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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
DESIGN
STANDARDS
COMPRISED OF
GENERAL REQUIREMENTS
&
DESIGN REQUIREMENTS
AUGUST 2004
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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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11/06/08 Design Standards Page xvii
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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 Engineering 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
Permit Center Valley Regional Fire Authority
Physical address: North Fire Station
Auburn Professional Plaza (2nd Floor) 1101 "D" Street NE
One East Main Street Auburn, Washington 98002-4016
Mailing Address: Phone: (253) 288-5800
25 West Main Street Fax: (253) 288-5900
Auburn, Washington 98001-4998
Public Works:
Phone: (253) 931-3010
Fax: (253) 931-3053
Planning & Development:
Building Phone: (253) 931-3020
Planning Phone: (253) 931-3090
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:
1.02.1.1 City of Auburn Engineering Construction Standards Manual
The Engineering 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
developments. The manual is comprised of two sections. Section I contains the
City’s Standard Special Provisions and Section II contains the City’s Standard Details.
The Standard Special Provisions are a supplement to, and a modification of, the
02/16/2010 Design Standards Page 1-01
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“Washington State Department of Transportation (WSDOT/APWA) Standard
Specifications for Road, Bridge and Municipal Construction,”. The Standard Details
are comprised of the City’s construction and design detail drawings for temporary
erosion control, grading, water, sanitary sewer, storm drainage, and street work within
the City that are supplemented by the “Washington State Department of
Transportation’s (WSDOT) Standard Plans.”
1.02.1.2 Engineering Handouts
The following Handouts are currently available from the City to aid the public in
planning and constructing development projects within the City of Auburn. Contact
the Permit Center 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. Public Facility Extension (FAC) Submittal Packet
B. Grading Permit (GRA) Submittal Packet
C. 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 Minimum T.E.S.C. Requirements for Small Sites.
B. Handout for Single Family Residential Roof Downspout and Footing Drain
Construction.
C. 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 Half-Street Requirements.
C. Summary of Guarantee/Bonding Requirements.
1.02.1.2.5 Technical Memos
These handouts contain information that are subject to change or are too specific
to be included in this manual:
A. Sanitary Sewer Pump Station Requirements and Standards.
02/16/2010 Design Standards Page 1-02
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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 Manual”
(latest edition).
C. American Association of State Highway and Transportation Officials’ (AASHTO)
“A Policy on Geometric Design of Highways and Streets” (latest edition).
D. State of Washington Department of Ecology’s “Criteria for Sewage Works
Design” (latest edition).
E. State of Washington Department of Health (DOH) “Water Systems Design
Manual” (latest edition).
F. American Water Works Association (AWWA) Standard Specifications (latest
edition).
G. “IES Lighting Handbook” (Illuminating Engineering Society of North America)
(latest edition).
H. American National Standard for Roadway Lighting ANSI/IESNA RP-8-00 (latest
edition).
1.03 Deviation from Standards
The engineering 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. The following deviations may be
obtained from the City of Auburn:
1.03.1 General Deviations
General deviations apply to all engineering design standards except for the Surface
Water Management Manual’s Minimum Requirement deviations.
The engineering design deviation when compelling supporting justification shall clearly
demonstrate that the proposed deviation will meet or exceed the corresponding City
standard for the following applicable criteria:
A. The functional intent of the design element.
B. Safety factors associated with the design element.
C. Operational concerns associated with the design element.
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D. Maintenance concerns associated with the design element.
E. Liability concerns associated with the design element.
F. The capacity and/or efficiency of the design element.
G. The design life, historical performance, and durability of the design element.
H. The aesthetic and visual impacts of the design element.
I. The cost effectiveness and availability of any replacement components or
materials.
J. Consistency with the spirit and purpose of the corresponding City design
standard.
K. Demonstration that the environment will not be adversely affected.
L. Supported by published industry standards.
1.03.2 Surface Water Management Manual Deviations
1.03.2.1 The Ten Minimum Requirements
A deviation request from any of the ten minimum requirements in the Surface Water
Management Manual (SWMM) goes through a different process which includes a
public notice requirement. This is to insure that the Department of Ecology mandated
surface water regulations are complied with. The ten Minimum Requirements of the
City of Auburn Surface Water Management Manual are as follows:
1. Stormwater Site Plan
2. Construction Stormwater Pollution Prevention Plan
3. Source Control of Pollution
4. Preservation of Natural Drainage Systems
5. On-site Stormwater Management
6. Runoff Treatment
7. Flow Control
8. Wetlands Protection
9. Operation and Maintenance
10. Off-site Analysis and Mitigation
1.03.2.2 Deviation Criteria
Deviations from the ten Minimum Requirements of the City of Auburn Surface Water
Management Manual may be requested, in writing, in accordance with ACC
13.48.226 to allow a waiver of a requirement, a reduction or modification of a
requirement, or to permit an alternative requirement. Public notice of application for a
deviation, decision, and written findings will be published in accordance with ACC
13.48.226. Deviations must meet the following criteria:
• The minimum requirements would impose a severe and unexpected economic
hardship; and
• The deviation will not increase risk to the public health and welfare, nor
injurious to other properties in the vicinity and/or downstream, and to the
quality of waters of the state; and
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• The deviation is the least possible exception that could be granted to comply
with the intent of the Minimum Requirements.
In accordance with ACC 13.48.226, the City Engineer may grant a deviation following
a documented finding that:
A. The deviation is likely to be equally protective of public health, safety and
welfare, the environment, and public and private property, as the
requirement from which an exception is sought; or
B. Substantial reasons exist under ACC 13.48.226 C., for approving the
requested deviation and the deviation will not cause significant harm. The
substantial reasons may include, but are not limited to:
o The requirement to be imposed is not technically feasible; or
o An emergency situation necessitates approval of the deviation; or
o No reasonable use of the property is possible unless the
deviation is approved; or
o The requirement would cause significant harm or a significant
threat of harm to public health, safety and welfare, the
environment, or to public and private property, or would cause
extreme financial hardship which substantially outweighs its
benefits.
