff for the 25-year and 100-year 24-hour developed design storm events. Drainage structures shall not be surcharged for the
10-year 24-hour storm peak rate event. Drainage structures shall only be surcharged to a maximum of two feet (2’) above the downstream pipe crown elevation and shall have one foot (1’)
of freeboard below the rim elevation for the 25-year 24-hour peak storm event. Overtopping of the manholes for the 100-year 24-hour peak storm event is allowed only when the overflow
is then conveyed within the curb/gutter and the pavement section of the roadway. C. For steep slope applications where flow velocities are greater than fifteen feet per second (15 fps),
applicant may size the proposed conveyance system under supercritical flow conditions with approval of the City. D. All exposed storm drainage pipe ends 15 inches (15”) in diameter and
larger shall have trash racks at both the inlet and outlet ends in conformance with Auburn’s Standard Detail No. STORM-09. E. All exposed storm lines shall have outlet protection or
other approved energy dissipation at both the inlet and outlet ends. The size and gradation of riprap shall be indicated on the plans. F. A minimum of ten feet (10') shall be provided
between the centerline of the conveyance system and any property line or obstruction that would impede maintenance. G. The minimum pipe size diameter for public storm lines shall be
12 inches (12"). H. The minimum velocity at design flow of the pipe shall be three feet per second (3 fps) for public systems. I. Catch basins and manholes shall be accessible to vehicles,
equipment, etc., for maintenance. J. Maximum spacing between structures (i.e., manholes or catch basins) for closed systems shall be four hundred feet (400’) of pipe length. K. Where
storm drainage is directed against a curb, the curb shall be either a concrete curb and gutter or concrete vertical curb. An extruded curb or asphalt wedge section in any form will not
be allowed. L. Open systems shall be designed with side slopes no steeper than 1 vertical to 3 horizontal (1V:3H) and with adequate slope stabilization and a minimum 8/9/2004 Design
Standards Page 6-26 REF. H\DEVELOPMENT\Design Standards\Chapter 6 (8-04)
freeboard of 1 foot (1') for the 100-year 24-hour peak storm event. The maximum distance from the edge of the adjacent access to the farthest point shall be eighteen feet (18’). M. Ditches
may be either "v" shaped or trapezoidal. N. Open ditches designed to accommodate a flows up to five feet per second (5 fps) shall be hydroseeded with a vegetative mixture approved by
the City. Velocities in excess of five feet per second (5 fps) will require erosion protection. 6.07.3 Public Street Drainage Conveyance System Requirements Storm drainage conveyance
for public street requirements are as follows: A. Maximum surface run without considering curve super elevation (gutter flow) between catch basins on paved roadway surfaces shall be
as follows: PAVEMENT SLOPE (%) MAX. FLOW LENGTH (ft) 0.5-1 200 1 to 6 300 6 to 12 200 B. The minimum longitudinal street gutter slope shall be one/half percent (0.5%). C. Catch basins
or manholes shall be located at all junctions of two (2) or more connecting storm drainage pipes and wherever there are changes in direction, slope, and pipe size. D. Catch basins shall
be installed at all low points in the surface drainage area. E. Vaned catch basin grates and through-curb inlets may be required for roadway grades in excess of six percent (6%). F.
At gutterline low points, insure positive flow to catch basins. In some situations this may require variation from the vertical curve at the low point in the gutterline. G. Storm manholes
or catch basins shall not be designed within the vehicular wheel paths. H. At street intersections, storm drainage catch basins shall be located at the appropriate PC’s and/or PT’s of
the gutterline radii to intercept flows entering the intersection to avoid ponding in the intersection. The catch basins shall also be located so as to not adversely impact wheelchair
ramp approaches. I. The design of street drainage conveyance should seek to minimize the number of structures and redundant pipes. 6.08 Stormwater Pollution Prevention Plan 6.08.1 Purpose
All non-single family projects creating impervious area draining to a private stormwater facility are required to prepare a Stormwater Pollution Prevention Plan outlining the maintenance
requirements for the system. 8/9/2004 Design Standards Page 6-27 REF. H\DEVELOPMENT\Design Standards\Chapter 6 (8-04)
6.08.2 Stormwater Pollution Prevention Plan General Requirements The Pollution Prevention Plan shall include at a minimum the following information: A. Title: Storm Drainage Pollution
Prevention Plan for (name of project or development), including the application or permit number for SEPA, Building, Grading and/or Public Facility Extension and the Storm permit. B.
Site Address: Include street address and tax parcel number. C. Introduction: Brief introduction describing site and facilities. Include the amount of impervious surface on the site.
Indicate the natural system to which runoff drains (i.e., Green River, Mill Creek, groundwater, etc.) and how the water gets there. D. Plan Goal: Brief description of the goal of this
plan. E. Prevention BMPs: Outline BMPs, Spill Response Plan (for facilities installed on site). F. Treatment BMPs: Outline BMPs. Give design criteria as needed (i.e., minimum height
to which grass in a swale must be maintained). G. Inspection: Indicate frequency (minimum two (2) per year) year) and state that records of inspection and maintenance will be kept for
five (5) years and will be available for City inspector review. Include a copy of the inspection checklist for the site. H. Maintenance: Outline frequency for routine maintenance and
what triggers asneeded maintenance. Indicate what maintenance results are to be. I. A list of the people responsible for the project, including owner and engineer information. A boilerplate
form of a Pollution Prevention Plan is available from the City upon request. 6.09 Public Storm Facility Easements A stormwater easement is required for the placement, operation, and
maintenance of storm facilities upon private property. Public stormwater easements shall meet the following requirements: A. Public stormwater easements shall extend a minimum of seven
and one-half feet (7½’) to each side of the centerline of the storm pipe and seven and one-half feet (7½’) beyond the outside extremity of a storm facility. Additional width may be required
depending upon the depth and site topography. B. Public stormwater easements shall be provided on the City’s standard easement form. Legal description of the easement and the property
that the easement encumbers, along with a sketch showing both, shall be sealed by a licensed Land Surveyor and incorporated into the easement form as exhibits. The legal descriptions
and sketch shall be on plain bond paper with margins acceptable to the County of recording. C. Public stormwater easements shall be reviewed by the City and then recorded in the appropriate
County prior to acceptance of the public storm system. 8/9/2004 Design Standards Page 6-28 REF. H\DEVELOPMENT\Design Standards\Chapter 6 (8-04)
8/9/2004 Design Standards Page 6-29 REF. H\DEVELOPMENT\Design Standards\Chapter 6 (8-04) 6.10 Material Requirements for Storm Drainage Systems The following list of storm materials is
for reference only. The complete list of acceptable materials and appurtenances for storm drainage construction is subject to weight loadings and construction placement. Please refer
to the City of Auburn’s Construction Standards manual (latest edition) for the most current information on these requirements. 6.10.1 Storm Sewer Pipes Pipe Type Application Pipe Cover
* Solid Wall Polyvinyl Chloride (PVC) Pipe, SDR-21 Public/Private Minimum 18” Solid Wall Polyvinyl Chloride (PVC) Pipe, SDR-35 Requires 13.5’ lengths. Public/Private Minimum 3’ ADS WTIB
Series (all sizes CPEP) Requires 13.5’ lengths Private Minimum 3’ HANCOR Blue Seal (all sizes CPEP) Requires 13.5’ lengths Private Minimum 3’ Plain Concrete Pipe (less than 12”) Class
3 Private Minimum 3’ Reinforced Concrete Pipe (12” or Larger) Class IV Public/Private Minimum 18” Ductile Iron Pipe Special Class 50 or 52 Public/Private Minimum 6” High Density Polyethylene
Pipe (H.D.P.E.) (Drisco Pipe) Public/Private Minimum 12” Corrugated Metal Pipe (CMP) (For underground storage only) Private Varies * * Maximum pipe cover based upon design conditions
and/or manufacturers recommendation. Maximum pipe cover for Public pipes is twenty feet (20’). 6.10.2 Storm Sewer Structures Structure Type (WSDOT) Pipe Diameter Maximum (I.D.) Depth
I 12” 5’ Maximum at I.E. I-L 18” 5’ Maximum at I.E. II-48” 30” 20’ Maximum at I.E. II-54” 36” 20’ Maximum at I.E. II-72” 42” 20’ Maximum at I.E.
Chapter 7 – Water Facilities 7.00 Preface The design of Public Water Facilities shall conform to the State of Washington Department of Health (DOH) Design Standards for Group A Public
Water Systems, Standard Specifications of the American Water Works Association (AWWA), and the most recent published and adopted edition of the Uniform Plumbing Code (UPC), unless modified
herein. Compliance with these standards does not alleviate the design engineer from using sound professional engineering practices. The design criteria contained herein are the minimum
acceptable under standard conditions. Special conditions may require more stringent requirements that will be addressed during the plan review process. The design criteria used to estimate
future line capacities are established in the City’s Comprehensive Water Plan. Anyone proposing to extend or modify the City’s water system should contact the Public Works Department
for information. Developers needing to construct water improvements shall enter into a Facility Extension Agreement (FAC) with the City. The Public Works Department can provide information
on this agreement as well as applicable permit and connection fee estimates. 7.01 Design Criteria 7.01.1 Water Mains The design of water mains shall meet the following requirements:
7.01.1.1 Water Main Sizing Public water mains shall be sized using the following criteria: A. Water mains in single-family residential areas shall be a minimum of eight inches (8”) in
diameter. B. Water mains in multi-family residential and non-residential areas shall be a minimum of twelve inches (12”) in diameter. Onsite water main loops, with no possibility of
future extension, serving two or less fire hydrants may be reduced to a minimum diameter of eight inches (8”). C. New mains shall be sized as indicated in the City's Comprehensive Water
Plan. D. Under fire flow and other emergency demand conditions, the flow velocity shall not exceed eight feet per second (8 fps) in distribution mains or five feet per second (5 fps)
in transmission mains. E. Exceptions to the minimum diameter allowed might be made in small cul-desacs and in areas where looping of a main is not feasible. In these cases the main stubs
could be a minimum of four inches (4”) in diameter if no fire hydrants are connected. If a conflict arises between two or more of these criteria, the water main should be designed using
the largest pipe diameter required. 8/9/2004 Design Standards Page 7-01 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 7 (8-04)
7.01.1.2 Water Main Location A. Water mains shall be installed with no less than forty-two inches (42”) and no more than seventy-two inches (72”) finished cover. B. Water mains shall
be located in the public right-of-way or within a public water utility easement. Water mains located in the public right-of-way shall meet the requirements of Section 9.01.2. C. Water
mains shall be located a minimum horizontal distance of ten feet (10’) from buildings and sanitary sewer mains and a minimum horizontal distance of five feet (5’) from all other utilities.
D. When crossing, water mains shall be located a minimum vertical distance of eighteen inches (18”) above sanitary sewer mains and a minimum vertical distance of twelve inches (12”)
from all other utilities. E. Water mains shall be extended through the full width of the property to be served. Whenever possible, provisions shall be made for looping all existing and
new dead-end mains associated with the project. If at the time of project approval this is not feasible, an easement shall be provided to the adjacent property line or right-of-way for
future looping of the dead-end main. 7.01.1.3 Water Main Fittings A. Blowoffs (See Standard Detail WATER-03 or WATER-04) are required on dead-end water mains with a diameter of six inches
(6”) or less; hydrants are required for dead-end mains over six inches (6”) in diameter. Blowoffs shall also be installed at the low point of a depressed “sag” section of a water main,
except where a fire hydrant is installed within fifty feet (50’) of said area. Blowoffs shall be placed in a level clear area within the right-of-way or easement and be easily accessible
to the City. B. Combination air release valves (See Standard Detail WATER-02) are required at high points in water mains when an abrupt vertical change in pipe elevation exceeds one
pipe diameter, except where fire hydrants are installed within fifty feet (50’). Combination air release valves shall be placed within a level clear area within the right-of-way or easement
and be easily accessible to the City. C. All bends shall have mechanical or flanged joints and concrete thrust blocking (See Standard Detail WATER-01). The City may require restrained
joints in lieu of thrust blocking in special conditions. D. Tees shall have mechanical or flanged joints and concrete thrust blocking (See Standard Detail WATER-01). When connecting
to an existing public water main, a tapping tee and valve shall be used unless otherwise approved or required by the City. E. The maximum allowable deflection per joint for ductile iron
water mains shall be four degrees (4°). 8/9/2004 Design Standards Page 7-02 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 7 (8-04)
7.01.2 Water Services See Standard Details WATER-06, -13 through -17 The City owns and shall maintain the service line to the meter, the meter and setter, the meter tailpiece, and the
meter box. The property owner owns and shall maintain the tailpiece connection fitting, service line, and other facilities such as pressure reducing valves, pumps, or backflow prevention
assemblies behind the meter. For fire sprinkler connections, City ownership and maintenance responsibilities cease at the edge of the public right-of-way or public water utility easement.
7.01.2.1 Domestic Services Domestic Services are defined as any service that connects directly to plumbing within a structure and is used for drinking, cooking, washing, and other standard
uses of potable water. Domestic services shall meet the following requirements: A. Installation of corporation stops, water services, and meters shall be per City of Auburn Standard
Details. The City may, at the City's option, install services from public water mains to the the meter in existing right-of-ways and easements. The developer/contractor will install
and/or replace all applicable services when installing new water mains required for the project. The City will furnish and install the meter for services of two inches (2”) and smaller.
B. Water services and meters of three inches (3”) and larger will be purchased and installed by the developer/contractor under City observation. Where vaults are required, the meter
shall be equipped with a remote read device that records water use in cubic feet. The remote read device shall be located near the hatch opening in a weather-tight enclosure. C. Water
meters shall be located in a level unobstructed area as close to the City main as possible with the distance not to exceed fifty feet (50’). D. Residential sites should have water meters
placed in landscape strips within the right-of-way. If no unpaved areas exist in the right-of-way, water meters may be placed outside the right-of-way in unpaved areas within a public
water utility easement. E. Commercial and industrial sites should have meters located near driveway entrances within the right-of-way or within public water utility easements in landscape
islands located near access driveways when placement in right-ofway is not practical. F. Domestic water meter sizing calculations shall be per the most recent adopted Uniform Plumbing
Code and will be provided by the Developer when requested. The length of the service between the meter and the structure should not exceed one hundred fifty feet (150’). G. When installing
multiple services to a public main, a minimum spacing of two feet (2’) shall be used between corporation stops and a minimum spacing of ten feet (10’) shall be used between tapping tees.
H. Domestic services shall protect the City’s water system from contamination by installing backflow prevention assemblies required by and in accordance with Washington State Law (WAC
246.290.490 or subsequent revisions), Auburn City Code (ACC), and the City of Auburn ”Cross Connection Control Program Manual.” Prior to installation, four (4) sets of backflow prevention
assembly plans, including the connection point to the City main, shall be submitted to City for approval by the City’s Cross Connection Specialist. 8/9/2004 Design Standards Page 7-03
REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 7 (8-04)
7.01.2.2 Other Services Irrigation and other non-domestic services must meet all the above requirements as well as the following: A. Backflow prevention assemblies shall be installed
on all non-domestic services. Double Check Valve Assemblies (DCVA) shall be used for “low hazard” services and Reduced Pressure Backflow Assemblies (RPBA) shall be used for “high hazard”
services. (For lists of low and high hazard services contact the City of Auburn’s Cross Connection Specialist.) Assemblies installed shall be on the current Washington State Department
of Health (DOH) Approved List. Backflow prevention shall be installed within one hundred feet (100’) of the City water main and inspected by the City. These assemblies shall be installed
as required by and in accordance with Washington State Law (WAC 246.290.490 or subsequent revisions), Auburn City Code (ACC), and the City of Auburn ”Cross Connection Control Program
Manual.” Prior to installation, four (4) sets of backflow prevention assembly plans, including the connection point to the City main, shall be submitted to the City for approval by the
Cross Connection Specialist. B. An Irrigation meter shall be installed in cases where water is used for landscape purposes and will not enter the sanitary sewer system. C. A sewer deduct
meter, if applicable, shall be installed between the domestic water meter and the point of connection for an approved industrial use. Sewer deduct meters shall be installed in accordance
with the City of Auburn Standard Detail WATER-06. D. For fire sprinkler service line requirements, see Section 7.01.5.2. 7.01.3 Water Valves Water valves shall meet the following requirements:
7.01.3.1 Water Valve Sizing A. Water valves for twelve-inch (12”) diameter and smaller water mains shall be of the resilient wedge gate variety. When water mains exceed twelve inches
(12”) in diameter, butterfly valves shall be used. 7.01.3.2 Water Valve Location See Standard Details WATER-18 A. Water valves shall be installed along the water mains at a maximum spacing
of four hundred feet (400') and at the intersection of lateral lines. B. Water valves shall be located in clusters when possible and shall be located so that each leg of the main line
system can be isolated separately. C. When extending public water mains, a water valve may be required near the end of lines where future extensions are projected. D. Water valves should
not be placed within the wheel path of vehicle traffic. E. An all-weather maintenance road shall be provided within the public water utility easement to allow access to valves and other
appurtenances located outside of the paved roadway. 8/9/2004 Design Standards Page 7-04 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 7 (8-04)
7.01.4 Pressure Reducing Stations See Standard Details WATER-10A through -12C Pressure Reducing Station installation may be required to maintain adequate pressure in the water system
between pressure zones. Contact the City Water Utility Engineer for specific requirements when applicable. 7.01.5 Fire Systems 7.01.5.1 Fire Hydrant Assemblies See Standard Detail WATER-07
& -08 Fire Hydrant Assemblies shall meet the following requirements: A. Fire hydrant assemblies shall conform to the standard details listed above. B. Fire hydrant assembly service lines
shall be installed at right angles to eightinch (8") minimum diameter supply mains. C. Fire hydrant assemblies shall stand plumb, be set such that the lowest outlet is a minimum of twenty-one
inches (21") above finish grade, and have a clear, level area around the hydrant with a radius of no less than sixty inches (60”). D. Fire hydrant assemblies shall be located no closer
than fifty feet (50’) to the surrounding structures. E. Fire hydrant assemblies shall be provided with two 2-1/2” National Standard Thread (NST) hose ports and one 4-1/2” NST by 5” hose
port with a Storz adapter and cap. F. The pumper port shall face the street or fire access road and be readily accessible to any fire vehicle for fire fighting and pumping operations.
G. The service line from the supply main to the fire hydrant assembly shall be six inches (6") in diameter unless the line extends over fifty feet (50’) in length, in which case pipe
eight inches (8”) in diameter shall be used. H. Fire hydrant assemblies shall be installed with a maximum spacing of six hundred feet (600') along streets in single-family zones and
three hundred feet (300') in all other zones. I. Buildings, other than single-family residences, located with portions of the building more than one hundred fifty feet (150’) in vehicular
travel from a fire hydrant assembly or with building fire flow over 2500 gpm shall require on-site fire hydrant assemblies. These hydrants shall be served by a public water main that
loops around the building, or complex of buildings, and reconnects back to a distribution supply main. 7.01.5.2 Fire Sprinkler Systems Fire Sprinkler Systems shall meet the following
requirements: A. Fire sprinkler systems shall be required in commercial/industrial and multifamily buildings according to the current fire code regulations. Sprinkler systems may also
be required in single-family residences when the length of the private access road exceeds one hundred fifty feet (150’). B. Fire sprinkler supply lines for commercial buildings, unless
designed by a Fire Protection Engineer, shall be the same diameter as the supplying water main. C. Fire sprinkler supply lines shall be separated from the public water main by a valve
located at the point of connection. 8/9/2004 Design Standards Page 7-05 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 7 (8-04)
D. The design of fire sprinkler supply lines for single-family/duplex shall be in accordance with City of Auburn Standard Detail No. WATER-09. E. A backflow prevention assembly shall
be installed on all fire sprinkler lines as required by and in accordance with Washington State Law (WAC 246.290.490 or subsequent revisions), Auburn City Code (ACC), and the City of
Auburn ”Cross Connection Control Program Manual.” When the distance from the point of connection at the main to the fire sprinkler riser assembly is less than one hundred feet (100’),
the backflow prevention assembly may be part of the sprinkler riser assembly and placed within the building’s riser room. Prior to installation, four (4) sets of backflow prevention
assembly plans, including the connection point to the City main, shall be submitted to City for approval by the City’s Cross Connection Specialist. F. A Washington State Certified Level
“U” contractor shall install underground fire sprinkler supply lines in accordance with WAC 212-80-010. Prior to installation, four (4) sets of underground fire sprinkler supply line
plans shall be submitted to the City for approval by the Fire Marshal. Both a State Certified Level “U” contractor and a Fire Protection Engineer shall stamp these plans. A letter from
a state certified sprinkler system designer stating “FOR DESIGN PURPOSES ONLY” may be attached in lieu of a stamp from the Fire Protection Engineer. G. A post indicator valve (PIV) shall
be installed on the fire sprinkler supply line between the public water main and the building. PIV’s shall be located in such a manner as to be easily visible to Fire Department personnel.