The decision to grant a deviation is within the sole discretion of the City, and the City
Engineer shall only approve a deviation to the extent it is necessary. The City
Engineer may impose new or additional requirements to offset or mitigate harm that
may be caused by approving the deviation. The City Engineer may require the
applicant to submit a licensed engineer’s report or analysis along with a request, in
writing, for a deviation. Deviations are intended to maintain necessary flexible working
relationship between the City and applicants.
The approval of a deviation shall not be construed to be an approval of any violation
of any of the other provisions of the City’s Municipal Code, or of any other valid law of
any governmental entity having jurisdiction.
Applications for a deviation from the Minimum Requirements of ACC13.48.225 must
be in writing and include the following information:
A. The current (pre-project) use of the site, and
B. How the application of the minimum requirement(s) restricts the proposed use
of the site compared to the restrictions that existed prior to the adoption of the
minimum requirements; and
C. The possible remaining uses of the site if the deviation were not granted; and
D. The uses of the site that would have been allowed prior to the adoption of the
minimum requirements; and
E. A comparison of the estimated amount and percentage of value loss as a
result of the minimum requirements versus the estimated amount and
percentage of value loss as a result of requirements that existed prior to
adoption of the minimum requirements; and
F. The feasibility for the owner to alter the project to apply the minimum
requirements.
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1.03.2.3 Public Notice Requirements
The public notice will be issued after the decision and any appeal of the decision per
Section 1.04 has been completed. The following public notice requirements apply
whenever a request for an exception to the Minimum Requirements contained in ACC
13.48.225 is received by the City:
A. Public notice (Notice) shall be made to inform the public about the contents of
the Request and the City Engineer’s decision to grant or deny it. Notice of the
Request and the decision to grant or deny the Request may be combined.
B. The Notice shall be published, at the requestor’s cost, in the City’s newspaper
of record and a local newspaper of general circulation within Auburn.
C. The Notice shall include: (i) a brief description of the Request; (ii) a brief
description of the City Engineer’s decision to grant the Request and reasons
supporting the decision, or a statement that the request is denied; (iii) where
the Request can be reviewed; and (iv) the name and contact information of a
City employee who can answer questions regarding the Request.
D. The City shall provide a hardcopy of the City Engineer’s decision to grant or
deny a Request to the requester. The City Engineer’s decision to approve or
deny a Request shall include a reference to the procedures in City of Auburn
Engineering Design Standards for contesting such a decision.
1.04 Appeal of City Engineer’s Decision
Appeal of the City Engineer’s decision (Section 1.03) shall follow the following procedure:
The applicant shall have fifteen (15) working days from the date of receipt of the City
Engineer’s decision in which to submit a written notice to the Public Works Director
contesting the written decision of the City Engineer. The Public Works Director shall then
have fifteen (15) working days to notify the applicant of his/her decision to uphold or modify
the City Engineer’s decision. For engineering deviations requests, the Director’s
determination shall be final.
If the Public Works Director determines the nature of the deviation requires a non-
engineering policy decision by the Public Works Committee of the Auburn City Council, the
Public Works Director shall seek such decision from the Committee at the next available
Committee meeting. The Public Works Director shall notify the applicant within five (5)
working days after the Committee’s decision.
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 five hundred cubic yards (500 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 five hundred cubic yards (500 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 the new
plus replaced impervious surface is five thousand square feet (5000 ft2) or more.
C. Alteration of site access requirements, and/or connect to and impact City streets
and utilities.
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D. Convert ¾ acres or more of native vegetation to lawn/landscaped area or convert
2.5 acres or more of native vegetation to pasture..
E. 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 City transportation facility.
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.
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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 the City of Auburn) 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, for the appropriate type of plans. This
packet contains information 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 City
for processing.
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
Site Plans
Geo-
technical
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 shall be dedicated to the City prior to final plan
approval. A title report will be required to confirm property ownership.
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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 Subdivisions, Subdivisions,
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
wet signed and dated.
J. Where the plan review process is running concurrent with other applications
(SEPA, Subdivisions, 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 sealed 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.”
C. If after plan approval but prior to construction the applicant chooses to make
changes to the approved plans, a revised plan reflecting such changes may be
required if the City determines the changes will impact the City’s ability to insure
construction is completed in conformance with City regulations. In such cases,
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the revised plans shall be submitted to the City for review and a new revised
Mylar shall be provided for approval with the changes shown, sealed by the
design engineer, and approved by the City.
2.02.4 Project Close Out
The following is the basic process required for accepting construction completion on a
project:
A. After completion of construction, a paper plan copy of the approved plan set shall
be utilized for a dry run “as-built” set prior to redlining the original Mylar set. A
copy of the “Record Construction Document Packet” which outlines the complete
record drawing process in detail can be obtained from the City.
B. All changes to the approved plan noted by the contractor and/or surveyor during
the construction process shall be clearly indicated on the paper copy of the
approved plan in red ink.
C. The “Record Drawing Certification” block on all sheets of the as-built paper set
shall be signed and dated by the Engineer or Surveyor making the corrections
and the plan set returned to the City for verification by the City prior to these
changes being made to the original Mylar set..
D. After approval of the redlined paper plan copy of the original approved plan set,
the approved original Mylars shall be checked out from the City, and the approved
corrections shown on the approved “as-built” paper plan set shall be made on the
original Mylars in red ink. . These record drawings will become final once the City
has verified the corrections are consistent with the approved paper set. Finalized
record drawings are required before the project will be accepted.
E. A final stormwater site plan with letter shall be submitted by the Engineer of
Record to the City verifying that the storm facilities were installed as designed.
F. Electronic copy of the Stormwater Site Plan and Geotechnical Report.
The following documents shall also be completed for 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 needed and executed.
B. A “Developers Contribution Document” shall be obtained from the City and
completed, if applicable.
C. All Maintenance Bonds or Assignments of Funds for the one-year maintenance
period shall be in place.
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 City of Auburn’s current Engineering Construction Standards Manual
which supplements or modifies the “Washington State Department of Transportation
(WSDOT) Standard Specifications for Road, Bridge and Municipal Construction,"
except where supplemented or modified by the City in this 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 Engineering 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 requires 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).
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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. Public Storm Drainage 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 engineer licensed in
the State of Washington. The stamp/seal on the final mylars, to be submitted for
approval, shall be wet signed and dated per WAC 196-23.
B. North arrow and plan alignment shall be to the top, right, or left.
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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") on each plan sheet shall be provided 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. A blank Auburn Engineering approval block is shown as
block B-1 in Appendix A of this chapter.
H. A sign-off block (4”x2”) on each plan sheet shall be provided for Record Drawing
certification, located directly to the left or directly above the approval block. A blank
Record Drawing Certification block is shown as block B-4 in Appendix A of this
chapter.
The locations of the title blocks, approval blocks, and engineering stamp shall remain
consistent throughout all the plan sheets.
3.03.2 Drafting Standards
Drafting requirements are as follows:
A. Plan sheets shall be printed on 24"x36" size paper. Any variation must be
approved by the City prior to plan submittal. 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, unless cold rolled. Margins
shall be set to provide for ½ size drawings to fit on 11x 17 inches sheet size.
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.
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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/Applicant, 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.
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.
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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. Construction Sequence outlining a basic construction schedule. (See Section
5.05) In addition, depending upon the nature of the project, the construction of
some public facilities may also dictate separate construction sequencing
requirements that will also need to be indicated on the plans.
S. The eight (8) City of Auburn General Notes as shown in Appendix B of this
chapter.
T. Provide a list of the additional non-building permits required for this project.
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. Marked clearing work limits, environmentally sensitive areas and their buffers, and
trees that are to remain.
B. Indicate the location of the construction entrance
C. Provide the onsite stormwater facilities during construction.
D. Indicate the minimum temporary erosion control measures to be used on the site
during construction, this may include, silt fencing, interceptor ditches, detention or
retention facilities, flow control structures, etc.
E. Show containment locations for storing pollutants, including waste materials and
demolition debris, prior to their removal from site.
F. In the construction sequence, provide a phasing schedule for installing and
removing TESC BMPs, including the transition from the temporary storm drainage
system to the permanent storm drainage system.
G. All existing site features and conditions shall be shown on this sheet including the
existing topography.
H. 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.
I. Provide the six (6) City of Auburn Grading and Erosion Control Notes as shown in
Appendix B of this chapter.
3.04.3 Grading and Private Storm Drainage 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 excavation quantities in cubic yards.
B. Indicate slope of any fill or cut slopes.
C. Show type of fill material and associated compaction requirements.
D. Show existing significant 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.
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E. Provide temporary storm drainage retention or detention facilities including City
control structure, water surface (W.S.) elevations, seasonal high groundwater
elevation, orifice sizes, design storms for the W.S. elevations, and release rates.
F. Show horizontal setback between the bottom of any fill placement and the top of
the bank of a defined drainage channel per requirements noted in section 5.03.3.
G. Show typical ditch sections.
H. Show connections of building roof and foundation drains to the site drainage
system.
I. Show the existing topography shaded back and overlaid by the proposed grades.
J. 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).
K. Reference standard City of Auburn Detail Numbers appropriately. If a project
specifies modification to a Standard Detail a new detail must be shown on the
plans.
L. Provide notes to protect and maintain erosion control facilities during grading
operations.
M. Provide arrows to indicate drainage flow direction on paved surfaces.
N. Show layout of the entire storm drainage pipe with length, slope, and material type
labeled and direction of flow indicated.
O. Provide site specific details and cross-section sheets for storm drainage detention
or retention facilities.
P. Indicate the emergency overflow to the public storm system.
Q. Show berm dimensions, materials, compaction requirements for ditches and
detention ponds where applicable.
R. Show locations of manholes and catch basins, indicating type, stationing, offset,
lid type, rim and invert elevations. Number manholes and catch basins
consecutively.
S. Show existing and proposed sanitary sewers and water mains (use ghost lines),
identifying crossing and minimum vertical distance between utilities.
T. Provide type of material and size of energy dissipaters (riprap, etc.).
U. Provide details of storm water quality control facility.
V. Provide limits of surface water ponding in parking lots.
W. Show trash racks, if applicable.
X. Show locations, widths and types of easements.
Y. Show locations and types of pumps, if applicable.
Z. Show bio-swale location, length, width, slopes, and cross-section.
AA. Provide planting and seeding requirements with establishment procedure in
construction sequence for water quantity and quality systems.
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BB. Show finish floor elevations.
CC. Show the controlling downstream storm drainage elevations including the
associated design conditions.
DD. Address other agency permit requirements, as necessary.
EE. For ponds, provide: aesthetics, fencing, power (if applicable), maintenance
access, control structure, critical water surface elevations, and other items, such
as walls and liners.
FF. Address bypass surface flows.
GG. Address subsurface flows and indicate water surface elevations.
HH. Clearly indicate private drainage facilities on the plans. Justification is needed for
any facility proposed to be a joint public and private facility, for City consideration.
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.
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 Public 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.
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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/BMP and/or cross-section sheets for storm drainage
detention or retention facilities such as the control discharge structure and pond
cross-sections. 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.
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.
T. Indicate separation from any pipe, infiltration trench, open ditch, and bioswale to
any property line or obstruction.
U. Address other agency permit requirements, as necessary.
V. For ponds, provide: landscaping, fencing, aeration, maintenance access, critical
water surface elevations, and other items, such as walls and liners.
W. Number the storm drain structures. (Numbers will be provided by the City prior to
final plan approval.)
X. Indicate any required easements including their dimensions.
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:
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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 and fitting 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 stations and associated valves, vaults and by-pass
piping as required.
G. Concrete blocking, mechanical, or restrained joint pipe support.
H. Watermain, water meter, and fire hydrant easements.
I. Meter size and service line size and location.
J. Irrigation meter size and service line size location.
K. Proposed fire line, FDC line and PIV locations.
L. Backflow prevention assembly and detector check meter size, type and
location.