A wallmounted PIV may be installed when the exterior wall of the building is of noncombustible construction. A detail containing this information shall be included with the submitted
plans. H. Fire Department Connections (FDC’s) shall be placed within fifty feet (50’) of a fire hydrant assembly or as directed by the Fire Marshal. I. Fire sprinkler supply lines will
require the installation of detector check meters. 7.01.5.3 Fire Flows New developments or redevelopment of existing sites are required to meet the minimum City fire flow requirements
listed below. The developer shall provide information to the City to define the building specific fire flow requirements. If the building specific fire flow requirements are greater
than the minimums listed below, facilities shall be designed to meet the greater requirement. The minimum fire
flow requirements are as follows: 1) Single Family Residential 1,500 GPM @2 Hours 2) Industrial/Commercial/Multi-Family 2,500 GPM @3 Hours Developers are responsible for installing all
facilities necessary to serve their property, complying with development standards, and providing the required fire flow established by the Fire Marshal. If off-site water system improvements
are necessary to meet these requirements, the Developer shall be responsible for said improvements. The change of use of existing structures or areas may also require the installation
of new facilities. 8/9/2004 Design Standards Page 7-06 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 7 (8-04)
8/9/2004 Design Standards Page 7-07 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 7 (8-04) 7.01.5.4 Fire Department and Hydrant Access Fire Department and hydrant access shall
meet the following requirements: A. Access roads shall be a minimum of twenty feet (20’) wide with a minimum vertical clearance of thirteen and a half feet (13½’). B. Turns in the access
road shall be designed using a minimum inside radius of twenty-eight feet (28’) and a minimum outside radius of forty-eight feet (48’). C. Private access roads that exceed one hundred
fifty feet (150’) in length and do not return to a public road shall be provided with a turnaround with a diameter of sixty-five feet (65’). D. On sites where the primary access may
become blocked, a secondary access road that is for emergency vehicles only may be required. 7.02 Public Water Utility Easements Public Water Utility Easements are required for the placement,
operation, and maintenance of water mains upon private property. Public Water Utility Easements shall meet the following requirements: A. Public Water Utility Easements shall extend
a minimum of seven and one-half feet (7½’) to each side of the centerline of the main, water meters, and all fire hydrants. B. Public Water Utility Easements shall be provided on the
City’s standard easement form. Legal description of the easement and the property that the easement encumbers, along with a sketch showing both, shall be stamped and signed by a licensed
land surveyor and incorporated into the easement form as exhibits. The legal descriptions and sketch shall be on plain bond paper with margins acceptable to the County of recording.
C. Public Water Utility Easements shall be reviewed by the City and then recorded in the appropriate County prior to acceptance of the public water main. 7.03 Material Requirements For
Water Systems Unless otherwise approved by the City, all water mains shall be constructed using Special Class 52 Cement Lined Ductile Iron Pipe. The list of acceptable valves, fittings,
and other appurtenances for water facility construction is subject to change as new and improved components become available. Please refer to the City of Auburn’s Construction Standards
manual (latest edition) for the most current information on these requirements.
Chapter 8 – Sanitary Sewer Facilities 8.00 Preface The design of sanitary sewer facilities shall be in conformance with the applicable sections of the State of Washington Department
of Ecology’s "Criteria for Sewage Works Design" manual unless modified herein. These standards are set forth as a minimum requirement for the planning and design of gravity sanitary
sewer facilities. Sewage lift stations and special facilities are not included within this design manual due to the complexity of these facilities. When designing lift stations and special
facilities, please contact the City for the specific requirements. Compliance with these standards does not alleviate the design engineer from using sound professional engineering practices.
The design criteria contained herein are the minimum acceptable under standard conditions. Special conditions may require more stringent requirements that will be addressed during the
plan review process. The City’s Comprehensive Sanitary Sewer Plan establishes drainage basins and design parameters used to estimate future line capacities. Anyone proposing to extend
or modify the City’s sanitary sewer system should contact the Public Works Department for information on proposed line sizes and locations. Sanitary sewer improvements shall be constructed
by means of a Facility Extension Agreement (FAC) between the developer and the City. The Public Works Department can provide information on this agreement as well as applicable permit
and connection fee estimates. 8.01 Design Criteria 8.01.1 Sanitary Sewer Mains The design of sanitary sewer mains shall meet the following requirements: 8.01.1.1 Sanitary Sewer Main
Sizing Public sanitary sewer mains shall be sized using the following criteria: A. All sanitary sewer mains shall be a minimum of eight inches (8") in diameter. B. All new lines shall
be sized as indicated in the City's current Comprehensive Sanitary Sewer Plan. C. Sanitary sewer mains should be designed and constructed to provide a minimum cleaning velocity of two
feet per second (2 ft/s) when flowing at eighty percent (80%) full. If at final build out the planned contributing area will not achieve this capacity, additional provisions may be required.
D. The following are the minimum slopes recommended by the City for the corresponding pipe sizes: Pipe Size Minimum Slope 8” 0.50% 10” 0.30% 12” 0.25% 8/9/2004 Design Standards Page
8-01 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 8 (8-04)
8.01.1.2 Sanitary Sewer Main Location A. The desired installation depth for sanitary sewer mains is between eight feet (8’) and fifteen feet (15’) below the finished surface elevation.
B. Sanitary sewer mains shall be located in the public right-of-way or within a public sanitary sewer utility easement. Sanitary sewer mains located in the public right-of-way shall
meet the requirements of Section 9.01.2. C. Sanitary sewer mains shall extend through the property being served. D. Sanitary sewer mains shall be located a minimum horizontal distance
of ten feet (10’) from structures and water mains and a minimum horizontal distance of five feet (5’) from all other underground utilities. If soil conditions are poor and/or the sanitary
sewer main is deep, the horizontal distance from structures may be increased. E. At crossings, sanitary sewer mains shall be located a minimum vertical distance of eighteen inches (18”)
from water mains, preferably below the water main, and a minimum vertical distance of twelve inches (12”) from all other underground utilities. 8.01.2 Sanitary Sewer Manholes Sanitary
sewer manholes shall meet the following requirements: 8.01.2.1 Sanitary Sewer Manhole Type and Size A. Sanitary sewer manholes shall be of the “Type I” variety topped with an eccentric
cone. B. Sanitary sewer manholes over fifteen feet (15’) deep and/or greater than sixty inches (60”) in diameter may require special provisions. C. Sanitary sewer manhole diameters shall
meet the following requirements based on the manhole depth and the size, number, and configuration of pipes entering: Manhole Diameter Number & Diameter of pipes. Depth of Manhole 48”
Diameter 1 Pipe, 21” 2 Pipes, 12” – 18” 3 Pipes, 8” – 10” 4’ Minimum 12’ Maximum 54” Diameter 1 Pipe, 36” 2 Pipes, 21” – 30” 3 Pipes, 12” – 18” 4 Pipes, 8” – 10” 6’ Minimum 15’ Maximum
60” Diameter 1 Pipe, 42” 2 Pipes, 24” – 36” 3 Pipes, 15” – 21” 4 Pipes, 10” – 12” 5 Pipes, 8” 8’ Minimum 20’ Maximum 72” Diameter 1 Pipe, 48” – 54” 2 Pipes, 36” – 42” 3 Pipes, 18” –
24” 4 Pipes, 12” – 15” 5 Pipes, 8” – 10” 8’ Minimum 25’ Maximum 8/9/2004 Design Standards Page 8-02 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 8 (8-04)
D. Drop manholes are discouraged. When necessary, drop manholes shall conform to Standard Detail SEWER-05 with the manhole diameter increased to offset the space occupied by the drop
pipe. 8.01.2.2 Sanitary Sewer Manhole Locations Sanitary sewer manholes shall be located using the following criteria: A. Sanitary sewer manholes shall be installed at a maximum spacing
of four hundred feet (400’). B. Sanitary sewer manholes shall be installed at all junctions of two or more sanitary sewer mains. C. Sanitary sewer manholes are required whenever connecting
to a sanitary sewer main with an eight-inch (8”) or larger diameter pipe. D. Sanitary sewer manholes shall be installed at all changes of direction, slope, and/or pipe size. E. All public
sanitary sewer lines shall end with a manhole unless otherwise approved by the City. Kor-n-Seal boots shall be supplied with one (1) length of sanitary sewer pipe stubbed out of the
manhole with a watertight cap to facilitate future sewer main extension. F. Sanitary sewer manholes are not to be located within the limits of parking lot detention facilities or in
areas of surface water ponding. G. Sanitary sewer manholes should be located outside the wheel paths of roadways. H. Sanitary sewer manholes shall not be located within sidewalks, trails,
or curb and gutter lines. I. An all-weather maintenance road shall be provided within the public sanitary sewer utility easement to allow access to manholes located outside of the paved
roadway. 8.01.2.3 Sanitary Sewer Manhole Parameters A. Sanitary sewer manholes shall provide a minimum of one-tenth of a foot (0.10’) of drop between the inlet pipe and the outlet pipe.
Pipes of various diameters shall be aligned so that the crowns of the pipes match. B. Pipes entering manholes are to be channeled to the outlet pipe, with the sidewalls of the channel
extended above the top of the pipe. The bench inside the manhole shall be sloped at a two percent (2%) grade to the channel. C. Manholes set in gravel shoulders or other non-paved, improved
areas shall be set at the center of a six-foot (6’) diameter concrete apron flush with the finished grade. D. Manholes set in non-paved and unimproved areas shall be set six inches (6”)
to twelve inches (12”) higher than the surrounding terrain and provided with a six-foot (6’) diameter concrete apron around the manhole lid. E. Sanitary sewer manholes shall be equipped
with a solid locking lid with the words “Confined Space Permit Required” cast into the lid. 8/9/2004 Design Standards Page 8-03 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 8
(8-04)
8.01.3 Side Sewers See Standard Detail SEWER -01 Side sewers are defined as that portion of the sewer system that extends from two feet (2’) outside of the outer foundation wall of the
structure to the sanitary sewer main. The City owns and maintains the side sewer from the sanitary sewer main to the edge of the right-of-way or public sanitary sewer utility easement.
The property owner owns and maintains the side sewer from that point to the building. Side sewers shall meet the following requirements: 8.01.3.1 Side Sewer Parameters A. A separate
and independent side sewer from the public main shall be provided for each and every building. B. Side sewers within the public right-of-way shall be a minimum of six inches (6”) in
diameter. C. Six-inch (6”) diameter side sewers shall be connected to sanitary sewer pipe by the use of a tee. D. Side sewers with a diameter of eight inches (8”) or greater shall be
connected to the sanitary sewer system by use of a sanitary sewer manhole. E. When constructing sanitary sewer mains in new developments, side sewer installation shall extend from the
connection on the main line to the edge of any utility easements or the public right-of-way whichever is further. F. When installing new sanitary sewer mains or replacing existing mains
in developed areas, side sewers shall be installed for all existing occupied structures and any buildable lots. Side sewers should be extended to the property lines and out of the public
right of way whenever possible. G. The maximum length of side sewer from the sanitary sewer main to the building should not exceed one hundred and fifty feet (150’). H. Side sewers shall
be designed to provide a minimum depth at the property line of five feet (5’) below the floor to be served or six feet (6’) below the street, whichever is deeper. In cases of vacant
properties, the side sewer shall be constructed at a two percent (2%) slope from the tee. I. Cleanouts shall be installed within three feet (3’) of the building foundation and at the
property line marking the location of the side sewer and providing an access point into said line for future maintenance. 8.01.4 Sanitary Sewer Cleanouts See Standard Detail SEWER-02
& -03 Sanitary sewer cleanouts shall meet the following guidelines and are not an acceptable alternative for sanitary sewer manholes: A. Sanitary sewer cleanouts may be used with City
approval at the end of a sanitary sewer main when the future extension of the sanitary sewer main is planned and the current end point is not a practical location for a manhole. B. A
sanitary sewer cleanout may be used in lieu of a manhole at the end of a long private side sewer. C. Sanitary sewer cleanouts shall be installed in side sewers for each change in direction
exceeding ninety degrees (90°). 8/9/2004 Design Standards Page 8-04 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 8 (8-04)
8.01.5 Fats, Oils, and Grease (FOG) and Sand/Grit Interceptors Fats, Oils, Grease and Sand Interceptors shall be designed using the Uniform Plumbing Code and meet the following requirements:
A. FOG interceptors shall be provided on all newly constructed or remodeled restaurants, cafés, lunch counters, cafeterias, bars or clubs; hotel, hospital, factory or school kitchens;
or other establishments that serve or prepare food where FOG may be introduced to the sanitary sewer system. They shall be provided for the proper handling of liquid wastes containing
petroleum-based (non-polar) or animal and vegetable (polar) oil and grease in excess of that identified in ACC 13.20.140(B) or any flammable wastes, sand, or other harmful ingredients.
The City shall approve the location of these devices. B. Private property owners should perform grease trap maintenance on a regular basis. Grease interceptor (GI) maintenance shall
be performed by permitted haulers or recyclers and consists of removing the entire volume (liquids & solids) from the GI and properly disposing of the material in accordance with all
Federal, State, and/or local laws. When performed properly and at the appropriate frequency, grease interceptor and trap maintenance can greatly reduce the discharge of animal/vegetable
fats, oils, or grease (FOG) into the wastewater collection system. C. A FOG Control Plan shall be submitted to the City for review prior to the issuance of a side sewer permit for any
establishment where FOG may be introduced into the sanitary sewer system. At a minimum, the following items shall be addressed in a FOG Control Plan: 1. A written policy articulating
management and corporate support for the plan and a commitment to implement planned activities and achieve established goals. 2. A description of the facility type and a summary of the
products made and/or service provided. 3. Quantities of FOG brought into the facility as raw product, amounts contained in products, and quantities discharged to the sewer. 4. Schematics
of process areas illustrating drains and discharge points connected to the sewer. 5. A description of current reduction, recycling, and treatment activities. 6. Identification of a full
range of potentially feasible reduction opportunities. 7. Specific performance goals and implementation schedule including cleaning frequency. 8. Signature of owner. D. Sand and Grit
Interceptors will be required if it is determined that excessive amounts of grit are being discharged into the sanitary sewer system. A control plan meeting the same requirements as
noted above shall be submitted with the installation of sand and grit interceptors. E. Once the interceptor is installed, the City will require copies of all maintenance and cleaning
reports within ten (10) days of service. These records shall be kept onsite for two (2) years. The required maintenance frequency for grease interceptors and traps depends greatly on
the amount of fats, oils, and grease discharged to the sanitary sewer system. Certification of maintenance shall be made readily available to Cityauthorized personnel for review and
inspection. Certification of maintenance records shall be submitted to the City and be kept on-site for two (2) years. 8/9/2004 Design Standards Page 8-05 REF. H:\DEVELOPMENT\Manuals\Design
Standards\Chapter 8 (8-04)
Establishments that implement the best management procedures should realize financial benefit through a reduction in maintenance frequency. 8.01.6 Sanitary Sewer Pumps The installation
of public and private pumping facilities are discouraged within the City’s sanitary sewer system. All proposed pumping facilities require the City Engineer’s approval. Please contact
the City for a handout containing the latest requirements. 8.02 Public Sanitary Sewer Utility Easements Public Sanitary Sewer Utility Easements are required for the placement, operation,
and maintenance of public sanitary sewers within private property. Public Sanitary Sewer Utility Easements shall meet the following requirements: A. Public Sanitary Sewer Utility Easements
shall extend a minimum of seven and onehalf feet (7½’) to each side of the centerline of the sanitary sewer main. Easements shall extend ten feet (10’) to either side when the sanitary
sewer main is over ten feet (10’) deep or soil conditions are unstable. B. Public Sanitary Sewer Utility Easements shall be provided on the City’s standard easement form. Legal description
of the easement and the property that the easement encumbers, along with a sketch showing both, shall be stamped and signed by a licensed land surveyor and incorporated into the easement
form as exhibits. The legal descriptions and sketch shall be on plain bond paper with margins acceptable to the County of recording. C. Public Sanitary Sewer Utility Easements shall
be reviewed by the City and then recorded in the appropriate County prior to acceptance of the public sanitary sewer facilities. 8.03 Material Requirements for Sanitary Sewer Systems
The following list of sanitary sewer materials is for reference only. The list of acceptable materials and appurtenances for sanitary sewer construction is subject to change as new and
improved components become available. Please refer to the City of Auburn’s Construction Standards manual (latest edition) for the most current information on these requirements. 8.03.1
Sanitary Sewer Pipes Pipe Type Minimum Depth Maximum Depth Solid Wall Polyvinyl Chloride (PVC) Pipe, SDR-21 18 inches 22 feet Solid Wall Polyvinyl Chloride (PVC) Pipe, SDR-35 (Requires
13.5’ lengths. 3 feet 18 feet Solid Wall Polyvinyl Chloride (PVC) Pipe, C900 12 inches 30 feet* Sewer Safe Ductile Iron Pipe (Protecto 401 Ceramic Epoxy Lined) 6 inches 30 feet* * Sanitary
sewers below thirty feet (30’) will require pre-approval of the City. 8/9/2004 Design Standards Page 8-06 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 8 (8-04)
8/9/2004 Design Standards Page 8-07 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 8 (8-04) 8.03.2 Sanitary Sewer Structures Structure Type Depth Extra Shallow MH (City Std. Detail
SEWER-06) 31” Minimum 48” Maximum Type I with eccentric cone (WSDOT Std. Plan B-23a) 4’ Minimum 20’ Maximum Type II (WSDOT Std. Plan B-23b) 20’ Minimum 30’ Maximum See also Section 8.01.2.1.
Chapter 9 – Utilities 9.00 Preface The design of public and private utilities located within City right-of-way shall be in conformance with these standards. Compliance with these standards
does not alleviate the design engineer from using sound professional engineering practices and meeting the requirements of the specific utility in question. The design criteria contained
herein are the minimum acceptable under standard conditions. Special conditions may require more stringent requirements that will be addressed during the plan review process. 9.01 Design
Criteria The City has established the following minimum requirements to ensure the efficient construction of utilities with the least impact to City transportation and utility infrastructure.
9.01.1 Private Utilities Located Within City Right-of-Way Unless otherwise provided in a public way agreement, franchise, or lease, a grantee, franchisee, or lessee with permission to
occupy a public way must locate its cable or telecommunications facilities underground. 9.01.1.1 Private Utilities Located Underground Private utilities located underground shall meet
the following requirements: A. Private utilities shall be installed with no less than thirty-six inches (36”) of finished cover. B. Private utility lines to be located within the City
right-of-way will require prior approval from the City. These utility companies shall have a current franchise or public way agreement consistent with Title 20 of the Auburn City Code.
C. Private utilities shall be located a minimum horizontal distance of five feet (5’) from buildings and public utilities. D. When crossing public utilities, private utilities shall
be located a minimum vertical distance of twelve inches (12”) from the public utility. 9.01.1.2 Private Utilities Located Aboveground On projects where underground requirements do not
apply, the following parameters will need to be addressed in locating aboveground utilities: A. Utility poles and other aboveground utility structures located on roads with a curb shall
be installed a minimum of two feet (2’) from the face of curb with the preferred location being at the edge of the right-of-way. For urban and rural roads where no curb is present, utility
poles and other aboveground utility structures shall be located outside the clear zone in accordance with the AASHTO manual “A Policy on Geometric Design of Highways and Streets.” B.