M. For buildings requiring fire sprinklers, the fire sprinkler notes shall be shown
on the plan, as shown in Appendix B of this chapter.
N. Table showing physical separation in feet between water lines and other
utilities at crossings, when a profile is not required.
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, 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. Indicate knockouts in manholes for future connections.
D. 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.
E. Drop manholes, if approved, are to be detailed on the plans.
F. Length, slope, type and class of material, and inverts for side sewers.
G. Stationing for side sewers from downstream manholes.
H. Connection of a side sewer to the City’s sanitary sewer pipe shall be
indicated with a tee.
I. Locations of sanitary sewer cleanouts.
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J. Locations of sanitary sewer easements.
K. Clearly define right-of-way and adjacent property lines. Parcel numbers for
all lots adjacent to the improvements shall be indicated.
L. 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.
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 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
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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.
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 luminaires, 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.
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B. Existing and proposed centerline 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.
A. Signal Plan Sheet
1. The plan sheet shall conform to the following requirements:
a. For areas that require greater detail (such as the corner that has the controller), a
blown-up detail may be necessary at a 1″=10′ scale.
b. All proposed signal equipment, including signal poles, mast arms, heads, signs,
junction boxes, conduit, loops, controller, and service cabinet shall be shown as
bold.
c. All existing and proposed right-of-way information shall be shown and labeled on
the plan, including easements needed for signal equipment. The line type shall
be different for easements and right-of-way.
d. All proposed curb, sidewalk, proposed striping, and existing curb/striping (to
remain) information shall be shown on the plan in gray scale (screened back).
e. Sight triangle lines shall be shown on plans in gray scale.
f. All proposed and existing underground and overhead utilities shall be shown and
labeled on the plan in gray scale.
g. Provide on the plan signal construction notes as shown in Appendix B of this
chapter.
2. Construction notes shall contain, but not be limited to:
a. Signal pole and foundation installation (including pole type, mast arm length, and
installation of items on the pole).
b. Controller cabinet and foundation installation.
d. Coordination of utility removal/relocation.
e. Coordination of connection of power, and power source type.
f. Interconnect connection to other signals.
g. Removal of existing signal and/or street light equipment.
3. Displays: The plan sheet shall include the following displays:
a. Phase diagram display.
b. Signal display showing signal layout of all vehicle signal heads and pedestrian
heads.
4. Detection: The plan sheet shall include:
a. Stop bar, intermediate and advanced loop location and numbering.
b. Pedestrian push button location.
c. Preemption detection location and numbering.
5. Signal Poles and Associated Equipment: The plan sheet shall contain, but not be
limited to:
a. Signal Pole Locations and Numbering: The locations shall be called out by the
major arterial station and offset.
b. Signal head location and numbering.
c. Pedestrian head location and numbering.
6. Controller and Service Location:
At least one corner of the controller/service foundation shall be called out by the
major arterial station and offset. The footprint of the foundation shall be shown on the
plans with the controller and service cabinets oriented on the foundation as they
would be placed in the field. If the information required to show all the
controller/service conduit connections and foundation footprint makes the plan too
cluttered, a blown-up detail of the corner containing this information is needed at a
1″=10′ scale.
7. Power Source Location:
The location of the power source shall be identified on the plans.
8. Wire Schedule:
a. A wire schedule table shall include run numbers, conduit size, wire type, and
comments.
b. Comments shall include, but not be limited to, number of twisted loop pairs for
runs between the detection loops and adjacent junction box, identification of
spare conduits, conduits utilized only by interconnect or illumination, and power
cables.
c. For designs that include modifications to an existing signal, all existing wire
runs affected by the design shall be shown on the wire schedule.
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9. Junction box type and approximate location.
10. Signing:
a. Signs shall be shown on all mast arms. Signs that are post mounted but are
signal related (such as a “signal ahead” sign) shall be shown on the signal
plan.
b. A sign display shall be shown on the plan with the MUTCD sign designation,
dimensions, and lettering type for all signs.
c. Indicate removal of existing stop signs after signal is in operation.
d. Installation of “New Signal Ahead” or “Signal Revision Ahead” signs.
11. Other Illumination:
a. Proposed illumination that will use the signal service cabinet, but is located
outside the four quadrants of the intersection, shall be shown as proposed on a
separate illumination plan sheet. On the signal plan sheet, the illumination shall
be shown as gray scale and labeled as “proposed illumination, see illumination
plans.” However, once the illumination enters the quadrants of the intersection
(i.e., when it is using the same junction box as the signal equipment), it shall be
shown as proposed on the signal plan and gray scale on the illumination plan.
b. Indicate the circuit that street lights are on .
B. Wire Diagram Plan
In general, the wire diagram shall include the following:
1. All signal heads, pedestrian heads, pedestrian push buttons, luminaires,
preemption detectors, loops, and junction boxes drawn in schematic forms.
2. All termination points in the controller cabinet. The wire diagram should include
every termination point the controller will have, including those that may not be
used for this particular signal design.
3. All wiring associated with the items above, as well as the wiring for interconnect.
The wire diagram should show how these items are connected to the controller.
4. Location of wire splices.
5. All termination numbering at each end of each wire. For example, the 5-conductor
cable connecting a signal head to the controller should have the termination
numbering called out at the signal head and in the termination points in the
controller.
6. All wire colors at each end of the wire.
7. A call out to each wire run noting the number and type of each wire.
8. Intersection schematic with a north arrow showing approach phase.
9. Pole, signal head, pedestrian head, preemption detection, and loops shall be
numbered on the wire diagram.
C. Pole Schedule Plan
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The pole schedule shall include the following:
1. The pole schedule shall include a signal standard detail chart.
2. The pole schedule shall include pole orientation attachment and base detail, pole
foundation detail, and signal standard detail.
3.04.9.7 Illumination
Street Light Plans shall be labeled as Street Light Plans, and shall be prepared, stamped,
signed and dated by a professional engineer licensed by the State of Washington.
Street Light Plans will include references to all applicable City of Auburn Standard Details
and/or Washington State Department of Transportation (WSDOT) Standard Plans, or copies
of other specific details applicable to the project shall be shown on the plans.