Utility poles and other aboveground utility structures should not be located within the sidewalk. If this is not possible, their locations shall provide a minimum of forty-eight inches
(48”) of travelway to meet ADA requirements. 8/9/2004 Design Standards Page 9-01 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 9 (8-04)
C. Utility poles and other aboveground utility structures shall be compatible with driveways, intersections, and all other road features. They shall not interfere with sight distance,
road signing, traffic signals, culverts, etc. This may require that existing poles be relocated at the developer’s expense. D. No utility pole or other aboveground utility structures
shall be located in such a way as to pose a hazard to the general public. Utility companies shall locate and replace poles and other structures with primary consideration given to public
safety and roadway functionality. When a developer-driven project requires the relocation of private utilities due to public utility extensions or other City required improvements, the
cost of relocation of the private utility shall be borne by the developer. 9.01.2 Public and Private Utilities Located Underground Within City Right-of-Way Any developer, utility, or
other entity intending to trench in the existing City street shall contact the City of Auburn Public Public Works Department and obtain a construction permit. A City permit must be obtained
prior to any work within the City right-of-way. Manholes, valve boxes, power vaults, etc., that are located in the paved area of a street shall be located outside of the wheel paths
of vehicles and flush with the pavement surface. Structures located within parking lots, sidewalks, and paths/trails shall also be flush with the surface. In areas where traffic will
pass over the structure, load-bearing lids shall be incorporated in the design. All trenches within paved areas shall have their edges sawcut and meet the following requirements: 9.01.2.1
Perpendicular Trenching in Asphalt Pavement A. Perpendicular trenching shall be in accordance to Standard Detail TRAFFIC-02 or as directed by the City. B. Pavement restoration shall
match existing pavement type and thickness unless otherwise directed by the City. C. In the process of perpendicular trenching, if the remaining section of pavement between the trench
and the edge of the pavement/gutter is less than four feet (4’), the patch will extend from the trench to the edge of the road pavement. D. Perpendicular trenching to roadways may not
be allowed on newer roads or streets that have been constructed or overlaid within the last five (5) years. E. Perpendicular trenching may not be allowed or may be limited to off-peak
hours and/or weekends on principal arterials or where the construction activity will seriously impede large volume traffic patterns. Utility connections that have to be made within the
roadway will be allowed after approval from the City. F. Jacking/boring alternatives may be required as substitute methods for perpendicular trenching. G. The minimum pavement patch
width for perpendicular trenches shall be six feet (6’). This width may be reduced upon City approval for narrow, shallow utility trenches. H. When multiple trenches are required in
close proximity, the asphalt patch shall encompass all the trenches. 8/9/2004 Design Standards Page 9-02 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 9 (8-04)
8/9/2004 Design Standards Page 9-03 REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 9 (8-04) I. The longitudinal edge of the perpendicular asphalt patch shall not lie within the
wheel paths of vehicles. 9.01.2.2 Longitudinal Trenching in Asphalt Pavement A. Longitudinal trenching shall be in accordance with Standard Detail TRAFFIC-03. B. Pavement restoration
shall match existing pavement type and thickness unless otherwise directed by the City. C. In the process of longitudinal trenching, if the remaining section of pavement between the
trench and the edge of the pavement/gutter is less than four feet (4’), the patch will extend from the trench to the edge of the road. D. Longitudinal trenches shall be backfilled and
paved to within one-inch (1”) of the existing pavement surface. The driving lane within which the trench is located shall be ground to a depth of one and one-half inches (1½”) and repaved
with asphalt concrete pavement. If the trench crosses lanes or encompasses more than one lane, the pavement shall be ground to a minimum width of eleven and one-half feet (11½’) with
the trench being the centerline. E. The longitudinal edges of the asphalt patch shall not lie within the wheel paths of vehicles. F. For newer roads, streets that have been constructed
or overlaid within the last five (5) years, principal arterials, or where open trenching will seriously impede large volume traffic patterns, the City may require that trenching be limited
to off peak hours and/or weekends or may require that jacking/boring be researched as an alternative. 9.01.2.3 Trenching in Concrete Pavement Trenching in concrete pavements shall conform,
where applicable, to the previous sections and the following: A. The edges of trenches in concrete pavement shall be sawcut prior to excavation to avoid damaging the slab. Concrete slabs
six inches (6”) and over shall be drilled for the installation of dowels. Dowels shall be one and one-quarter inches (1¼”) in diameter, eighteen inches (18”) long, and spaced twelve-inch
(12”) 12”) center to center. B. The minimum pavement patch width for concrete trenches shall be four feet (4’). C. In the process of trenching concrete, if the section of pavement between
the trench and the edge of the existing concrete panel is less than four feet (4’), the section will need to be removed and replaced. D. Longitudinal trenches in concrete may be repaved
with an asphalt pavement thickness of equivalent strength upon City approval. 9.01.2.4 Trenching in Other Right-of-Way Surfaces Trenching in other right-of-way surfaces, including sidewalks,
gravel shoulders, and landscape strips, shall conform, where applicable, to the previous sections and replace the disturbed material in kind or as directed by the City.
Chapter 10 – Streets 10.00 Preface The design of Streets within the City of Auburn shall generally conform to American the State of unless modified herein. the AASHTO m using sound the
minimum al criteria that ain conditions e plan review in the City’s or modify the City’s street system should to construct . The Public licable permit ry, all streets Downtown Urban
Center Zone boundaries as depicted on the Comprehensive Zoning Map, other than that area west of the BNSF Railroad right-of-way, e “Downtown Auburn Sidewalk Design Guidelines” (Guidelines).
Should any conflict exist between the Guidelines and the design criteria, Chapter 10,
of this Urban Center Association of State Highway and Transportation Officials (AASHTO) and Washington Department of Transportation (WSDOT) standards The majority of AASHTO standards
referenced in this manual can be found in Manual “A Policy on Geometric Design of Highways & Streets: 2001 Edition.” Compliance with these standards does not alleviate the design engineer
fro professional engineering practices. The design criteria contained herein are acceptable under standard conditions. Some roadway designs require technic are above the scope of this
manual and therefore not covered. In these cases the abovereferenced manuals should be used for a basis of design. Additionally, cert may require more stringent requirements that will
be addressed during th process. The design criteria used to estimate future street usage are established Transportation Plan. Anyone proposing to extend contact the Public Works Department
for information. Developers needing street improvements shall enter into a Facility Extension Agreement (FAC) Works Department can provide information on this agreement as well as app
fee estimates. It is provided, however, that notwithstanding any provisions to the contra located within the shall be subject to th document, the Guidelines shall control in those portions
of the Downtown Zone described above. 10.01 Street Classifications All streets in the City of Auburn have been classified using the Federal Functional stem. A complete listing of all
roads by classification is available from the ublic Works. contains information relating to each streets design requirements for widths, typical speed limits, and other information.
This section also contains references to ion for each street. These cross-sections contain information on street layouts and the widths of various street elements. 10.01.1 Arterials
street classification. They fall under the following two categories: Classification sy Department of P The following section contains descriptions of the street classifications used
in the City. Table 10-1 radii, Standard Details that show a typical cross-sect Arterials are the highest level of City 9/15/2008…………........……….…..Design Standards………..…….…………..…………….10-01
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10.01.1.1 Principal Arterial Standard Detail Principal Arterials are designed to move traffic between locations wit and to access the freeways. Design emphasis should be placed on providing
TRAFFIC-27 hin the region to accommodate five (5) lanes of traffic g speed of thirty-five to fo 45 mph). The l TRAFFIC-28 ls and provide evel of travel mobility than not classified phasis
on land . (4-5) lanes of 5 mph). They generators such as community business centers, athletic hborhood shopping centers, major parks, multifamily residential areas, ighborhood to 10
y fall under the gories: l TRAFFIC-29 ets, residential ds, commercial areas, industrial areas, and community centers to minor travel lanes an operating 500 to 10,000 TRAFFIC-30 munity
access connecting nonies with activity centers and recreational facilities. Non-Residential lanes and a per hour (30 ). They may serve neighborhood traffic generators such as one store
or a small group of stores, elementary schools, churches, clubhouses, small hospitals or clinics, areas of small multifamily developments, as well as other commercial/industrial parcels.
The design year ADT is 2,500 to 5,000 vehicles per day. Standard Detail TRAFFIC-31 Rural Collectors are routes that (regardless of traffic volume) the majority of travel distances are
shorter than on arterial routes and residential neighborhoods to activity centers. movement of inter-city through-traffic rather than intra-city traffic. Direct access commercial and
industrial land uses is permitted. Principal arterials are typically constructed to with an operatin rty-five miles per hour (35-design year ADT is greater than 15,000 vehicles per day.
10.01.1.2 Minor Arterial Standard Detai Minor Arterials should interconnect with and augment principal arteria service to trips of moderate length at a somewhat lower l principal arterials.
The minor arterial street system includes all arterials as a principal or collector and consists of facilities that place more em access than the higher system and offers a lower level
of traffic mobility Minor Arterials are typically constructed to accommodate four to five traffic with an operating speed of thirty to thirty-five miles per hour (30-3 may serve secondary
traffic fields, neig medical centers, large church complexes, hospitals, and traffic from ne neighborhood within the city. The design year ADT is 10,000 to 20,000 vehicles per day. .01.2
Collectors Collectors are a step below Arterials in the City classification system. The following three cate 10.01.2.1 Residential Collector Standard Detai Residential Collector Arterials
are used to connect intra-community stre neighborhoo and principal arterials. Residential Collectors are typically constructed to accommodate two (2) and a two-way left-turn lane or
two (2) travel lanes and bike lanes with speed of thirty miles per hour (30 mph). The design year ADT is 2, vehicles per day. 10.01.2.2 Non-Residential Collector Standard Detail Non
Residential Collector Arterials provide intra-com residential propert Collector arterials are typically constructed to accommodate two (2) center two-way left-turn lane, with an operating
speed of thirty miles mph 10.01.2.3 Rural Collector 9/15/2008…………........……….…..Design Standards………..…….…………..…………….10-02 H:\DEVELOPMENT\Manuals\Current Manuals\2004 Design Standards\Chapter
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Rural Collectors provide access to all levels of arterials, are typically accommodate two (2) lanes with gravel shoulders on both sides, a operating speed of thirty to forty miles per
hour (30-40 mph). The g may be reduced on one side to provide a wider shoulder on the other constructed to nd provide an ravel shoulder for equestrian permission from the City Engineer.
The design year ADT is 1,000 to s per day. ost common streets classified in the City. This classification can l TRAFFIC-32 s. They offer is designed to er streets. As the lowest order
gh traffic and c movement is o (2) lanes of the nty-five miles Local Non-Residential Standard Detail TRAFFIC-33 r classification ets and serve primarily industrial/manufacturing land
uses. They offer lower level h movement is erating speed T is 400 to 1,200 vehicles l TRAFFIC-34 ential streets primarily provide access to the adjacent land and . o (2) lanes of enty-five
miles y. ts, owned and al accesses in shall be limited to those streets accessing properties within a planned area or properties immediately adjacent. Private streets shall not be used
by residents to ther. The design of a private street shall be such non-residents. A private street will not be allowed if it will result in land locking present or planned parcels. Private
streets shall be in conformance with the street standard that most closely reflects their intended use, with a minimum of 34 feet of pavement width or 28 feet of access, with 5,000 vehicle
10.01.3 Local Streets Local streets are the m be broken up into four categories as follows: 10.01.3.1 Local Residential Standard Detai Local Residential streets provide access to abutting
residential parcel the lowest level of mobility among all street classifications. The street conduct traffic between dwelling units and higher ord street in the hierarchy, the access
street usually carries no throu includes short streets, cul-de-sacs, and courts. Service to through traffi discouraged and the street usually contains no transit bus routes. Local Residential
streets are typically constructed to accommodate tw traffic, on-street parking (one side only, on the side with the abutting sidewalk; other side shall be signed “No Parking”), and an
operating speed of twe per hour (25 mph). The design ADT is 200 to 1,200 vehicles per day. 10.01.3.2 Local Non-Residential streets provide direct access to higher orde stre of mobility
and accommodate heavy vehicle traffic. Service to throug discouraged. Typically constructed to accommodate two (2) lanes of traffic with an op of twenty-five miles per hour (25 mph).
The design year AD per day. 10.01.3.3 Rural Residential Standard Detai The Rural Resid distribute traffic to and from the principal or minor arterials and local access streets. The travel
distance is relatively shorter as compared to Rural Collectors Rural Residential roads are typically constructed to accommodate tw traffic with gravel shoulders on both sides and an
operating speed of tw per hour (25 mph). The design year ADT is 100 to 1,000 vehicles per da 10.01.3.4 Private Street Community street requirements are usually best served by public
stree maintained by the City. Private streets may be appropriate for some loc very limited usage. Private streets shall provide a direct access to City streets and travel from one public
street to ano that it will discourage any through traffic of 9/15/2008…………........……….…..Design Standards………..…….…………..…………….10-03 H:\DEVELOPMENT\Manuals\Current Manuals\2004 Design
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pavement width with a marked fire lane on one side. Private street ne config tworks shall be ured to deter speeding. Traffic calming measures may also be required to deter providing
legal homeowner’s short plat with Private Street Maintenance Agreement Storm Water Easement and Maintenance Agreement that obligate the future ty and are not e rear or side n alleviate
traffic problems on City streets from deliveries and other ity streets. In All new alleys private. streets; however, rds that differ ones shall be reet standard, are not required along
y storm water apron. termined on a inimum these vehicular, and g, and lighting. or Easements (Shared Driveways) nts, also known as shared driveways, up to six (6) ot have direct maintained
by All access roads shall meet the following general standards: speeding. Private streets shall have a permanently established tract or easement access to each lot served. A capable,
legally responsible owner or association shall be established to maintain private streets. A plat or private streets requires an executed recorded and a property owners to maintain the
infrastructure indefinitely. 10.01.4 Alleys Alleys afford a secondary means of vehicular access to abutting proper intended for general traffic circulation. By providing vehicular access
to th of a building, alleys ca vehicle-related services. Alleys should provide through access between C cases where this is not feasible, adequate turnarounds shall be provided. in new
plats shall be Alleys incorporate much of the design criteria used in designing local there are some exceptions. The following is a list of alley design standa from local street elements:
A. Alleys shall have a minimum width of twenty feet (20’) of asphalt pavement. B. The pavement section for alleys located in non-single family z consistent with a local non-residential
st C. Curb and gutter, sidewalk, lighting, and landscaping alleys. D. Alleys may be paved with inverted crown at centerline to conve into catch basins located at low points in the invert.
E. Alleys shall connect to City streets via a commercial driveway The design requirements for alleys serving alley loaded lots shall be de case-by-case basis depending upon the specific
application. As a m types of alleys shall meet the functional requirements of pedestrian, emergency access, with considerations for parking, drainage, landscapin 10.01.5 Private Access
Roads on Access Tracts Access roads provided on access tracts or easeme provide access for up to four (4) residential units in short plats and residential units in long plats on panhandle/flag
lots and rear lots that do n access to public street frontage. They will be private roads that shall be the property owners who use them to access their property. A. Access roads shall
be limited to 600 feet in length. B. The width of the access tract/easement shall match the required pavement width, including the width of any pedestrian improvements, and the area
needed for private drainage facilities. If the access is also acting as a joint utility easement or tract, the width must accommodate the public utility requirements. 9/15/2008…………........……….…..Desi
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C. The connection of an access road to the public street shall be by a commercial driveway apron. The connection of individual lots to the access road shall be by a residential driveway
apron. D. Access roads shall meet the geometric design standards for local residential streets. E. Access roads shall be signed as private drives inclusive of all addresses being served
off the access road. New and/or existing access roads serving 2 residential units shall meet the following additional standards: A. The minimum pavement width shall be 24 feet. The pavement
width may be reduced to 20 feet if the new residential unit using the access road has a residential fire sprinkler system installed or a fire hydrant exists within 450 feet of the residences
measured as the fire vehicle lays its hose. Existing access roads serving 3 to 6 residential units when only one additional residential unit is being created or developed shall meet
the following additional standards: A. The minimum pavement width shall be 24 feet and be marked as a fire lane per ACC 15.36A. The pavement width may be reduced to 20 feet if the new
residential unit using the access road has a residential fire sprinkler system installed or a fire hydrant exists within 450 feet of the residences measured as the fire vehicle lays
its hose. B. An additional 5 foot wide pedestrian pathway along one side of the paved access road separated by a 4-inch wide painted line. C. Access roads exceeding 150 feet in length
shall also include an adequate turnaround at the end of the road. New access roads serving 3 to 6 residential units shall meet the following additional standards: A. Access roads 75
feet or less in length shall have a minimum pavement width of 20 feet and shall be marked as a fire lane per ACC 15.36A. B. Access roads exceeding 75 feet in length shall have a minimum
pavement width of 34 feet. The pavement width may be reduced to 24 feet if one side of the access road is marked as a fire lane per ACC 15.36A. C. Access roads exceeding 150 feet in
length shall also include an adequate turnaround at the end of the road. D. An additional 5 foot wide sidewalk and cement concrete traffic curb per F-10.12-00 is required on both sides
of the access road. The material for the sidewalk shall be consistent with the surrounding neighborhood sidewalks. 10.01.6 Half-Streets A Half Street could be comprised of any one of
the above street classifications. Half Streets require, at a minimum, the construction from one side of the street, including the curb & gutter, storm drainage, sidewalk and landscape
strip, to the street centerline. Half en a proposed new development or redevelopment is not currently built to City standards. Half Street construction may also be required for property
that abuts future streets proposed in the City’s Comprehensive Plan. Streets will need to be constructed wh of a property is located on a public street that 9/15/2008…………........……….…..Design
Standards………..…….…………..…………….10-05 H:\DEVELOPMENT\Manuals\Current Manuals\2004 Design Standards\Chapter Chapter 10 (9-08).doc
9/15/2008…………........……….…..Design Standards………..…….…………..…………….10-06 H:\DEVELOPMENT\Manuals\Current Manuals\2004 Design Standards\Chapter 10 (9-08).doc design of the ditions. This could
require ved areas, a ses, the street or the constructed portion of the street. system to the If f a cul-de-sac W ition tapers will be required when edges of pavement do not match. The
fo necessary to determine the length of th For street design speeds of less than forty miles per hour (40 mph) w = the width of the pavement offset mph per ment offset r proposed utilities
located within the portion of the street being built, shall be installed ing of existing The unfinished side of the Half Street shall be finished with temporary curbing, shoulders, ditches
and/or side slopes so as to assure proper drainage, bank stability, and traffic safety. When Half Streets connect to an intersection, the intersection shall be designed and constructed
for the full build-out of the street. The intersection design and construction shall extend at least fifty feet (50’) from the travel way of the cross street. When Half Street construction
is required on an existing paved street, the Half Street shall be consistent with the existing street con construction of more than half the street for safety and drainage reasons. When
Half Street construction is required on unpaved streets or unimpro minimum of twenty-four feet (24’) of pavement will be required. In these ca should be designed to provide drainage
f Provisions shall be made to allow for extension of the storm drainage undeveloped portion of the street for future construction. The construction of a Half Street may require the dedication
of additional right-of-way. a Half Street does not connect at both ends to other streets, construction o will be required. here Half Streets are connected to existing streets, trans
llowing formula provides the information e tapers for a specific situation: = L s = the design speed in L = the length of the ta For street design speeds of greater than or equal to
forty miles per hour (40 mph) w = the width of the pave ws = L s = the design speed in mph L = the length of the tape All during construction. Half Street construction may also require
the upgrad utilities if said upgrading was necessary for the proposed development. WS2 60
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Standards\Chapter 10 (9-08).doc 10.02 Street Design Requirements 10.02.1 Table 10-1 RESIDENTIAL CLASSIFICATION SECTION PRINCIPAL COLLECTOR ARTERIAL MINOR ARTERIAL With Center Turn Lane
With Bike Lane NONRESIDENTIAL COLLECTOR RURAL COLLECTOR LOCAL RESIDENTIAL LOCAL NONRESIDENTIAL RURAL RESIDENTIAL Roadway Section TRAFFIC-27 TRAFFIC-28 TRAFFIC-29 TRAFFIC-29 TRAFFIC-30
TRAFFIC-31 TRAFFIC-32 TRAFFIC-33 TRAFFIC-34 RIGHT-OF-WAY Width (ft) 10.02.3 87 71/82 55 55 65 60 50 55 50 Intersection Radii-Min. (ft) 22 22 19.5 19.5 19.5 17 9 19.5 7 TRAVELWAY Roadway
Width (ft) 10.02.4 61 50/61 34 34 44 28 28 34 24 Curb/Gutter 10.02.4.4 Y Y Y Y Y N Y Y N Number Of Lanes 10.01 5 4/5* 3 2 3 2 2 2 2 Inside Through Lane Width (ft) 10.02.4.1 11 11 N/A
11 N/A N/A 10 N/A N/A Curb Lane Width (ft) 10.02.4.1 14 14 11.5 N/A 16 14 10 17 12 Center Turn Lane Width (ft) 10.02.4.2 11 11 11 N/A 12 N/A N/A N/A N/A Bikeway Width (ft) 10.06 N/A
N/A N/A 6 N/A N/A N/A N/A N/A Intersection Curb Radii (ft)1 50 40 30 30 30 30 20 30 20 Parking Allowed N N N N N N Y, one-side N Y/two-sides4 ROADSIDE Shoulder Width (ft) 10.02.4.4 N/A
N/A N/A N/A N/A 8 N/A N/A 3 Sidewalk Width (ft) 10.05.1 10 10 5 5 10 0 5 10 0 Landscape Strip Width (ft) 10.08.1 N/A5 N/A5 5 5 N/A5 N/A 5.5 N/A5 N/A Illumination 10.10 Y Y Y Y Y Only
at Intersections Y Y Only at Intersections Geometric Design Criteria2 POSTED SPEED (mph) 45 40 35 35 30 30 30 30 40 35 30 25 30 25 DESIGN SPEED (mph) 55 50 45 45 40 35 35 35 45 40 35
30 35 30 Min. Horizontal Curve Radius (ft) 10.02.2.1 960 758 600 600 464 527 527 527 600 464 348 375 419 375 Max. Degree of Curvature (degree) 10.02.2.2 6.0 7.6 9.5 9.5 12.4 10.9 10.9
10.9 9.5 12.4 16.5 15.3 13.7 15.3 Min. Tangent Between Reverse Curves (ft) 10.02.2.3 150 150 150 150 150 150 100 150 100 Maximum Rate of Superelevation, e (%) 10.02.2.4 8 8 0 0 0 8 0
0 0 Max. Vertical Grade Grade (%)3 10.02.2.5 6 6 6 6 6 6 6 6 6 Recommended Cross Slope (%) 10.02.2.6 3 3 3 3 3 3 2 2 2 DRAINAGE Closed System 6.00 Y Y Y Y Y Only at Driveways Y Y Only
at Driveways Open System 6.00 Y Y * Minor Arterials may be designed as either a four (4) lane road (two lanes in either direction) or a five (5) lane road (two lanes in either direction
and a center turn lane) based on the Transportation Comprehensive Plan designation. 1 At intersections with two different classifications, use the highest classification for curb radii
except at residential intersections. 2 Table values are for standard cross sections with a relatively level grade and are for reference only. For accurate design values reference the
AASHTO Manual “A Policy on Geomtric Design of Highways & Streets.” 3 Max. Vertical Grade may be increased up to 12% upon approval of the City Engineer. Vertical curves will be required
when the algebraic grade difference is more than 1%. 4 Parking shall be located where space is available, outside of the required three-foot (3’) shoulder. 5 Street trees placed in tree
pits with tree grates are required. See standard detail TRAFFIC-64
D = ence the AASHTO f Highways & Streets,” latest adopted edition. icles to safely is radius is established by the ich the turn is located. On some streets, this radius ed by a one orizontal
curve. It is a measure of the sharpness of construction of a horizontal radius of a 5729.6 10.02.2 Street Geometry For in-depth design information on the following criteria, please refer
Manual “A Policy on Geomtric Design o 10.02.2.1 Minimum Horizontal Curve Radius Horizontal curves must be limited to minimum radius to allow for veh negotiate a turn without leaving
their driving lane. Th design speed of the street on wh could be reduced slightly by superelevating the road cross-section. 10.02.2.2 Degree of Horizontal Curvature The degree of horizontal
curvature is defined as the angle subtend hundred foot (100’) arc along the h the curve and may be used instead of the radius in the curve. The degree of a horizontal curve can be calculated
from the horizontal curve using the following formula: D = Degree of curvature R = Radius re are listed in roadway must be designed between curves to avoid quick left-The length of feet
(150’) for s. process of superelevating a street provides a constant slope from one edge to ws vehicles to travel around a turn at a higher velocity than would n arterials and treets
is eight r (35 mph) or l, is limited to a 5%). Vertical al of the City ity engineer shall consider the public benefit of any deviation request tion of the roadway, traffic circulations,
traffic congestion, pact to public treet grade of onstrated that If approved, lve percent (12%) may trigger additional ertical grades is greater than a one percent (1%) algebraic grade
difference along the centerline, a vertical curve needs to be designed. Vertical curves are needed to achieve the required minimum stopping sight distance for the streets design speed.
The distances for minimum stopping sight distance are listed in Table 10-2 in Section 10-03. There are two types of vertical curves: Crest Vertical Curves are required when the initial
slope is greater than the final slope. Sag Vertical Curves are required when R Recommended values for the maximum degrees of horizontal curvatu Table 10-1. 10.02.2.3 Tangents Between
Reverse Curves Sections of straight right transitions that could potentially lead to loss of vehicular control. these straight sections should be a minimum of one hundred fifty arterials
and collectors and one hundred feet (100’) for residential street 10.02.2.4 Superelevations The the other. This allo be possible if the road was flat. Superelevations are allowed only
o rural collectors. The maximum superelevation rate allowed for city s percent (8%) and requires a design speed of thirty-five miles per hou greater. 10.02.2.5 Vertical Grades Vertical
Grades, the amount of slope of a street in the direction of trave maximum of six percent (6%) and a minimum of one-half percent (0. grades may be increased up to twelve percent (12%)
upon approv Engineer. The C including the classifica emergency access, adjacent property access, length of grade, im utilities, or any operational or safety factors. Deviations to the
vertical s a classified roadway shall generally not be granted unless it can be dem the public benefits significantly outweigh any potential detriments. grades between six percent (6%)
and twe design considerations. 10.02.2.5.1 Vertical Curves When the change in v 12/4/2009…………........……….…..Design Standards…………..…..………..…….10-08 H:\DEVELOPMENT\Manuals\Current Manuals\2004
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12/4/2009…………........……….…..Design Standards…………..…..………..…….10-09 H:\DEVELOPMENT\Manuals\Current Manuals\2004 Design Standards\Chapter 10 (9-08).doc ither negative itive or both, but
should be measured on an absolute scale when required. All vertical curves must be arabolic, and meet AASHTO standards. utterline. The al streets and des of greater llectors and arterials
have a steeper cross slope since the s associated with these roads require that water drain more quickly from et and other right-of-way to torm facilities, requirements may be variable
within a street corridor due to on a recorded plat or by a right-of-way ent. ns are listed in Special cases treet classification and the amount of existing and projected traffic will
determine equired for a street. tors and local wide. Streets es based on street classifications and/or volumes. The minimum width for inside through lanes shall be eleven and minor arterials
and collectors where conditions present a high number of left turn movement opportunities. Center turn lanes shall be a minimum of eleven feet (11’) wide. 10.02.4.3 Other Lanes Acceleration
and deceleration lanes may be required for sites located on arterials would the initial slope is less than the final slope. These slopes could be e or pos determining whether a Crest
or Sag Vertical Curve is symmetrical, p 10.02.2.6 Cross Slopes City streets shall be crowned in the middle to provide drainage to the g cross slopes created by this crown shall be two
percent (2%) for loc three percent (3%) for collectors, arterials, and roads with vertical gra than six percent (6%). Co higher speed the roadway to avoid hydroplaning. 10.02.3 Right-of-Way
The required right-of-way will depend upon the width of the stre improvements. Excluding cul-de-sacs, the typical requirement is for the extend a minimum of ten feet (10’) behind the
curb line on each side of the street. Additional right-of-way may be required for bike/pedestrian trails and/or s for example. Right-of-way intersections, turn lanes, bus loading zones,
and other street features. Right-of-way shall be conveyed to the City dedication or separate instrum The minimum right-of-way requirements for the various street classificatio Table
10-1. 10.02.4 Roadway Width (Travel Way) The roadway width or travel way consists of inside through lanes and/or curb lanes, center turn lanes and/or bike lanes (where required), and
curb and gutter. may also require acceleration and deceleration lanes and right and left turn pockets. Total roadway width is measured from the face of curb to the face of curb. 10.02.4.1
Inside Through Lanes and Curb Lanes The s the number of lanes r Curb lanes or outside lanes on all streets excluding residential collec and rural residential streets shall be a minimum
of fourteen feet (14’) will be widened to include inside through lan projected traffic feet (11’). 10.02.4.2 Center Turn Lanes Center turn lanes will be required on principal where heavy
volumes and/or heavy truck movements into and out of the site impact the speed and safety of the the arterial.
12/4/2009…………........……….…..Design Standards…………..…..………..…….10-10 H:\DEVELOPMENT\Manuals\Current Manuals\2004 Design Standards\Chapter 10 (9-08).doc ge numbers of e a minimum of eleven
feet (11’) wide ockets a minimum of twelve feet (12’) wide. crete curb and d with a gravel ) wide for rural (3’) wide for rural residential) and a ditch for drainage. Rural lso meet
AASHTO standards for a clear zone between the edge of er a series of ile preventing should exist to y will continue a series of arterials and collectors designed to national standards
to provide munity. Ample alternatives should also exist to accommodate and between e designed to enetrating the exceed 1,300 elling units. s the number lopments with s, multi-family
l or collector. Residential developments with less than 75 dwelling ents or any al or collector. ide a second to connect to temporary or will only be other streets is hundred feet y
or existing -de-sacs shall ed paths
shall shorten walking distances to an adjacent arterial or public facilities including, but not limited to, schools or parks. Existing stubend streets that are greater than eight hundred
feet (800’) in length shall be linked to he opportunity arises, unless it can be demonstrated that such connections would lead to a substantial rerouting of through traffic onto the
street. Dead-end streets longer than eight hundred feet (800’) shall not be allowed to serve substantial new development. Left turn and right turn pockets may be required at intersections
with lar left and/or right turns. Left turn pockets shall b with right turn p 10.02.4.4 Road Edge All urban roads within the City of Auburn shall be designed using con gutter (WSDOT
Plan F-1). Rural roads within the City may be designe shoulder (minimum of 2⅝” CSTC over 8” of “gravel base”; eight feet (8’ collectors and three feet roads shall a pavement and any
obstructions. 10.02.5 Street Layout An efficient transportation system seeks to spread vehicle movements ov planned streets. The goal of the system is to encourage connectivity wh unacceptably
high traffic volumes on any one street. Ample alternatives accommodate access for emergency vehicles. For these reasons the Cit to plan efficient service to the com non-motorized transportation
on arterials, collectors and local roads within subdivisions. 10.02.5.1 Residential Streets The internal local residential street network for a subdivision should b discourage regional
through traffic and non-residential traffic from p subdivision or adjacent subdivisions. Local residential streets shall not feet in length between intersections and shall not serve
more than 75 dw Residential developments should be planned in a manner that minimize of local street accesses to arterials and collectors. Residential deve greater than 75 dwelling units,
including single family development developments or any combination thereof, shall have a minimum of two accesses to either an arteria units, including single-family developments, multi-family
developm combination thereof, may limit general access to one access to an arteri Developments with between 25 and 75 dwelling units shall also prov access route to an arterial or collector
for emergency vehicle access. 10.02.5.2 Cul-de-sacs Where possible, streets shall be planned, designed and constructed future developments. All dead-end streets shall end in either a
permanent cul-de-sac. Permanent dead-end streets or cul-de-sacs allowed where a through street to connect adjacent properties and/or not needed or possible. Dead-end streets shall not
be more than six (600’) in length, unless the city determines that due to topograph development patterns there are no feasible alternatives and emergency services can be effectively
provided. Dead end streets ending in permanent cul serve a maximum of 25 dwelling units. When applicable, non-motoriz be provided at the end of the street to other streets whenever t
10.02.5.2.1 Temporary Cul-de-sacs Temporary cul-de-sacs may be provided only when there is a plan the street. for extending er of sixty-five shall be posted at the back of the temporary
cul-de-sac stating that the road the future and to contact the City of Auburn for further otherwise directed by the City. et (90’) unless dition of the to result in traffic volumes that
will exceed acceptable volumes for the road’s classification. City of Auburn’s 1997 Comprehensive tion Plan (Table 2.1 Functional Classification System, Characteristics of the Roadway
Function). Consideration may also be given to the character and nature Temporary cul-de-sacs shall have a paved surface with a diamet feet (65’). A sign is planned to be extended in
information. 10.02.5.2.2 Permanent Cul-de-sacs Permanent cul-de-sacs shall have a paved surface with a diameter of seventy-five feet (75’) unless Permanent cul-de-sacs right-of-way shall
have diameter of ninety fe otherwise directed by the City. 10.02.5.3 Traffic Volumes Projected trip generation shall be calculated based on the current e Institute of Transportation
Engineers (ITE) Trip Generation Manual. Stub end streets shall not be linked to a new street if the connection is likely These volumes are defined by the Transporta of the neighborhoods
proposed to be connected. 10.03 Sight Distance Sight distance is defined as the length of roadway that is entirely visible to the driver. All points should be designed to provide adequate
sight di 10 following four 10.03.1.1 Stopping Sight Distance Stopping sight distance is the distance required for a vehicle traveling at or near the road’s design speed to come to a
stop before colliding with a fixed object in the roadway. This is the distance the design vehicle travels between the time the driver sees the object and applies the brakes combined
with the distance traveled during braking. As road conditions deteriorate due to weather and other occurrences, more sight distance will be required. roads, intersections, and access
stance for all normal driving situations. .03.1 Sight Distance Categories When designing roads, intersections, and access points within the City, the types of sight distance situations
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10.03.1.2 Decision Sight Distance Decision sight distance is greater than stopping sight distance. This m used in cases where the driver is required to detect unexpected situations and
then make appropriate changes in their driving style or could mean changing lanes, slowin easurement is or confusing method. This g down, or coming to a complete stop. Decision a considerable
amount depending on the driver. When ements are applicable, the guidelines presented in the ring a street to hows the sight tersection (an Figure 10-2 n uncontrolled ithout a stop/yield).
Sight triangles for all intersections rb, or from the nces shown in When roads of different speeds intersect, the higher speed shall be used easurements. TO manual “A the ITE Traffic
stopping sight istances were level roadways. As roadway grades d only be used ere roadways lculated using ssumed to be tance triangles shall be provided for all projects where new driveways
are being ts. Drawings rovided for all The area within the sight distance triangle must be free from any sight-obscuring objects from between three feet (3’) and eight feet (8’) above
the ground. Sight-obscuring ings, parked vehicles, signs, fences, and The sight distance triangle should be located completely within the City right-of-way in order to ensure proper
maintenance. The City may require additional right-of-way as a condition of development approval to ensure the sight distance triangle is contained sight distance will need to be addressed
when designing roads with tight turns and unexpected driveway and street connections. 10.03.1.3 Passing Sight Distance Passing sight distance should be addressed when designing two (2)
lane roads where vehicle speeds can differ by passing sight distance requir latest edition of AASHTO shall be used. 10.03.1.4 Intersection Sight Distance Intersection sight distances
are the distances required for a driver ente decide whether or not there is a sufficient gap in traffic. Figure 10-1 s distance triangles required for a left and right turn from a controlled
in intersection with a stop/yield prior to proceeding) and for driveways. shows the sight distance triangles required for left and right turns from a intersection (intersections w shall
be measured from a point ten feet (10’) behind the face of the cu edge of traveled way if no curb exists, and shall incorporate the dista Table 10-2. for all sight distance m For a more
in-depth explanation on sight distance, please see the AASH Policy on Geometric Design of Highways and Streets,” latest edition, and Engineers Handbook. 10.03.2 Sight Distance Design
Table 10-2 contains the minimum distances that should be used for distance, decision sight distance, and intersection sight distance. These d taken from the AASHTO manual and are for
change, the sight distance requirements will also change. This table shoul as a quick reference guide for sight distances requirements. For cases wh are not level or other problems arise,
sight distances should be ca AASHTO’s methods. In determining sight distance, the driver's driver's eye is assumed to be three and a half feet (3.5’) above the roadway and the height
of object is a two feet (2’) above the roadway. Sight dis installed except for single-family residences on local residential stree showing appropriate intersection sight distance triangles
shall also be p new intersections being designed within the City. objects include but are not limited to: build landscaping. 12/4/2009…………........……….…..Design Standards…………..…..………..…….10-12
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completely within the City right-of-way. If this is not practical and the triangle falls outside the right-of-way, a “Sight Distance Easement” shoul from sight distance d be acquired
the property owners to allow the City to remove any objects that become a sight 10.03.3 Table 10-2 Speed p Sight Distance (ft) eSight Distance to Stop ( DeSig Distance to Avoid (ft)
IDistance for Left Turn (ft)* Intersection Sight Distance for Right Turn (ft)* hazard. Design (mph) Sto ping D cision ft) cision ht ntersection Sight 15 80 225 320 170 145 20 115 310
430 225 195 25 155 395 535 280 240 30 200 490 620 335 290 35 250 590 720 390 335 40 305 690 825 445 385 45 360 800 930 500 430 50 425 910 1030 555 480 55 495 1030 1135 610 530 60 570
1150 1280 665 575 Data for this table applies to both controlled and uncontrolled intersec been taken from the 4th edition of AASHTO’s “A Policy on Geome Highways and Streets” manual’s
Exhibit 3-1 Stopping Sight Distance Decisio tions and has tric Design of , Exhibit 3-3 n Sight Distance, Exhibit 9-55 Design Intersection Sight Distance-Left Turn from Stop, and Exhibit
9-58 Design Intersection Sight Distance-Right Turn from Stop and Crossing Maneuver. * Intersection sight distance shown is for a stopped passenger car to turn onto a two-lane road with
no median and grades of three percent (3%) or less. For other conditions, the time gap may need to be adjusted and the sight distance recalculated 12/4/2009…………........……….…..Design
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10.03.4 Figure 10-1 12/4/2009…………........……….…..Design Standards…………..…..………..…….10-14 H:\DEVELOPMENT\Manuals\Current Manuals\2004 Design Standards\Chapter 10 (9-08).doc
10.03.5 Figure 10-2 12/4/2009…………........……….…..Design Standards…………..…..………..…….10-15 H:\DEVELOPMENT\Manuals\Current Manuals\2004 Design Standards\Chapter 10 (9-08).doc
10.04 Street Access Points All access points to and from City streets including intersections and drive approved ways shall be by the City prior to construction. These access points
shall meet all the nd other safety rsections and ar situation in e City. These es only and may be modified according to traffic volume ehicle makeup, topography, design speed, design
vehicle ctions ersect. These Intersection Spacing tersections is of intersecting corner of the r vehicles to safely execute a right turn at a reasonable rate of speed . When an intersection
is between streets with two different hirty feet (30’) uired to install roadway appurtenances. These values are . landing approach is the portion of the street adjacent to the intersection.
The roach shall be near level for a specific length. These values Proposed public streets grades must intersect each other in such a manner as to provide drainage away from the higher
street classifications. See Table 10-3 for values. 10.04.2 Private Street Intersections Private street intersections are those intersections where a private street intersects a City
street. These intersections should be designed in the same manner as public street intersections, except that the private street will be stop-controlled in all cases. requirements contained
throughout this chapter for sight distance, spacing, a considerations. The following section contains design criteria on all access points including inte driveways. The adequacy of all
criteria given in this section to the particul question should be checked by an engineering analysis and approved by th criteria are minimum guidelin (existing and/or projected), v requirements,
drainage, and other conditions, both existing and projected. 10.04.1 Public Street Interse Public Street Intersections are intersections where two (2) City streets int intersections
should be designed using the following criteria: 10.04.1.1 Minimum centerline spacing between public street intersections shall not decrease from the values as shown in Table 10-3. Use
of offset Tee in discouraged. 10.04.1.2 Horizontal Approach Angle The horizontal approach angle is the acute angle between centerline streets. 90° is desirable; 85° and 95° are maximums.
10.04.1.3 Curb and Right-Of-Way Radius A curb radius is the minimum pavement radius required at the intersection fo without crossing lanes classifications, the curb radii for the higher
classification shall be used. The exception to this rule is for local residential streets where a maximum radius of t shall be used. The right-of-way radius is the additional radius
req sidewalks, landscape strips, and other listed in Table 10-1 10.04.1.4 Landing Approach The grade of the landing app are listed in Table 10-3. 10.04.1.5 Street Crowns 12/4/2009…………........……….…..D
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10.04.3 Table 10-3 Intersection Spacing from Centerline to Centerline RESIDENTIAL PRINCIPAL MINOR & NON-RURAL LOCAL ARTERIAL ARTERIAL RESIDENTIAL COLLECTORS COLLECTOR STREETS 500 250
200 150 125 LOCAL STREET ACCESS 1000 500 250 200 150 RURAL COLLECTOR 1500 1000 500 250 200 RESIDENTIAL & NONRESIDENTIAL COLLECTORS 2000 1500 1000 500 250 MINOR ARTERIAL 2650 2000 1500
1000 500 PRINCIPAL ARTERIAL Intersection Design Information Min Horizontal Approach Angle (degree) 90, +/-5 degrees Min. Curb Radii (ft.) See Reference Table 10-1 Min. Right-of-way (ft.)