Street Light Plans shall be provided on separate and uncluttered sheets that do not show
unrelated street, utilities, or on-site improvements. Street Light Plans shall be drawn to an
engineer's scale of 1" = 40'.
Street Light Plans shall at a minimum include the following applicable items for new or
existing street lighting system:
A. Lighting schedule with the following information in a table format:
1. Luminaire make and model
2. Lamp/Ballast type
3. Lamp wattage
4. Uniformity Ratio
5. Veiling Luminance Ratio
6. Average Maintained Light Level
7. Light standard type
8. Mounting height (ft)
9. Bracket or davit arm length (ft)
10. Light distribution pattern
11. Luminaire spacing distance (ft)
12. Light standard locations by station and offset from the centerline of the street to the
center of the light standard. Show all existing street lights for a distance of 500 feet
in both directions from the limits of the project site, including both sides of the
street(s) and in medians.
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B. Wiring/Conduit schedule with the following information in a table format:
1. Circuit number
2. Conduit size, material, and purpose (street lighting, traffic signal interconnect,
spares, etc.).
C. Location of points of service (the PSE connection or service location and the new or
existing City Electrical Service Cabinet(s).
D. Location of junction boxes. Indicate junction box type and purpose (lighting, traffic
signal, etc.).
E. Existing topography, including but not limited to the location of driveways, street trees
(including species), street intersections, overhead utilities (including maximum and
minimum heights), underground utilities (including sizes), medians, curb, and lane
widths (pavement markings).
3.04.9.8 Streetscape
Provide information on planting of the public landscape strips along the street frontage.
Information should include the following:
A. Type and size of trees.
B. Tree spacing.
C. Type of ground cover.
D. Root control/barrier.
E. Irrigation if applicable.
F. Show all proposed and existing surface features and underground utilities.
3.04.9.9 Other Features
Include locations of any other feature including mailboxes and bus stops. Any mailbox
placement that requires approval from the postmaster shall include the Postmaster approval
block B-6 as shown in Appendix A of this chapter.
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. Show all proposed and existing surface features and underground utilities.
J. The Planning approval block B-2 as shown in Appendix A of this chapter.
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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.
E. Show the existing and/or proposed location of all parcel lines.
3.04.12 Critical Area Restoration/Mitigation
A critical area restoration or mitigation sheet, when required, shall include the items as required by
the City pursuant to chapter 16.10 of the Auburn City Code, and have the Critical Area approval
block B-3 as shown in Appendix A of this chapter.
3.04.13 City Parks and Open Spaces
Any plan sheet that includes a park or open space that is to be dedicated to the City shall include
the Auburn Parks approval block B-5 as shown in Appendix A of this chapter.
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Appendix A – Approval Blocks
Sample Engineering Approval Block (B-1):
PROJECT REF: __________________________
THESE PLANS ARE APPROVED FOR
CONFORMANCE WITH THE CITY OF AUBURN’S
ENGINEERING REQUIREMENTS.
APPROVED BY: _________________________
DATE APPROVED: _______________________
Sample Planning Approval Block (B-2):
PROJECT REF: _________________________
THESE PLANS ARE APPROVED FOR
CONFORMANCE WITH THE CITY OF AUBURN’S
PLANNING DEPARTMENT REQUIREMENTS.
APPROVED BY: _________________________
DATE APPROVED: ______________________
Sample Critical Area Approval Block (B-3):
PROJECT REF: _________________________
THESE PLANS ARE APPROVED FOR
CONFORMANCE WITH THE CITY OF AUBURN’S
CRITICAL AREA REQUIREMENTS.
APPROVED BY: _________________________
DATE APPROVED: ______________________
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Appendix A (continued)
Sample Record Drawing Certification Block (B-4):
RECORD DRAWING CERTIFICATION
THESE DRAWINGS CONFORM TO THE
CONTRACTOR’S CONSTRUCTION RECORDS.
BY _______________________ DATE ___________
TITLE/POSITION _____________________________
CONFIRMED BY CITY ____________ DATE _______
Sample Parks Department Approval Block (B-5):
PROJECT REF: _________________________
THIS PLAN SHEET REFLECTS THE CITY OF
AUBURN PARKS DEPARTMENT MINIMUM
REQUIREMENTS
APPROVED BY: _________________________
PARKS DIRECTOR
DATE APPROVED: ______________________
Sample Postmaster Approval Block (B-6):
CITY OF AUBURN POSTMASTER APPROVAL
APPROVED BY: ________________________
TITLE/POSITION: _______________________
DATE APPROVED: ______________________
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Appendix B – Standard Notes
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 (2008),” 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 CONSTRUCITON.
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 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 CABLE).
5. IF A PROPOSED ROUTE IS NOT INCLUDED ON THESE PLANS, A PROPOSED ROUTE AND
SCHEDULE FOR HAULING MATERIAL TO THE SITE SHALL BE SUBMITTED TO THE CITY
FOR APPROVAL PRIOR TO THE START OF CONSTRUCTION. IF THE CITY BELIEVES
THAT THE PROPOSED HAUL ROUTE WILL ADVERSELY IMPACT THE STREET NETWORK,
A SEPA AMENDMENT MAY BE REQUIRED TO EVALUATE THE IMPACTS AND DETERMINE
MITIGATION REQUIREMENTS BEFORE BEGINNING WORK. HAULING MAY BE LIMITED TO
APPROPRIATE OFF-PEAK HOURS OR ALTERNATIVE ROUTES, AS DETERMINED BY THE
CITY.
6. THE CONTRACTOR SHALL BE RESPONSIBLE FOR PUBLIC SAFETY ON AND AROUND
THE 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 AND PROPERTY SUFFERED BECAUSE OF
CONTRACTORS OPERATIONS OR NEGLIGENCE CONNECTED WITH THEM.
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.
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Appendix B (continued)
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
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 PERMITEE.
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 MAY 1ST TO SEPTEMBER 30TH, AREAS AT FINAL GRADE AND THOSE
THAT ARE SCHEDULED TO REMAIN UNWORKED FOR MORE THAN SEVEN (7)
DAYS SHALL BE STABILIZED.
FROM OCTOBER 1ST TO APRIL 30TH 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 TWO (2) DAYS SHALL BE STABILIZED
IMMEDIATELY.
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Appendix B (continued)
FIRE SPRINKLER SYSTEMS NOTES
SPRINKLER SYSTEMS SHALL MEET CITY OF AUBURN STANDARD 7.01.5.2 AND THE
FOLLOWING REQUIREMENTS:
1. PROPOSED 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 SUPPLY
LINE SHALL BE APPROVED BY THE FIRE MARSHALL AND INSTALLED BY A
WASHINGTON STATE CERTIFIED LEVEL “U” CONTRACTOR IN ACCORDANCE WITH
WAC 212-80-010.
4. A POST INDICATOR VALVE SHALL BE INSTALLED ON THE FIRE SPRINKLER SUPPLY
LINE TO ISOLATE THE SYSTEM FROM THE CITY’S WATER SYSTEM WHEN
REQUIRED FOR REPAIR.
5. BLOCKING, PIPING, AND RODDING DETAILS SHALL BE PROVIDED WITHIN THE
SUBMITTAL.
6. APPROVAL OF THE CIVIL PLANS DOES NOT APPROVE THE INSTALLATION OF THE
SPRINKLER SYSTEM SUPPLY PIPING.
CROSS CONNECTION CONTROL NOTES
CROSS CONNECTION CONTROL SHALL MEET THE FOLLOWING REQUIREMENTS:
1. ALL BACKFLOW PREVENTION ASSEMBLIES SHALL BE INSTALLED IN A MANNER
THAT WILL ALLOW PROPER OPERATION, AND IN-LINE TESTING AND
MAINTENANCE..
2. A BACKFLOW ASSEMBLY PLUMBING PERMIT IS REQUIRED FOR ALL ASSEMBLIES
INSTALLED WITHIN THE CITY OF AUBURN, AND/OR THE CITY’S WATER
DISTRIBUTION SYSTEM.
3. BACKFLOW ASSEMBLIES MUST BE ON THE CURRENT WASHINGTON STATE
DEPARTMENT OF HEALTH – BACKFLOW ASSEMBLIES APPROVED FOR
INSTALLATION LIST.
4. BACKFLOW ASSEMBLIES MUST BE TESTED BY A STATE CERTIFIED BACKFLOW
ASSEMBLY TESTER, AND INSPECTED AND APPROVED BY A CITY OF AUBURN
CROSS CONNECTION CONTROL SPECIALIST.
5. PRIOR TO INSTALLATION, SUBMIT TO THE DEVELOPMENT REVIEW ENGINEER
FOUR (4) SETS OF BACKFLOW PREVENTION ASSEMBLY PLANS, INCLUDING THE
CONNECTION POINT TO THE CITY MAIN FOR REVIEW AND APPROVAL.
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Appendix B (continued)
SIGNAL CONSTRUCTION NOTES
1. THE LOCATION OF ALL CONDUIT, JUNCTION BOXES, AND CABINETS SHOWN ON
THIS PLAN ARE FOR GRAPHIC PRESENTATION ONLY AND FINAL LOCATION SHALL
BE DETERMINED BY THE ENGINEER.
2. ALL TRAFFIC SIGNAL AND PEDESTRIAN HEADS AND PUSH BUTTONS SHALL BE
SECURELY AND COMPLETELY COVERED WHILE SIGNAL IS NOT IN OPERATION.
3. ALL CONDUCTORS FOR SIGNAL HEADS, LOOPS, PEDESTRIAN HEADS, PUSH
BUTTONS AND STREETLIGHTS SHALL BE LABELED IN EACH JUNCTION BOX.
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 engineering reports shall be bound with the civil engineer’s 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, there may be other
reports required that are specific to a particular project.
A. Geo-Technical Reports See Section 4.03.1
B. Stormwater Site Plans See SWMM Volume 1 Ch. 4
C. Critical Area Report See Section 4.03.3
D. Traffic Impact Analysis See Section 4.02.4
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.
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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 Stormwater Site Plans
Stormwater Site Plans shall contain the information as noted in the City of Auburn
Surface Water Management Manual (SWMM) Volume I Chapter 4. The City of Auburn
SWMM has replaced the standards formerly listed here.
4.03.3 Critical Area Report
A. Title Page including project name, contact information, description of the
proposal, and identification of all local, state, and other wetland related permits
required for the permit.
B. State accuracy of the report.
C. Documentation of field work.
D. Description of methodologies used in study.
E. Identify and characterize of all critical areas, wetlands, water bodies, buffers, etc.
on or adjacent (within 300 feet of the project boundaries) to the proposed project
area.
F. Provide wetland rating, required buffers based on a professional survey.
G. A description of proposed actions including estimate acreages of impacts to
wetland and buffers.
H. An assessment of probable cumulative impacts to the wetlands and buffers.
I. Mitigation measures proposed.
J. Scaled site plan.
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4.03.4 Traffic Impact Analysis
A. Title Page including project name and address.
B. Executive Summary.
C. Table of Contents.
D. Introduction consisting of a description of the project, location, site plans with
access to city streets, circulation network, land use and zoning, phasing plan,
project developer and contact person, reference other studies.
E. Traffic Analysis to include assumptions, existing and projected traffic volumes,
project trip generations, trip distribution, level of service (LOS), and warrant
analysis.
F. Appendix with all calculations.
4.03.5 Winterization Report
See Section 5.01.4 to the Engineering Design Standards and Construction Stormwater
Pollution Prevention Plan of the Surface Water Management Manual, Volume 2, Chapter
2.
4.03.6 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 as identified in
Volume II of the City of Auburn Surface Water Management Manual (SWMM), and follow
City of Auburn grading requirements.
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
The detention shall be defined as the active storage available a minimum of one foot (1’)
above the seasonal high ground water.