See Reference Table 10-1 Min. Landing Approach Length (ft.) r 20 feet ured from the treet. 30 feet approaching an arterial o approaching a non-arterial, meas nearest R/W line of intersecting
s Max. Landing Approach Grade (%) Not to exceed 3% approaching an arterial, or 5% approaching a non-arterial. Street Crowns Variance may be traffic control ices at the intersection and
upon the approval he City Engineer. Carry the grade through the intersection for the higher roadway classification. Match grades at the center of the intersection for equal roadway classifications.
applicable, depends on specific dev of t Stopping Sight Distance See Table 10-2 and Section 10-3. Entering Site Distance See Table 10-2 and Section 10-3. Wheel Chair Ramps Required at
all radii of improved intersections. See Standard Details TRAFFIC-25 & TRAFFIC-26. Drainage See Chapter 6. 12/4/2009…………........……….…..Design Standards…………..…..………..…….10-17 H:\DEVELOPMENT\Manuals\Cu
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10.04.4 Driveways Standard Detail TRAFFIC-07 through TRAFFICexcept single ential. to and during t to provide an access is not lley, or two or contiguous properties may be required to
share a single driveway. When a on the te otherwise. y review and ilable may be t-out driveway. Additionally, these properties may be to C-curb, to at the existing driveways be g driveway
not cal to maintain s except local Figure 10-3 ing up to the is the area stop, and wait ering distance of an intersection is measured from the stop bar or point of curvature/point of
tangency (PC/PT) of the curb return. Parameters that must be evaluated in the determination of the maneuvering distance include the following: d : Decision Distance. The distance traveled
during the reaction time required by aring to brake or to change lanes and brake. d2 : Lane Change Distance. Braking while moving laterally is a more complex maneuver than braking alone.
11 Driveways can be broken into the following classifications: A. Residential Driveways – Driveways to single family residences. B. Commercial/Industrial Driveways – Driveways to all
properties family resid C. Temporary Driveways – Driveways to property allowed prior construction only. D. Emergency Driveways – Driveways required by the fire departmen alternative
emergency-only access to the property. E. Secondary Driveways – Driveways allowed only upon approval of the City used to improve ingress and egress to high traffic and large sites. 10.04.4.1
Driveway Locations While no property will be denied access to the City streets, direct street guaranteed. Properties may be required to access the street via an a more property has frontage
on two or more streets, the driveway shall be located street with the lowest classification unless safety considerations dicta Multiple access points to a property will be allowed only
after Cit approval. Properties located on arterials where no alternate access is ava restricted to a right-in-righ required to construct street improvements, including but not limited
preclude left turning traffic. The redevelopment of a property will not guarantee th retained. The City may eliminate or require modification to any existin in conformance with City
standards. The spacing of driveways and their separation from intersections is criti traffic flow while providing safe ingress and egress. For all street residential streets, the “Functional
Intersection Boundary” rules apply. 10.04.4.1.1 Functional Intersection Boundary See Table 10-4 & A functional intersection boundary is the portion of the street lead intersection required
to allow vehicle movements and storage. This within which drivers identify the situation, change lanes, come to a before proceeding through the intersection. The minimum maneuv assumes
the driver is in the proper lane and only needs to change lanes for a right or left turn pocket. The functional length 1 the driver for prep 12/4/2009…………........……….…..Design Standards…………..…..………..
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H:\DEVELOPMENT\Manuals\Current Manuals\2004 Design Standards\Chapter 10 (9-08).doc o a stop or to a ction. This length will depend on the volume 0.04.4.1.2 Table 10-4 Distance Requirements
for Functional Intersection Bounda Speed Speed ft/sec eacti Time (sec) Decision Dista (ft) ”d Lane Change Distance ” Braking Distance Length* ) ” Functional Intersection Boundary Length
d1+d2+d3+d 4 (ft) d3 : Braking distance traveled during full deceleration and coming t speed at which a turn can be comfortably executed. d4 : The storage length of the interse of traffic
the intersection was designed for. 1 ries mph R on nce 1” (ft) d2” (ft) ”d3” Storage (ft ”d4 25 mph 37 1 37 25 60 100 222 30 mph 44 1 44 40 86 100 270 35 mph 51 1 51 60 118 100 329 40
mph 59 1 59 85 154 100 398 45 mph 66 1 66 105 194 100 465 50 mph 73 1 73 140 240 100 553 The preceding table lists the minimum distances required. The numbers sho average pas wn are
for e senger vehic . Intersections with e ceptionally high volumes of truck traffic require longer distances in all categories. istan has been set at one hundred feet (100’). Intersections
that exhibit e distances ba d 10.04.4.1.3 Figure 10-3 Functional Length Diagram of an Intersection with Right and/or Left-Turn Lane d2 d1 Storage Braking Lane Change Decision th will
se le ce x * Minimum storage d high volumes of traffic on a consistent basis will be required to design storag on a traffic study. d4 d3 Distance Distance Distance Distance Physical
Length Functional Length 12/4/2009…………........……….…..Design Standards…………..…..………..…….10-19
For intersections where left and right turns are not provided with there own turn pockets, the lane change distance (d2) will become zero (0). 12/4/2009…………........……….…..Design Standards…………..…..………
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12/4/2009…………........……….…..Design Standards…………..…..………..…….10-21 H:\DEVELOPMENT\Manuals\Current Manuals\2004 Design Standards\Chapter 10 (9-08).doc Street intersections will heavily
influence driveway locations. Driveway allowed within the physical length (d4+d3+d2) portion of the “Functiona Boundary” for the side of the street where traffic is entering th Restricted
access, right-in-right-out, may be allowed within the decision portion of the “Functional Intersection Boundary” along the direction of t side of the street where traffic is exiting
s will not be l Intersection e intersection. distance (d1) raffic. For the the intersection, restricted access will be tance equal to half the stopping distance (½d3) plus the decision
1 10-4 3+d2 d A PROHIBITED ACCESS B RESTRICTED ACCESS C UNRESTRICTED ACCESS allowed a dis distance (d ) from the intersection. (See Figure 10-4) 10.04.4.1.4 Figure d4+d 1 A A B B C C
d3+d2 2 +d1
10.04.4.2 Driveway Layout Driveways shall be designed in such a manner as to allow for effic ingress and egress from the City streets. Driveways and on-site parki that for single-family
residences on unclassified roads, shall be desi vehicle-backing maneuvers will not occur onto the street. A prop driveway shall allow the largest ient and safe ng, other than gned such
that erly designed typical vehicle that will use the driveway (i.e. tractord exit the site of ten feet (10’) nce should be aration is not ired. circulation shall be such ay impeding
vehicles in the public street. driveways with ets. riveways should be aligned horizontally to as near perpendicular to the City street as than seventyd exiting lanes ated by a raised
“pork chop” may reduce the angle to forty-five degrees behind ent (12%) and shall be designed in such a way as to preclude vehicles dragging when entering or 1 See Standard Detail Traffic-07
& -r living units. um of twentyg a minimum ches (6”) of non-reinforced concrete. affic-09 & 10 mber of lanes ways shall be rced concrete three categories described below will be determined
based on the vehicles A. Light commercial/industrial driveways should be used for sites where the average vehicle use will range from passenger vehicles to small size delivery trucks.
Examples include mini marts, strip malls, fast-food restraints, triplexes, buildings. Driveways will have one entering lane and up restricted to a maximum of twelve feet (12’). B. Medium
commercial/industrial driveways should be used for sites where the average vehicle use will range from medium to high volumes of passenger trailers at large warehouses, beer trucks at
mini marts) to enter an without encroaching into opposing traffic. Driveways for adjacent properties should be separated by a minimum for residential and fifty feet (50’) for commercial/industrial.
This dista measured from the outside edge of the driveway apron. When this sep obtainable, a single driveway centered on the property line may be requ When designing site layout and
driveway access, internal that onsite traffic will not backup the drivew The City may require sites with internal traffic congestion to design long throat lengths to provide extra storage
to avoid impacting City stre 10.04.4.3 Driveway Alignment (Horizontal & Vertical) Dpossible. The angle of intersection to the City street may not be less five degrees (75O). Right-in-right-out
driveways where the entering an are separ (45O). The vertical grade the driveway shall not exceed twelve perc exiting the site. 0.04.4.4 Driveway Widths 10.04.4.4.1 Residential 08 Residential
driveways shall be used when serving four (4) or fewe Driveway widths shall be a minimum of ten feet (10’) and a maxim four feet (24’). Residential driveways shall be constructed usin
thickness of six in 10.04.4.4.2 Commercial/Industrial See Standard Detail Tr Commercial and industrial driveway widths shall be based on the nu used on the driveway and the type of use.
Commercial drive constructed using a minimum thickness of eight inches (8”) of reinfo The expected to use the site. and small apartment to two exiting lanes with the lane widths 12/4/2009…………........
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vehicles to multiple medium delivery trucks per day and the oc tractor/trailer delivery truck. Examples included supermarkets stores, shopping malls, large apartment buildings, and busy
located on arterials. Driveways will have one entering lane and up to casional large , large outlet retail stores two fourteen feet s where high xit every day. nufacturing and storage
warehouses. Driveways will restricted to a on the street use that may rmally fall under the light commercial/industrial classification may be upgraded dustrial classification if it is
located on a principal or more efficient left-hand turns ties where the and without riveway. The b” at the road lane to prevent left turns. In some cases a raised median may be required.
rds will not be exiting lanes with the lane widths restricted to a maximum of (14’). C. Heavy commercial/industrial driveways should be used for site volumes of medium to large tractor/trailer
trucks enter and e Examples include ma have one entering lane and one exiting lane with the lane widths maximum of sixteen feet (16’). Driveway uses discussed above may be subject to
change based classification on which they are located. For example: a site no to a medium commercial/in minor arterial to facilitate moving vehicles off the right-of-way in a manor.
10.04.4.5 Restricted Access Driveways Restricted Access Driveways are typically driveways that do not allow out of or into the driveway. Development or redevelopment of proper required
setback from an intersection cannot be achieved in any direction other ways to access the site will be allowed a restricted access d installation of the driveway may require the developer
to install “C-cur centerline or at the edge of the center turn Restricted Access Driveways will only be allowed upon City approval. The existence of other driveways in the vicinity that
do not meet the above standa grounds for allowing further substandard driveways. 10.05 Sidewalks Sidewalk requirements are based on street classifications as shown in the re section
for each street classification, Table 10-1, and the corridors continuity. required along both sides of all street classifications except for rural streets. can be eliminated on one side
of the street only if topography or safety prohibi and pedestrian needs can be satisfied. (City Engineer’s approval required). ference cross-Sidewalks are The sidewalk ts construction
t (5’) in width for all local residential and lector streets. Sidewalks shall be a minimum of ten feet (10’) in width for all on-residential entified above provide an unobstructed path
of less than four feet (4’) in width. Wider sidewalk may be required at bus stops to allow bus riders a place to stand without ents or handicap access. 10.05.2 Thickness Concrete sidewalks
shall be 4 inches (4”) thick. When the sidewalk is installed at the back of the curb, a thickened edge shall be provided as shown in City of Auburn 10.05.1 Width Sidewalks shall be a
minimum of five fee residential col principal arterials, minor arterials, non-residential collectors, collectors, and local n streets. Non-standard widths of sidewalk greater than the
standards id may be required to provide corridor continuity. At no location shall a sidewalk hindering pedestrian movem 12/4/2009…………........……….…..Design Standards…………..…..………..…….10-23
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Standard Detail TRAFFIC-24, and a base of a minimum of two inches ( surface top course (CSTC) shall be required. When the sidewalk is a landscape strip, the sidewalk shall not have a
2”) of crushed djacent to the thickened edge but will have the same minimum two inches (2”) of CSTC base (See TRAFFIC-23). f meandering et trees, fire deviation from the required accommodate
isability Act) ent (2%) and vertical curb l streets and rsections. Every wheel chair ramp shall have at least one receiving ramp. In special conditions wheel chair ramps shall also be
provided to enable passage rbed radius return access points. Wheel chair ramps located on arterials and collectors shall have detectable
warning patterns formed with manufactured truncated 10.05.3 Meandering Sidewalks The City Engineer may approve meandering sidewalks. The design o sidewalk shall address obstructions,
including mailbox mountings, stre hydrants, power poles, driveways, and street signs, without design width. Additional right-of-way (or easement) may be required to the obstructions
or the meander of the sidewalk. 10.05.4 ADA Access See Standard Detail TRAFFIC-25, 25A, 26 & 26A All sidewalks shall be designed according to ADA (American D specifications. This includes
cross slopes of no greater than two perc slopes of no greater than twelve to one (12:1). Wheel chair ramps shall be provided at all pedestrian crossings having sections. One ramp shall
be used on each curb return on residentia unsignalized inte across cu domes painted yellow. 10.06 Bikeways The minimum design standards for bikeways shall be per “Guide for the D ycle
Facilities,” prepared by the AASHTO task force on geometric design, Aevelopment of Bic ugust 1991. they may be ted from motor vehicle roadways but may um pavement phalt concrete . Signs
and e lane. The Class II bikeway shall have the treet. te but not marked on vement cross-D. A Class IV bicycle route shares the motor vehicle roadways, with no special designation or
design criteria toward bicycle use. appropriate, shall be provided for: A. Wherever called for in the City of Auburn Comprehensive Non-Motorized plan. B. When traffic analysis or traffic
planning indicates substantial bicycle usage that would benefit from a designated bicycle facility as determined by the City. Typically, bikeways are shared with other transportation
modes, although provided exclusively for bicycle use. Bikeways are categorized as follows: A. A Class I bicycle route is physically separa be shared with pedestrians. The Class I bikeway
shall have a minim section of 6 inches (6”) of CSBC and 2 inches (2”) of Class “B” as pavement. B. A Class II bicycle route is adjacent to the motor vehicle roadway pavement markings
designate the bik same pavement cross-section as the adjacent s C. A Class III bicycle route is designated with signs as a bicycle rou the roadway surface. The Class III bikeway shall
have the same pa section as the adjacent street. Class I, II, III, or IV Bikeways, as 12/4/2009…………........……….…..Design Standards…………..…..………..…….10-24 H:\DEVELOPMENT\Manuals\Current
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10.07 Pavement Design This section of the Standards has been prepared for engineers to use in the design of pavement sections for City streets. The use of the following information w
paved transportation corridors are adequately built or improved in a uniform manner. The information contained in Table 10-5 has been establish ill ensure that and consistent ed to minimize
the structural gineers will be SHTO design plete range of plified so that puter analysis is not necessary for developing pavement designs for ls and streets per day and tered, such as
the “City of Auburn Comprehensive Transportation Plan”. along the freight route to determine the vehicle mix and vo ing tables and ne 10 be obtained of a street will uired to determine
the volume and mix of vehicles for which it is designed. e a street has yet to be designated a specific classification, street An anticipated ent of Public ame manner. information, as
10.07.1.2 Street Subgrade For the purpose of pavement design, the California Bearing Ratio (hereafter referred to as CBR) will be used to classify the type of existing subgrade soils.
CBR’s are used because most independent testing laboratories and geotechnical firms have the ata. The scope of this section does not cover existing subgrade with a CBR less than “3”.
When the CBR is less than “3”, a Geotechnical Design is required. failures in streets, due to traffic loadings and/or existing soils conditions. En allowed to do their own pavement designs
in accordance with the current AA procedure and the minimum City requirements supplied in Section 10.07.3. The pavement design information contained herein was established for a com
street and traffic conditions excluding principal arterials. It has been sim extensive data and com most projects. A separate design study will be required for principal arteria where
the daily average traffic count is expected to exceed 15,000 vehicles streets where unusually heavy truck and bus traffic is expected or encoun freight routes and bus routes. Freight
routes are defined in Studies should be performed lumes. Pavement sections for freight routes are not defined in the follow ed to be designed to accommodate anticipated volumes. .07.1
Design Requirements 10.07.1.1 Street Classification The classification of a particular street (i.e. Residential Collector) can from the City of Auburn Department of Public Works. The
classification be req In some cases wher pavement should be designed based on the anticipated traffic volume. daily traffic count can be obtained from the City of Auburn Departm Works
for the street in question or a similar street that functions in the s The City may, however, require the applicant to obtain additional traffic warranted. ability to provide CBR d 12/4/2009………….....
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The subgrade under the proposed street shall have its CBR eva independent testing laboratory or geotechnical firm. The existing subgr be classified as determined in the soils classification
section (Section proposed roadway shall have a minimum of one CBR test for every 1,000 feet of road luated by an ade shall then 10.07.3). The o (2) tests per ng any street base material,
the subgrade shall be rolled and compacted ASTM D-1557 a depth where l that can be ed by ASTMeer. existing subgrade is classified as a poor subgrade, then a geotextile fabric may aterials.
The shall be a woven, permeable fabric produced for placement in road ning wall, are ement Sections the pavement r geotechnical etermining the d civil engineer may also design street
pavement sections. However, the of asphalt will be a two-inch (2”) leveling course with a ickness for a s (5”) for Class ment design 10.07.2 Pavement Section Design Chart The following
chart contains the minimum allowed pavement design base on traffic volumes and CBR’s unless otherwise designed by a licensed civil engineer. Due to high traffic volumes and/or the large
amount of truck and bus trips, Principal Arterials, bus routes, and/or freight routes, as designated by the City, are not included and shall be designed on a case-by-case basis. and/or
for every obvious change in subgrade material (minimum of tw street). Prior to placi to a minimum of 95% of the maximum density as determined by (Modified Proctor). Any sections of a
roadway that exhibit “pumping” shall be removed to the pumping ceases and replaced with granular imported materia compacted to the required 95% of the maximum density as determin 1557
without pumping, or as directed by a licensed Geotechnical Engin If the be required on the subgrade prior to placing any subbase or base m geotextile fabric bases. Other requirements
for subgrade grading, including slopes and retai covered in Chapter 5. 10.07.1.3 Street Pav Street pavement section requirements can be determined by using design chart in Section 10.07.2.
The CBR obtained from the testing o firm, the type and class of road from the City of Auburn, will assist in d appropriate chart column. A license minimum allowable thickness two-inch
(2”) overlay of class “B” asphalt. The maximum allowable th single lift of asphalt shall be two inches (2”) for Class “B” and five inche “E”. Section 10.07.3 provides additional information
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Poor Soils (CBR 3-5) (CBR 6-10) G (CBR 11-20) Excellent Soils (CBR >20) Medium Soils ood Soils Private Streets Alleys ads 2” CL “B” 5” CL “E” Gravel 2” CL “B” 2” CL “E” 8” Grav 2” CL
“B” 2” CL “E” 6” Gravel Base 2” CL “B” 2” CL “E” 4” Gravel Base Access Ro 12” Base el Base Local Residential sidential 2” CL “B” 5” CL “E Gravel 2” CL “B” 2” CL 8” Grav 2” CL “B” 2”
6” Gravel Base 2” CL “B” 2” CL “E” Rural Re 12” 4” Gravel Base ” Base “E” el Base CL “E” Local Non-Residential 2” CL “B 5” CL “E a 2” CL 4” CL r 2” 3” 6” 2” CL “B” 2” CL “E” 4” Gravel
Base ” ” 12” Gr vel Base 8” G “B” “E” avel Base CL “B” CL “E” Gravel Base Residential C Rural Co ollecto llecto 2” CL “B C 2” CL 4” 2” 8” Gravel Base 2” CL “B” 2” CL “E” 6” Gravel Base
rs rs 5” 12” Gravel Base ” L “E” 10” Gravel Base “B” CL “E” CL “B” 3” CL “E” Non-Residenti Collectors 2” CL “B C 12” Gravel Base 2” CL 5” 10” Gravel Base 2” 8” Gravel Base 2” CL “B”
3” CL “E” 6” Gravel Base al 6” ” L “E” “B” CL “E” CL “B” 4” CL “E” Minor Arterials 8” CL “E” 12” Gravel Base 7” CL “E” 10” Gravel Base 6” CL “E” 8” Gravel Base 6” Gravel Base 2” CL “B”
2” CL “B” 2” CL “B” 2” CL “B” 5” CL “E” 10 for Design of criteria: ine the amount btain the most ssuming there /50 split must sumed in the design lane, regardless of the number of lanes
in each direction. (Additional traffic information may be required.) The existing traffic levels shall then be inflated to match the projected traffic at the end of the roadways design
life (in most cases a twenty-year design life will be used). The rate of growth is one and a half percent (1.5%) for residential streets and three and a l streets and arterials streets.
The one ) growth can be waived in closed subdivisions with City approval. .07.3 Requirements for Engineered Pavement Sections Engineered pavement designs should follow the latest “AASHTO
GUIDE Pavement Structures” for flexible pavements and be based on the following 10.07.3.1 Traffic Requirements For projects where a traffic analysis report was not required, to determ
of traffic for which a street should be designed, contact the City to o recent street classification and traffic counts. Traffic counts are done a is a 50/50 split in the direction of
traffic. One hundred percent of the 50 be as half percent (3.5%) for commercial/industria and a half percent (1.5% 12/4/2009…………........……….…..Design Standards…………..…..………..…….10-27
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10.07.3.2 Pavement Minimums For designers, the minimum allowable thicknesses of pavement sections are as Gravel Base 6” o three (every asphalt may be replaced with three inches (3”)
of crushed rock). At phalt be placed in less than a two inch (2”) thick lift. el base where e pavement thickness, the soils condition of the area in which the f the following the tested
soil , ML, CL, OL, e CBR values mounts of silt. Unified Soils Classification System. The CBR value would range from 6 to 10. city when wet. as per the Unified Soils Classification System.
The CBR value for these materials may range from 10 to 20. 10.07.3.3.4 Excellent Soils These soils are basically unaffected by moisture or frost. These soils would be classified as GW,
GP, GM, GC, SW, or SM as per the Unified Soils Classification System. The CBR value for these materials would be greater than 20. follows: CL.“B” CL.“E” Minor Arterials 2” 5” 6” Residential/Rural
Collectors 2” 2” Residential Streets 2” 2” 4” Local Non-Residential 2” 2” 4” Class E asphalt may be replaced with crushed rock at a ratio of two t two inches (2”) of no time however
shall as Geo-textile fabric may be required between the subgrade and the grav soil conditions are poor. 10.07.3.3 Soils Classifications Prior to designing th road or street is to be
built shall be evaluated and classified into one o four different categories in this Section. These classifications and properties shall then be used in the pavement design. 10.07.3.3.1
Poor Soils These soils are relatively soft and plastic when wet and may contain appreciable amounts of clays and silts. These soils would be classified as SC MH, CH, or as OH as per
the Unified Soils Classification System. Th for these materials range from 3 to 5. 10.07.3.3.2 Medium Soils These soils are relatively firm when wet and may contain some a These soils
would be classified as SP, SM, or SC as per 10.07.3.3.3 Good Soils These soils retain a substantial amount of their load-bearing capa These soils would be classified as GM, GC, SW, or
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10.07.3.3.5 Unified Soils Classification Symbols G es. G vel-sand mixtures with little or no fines. G es. GC: S ravelly sands with little or no fines. S velly sand mixtures with little
or no fines. SSC: M ilts and very fine sands, rock flour, silty or clayey fine sands or C andy clays, silty ays, lean clays. O ys of low plasticity. M sand or silty soils, elastic ysis
report to the City of Auburn orks, including a narrative of the site conditions, the pavement al. The report ation on the ot a substitute r tests to support soil capacity.) of Auburn’s
nd are subject tion Standards se se shall be bank run gravel, defined as naturally occurring material having mpacted in place on the roadway, it will provide a the subgrade on which
it is placed. It shall be from a pit approved by the City Engineer and shall be specified in Division 9-03.10 of the “WSDOT Standard Specifications.” 10.07.4.2 Crushed Rock Crushed rock
use in City street construction will fall under the following two classifications: A. Crushed Surfacing Top Course (CSTC) W: Well graded or gravel-sand mixtures with little or no fin
P: Poorly graded gravels or gra M: Silty gravels or gravel-sand mixtur Clayey gravels or gravel-sand-clay mixtures. W: Well graded sands or g P: Poorly graded sands or gra M: Silty sands
or sand silt mixture. Clayey sands or sand-clay mixtures. L: Inorganic s clayey silty that are slightly plastic. L: Inorganic clays of low to medium plasticity, gravelly clays, s cl
L: Organic silts and organic silt cla H: Inorganic silts, micaceous or diatomaceous fine silts. CH: Inorganic clays of high plasticity, fat clays. OH: Organic clays of medium to high
plasticity and organic silts. 10.07.3.4 Report Submittal The applicant must submit a roadway anal Department of Public W sections, and applicable background information for review and
approv must detail data on how the design was achieved including inform subgrade soils. (Note: The soils classification in Section 10.07.3.3 is n fo 10.07.4 Materials Specifications
The following material requirements are referenced from the City Construction Standards Manual and “WSDOT Standard Specifications” a to change. For the most current definitions, please
reference the Construc Manual. 10.07.4.1 Gravel Ba Gravel ba characteristics such that when co course having greater supporting value than 12/4/2009…………........……….…..Design Standards…………..…..………..……
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B. Crushed Surfacing Base Course (CSBC) CSTC and CSBC shall be in accordance with Section 9-03.9(3) of the “WSDOT City street construction will typically fall under the following two
“B” Asphalt Asphalt Concrete Pavement shall be in accordance With “WSDOT Standard tions.” Standard Specifications.” 10.07.4.3 Asphalt Concrete Pavement Asphalt use in classifications:
A. Class “E” Asphalt B. Class Specifica 10.08 Landscaping of all street is landscape strip is an integral part of the roadway cross-section. It by providing a a narrower travel the aesthetic
ce with these standards. The proposed design shall be reviewed and approved by the City. collector streets. cape strips shall loper shall provide d plant street trees within the landscape
strip in accordance with these design standards. ncipal arterials, minor arterials, non-residential collectors, walk in tree in section ps contain several components. These include soil,
the plants ctural items such as root barriers and tree grates, and may include street furnishings such as luminaries, traffic signs, bus stops or shelters, benches, and mail boxes. 10.08.3
Landscape Strip Dimensions nate either five-foot (5’) or five-and-a-half-foot (5½’) wide landscape strips. 10.08.4 Plant Layers 10.08.1 General Landscaping Requirements An area devoted
to landscaping is included within the right-of-way classifications. Th serves several important functions, including improving pedestrian safety buffer between traffic and the sidewalk;
providing the perception of corridor, thereby slowing traffic; improving air quality; and improving appearance of the street. The developer shall design and install the landscape strip
in accordan design Landscape strips are required for local residential streets and residential The minimum width required for landscape strips is five feet (5’). Lands be located between
the back of the curb and the sidewalk. The Deve for an Street trees are required for pri and local non-residential streets. Street trees shall be placed within the side pits with tree
grates and spaced in accordance with the standards identified 10.08.5.1. 10.08.2 Landscape Strip Components Landscape stri themselves, stru The roadway sections desig 12/4/2009…………........……….…..Desi
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It is recommended that a multi-layer planting be used in the landsca instance, grass or a ground cover should be used at the ground leve shrubs may comprise the next layer, and trees
form the upper or cano pe strip. For l, low-growing py level. Within the Plant Selection section below. ontain the following layers: ubs with a mature height of three feet (3’) or less—Optional
10 et intersection, placed in tree within the sidewalk per City of Auburn Standard Detail TRAFFIC-64. safety or ns: Tree Siz eig mende Landscape Strip Widths this general framework are
many choices, outlined in In summary, the landscape strip will c 1. Ground Cover(s) or Grass—Required 2. Shr 3. Trees—Required .08.5 Trees 10.08.5.1 Placement and Spacing Trees shall
be placed so that they do not obstruct the view of any stre driveway, or visibility of any traffic control device or sign. Sight distance triangles shall be used to analyze visibility
at street intersections. Trees shall be centered in the landscape strip. When a landscape strip is not required, trees shall be pits with tree grates Trees will be spaced as follows,
except where special site conditions require variation for other reaso e H ht Recom d Spacing Small To 25 Feet 15 -20 Feet Apart 5 Feet Medium 25 -50 Feet 20 – 30 Feet Apart 5.5 -8 Feet
Large 50 – 70 Feet 30 – 50 Feet Apart 8 – 12 Feet Very Large 70 Feet + 50 Feet or Greater 12 Feet + Nearby features such as buildings or overhead wires will also affect where trees h
(2”) caliper, sidewalk, the Trees with a idal, columnar, or oval shaped canopy are preferable; a tree with a round head pecies with a Street Lighting: Trees should generally be at least
twenty feet (20’) from light standards. Planting locations should be coordinated with locations of lighting standards. Clearance: Trees shall be pruned as they grow to provide at least
seven feet (7’) vertical clearance above sidewalks and fourteen feet (14’) of vertical clearance above should be located. Minimum size for street trees shall be a two-inc measured two
feet (2’) 2’) above the root ball. Planting Next to a Building: Where a building is placed close to the mature size of a tree should be considered when selecting species. pyram is generally
unsuitable in this situation. Overhead Wires: When trees must be planted under utility lines, s maximum height of twenty-five feet (25’) should be selected. roadway surfaces. 12/4/2009…………........………
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nt factor in the selection of street trees. The his in turn will red below includes information about which tree canopy shapes t conditions. Table 10-4 offers information about tree
species opies that are om and broad at the top. The American Elm is a classic hape. V-shaped trees may have arching branches that form a problems with d at the base of the canopy and
inted at the top. European Beech is one tree that becomes een unwanted droop with age and may have in later years to provide the needed clearance. ce than other ic. Oval trees, le interference
room between columnar trees tend to grow up rather than out. Many branch lower than other types of trees shall use a root ots downward into the soil. These devices are used to eliminate
damage to sidewalks as the tree roots extend beyond the original planting pit. The root barrier should be placed along two sides of the tree, parallel to the sidewalk der specific circumstances,
wider strips that contain utilities may also need root barriers to reduce conflicts. Plan submissions should indicate the location of root barriers and provide a specification sheet
on the product to be used. 10.08.5.4 Tree Planting Wells and Grates 10.08.5.2 Tree Canopy Shape Tree canopy shapes are an importa setting will often dictate which canopy shapes are most
appropriate. T aid in the selection of the most suitable species. The guidance offe work best under differen and their canopy shapes. 10.08.5.2.1 V-Shaped Trees V-shaped (sometimes also
called “vase shaped”) trees have can narrow toward the bott street tree with this s canopy over both street and sidewalk. They generally do not cause overhead power lines or traffic.
10.08.5.2.2 Pyramidal Trees Pyramidal or cone-shaped trees are typically broa are somewhat po pyramidal with age. Planted close together, pyramidal trees can scr views or create vistas.
Lower branches sometimes to be limbed up 10.08.5.2.3 Round Trees These are generally wide spreading trees that need more spa shapes. The Red Sunset Maple is one example of a round tree.
10.08.5.2.4 Oval Trees An oval tree is a good choice around buildings and adjacent to traff like the Raywood Ash, are taller than they are wide and cause litt with traffic. 10.08.5.2.5
Columnar Trees Columnar trees are useful in locations where there is little available the street and buildings, awnings, or other features. Branches of without causing problems with
traffic or pedestrians. 10.08.5.3 Root Direction Devices All street trees planted within a five-foot (5’) wide landscape strip direction device to deflect tree ro and to the curb line.
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In highly urbanized settings such as downtown, it may be necessary t trees into an existing street and sidewalk setting. Where high levels traffic is expected, it may be necessary to
place trees into a paved are landscape strip. In these situations planting wells and grates may be necessary. o install street of pedestrian a rather than a The or greater. A ily traveled
pedestrian area, their roots can be easily in sand will be provide planting details, specifications, and for proposed tree-planting wells and tree grates. See Standard plant choices
for each layer of the landscape strip. Selection is the landscape strip ves t available or sture in the soil; and ies desired. dscape strips, magnolias are 10-5 provides several acceptable
species of ground covers, shrubs less than 3 feet high, and a variety of flowering or standard street trees. Many other plants are appropriate; alternative selections may be proposed
if desired. Alternative plant choices evalu proved by the City. column headings follows: 25 Feet MMa f sun Shade Shade to part shade. Protect from full sun, especially in afternoon H20
Req. (Requirement): Low Drought tolerant after 1st year r need. May need supplemental watering during dry season. High Requires irrigation Canopy Shape: “V” V-shaped Trees (sometimes
also called “vase shaped trees”) desirable size for a tree planting well is thirty-six square feet (36 sq.ft.) minimum of twenty-five square feet (25 sq.ft.) should be provided. Where
trees are within a heav damaged. In these areas tree grates or other means such as pavers required to protect the health of the tree. Where tree wells or grates are necessary, product
sheets Details TRAFFIC-14 and TRAFFIC-15. 10.08.6 Plant Selection There are innumerable based on: • Size of • Canopy shape of trees • Size and type of lea • Root shape • Site environmental
conditions, such as the amount of sunligh moi • Aesthetic qualit Needled evergreens, such as firs or spruces, shall NOT be used in lan unless the strips are very wide. Broad-leaved evergreens
such as acceptable. 10.08.7 Plant Selection Table Table will be ated and ap Column Headings: A short description of several of the Size: Small To edium 25 to 50 Feet L rge 50 to 70 Feet
Sun: Sun Needs full sun Sun/Shade Takes sun to part shade; needs at least ½ day o Mod Moderate wate 12/4/2009…………........……….…..Design Standards…………..…..………..…….10-33 H:\DEVELOPMENT\Manuals\Current
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Pyramid Pyramidal trees or cone shaped trees s Col. Columnar trees A T Round Round tree Oval Oval trees T BLE 10-5 ( REES) Botani Namecal mam La e Width CoN mon e Size Sun H2O Req. Min.
ndscap Strip Canopy Shape Remarks Acer campestre Hedge ap Med Sun/Shade 5 t ban plant. Any well-drained w fall color. Broad crown. May M le bed up when young. Small/Mod -8 Fee Round.
soil. Yello need to be lim Tough ur Acer ginnal a ur M Small /Shade scarlet fall color. Fast Tolerant of many soils, pollution, salt and drought. Am aple Sun Low 5-8 Feet “V” Spectacular
growing. Acer platan ‘Armstron ‘Columnaroides g’ e’ ri’ rw Maple Large Med 8-12 Feet 5-8 Feet 5-8 Feet 8-12 Feet e to soil and climate cult to grow grass under. ltivars w/varying heights
& ‘Schwedle No ay Med Large Sun Mod Oval Col. Round. Very adaptabl condition. Diffi Many cu Oval shapes. Acer rubrum set’ ry’ ailable d M Med/Large t able: will grow in swamps or eeds
shade over root used as a street tree. ‘Red Sun ‘Oct. Glo Others av Re aple Sun Mod 5-8 Fee Oval Very adapt on rocky slopes. N area when Car ’Colum pinus betulu aris’ rop rnb Small/e
earance: needs no pruning. e free. s Eu Ho ean eam Med Sun/Shad Mod 5-8 Feet Col. Elegant app Pest & diseas Cercidy japonicum phyllu tsu ree 5-8 t /delicate texture, red , good fall
color. Shape e multi-stemmed. ly spring. Rich, ained soil. m KaT ra Med Sun Mod Fee Round Beautiful tr tinged leaves varies; can b ee w Transplant B&B, ear moist, well-dr Cercis canadensis
ast Redbud Small /Shade 5 t rple flowers, early spring. habit w/flat top. Transplants hen small. Effective in clusters. E ern Sun Mod -8 Fee Round. Reddish-pu Spreading best w Fraxinus
oxycar pa ’Golden Desert’ ld Med Sun 5-8 t leaves give a tidy, fernigs, attractive ed to purple fall color. Go en Desert Ash Mod Fee Oval Small, narrow like appearance. Gold tw in winter.
R Ginkgo biloba Ginkgo Large Sun Mod 5-8 Feet n-shaped leaf. Light green ring; bright yellow in fall. trees only. Slow growing. ide variety of soil Col. to Oval Distinctive fa foliage
in sp Plant male Tolerates w conditions. Liquidamb styraciflua ar etg L t py of 5-lobed, star shaped w to red fall color. Pointed, sance. Swe um arge Sun Mod 5-8 Fee Col. to Oval Dense
cano leaves. Yello woody fruit can be a nui Pyrus ca and vari lleryan eties Callery Pea lowe Pear) lossy leaves in summer, Heavy clusters of white pring. May need corrective young. Varieties
hanticleer’, ‘Redspire’ y of canopy shapes. a (F r ring Med Sun Low 5-8 Feet Pyramid to Oval reen g scarlet in fall. flowers in s pruning when ‘Aristocrat’, ‘C Dark g have a variet Quercus
rubra Red Oak Large/Very Large Sun High 8-12 Feet plant. Needs fertile, wellenty of water. Tolerates on. High branching and fairly open shade make it a good choice for big lawns and
blvds. Dark red, or orange fall color. Fast growing. Round Easy to trans drained soil, pl polluti Tilia cordata ‘Greenspire’ Littleleaf Liden Med Sun/Shade Mod 5-8 Feet Oval/Pyramid
Formal look. Upright branching. Needs well-drained, fertile soil. Tolerant of urban conditions. Easy to transplant. Fragrant yellowish flowers in clusters in June. Zelkova serrata ’Village
Green’ Zelkova Med Sun Mod 8-12 Feet ‘V’ Graceful vase-shaped tree resembling the elm. Fair tolerance of soils, best in moist deep loam. Leaves light green in spring, yellow to russet
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TABLE 10-5 (GROUND COVER/LOW SHRUBS) Botanical Common m Size Spa Landscape Strip Width Name Na e cing Sun. Remarks Min. Flowers Arctostaphylo in Small 5-8 Feet seful on slope, poor or
dry soils. Slow to establish; must ress early weed problems. s Kinnik una-ursi nick Bearberry Sun/Shade ♦ Uadd C. dammeri rb ne 3”-6” 5-8 Feet Fast growing, roots freely. Bea erry Coto
aster Sun/Shade ♦ Hedera helix English Ivy 6”-12” 12”-18” Shade 5-8 Feet Vigorous, should be within a tained area. Will climb l surfaces. Sun/con vertica H. h. ‘Baltica’ 6”-12” 1 Shade
5-8 Feet r leaf than English Ivy; not Baltic Ivy 2”-18” ressive. Sun/Smalle as agg Hypericum caly um St. Johns Wort to 12” 18” Sun/Shade 5-8 Feet ♦ Tolerant of poor soils, some drought.
Competes well with trees. Must be in confined space or overtakes other plants. Showy yellow flowers. cin Vinca minor Periwinkle 6” 12”-18” Shade 5-8 Feet ♦ Needs regular watering. 10.08.8
Planting Methods and Maintenance ctice should be employed in the preparation of the soil and planting il and replacing it on the site. the landscape ct. Because lude providing dry periods.
Weeds, diseases, and insect pests must also be controlled. dards difficult. aragraphs list rture from the Root Direction Device: The root direction device may be omitted if the planting
strip is very wide or if the variety of tree to be planted is known to cause no sidewalk upheaval. Grass or Ground Cover: Where it is extremely difficult to maintain grass or ground
cover in a landscape strip, heavy stone aggregate such as a washed river rock may be an acceptable substitute. Lightweight rock such as lava rock is not acceptable. Paving over the landscape
strip will rarely be acceptable. Good horticultural pra pits. This will include: 1. Conserving topso 2. Performing soil tests. 3. Providing corrective soil preparation as necessary.
10.08.9 Establishment Period The developer will be responsible for maintaining the trees and plants in strip in a healthy condition for one (1) year after acceptance of the proje landscape
strips do not usually include irrigation, maintenance will inc water during 10.08.10 Deviations from the Landscape Strip Standards Site conditions may occasionally make adhering to the
landscape strip stan Deviations from the standards may be requested. The following p circumstances that may be appropriate conditions for requesting a depa design standards: 12/4/2009…………........……….