5.01.3 Winterization Plan
Any project with exposed soil meeting the requirements of the SWMM Volume 2, Chapter
2 shall prepare a winterization plan. The plan shall follow the Construction Stormwater
Pollution Prevention Plan (SWPPP) of the Surface Water Management Manual, and
contain the following information:
A. Purpose is to be clearly stated.
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 for the wet season.
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F. Inspection and monitoring schedule including the contact information for the third
party monitor to be used to complete all required inspections and reports.
G. Maintenance and repair responsibility clearly identified.
H. Identification of stockpile(s) of TESC materials and their location(s).
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 supersede 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, shrubs, or ground cover.
C. Clearing associated with continuous agricultural uses, excluding timber cutting not
otherwise exempted.
D. Clearing not to exceed 6,999 square feet within individual lots, for the purpose of the
construction of a single-family home or duplex, provided a building permit has been
issued by the city prior to commencing the clearing activities and construction of the
structure starts within ninety days of commencing the clearing activities. A permit will
be required if said clearing is proposed in any critical area or within its buffer.
E. The removal of up to six trees per lot within any 12-month period, or for lots greater
than one acre, up to six trees per acre within any 12-month period, with fractional
acres of one-half acre or more considered to be a whole acre.
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.
H. Removal of trees and vegetation consistent with an approved surface mining permit.
I. Removal of a tree from property zoned residential that endangers a permanent
structure by being closer to the structure than the distance from the base of the tree
to its top, regardless of whether the tree is located on the same property as the
structure.
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:
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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.
F. The area to be cleared or disturbed in square feet.
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 Purpose
The following section establishes the requirements for grading. These requirements do
not supersede nor are they intended to be inconsistent with any landscaping requirement
established by the Zoning Ordinance or other City action. A grading permit shall be
required except for the following situations:
A. Removal of dead or diseased trees, shrubs, or ground cover.
B. Clearing and grading associated with continuous agricultural uses, excluding timber
cutting not otherwise exempted.
C. Clearing and grading not to exceed 6,999 square feet of area within individual lots,
for the purpose of the construction of a single-family home or duplex, provided a building
permit has been issued by the city prior to commencing the clearing and grading activities
and construction of the structure starts within 90 days of commencing clearing and
grading activities. A permit will be required if said grading is proposed in any critical area
or within its buffer.
D. The removal of up to six trees per lot within any 12-month period, or for lots greater
than one acre, up to six trees per acre within any 12-month period, with fractional acres of
one-half acre or more considered to be a whole acre.
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E. Clearing and grading for the construction and maintenance of public facilities as
approved by the city engineer to include water, sanitary sewer, streets, highways, storm
drainage and related facilities.
F. Removal of trees, shrubs, and ground cover in emergency situations involving
immediate danger to life or property.
G. Routine landscape maintenance and minor repair.
H. Removal of trees and vegetation consistent with an approved surface mining permit.
I. Removal of a tree from property zoned residential that endangers a permanent
structure by being closer to the structure than the distance from the base of the tree to its
top, regardless of whether the tree is located on the same property as the structure.
J. Upon approval of the city engineer or his/her designee, excavations of less than five
feet in vertical depth and/or fills less than eight inches of vertical depth on any portion of a
site and involving the deposit or displacement of not more than a total of 500 cubic yards
of material during any 24-month period.
K. Upon approval of the city engineer or his/her designee, the temporary stockpiling of
less than 500 cubic yards, combined, of topsoils, crushed rock, sawdust, mulch, bark,
chips, or similar materials on a lot, tract, or parcel of land for a period not ot exceed 12
months; provided, that the stockpile has adequate coverage to prevent erosion.
L. Upon approval of the city engineer or his/her designee, the broadcasting of less than
500 cubic yards of topsoil, peat, sawdust, mulch, bark, chips, or solid nutrients used for
landscaping or soil conditioning on a lot, tract or parcel of land during any 24-month
period, provided the finished depth does not increase the grade from the existing grade
by more than eight inches.
M. Upon approval of the city engineer or his/her designee, the temporary stockpiling of
organic or inorganic materials used in an approved construction project, provided the use,
location, duration, and extent of the stockpile was disclosed through the environmental or
development review process, In no case shall a temporary stockpile remain beyond a 24-
month period.
N. The creation of impervious surfaces which have a surface area less than 2,000
square feet.
O. Emergency temporary sandbagging, diking ditching, filling or similar work during or
after periods of extreme weather conditions when done to protect life or property,
provided such measures do not adversely impact adjacent properties or public facilities.
5.03.2 Excavations
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, hydro-
seeding, or by other planting or surfacing materials acceptable to the City.
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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.
5.03.3 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 analysis 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.
D. 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.
E. When filling a site, particular care should be taken to prevent impeding the existing
upstream surface drainage flow.
5.03.3.1 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.
5.03.3.2 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.
5.03.4 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.
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
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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 (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, (e.g., 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.
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 5.04.1.3)
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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)
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5.05 Construction Sequence
5.05.1 Requirements
A construction sequence is intended to ensure that the timing and installation of 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.
E. Construction of storm drainage control (applicant to 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 perimeter 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 30). A separate winterization may be
required.
4. Prevent tracking of sediment onto City streets.
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REF. H\DEVELOPMENT\Design Standards\Chapter 5 (2-10)
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 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. The standards
also are required to control runoff from development, redevelopment and construction sites to
comply with the Western Washington Phase II Municipal Stormwater Permit issued by the
State of Washington Department of Ecology.
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 Requirements
All requests for developing a storm drainage system must comply with the City of Auburn
Surface Water Management Manual (SWMM). The City of Auburn SWMM has replaced the
standards formerly listed here.
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REF. H\DEVELOPMENT\Design Standards\Chapter 6 (02-10)
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-de-
sacs 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.
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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°).
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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 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-of-
way 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.
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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.
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 Through -18b
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.
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REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 7 (8-04)
7.01.4 Pressure Reducing Stations See Standard Details WATER-10 Through -12b
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 eight-
inch (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.
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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 wall-
mounted PIV may be installed when the exterior wall of the building is of non-
combustible 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.
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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%
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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
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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.
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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°).