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10.09 Mailboxes See Standard Details TRAFFIC-16 Thru TRAFFIC-19 Locating and installing mailboxes in connection City street shall follow AA with the construction or reconstruction of
a SHTO and Post Office guidelines. ce of curb on be determined ll be detailed cated in the sidewalk, individually or in clusters, sidewalks shall be he mailboxes. y. The owners or residents
served by mailboxes will install and thereafter maintain their own . Postal Service. 17, TRAFFIC-18, and TRAFFIC-19. 10.09.1 Mailbox Locations Mailboxes shall be located a minimum of
two feet (2’) back from the fa streets which have a curb. For streets without a curb, setbacks shall using ASSHTO standards. When locating mailboxes, access, sight distance, and landscaping
requirements shall be taken into account. Final locations sha on the civil plans and approved by the serving Post Office and the City. When mailboxes are lo widened to provide a minimum
five feet (5’) of clearance around t Widening of the sidewalk may require the dedication of additional right-of wa 10.09.2 Mailbox Installation individual, clustered, or separated mailboxes
as instructed by the U.S Mailbox installation shall follow City of Auburn Standard Details TRAFFIC-16, TRAFFIC-10.10 Illumination See Standard Details TRAFFIC-43 Thru TRAFFIC-48 terials.
Single 0-6 contains ations. Local n ornamental ed by lighting Table 10-6 tted to the City for approval. Roadway lighting design shall meet the design (Illuminating ity of Auburn type,
luminaire l sample of the exact product 10.10.2 Design All non-calculated designs and construction must meet the City of Auburn’s design criteria. All poles and bracket arms shall be
designed for the street lighting luminaire with a minimum weight of fifty pounds (50 lb.) and to withstand pressures caused by wind loads of eighty miles per hour with a gust factor
of one point three (1.3). lude a lighting schedule. Each luminaire shall be numbered such that the circuit number is indicated. 10.10.1 General The City of Auburn prefers staggered lighting
on all Principal and Minor Ar sided lighting may be acceptable if approved by the City. Table 1 information on placement and type of lights for specific street classific Residential
streets will have a choice between a standard light and a alternative. Final light standard location and design shall be confirm calculations that substantiate a predicable minimum illumination
level or from and submi criteria in the most recent edition of the “IES Lighting Handbook” Engineering Society of North America) and applicable WSDOT and C Standard Details and Specifications.
Any deviations in materials, i.e. pole fixture type, must be submitted for pre-approval. A physica to be used shall be submitted to the City for approval. All illumination plans shall
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10.10.3 Table 10-6 Lighting Sch L edule TAB E 10-6 Street Classificati Street Wi La Watt A Maintained F candle Required Uniformity na gh Light Pat Davit Arm Length on dth Spacing mp
age verage oot-Ratio lumi ire Mounting Hei t tern Principal Arterial 61 ft. 400 1.4 M-C III 12 ft. 190 ft. 3 To 1 35 ft. Minor Arteri 50/61 ft. 250 0.9 3 To 1 35 ft. M-C III 10 ft. 190
ft. al Non-Residen Arterial 44 ft. 250 0.9 3 To 1 35 ft. M-C III 6 ft. 200 ft. tial Collector Residentia or l 35 f 150 0.6 3 To 1 30 ft. M-C II 6 ft. 175 ft. l Collect Arteria t. I Local
No Reside nntial 34 ft. 150 0.6 3 To 1 35 ft. M-C III 6 ft. 160 ft. Rural Collector* Local Residential 28 ft. 100 0.4 6 To 1 30 ft. M-C III 8 ft. 185 ft. Local Residential Ornamental
0.4 A N/A 140 ft. lternative 28 ft. 100 6 To 1 12 ft. M-C III * Illuminate Signalized Intersections only see Section 3.10.11. ** Street trees shall be located a minimum of twenty feet
(20’) from all stree 10.10.4 Light Standard Foundations See Standard Detail A. Foundations for light standards shall conform to S tlights. TRAFFIC-44 tandard Detail TRAFFIC-44. Each
base for each tion 9-29.6(5) Hardware, City of Auburn Special Provisions) and Standard Detail t arms to be d two feet (2’) ch (3”) slump) Portland Cement. (4”) below the tandard Detail
undation and such that the walk. il TRAFFIC-45 otocell installed for luminaire control. A three-wire electrical service (120/240 volts) shall be extended from a PSE connection to the
service cabinet. The number of luminaires per service will be based upon the type of luminaire and the capacity of the service. Testing may be required to determine if additional luminaires
may be added to an existing service. 10.10.6 Service Cabinet Foundations See Standard Detail TRAFFIC-45 tion shall be a twenty-four inch by twenty-four inch by sixinch (24”x24”x6”) concrete
pad and conform to Standard Detail TRAFFIC-45. pole shall have a conduit sweep from inside the pole through the concrete direction of wire run and shown on the plans. Anchor bolts per
Sec (Foundation TRAFFIC-44 shall be installed in foundations to enable luminaire mas installed perpendicular to the centerline of the roadway served. B. Luminaire pole foundations shall
be four and one-half feet (4½’) deep an square or three feet (3’) in diameter, Class 3000 Concrete (three in C. Pole foundations next to or in sidewalks shall be placed four inches finished
surface of the sidewalk. A four-inch (4”) concrete pad per S TRAFFIC-44 shall be poured concurrently with the sidewalk. The fo sidewalk shall be separated by a three-quarter inch (3/4”)
expansion joint foundation can be removed without damage to the surrounding side 10.10.5 Service Cabinet See Standard Deta Service cabinets installed for luminaries shall be metered
and have a ph The Service Cabinet founda 12/4/2009…………........……….…..Design Standards…………..…..………..…….10-37 H:\DEVELOPMENT\Manuals\Current Manuals\2004 Design Standards\Chapter 10 (9-08).doc
10.10.7 Conduit Street light conduit shall be Schedule 40 PVC-ASTM D1785. All cond crossings shall be Schedule 80 PVC-ASTM D1785. All conduits installed and driveway areas shall be Schedule
40 PVC ASTM D1785. Conduit change within a run. Conduits installed under paved roadway, not cro uits for street under sidewalk type shall not ssing the roadway, llel to the curb l TRAFFIC-46
e of the type of WSDOT h a landscape in the shoulder il TRAFFIC-44 five-foot-nineavit Arms, City of e with City of Construction AFFIC-44. the davit arm ity of Auburn Luminaire Pole Detail
TRAFFIC-44. ative shall be th seventeen-inch (17”) diameter base r DG). l TRAFFIC-44 inal non-flush del “SST-IES” or ontrols) of the ervice cabinet, ll will be required per service cabinet.
ral requirements of Section 9-29 (Illumination, Standards with the following modifications: 1. 400 Watt, clear burning, high pressure sodium light source rated at a minimum of 50,000
initial lumens with an average rated life of 24,000 hours shall be used on s at intersections; 2. Clear burning high-pressure sodium light sources of the ratings shown in the lighting
schedule shall be used. 3. Luminaires shall operate on 240 Volt AC. shall be Schedule 80 PVC-ASTM D1785 and located three feet (3’) para line if possible. Conduits shall have a minimum
of twenty-four inches (24”) of cover. 10.10.8 Junction Boxes See Standard Detai A. Street Junction boxes shall be shown on the plans in conformance with the City of Auburn Uniform Wiring
Detail TRAFFIC-46. Junction boxes shall b specified on the plans and shall conform to the requirements Standard J-11a. B. Type 1 junction boxes shall be located adjacent to the sidewalk
wit strip on roadside, at back of sidewalk without landscape strip, or with of a non-curbed roadway. 10.10.9 Light Standards See Standard Deta A. All lighting standards shall be tapered
aluminum, davit-style units, with inch (4’9”) radius per Section 9-29.6(1)A (Lighting Standards and D Auburn Construction Standards), and shall be installed in conformanc Auburn Luminaire
Pole Detail TRAFFIC-44. B. Anchor bases per Section 9-29.6(2) (Anchor Bases, City of Auburn Standards) shall conform to the City of Auburn Luminaire Pole Detail TR C. Light standards
shall have two stainless steel through-bolts where intersects the pole per C D. The light standard for the Local Residential Ornamental Altern Holophane Wadsworth series fluted shaft
wi (W12F4/17CA/BK o 10.10.10 Light Standard Handholes See Standard Detai Light Standards handholes shall be four inches by six inches (4”x6”) Nom type in accordance with the City of
Auburn's Luminaire Pole Detail TRAFFIC-44. 10.10.11 Photoelectric Controls Photocells installed on the service cabinet shall be “SST” Series mo approved equal in conformance with Section
9-29.11(2) (Photoelectric C Standard Specifications. A bypass switch shall be required inside the s clearly marked PE Bypass. One photoce 10.10.12 Luminaires A. Luminaires shall meet
the gene Signals, Electrical) of the Construction traffic signal standard 12/4/2009…………........……….…..Design Standards…………..…..………..…….10-38 H:\DEVELOPMENT\Manuals\Current Manuals\2004
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4. IES-ANSI Light distribution pattern: e III edium l) as approved nd be bracketnetic-regulator requiring only ire power door gh the use of by means of anufacturer to 2-wire power sodium
lamp rated 24,000 hours (minimum). All luminaires shall be cutoff units for ontrol. All luminaires sure m cutoff type III s m Gene proved ted in Table 10-7: Lateral: Typ Vertical: M
Control: Cutoff B. The luminaires shall be flatglass high-pressure sodium (G.E. or equa by the City Engineer. The luminaire housing shall contain the ballast a arm mounted. The ballast
shall be 240 volt plus 10 percent with mag design and be prewired to the lamp socket and terminal board, connection of the power supply leads to the terminal board. The ent assembly
shall be quickly and easily removable and replaceable throu quick disconnect plugs. The luminaire shall be bolted to the standard cast-in inserts and this detail shall be coordinated
with the standard m ensure proper fit. The terminal board shall have lugs of a 240-volt source. Each fixture shall include the shorting cap, the ballast, and high-pressure glare c units
a shall be high-pres ral Electric or ap sodium, mediu anufactured by equal as lis TABLE 10-7 Wattage I Lamp t Number Max. Luminaires ANS Type G.E. Par Per Circuit 100 S54 M2AC10S3M1GMC32
14 150 S55 M2AC15S3M1GMC32 12 250 S50 MDCL25S3M12FMC32 8 400 S51 MDCL40S3M12FMC32 7 of light source and wattage per Section 9-29.10 (Luminaires) of the Construction Standards. A maximum
of five percent (5%) voltage drop across each circuit will be permitted. on systems. C. All luminaires shall be provided with markers for positive identification Voltage drop calculations
will be required for all non-standard illuminati 10.11 Survey Monuments See Standard Details TRAFFIC-20 Thru TRAFFIC-22 Survey monuments shall be placed or replaced in accordance with
good practice in land equired along the centerline of improvement of all new or d streets. Monuments shall be placed at intersections, P.C. (points of curvature), and P.T. (points of
tangency). be replaced by a registered land surveyor registered in the State of Washington at the expense of the responsible builder or developer. surveying. Monuments are r reconstructe
All existing survey monuments that are disturbed, lost, or destroyed during construction shall 10.12 Guardrail Evaluation of embankments for guardrail installations shall be in accordance
with Chapter 710 of the WSDOT Design Manual. 12/4/2009…………........……….…..Design Standards…………..…..………..…….10-39 H:\DEVELOPMENT\Manuals\Current Manuals\2004 Design Standards\Chapter 10
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Guardrail installations shall conform to WSDOT/APWA Plan C-1, Beam Guardrail Type 1. End anchors shall conform to WSDOT/APWA Plan C-6, Beam Guardrail Anchor Type 1. 10.13 Bollards See
Standard Detail TRAFFIC-06 When necessary to deny vehicle access to an easement, tract, or tra maintenance or emergency vehicles) the point of access shall be closed bollards. These
shall include one or more fixed bollards on each side of the and removable, locking bollards across the traveled way. Spacing shall provid on centerline of the trail and other bollards
at a maximum spacing of thre preclu il (except for by a line of traveled way e one bollard e feet (3’) to de vehicular access. Bollard design shall be in conformance with Standard Detail
TRAFFIC-06. Fire access roads shall not be blocked in this manner without the the Fire Marshal. Bollards shall be ten feet (10’) from the paved edge of concurrence of roadway. 10.14
Transit Stops he following are guidelines that : r boarding and debarking conditions warrant. to in lane stopping. ersections and intersections immediately following the intersection.
Distance rside pullouts are not possible, nearside pullouts will be evaluated. Mid-block s pullout is the uate separation between access points, intersections, and bus the transit n
to existing access points. E. Bus pullouts must meet sight distance requirements. See Section 10.03. 10.14.3 Design Of Bus Pullouts w applicable guidelines for facilities used by the
physically challenged (Americans With Disabilities Act). The King County Metro Transit Planning Office or Pierce County Transit should be contacted for specific design questions. 10.14.1
Bus Pullout Requirements Bus pullouts are at the discretion of the City Engineer. T would indicate pullouts would be appropriate A. Traffic and passenge B. Traffic flow would be greatly
hindered due C. The posted speed limit is in excess of 35 mph. 10.14.2 Locations for Bus Pullouts Bus pullout locations shall meet the following requirements: A. Placement of bus pullouts
shall be on the the farside of signalized int non-signalized between pullouts should not be less than one thousand feet (1000’). B. If fa pullouts are discouraged. If a situation arises
where a mid-block bu only option, pullouts should be constructed on both sides of a two-way street in a complementary pair. C. Maintaining adeq pullouts can increase the safety and efficiency
of both the roadway and service. D. When locating a bus pullout consideration shall be give All pullout designs must follo 12/4/2009…………........……….…..Design Standards…………..…..………..…….10-40
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10.15 Traffic Control Devices 10.15.1 Pavement Markings See Standard Detai Pavement markings, raised markers, or striping shall be used to l TRAFFIC-35 delineate or guide traffic. prove
all channelization plans and crosswalk locations. prior to ru TRAFFICnals and other ngitudinal bars bars should be painted space. il TRAFFIC-36 t (150’) of fullgth for posted be in included
The standard width of a left-turn lane will be ten feet (10’). Leftbehind the stop bar. Additional storage may be required for long vehicles or storage length one hundred fifty feet
(150’), auxiliary turn arrows will be installed at one 0’) intervals. ail TRAFFIClanes shall conform to Standard Detail il TRAFFIC-35 arate or channelize traffic shall be per Standard
arterial street . A four-inch Painted islands will be on a case-by-case basis. Pavement markings for the island portion will be under the discretion of the City. rn Lanes See Standard
Detail TRAFFIC-35 The installation of two-way left-turn lanes on City streets will be determined determined by the City based on street classifications and left turn requirements. The
minimum width of a two-way left-turn lane shall be eleven feet (11’). The delineation lines shall be SBY channelization, lane endings, crosswalks, and longitudinal lines to control The
City shall ap All pavement markings must be laid out with spray paint and approved by the City permanent installation. 10.15.1.1 Crosswalks See Standard Details TRAFFIC-37 Th 39 Crosswalks
shall be installed at all intersections controlled by traffic sig areas approved by the City. Crosswalks shall be a piano key or lo consisting of white thermoplastic material. The position
of the cross spaced in such a way as to allow majority wheel traffic to pass in the un 10.15.1.2 Left-turn Channelization See Standard Deta Left-turn channelization shall include a minimum
of one hundred fifty fee width lane to include storage and a reverse curve ninety feet (90’) in len speed up to forty-five mile per hour (45 mph). The reverse curve may in the taper
distance. turn arrows per Standard detail TRAFFIC-36 shall be installed twenty-five feet (25’) anticipated left-turn queues longer than the minimum storage. If exceeds hundred foot (10
10.15.1.3 Left-turn Lane at End of Two-way Left-turn Lane See Det 40 Left-turn lane at the end of two-way left-turn TRAFFIC-40. 10.15.1.4 Lane Division See Standard Deta All pavement
markings used to sep Detail TRAFFIC-35. Raised pavement markings are preferred for channelization. Paint will be acceptable for non-arterial channelization (4”) wide white stripe is
permitted for foglines in all cases. 10.15.1.5 Painted Islands 10.15.1.6 Two-way Left-tu 12/4/2009…………........……….…..Design Standards…………..…..………..…….10-41 H:\DEVELOPMENT\Manuals\Current
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(Single Broken Yellow) and a SSY (Single Solid Yellow) along the oppo MUTCD. Two-way traffic arrows shall be spaced every one hundred along this lane. The designer should pay special
attention to the endings of this type of lane and use sing lanes per fifty feet (150’) beginning and clearly defined tapers or islands to maintain traffic safety. may be requir ts and
to aid in See Standard Details TRAFFIC-49 and TRAFFIC-51 UTCD) as a le for providing and installing all traffic control signs, STOP and NO ired. rriers, warning n construction onstruction
is in progress on all streets, and access points in the construction area. rea traffic control activities will be permitted without an approved traffic control plan. Plans shall be submitted
to the City of Auburn for review a minimum of 10.15.1.7 C-Curb C-Curb ed in certain areas to control turning movemen channelization of roadways. 10.15.2 Signing City of Auburn uses “Manual
on Uniform Traffic Control Devices” (M guideline for signing, except as modified. The developer shall be responsib including but not limited to street name signs, regulatory signs (including
PARKING), warning signs, barricades, and bicycle/pedestrian signs as requ 10.15.3 Construction Area Traffic Control The contractor shall be responsible to provide and maintain all signs,
ba lights, striping, and flag control required for maintaining public safety i areas. Traffic control shall be maintained at all times when c No construction a three (3) days prior to
any construction activities in the public right-of-way. 10.16 Roadway Barricades See Standard Detail TRAFFIC-05 Temporary and permanent barricades shall conform to the standards Section
6C-8 of the Manual on Uniform Traffic Control Devices (MUTCD) Detail TRAFFIC-05. A. Type I or Type II barricades may be used when traffic is maintained th being constructed/reconstructed.
described in and Standard rough an area ffic. Type III here provision of equipment and authorized vehicles, the Type III when work is ry. Where job icades, the developer or contractor
shall assure proper closure at the end of each working day. C. In the general case, Type III barricades shall be installed to close arterials or other through streets hazardous to traffic.
They shall also be used to close off lanes where tapers are not sufficiently delineated. D. Type III barricades shall be used at the end of a local access street terminating abruptly
without cul-de-sac bulb or on temporarily stubbed off streets. Each such barricade shall be used together with an end-of-road marker. B. Type III barricades may be used when streets
are closed to tra barricades may extend completely across the street (as a fence). W must be made for access barricades may be provided with movable sections that can be closed not in
progress, or with indirect openings that will discourage public ent site access is provided through the Type III barr 12/4/2009…………........……….…..Design Standards…………..…..………..…….10-42
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12/4/2009…………........……….…..Design Standards…………..…..………..…….10-43 H:\DEVELOPMENT\Manuals\Current Manuals\2004 Design Standards\Chapter 10 (9-08).doc 10.17 Traffic Impact Analysis Traffic
Impact Analysis that are herein adopted by reference. These guidelines are used to identify capacity and safety engineering neer may require a onditions, traffic fety considerations,
community concerns, and other uirement for • The development generates more than 30 PM peak hour trips on a corridor. • street system as sportation n project. • The original Traffic
Impact Analysis for a future development is outdated due to changes in traffic volumes in the vicinity of the proposed project or approved pipeline projects or a change in the proposed
land use’s trip generation and/or distribution. • The development could potentially affect safety or requires an analysis to assist in designing appropriate access. The City of Auburn
has established guidelines for concerns, to assist in the evaluation of site design as it relates to to traffic issues, and to identify appropriate solutions and mitigation. To adequately
assess a development’s traffic impact, the City Engi Traffic Impact Analysis. The requirement for a Traffic Impact Analysis will be based on the size of the development proposed, existing
street and intersection c volumes, accident history, sa pertinent factors relating to traffic impacts attributable to the development. The following is a list of some specific conditions
that may dictate the req preparing a Traffic Impact Analysis. The development may potentially affect the implementation of the outlined in the Comprehensive Transportation Plan and Six
Year Tran Improvement Program (TIP), or of any other documented transportatio • The development proposes a rezone of the subject property.
Chapter 11 – Site Design 11.00 Preface The design of building sites within the City of Auburn shall conform to the City of Auburn Municipal Code unless modified herein. Compliance with
these standards does not alleviate the design engineer from using sound professional engineering practices. The design criteria contained herein are the minimum acceptable under standard
conditions. Special conditions may require more stringent requirements that will be addressed during the plan review process. The intent of this Chapter is to provide a cross-reference
listing and brief description of the other requirements that may apply to projects that are defined by other Codes and regulations. 11.01 Zoning Code Requirements Title 18 of the Auburn
City Code (Zoning) identifies the regulations that implement the city’s Comprehensive Plan, protect the health safety and welfare of the community, and defines the development standards
(setbacks, height, permitted uses, etc.) applicable to the Zoning District the project is located. The requirements of the Zoning Code are in addition to all of the requirements to this
manual. 11.01.1 Building Setbacks and Lot Orientation Requirements Each zoning district within the City defines the building setback to streets and interior property lines. While the
required setbacks vary for each Zoning District (please refer the “development standards” applicable to each zone, Auburn City Code 18.06 to 18.44) the lot orientation requirements remain
the same, in accordance with Auburn City Code 18.04.570. The front yard setback is measured from the property lines along the right-of-way. When the property has frontage on more than
one street and one of those streets is street classified by the city’s Comprehensive Transportation Plan as an “arterial,” the front yard setback is always measured from that edge of
right-of-way. If the parcel fronts more than one street and more than one of those streets, or none of those streets, are classified as an “arterial,” the front yard setback is determined
by the applicant. If the property does not have street frontage and is accessed by a private easement, coordination is required with the Planning Department for the application of building
setback requirements for the parcel. Please keep in mind that other requirements of the Zoning Code may require an additional building setback beyond the development standards of the
specific zone. 11.01.2 Landscaping Landscaping is a Code requirement applied to projects in the majority of zones within the city. The general intent of the city’s landscaping provisions
is to maintain and protect property values, provide visual unity, improve the character of areas, replace vegetation lost during development, and in some cases create visual screens
or buffers. Auburn City Code 18.50 defines both the requirements of landscaping in each zone (plant spacing, landscaping width, and plant size) and the characteristics of plant 8/9/2004
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spacing. Each of these requirements varies depending on the zone the project is located within, the zones adjacent to the parcel, and the type of uses being proposed on the parcel. For
example, in zones that permit outdoor storage areas, the landscaping Code requires screening of those storage areas. Please contact the Planning Department with questions related to
the landscape requirements of the project. 11.01.3 On-Site Parking Requirements Code-required parking is based on the land use of the property. Auburn City Code 18.52 defines the number
of stalls required for each land use and the size of stall required when using ninety degrees (90°) or some other adopted angled parking stall. 11.02 Land Use Approvals 11.02.1 Subdivisions
Auburn City Code Title 17 defines the regulations applicable to preparing and processing applications for subdivision. A preliminary plat application is filed when applicants seek to
create five (5) or more lots. This application requires
preliminary approval followed by construction of the improvements (installation of utilities, roads, etc.). A final plat application is also required which will demonstrate the construction
has been completed in accordance with the approved preliminary plat. The City Council must approve both applications. A short subdivision application is filed when applicants seek to
create four (4) lots or less. Before the City can approve the application, the applicant must complete or guarantee all the required subdivision improvements. The City relies on a one-step
process for short subdivision applications. Please review the applicable requirements from Title 17 before filing your applications. Please contact the Planning Department with any questions.
11.02.2 Planned Unit Developments The City has adopted Planned Unit Development (PUD) regulations to allow for a greater flexibility in design for some projects. To qualify, the property
must be at least 10-acres in size unless it contains environmentally sensitive areas or features of importance to the neighborhood or community that warrants preservation or is located
on sites adjacent or contiguous to an existing PUD such that the new proposal will function as an extension of that PUD. Auburn City Code 18.69 defines the requirements for PUD proposals.
Please note that a pre-application meeting is required before the City will accept a PUD application. Please contact the Planning Department with questions you have related to the PUD
Code or the pre-application meeting process. 11.02.3 Gated Communities Provisions for gated communities were adopted in 2002 to provide for additional flexibility in designing quality
residential projects. While Auburn City Code 18.48 does define the Zoning Code requirements for gated communities, it is important to remember that all applicable provisions of the Zoning
Code apply in addition to the requirements of this manual. Please contact the Planning Department with questions you may have related to gated communities. 8/9/2004 Design Standards
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8/9/2004 Design Standards Page 11-03 REF. H\DEVELOPMENT\Design Standards\Chapter 11 (8-04) 11.03 Other Site Design Criteria This Chapter will in the future also contain information on
the following: • Garbage dumpster locations and design. • ADA Accessibility. • Building related issues. • On-site traffic circulation. • Fences. • Other.
Chapter 12 – City Telecommunication Utility 12.00 Preface The design of City Telecommunications facilities located within City right-of-way shall be in conformance with these standards.
Compliance with these standards does not alleviate the design engineer from using sound professional engineering practices. The design criteria contained herein are the minimum acceptable
under standard conditions. Special conditions may require more stringent requirements that will be addressed during the plan review process. City telecommunications facilities shall
be included in the Facility Extension Agreement (FAC) between the developer and the City when the Agreement includes street improvements per ACC 12.64. 12.01 Design Criteria The City
has established the following minimum requirements to ensure the efficient construction of City telecommunication utilities with the least impact to City transportation and other utility
infrastructure. The design of City telecommunications facilities shall also meet the requirements of Section 9.01.2, Public and Private Utilities Located Underground Within City Right-of-Way
with the exception that a construction permit is not required if this work is completed as part of a Facility Extension Agreement. City telecommunications facilities may be required
in conjunction with street improvements on all roadways classified as Arterial or Collector. Such facilities, when required, shall be extended the full length of the street improvement.
When feasible, placement of the facilities shall accommodate connection with other existing or future telecommunication facilities within the corridor. 12.01.1 Conduits City telecommunication
conduits shall be 3-inch PVC Schedule 40 and shall have a minimum of 24 inches of cover and, except for street crossings, shall be located under the sidewalk per Standard Detail TRAFFIC-54.
If no sidewalk is included in the scope of the required street improvements, the conduit will be installed in the most feasible location within the street construction limits as directed
by the City. Roadway crossings shall be minimized and sweeps shall be long sweep 90 degree bends. Trace wire shall be placed within the conduit. Conduits shall be placed a minimum of
5 feet from other utilities. 12.01.2 Splice Vaults and Pull Boxes When required, splice vaults and pull boxes shall be per the standard details GENERAL-05 and GENERAL-06, respectively.
Splice vaults shall be placed every 1,500 feet. Pull boxes shall be placed every 500 feet and at all arterial and collector intersections. 10/8/2007 Design Standards Page 12-01 REF.
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DEFINITIONS AASHTO -American Association of State Highway and Transportation Officials. Access Point -A driveway or private street that connects to the general public street system.
A public street is not considered an access point. ACP -Asphalt Concrete Pavement. Activity Centers -Locations such as schools, parks, retail areas and shopping centers, places of employment,
or public service areas that attract people. ADT -Average Daily Traffic. The total two-directional volume of traffic passing through a given point during a given time period, divided
by the number of days in that time period. Aggregate -A mixture of various soil components (e.g. sand, gravel, and silt). Alley -Right-of-way, usually narrower than a street with an
all weather surface, which provides access to the rear boundary of two (2) or more residential or non-residential properties and is not intended for general traffic circulation. Applicant
-The owner or their agent seeking approval from the city for any land use or other related permit or approval referenced in City of Auburn Code and which requires utilization of these
Standards. References: See Developer. Appurtenance -Equipment and/or accessories that are a necessary part of an operating utility system or subsystem. APWA -American Public Works Association.
ASTM -American Society for Testing and Materials. Backfill -Replacement of excavated material with suitable material compacted as specified. Backwater -Water held back by some obstruction,
natural or artificial. Backwater Curve -A plot of depth versus location along the channel containing backwater. Bicycle Facilities -A general term referring to improvements that accommodate
or encourage bicycling, including parking facilities, bike racks, bicycle route mapping and bicycle route development. Boring/Jacking -Grade and alignment-controlled mechanical or other
method of installing a pipe or casing under a street without disturbing the surrounding medium. Breakaway Structure or Breakaway Design -A structure or installation that has been crash
tested in accordance with National Cooperative Highway Research Program procedures. (NCHRP 230). Capacity – (1) The maximum number of vehicles that have a reasonable expectation of passing
over a given roadway or section of roadway in one direction during a given time period under prevailing roadway and traffic conditions. (2) The volume of liquid or gas that can be transported
by a pipe. (3) The load-carrying limit of a structure. Carrier -Pipe directly enclosing a transmitted fluid or gas. Casing -A larger pipe enclosing a carrier for the purpose of providing
structural or other protection to the carrier and/or to allow for carrier replacement without re-excavation, jacking or boring. CF -Cubic Feet. 8/9/2004 Design Standards Page D-01 REF.
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Channelization -The separation or regulation of conflicting traffic movements into definite paths of travel by the use of pavement markings, raised islands or other suitable means to
facilitate the safe and orderly movement of both vehicles and pedestrians. Check -A short section of built-up channel placed in a canal or irrigation ditch and provided with gates or
flashboards to control flow or raise upstream level for diversion. Check Dam – Short berm used as erosion protection on steep drainage ditches. City -The City Engineer or any designee
thereof. References: See City Engineer. City Council -The city legislative authority. City Engineer -The City Engineer for the City of Auburn. References: See Engineer. Clean-Out -A
pipe through which plumbing snakes can be pushed to unplug a sewer. Clear Zone -The total streetside border area, starting at the edge of traveled way, available for safe use by errant
vehicles. This area may consist of a shoulder, a recoverable slope, a non-recoverable slope, and/or a clear run-out area. The desired width is dependent upon the traffic volumes, speeds,
and the streetside geometry. CMP -Corrugated Metal Pipe. Coating -Protective material applied to the exterior of a pipe or conduit to prevent or reduce abrasion and/or corrosion damage.
CY -Cubic Yard. Dedication -The transfer of land or the interest of land by the owner of such land to the City for public uses, reserving no other rights than such are compatible with
the full exercise and enjoyment of the uses the property has been dedicated. Conduit -An enclosed tubular runway for protecting wires or cables. Contractor -The individual, partnership,
firm, corporation or joint venture, contracting with the Developer to do prescribed work. Commercial Property Use -Property with residential developments with four or more dwelling units
per parcel or commercial developments. This is consistent with building permit administration in City of Auburn. Concrete Plain -Concrete that is not reinforced with steel. Concrete
Thrust Blocking – Concrete that is used to support fittings in water mains. Control Zone -That Streetside area defined by the "Control Zone Distance Table"; found in Appendix 5 of the
WSDOT Utilities Manual, within the street right-of-way in which placement of utility objects is controlled. Corporation Stop – A brass fitting used to connect service lines to a water
main. Cover -Depth to top of pipe, conduit, casing or gallery below the grade of a street or ditch. Cross Connection -Connecting fire, irrigation and drinking water supplies together,
or connecting storm and sanitary sewers together. Cul-de-sac -A street closed at one (1) end by widened pavement of sufficient width for vehicles to turn around. CSBC -Crushed Surfacing
Base Course. CSTC -Crushed Surfacing Top Course. 8/9/2004 Design Standards Page D-02 REF. H:\DEVELOPMENT\Design Standards\Definitions (8-04)
Dead End Street -Street that accesses the roadway system only at one end. Dead end streets are permanent conditions and should end in a cul-de-sac where appropriate. See Also Stub End
Street. Design Speed -Design speed is the maximum safe speed that can be maintained when conditions are so favorable that the design features of the highway govern. Detention Tanks and
Vaults -Detention tanks and vaults are underground facilities for the storage of surface water. Tanks are typically constructed from corrugated metal pipe. Vaults are constructed from
reinforced concrete. Detention Time -The average time spent by water in a basin or structure. Developer -The Owner and any agent of the Owner authorized to represent the Owner. References
see Applicant. Development -All structures and other modifications of the natural site above and below ground on a particular site. DHV -Design Hour Volume. Hourly traffic volume used
for street design and capacity analysis, usually one or more peak hours during a 24-hour period. Director -The Director of the City of Auburn Public Works Department or his/her authorized
representative. Drain -Appurtenances to discharge accumulated liquids from casings or other enclosures. Driveway Approach -See Access Point. Easement -A right to use or control the property
of another for designated purposes. Edge of Traveled Way -The face of curb for streets that are, or will be constructed to urban standards and the edge of pavement (not shoulder) for
streets that are, or will be constructed to rural standards. Embankment -A raised structure constructed of natural soil from an excavation or borrow source. Encroachment -Occupancy of
city right-of-way by non-roadway structures or other objects of any kind. Engineer -The City Engineer for City of Auburn or any designee thereof. Force Main -A sewer line that is pressurized.
Franchise -Occupancy and use document granted by the city required for occupancy of street rights of way. Geometrics -The arrangement of the visible elements of a street such as alignment,
grade, sight distance, widths, and slopes. Grade -Rate or percent of change in slope, either ascending or descending from or along the roadway. It is measured along the centerline of
the roadway or access point. Gravity Distribution -A water supply that uses natural flow from an elevated tank or mountain reservoir to supply pressure. Hazard -A side slope, an object,
water, or a drainage device that, if impacted, would apply unacceptable impact forces on the vehicle occupants or place the occupants in a hazardous position. It may be either natural
or man-made. Headwall -Entrance to a culvert or sluiceway. 8/9/2004 Design Standards Page D-03 REF. H:\DEVELOPMENT\Design Standards\Definitions (8-04)
Hydraulic Jump -The rapid change in the depth of flow from a low stage to a high stage resulting in an abrupt rise of water surface. Impervious Layer -A geologic layer through which
no water can pass. Infiltration – (1) The act of stormwater permeating into the ground. (2) Groundwater that enters sewer pipe through cracks and joints, or the movement of water through
the upper soil. Interception -Rain that falls on vegetation and other impervious objects, which evaporates without contributing to the runoff. Intersection Sight Distance -The distance
required for a vehicle, traveling at or near the posted speed on a major street, to reduce speed to avoid overtaking a vehicle, which has entered the intersection from the minor street.
The entering vehicle can be making right, leftturning movements or crossings. Island -A defined area between traffic lanes for control of vehicle movements and/or for pedestrian refuge.
Joint Use Driveway Tract -A jointly owned and maintained tract or easement serving two (2) properties. Landing -A road or driveway approach area to any public or private road. Lateral
-A sewer line that goes off at right angles to another. LF -Linear Feet. Manhole -An opening in an underground utility system into which workers or others may enter for the purpose of
making installations, inspections, repairs, connections, cleaning, and testing. Median -That portion of a divided roadway separating the traveled ways for traffic in opposite directions.
Mode Split -The percentage of overall trips made by different means of transportation. MPH -Miles per hour. MSE Walls -Mechanically Stabilized Earth Walls. MUTCD -The Manual on Uniform
Traffic Control Devices. MVO – Minimum valve opening. NDCBU -Neighborhood Delivery and Collection Box Unit. Outfall -The pipe that discharges completely treated wastewater into a lake,
stream or river. Passing Sight Distance -The minimum sight distance required for the driver of one vehicle to pass another vehicle safely and comfortably. Pavement -The combination of
gravel base, crushed rock, and asphalt concrete pavement placed on a subgrade to support the traffic load and distribute it to the subgrade. Pavement Width -The distance measured from
face of curb to face of curb for curbed sections of roadway or the distance measured from outside edge of shoulder to outside edge of shoulder for shouldered sections of roadway. PC
-Point of Curvature. PCC -Portland Cement Concrete. 8/9/2004 Design Standards Page D-04 REF. H:\DEVELOPMENT\Design Standards\Definitions (8-04)
Peak-Hour -That period experiencing the highest volume of traffic. Peak Period -Two hours during any a.m. or p.m. period when vehicle arrival and departure from the site or corridor
is the highest. Perimeter Streets – Public streets comprising the perimeter of a particular commercial/industrial development. Permit -A document including any license, permit or franchise
authorizing specified use of city right-of-way and granted under the authorization of the regulating agency. Pipe -A structural tubular product designed, tested, and produced for the
transmittance of specific liquids and gases under specific conditions. PI -Point of Intersection. Plowing -Direct burial of utility lines by means of a `plow' type mechanism, which breaks
the ground, places the utility line at a predetermined depth, and closes the break in the ground. Posted Speed -Is the signed speed limit along a street. Potable -Drinkable PRC -Point
of reverse curvature. Pressure -Internal gage pressure in a pipe in pounds per square inch, gage gage (psig). Private Street -A privately owned and maintained access provided for by
a tract, easement or other legal means. Professional Engineer -An engineer licensed to practice in the State of Washington. Professional Land Surveyor -A surveyor licensed to practice
in the State of Washington. Public Street – A publicly owned facility that provides access, including the roadway and all other improvements. PT -Point of Tangency Relocation -Planned
change of location of an existing facility to a more advantageous place without changing the character or general physical nature of the facility. Replacement -Installation of a like
element of a utility system or subsystem in the same or near-same physical location normally due to damage, wear or obsolescence of the element. Restoration -All work necessary to replace,
repair or otherwise restore the right-of-way and all features contained within to the same or equal condition as before any change or construction thereto. Retention Period -See “Detention
Time.” Reviewing Agency -City of Auburn. Restricted Access Point -A driveway or private street that connects to the general public street system, that turning movements are restricted
to right in and out only. Right-of-way (R/W) -All property in which the City has any form of ownership or title and which is held for public street purposes, regardless of whether or
not any street exists thereon or whether or not it is used, improved, or maintained for public travel. Riprap -Pieces of broken stone used to protect the sides of waterways from erosion.
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Rural -All lands regardless of current comprehensive plan designation not meeting the definition of Urban. Sand Trap -A section constructed deeper than the rest of the channel to allow
sediment to settle out. Separate Turn Lane -An auxiliary lane for traffic in one direction which has been physically separated from the intersection area by a traffic island or stripe.
Separate turn lanes may be included within intersections or separated from intersection areas by traffic islands. SF -Square Feet Shoulder -That portion of the roadway contiguous with
the traveled way for accommodating stopped vehicles, for emergency use, and for lateral support of base and surface courses. Single Main System -One main supplies both drinking water
and fire fighting water. Single Occupancy Vehicle (SOV) -Automobiles transporting the driver only. Slab -A cast concrete member of uniform thickness. Standards – The City of Auburn Design
Standards. Stopping Sight Distance -The distance needed for a vehicle traveling at or near design design speed to stop before reaching a stationary object in its path. Street or Roadway
-A public way, open for the passage of vehicles, persons and animals. Limits include the outside edge of sidewalks, or curbs and gutters, or side ditches, including the appertaining
shoulder and all slopes, ditches, channels, waterways, and other features necessary for proper drainage and protection within the right-of-way. Street Frontage -Any part of private or
public property that borders a public street. Street Tree -A tree placed within the public right-of-way. Stub End Street -A dead end street that is planned to be extended and connected
to future streets in an adjacent development. Depending on its length, it may or may not require a temporary cul-de-sac. Subtended – To be opposite to and delimit <In a triangle, the
hypotenuse subtends a right angle.> Surface Retention -That part of a storm that does not immediately appear as infiltration or surface runoff. Retention is made up of depression storage,
interception interception and evaporation. Time of Concentration -The time required for water to flow from the most distant point on a runoff area to the measurement or collection point.
Traffic Control -Those activities necessary to safeguard the general public, as well as all workers, during the construction and maintenance of roadway and other facilities within the
right-of-way. Traveled Way -That portion of the roadway intended for the movement of vehicles, exclusive of shoulders. Trenched -Installation of a utility in an open excavation. Trip
-A one-direction movement that begins at the origin and ends at the destination. For example, a trip movement from a residence to a work place is a trip from home to work. Trip Generation
-A general term describing the analysis and application of the relationships that exist between the trip makers, the traffic study area, and the trip making. It relates to the number
of trip ends in any part of the traffic study area. 8/9/2004 Design Standards Page D-06 REF. H:\DEVELOPMENT\Design Standards\Definitions (8-04)
8/9/2004 Design Standards Page D-07 REF. H:\DEVELOPMENT\Design Standards\Definitions (8-04) Uniform Flow -Flow that has a constant depth, volume, and shape along its course. Unopened
Right-of-way -A city right-of-way that exists by dedication or deed, but for which no vehicular roadway has been constructed by the city or other parties, and the street is not maintained
by the city. Unrestricted Access Point -A driveway or private street that connects to the general public street system, that has no limitations on turning movements. Left, right turns
in and out are permissible. Untrenched -Installation of a utility without breaking the ground or pavement surface such as by jacking or boring. Utility -A company providing such public
services as gas, electric power, telephone, water, sewer, or cable television, whether or not such company is privately owned or owned by a governmental entity. Vent -Appurtenance to
discharge gaseous contaminants from casings or other enclosures. Wetpond – A stormwater pond that has been designed to retain a permanent pool of water “wetpool” to provide treatment
of storm runoff. Wetpool – The permanent pool of water retained in a wetpond or wetvault. Wetvault – A stormwater vault that has been designed to retain a permanent pool of water “wetpool”
to provide treatment of storm runoff.