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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 on-
site 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 City-
authorized personnel for review and inspection. Certification of maintenance
records shall be submitted to the City and be kept on-site for two (2) years.
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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 one-
half 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.
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REF. H:\DEVELOPMENT\Manuals\Design Standards\Chapter 8 (8-04)
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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.
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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 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.
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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”) 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 intent of this chapter is to encourage the uniform development of an integrated and
accessible public street system that will support present and future multimodal
transportation. Through the implementation of these standards, streets are built as
transportation facilities as well as public space, contributing positively to the character of an
area. These standards help create an efficient multimodal transportation system with
minimal environmental impact to the community.
The design of Streets within the City of Auburn shall conform to the standards provided
herein. The latest additions of the American Association of State Highway and
Transportation Officials (AASHTO) and the State of Washington Department of
Transportation (WSDOT) standards shall be utilized by the City Engineer when the design
standards, standard specifications, or standard drawings are not covered by the scope of the
City’s standards.
The design criteria used to estimate future street usage are established in the City’s
Transportation Plan. Anyone proposing to extend or modify the City’s street system should
contact the City of Auburn for information. Developers needing to construct street
improvements shall enter into a Facility Extension Agreement (FAC). The City of Auburn
can provide the information on this agreement as well as applicable permit fee estimates.
It is provided, however, that notwithstanding any provisions to the contrary, all streets
located within the Downtown Urban Center Zone boundaries as depicted on the
Comprehensive Zoning Map, other than that area west of the BNSF Railroad right-of-way,
shall be subject to the “Downtown Auburn Sidewalk Design Guidelines” (Guidelines).
Should any conflict exist between the Guidelines and the design criteria, Chapter 10, of this
document, the Guidelines shall control in those portions of the Downtown Urban Center
Zone described above.
10.01 Street Classification
All streets in the City of Auburn have been classified using the Federal Functional
Classification system. A complete listing of all roads by classification is available from the
Department of Public Works.
The following section contains descriptions of the street classifications used in the City.
Table 10-1 contains information relating to each streets design requirements for widths,
radii, typical speed limits, and other information. This section also contains references to
Standard Details that show a typical cross-section for each street. These cross-sections
contain information on street layouts and widths of various street elements.
10.01.1 Arterials
Arterials are the highest level of City Street classification. They fall under the following
two categories:
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
10.01.1.1 Principal Arterial See Standard Detail TRAFFIC-27
Principal Arterials are designed to move traffic between locations within the region
and to access the freeways. Design emphasis should be placed on providing
movement of inter-city through-traffic rather than intra-city traffic. Direct access to
commercial and industrial land uses is permitted.
Principal Arterials are typically constructed to accommodate five (5) lanes of traffic
with an operating speed of thirty-five to forty-five miles per hour (35-45 mph). The
design year ADT is greater than 15,000 vehicles per day.
10.01.1.2 Minor Arterial See Standard Detail TRAFFIC-28
Minor Arterials should interconnect with and augment principal arterials and provide
service to trips of moderate length at a somewhat lower level of travel mobility than
principal arterials. The minor arterial street system includes all arterials not classified
as a principal or collector and consists of facilities that place more emphasis on land
access than the higher system and offers a lower level of traffic mobility.
Minor Arterials are typically constructed to accommodate four to five (4-5) lanes of
traffic with an operating speed of thirty to thirty-five miles per hour (30-35 mph). They
may serve secondary traffic generators such as community business centers, athletic
fields, neighborhood shopping centers, major parks, multifamily residential areas,
medical centers, large church complexes, hospitals, and traffic from neighborhood to
neighborhood within the City. The design year ADT is 10,000 to 20,000 vehicles per
day.
10.01.2 Collectors
Collectors are a step below Arterials in the City classification system. They fall under the
following three categories:
10.01.2.1 Residential Collector See Standard Detail TRAFFIC-29
Residential Collector Arterials are used to connect intra-community streets, residential
neighborhoods, commercial areas, industrial areas, and community centers to minor
and principal arterials.
Residential Collectors are typically constructed to accommodate two (2) travel lanes
and a two-way left-turn lane or two (2) travel lanes and bike lanes with an operating
speed of thirty miles per hour (30 mph). The design year ADT is 2,500 to 10,000
vehicles per day.
10.01.2.2 Non-Residential Collector See Standard Detail TRAFFIC-30
Non-Residential Connector Arterials provide intra-community access connecting non-
residential properties with activity centers and recreational facilities. Non-Residential
Collector arterials are typically constructed to accommodate two (2) lanes and a
center two-way left-turn lane, with an operating speed of thirty miles per hour (30
mph). 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.
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10.01.2.3 Rural Collector See 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.
Rural Collectors provide access to all levels of arterials, are typically constructed to
accommodate two (2) lanes with gravel shoulders on both sides, and provide an
operating speed of thirty to forty miles per hour (30-40 mph). The gravel shoulder
may be reduced on one side to provide a wider shoulder on the other for equestrian
access, with permission from the City Engineer. The design year ADT is 1,000 to
5,000 vehicles per day.
10.01.3 Local Streets
Local Streets are the most common streets classified in the City. This classification can
be broken up into four categories as follows:
10.01.3.1 Local Residential See Standard Detail TRAFFIC-32
Local Residential streets provide access to abutting residential parcels. They offer the
lowest level of mobility among all street classifications. The street is designed to
conduct traffic between dwelling units and higher order streets. As the lowest order
street in the hierarchy, the access street usually carries no through traffic and includes
short streets, cul-de-sacs, and courts. Service to through traffic movement is
discouraged and the street usually contains no transit bus routes.
Local Residential streets are typically constructed to accommodate two (2) lanes of
traffic, on-street parking (one side only, the other side shall be signed “No Parking”),
and an operating speed of twenty-five miles per hour (25 mph). The design ADT is
200 to 1,200 vehicles per day.
10.01.3.2 Local Non-Residential See Standard Detail TRAFFIC-33
Local Non-Residential streets provide direct access to higher order classification
streets and serve primarily industrial/manufacturing land uses. They offer lower level
of mobility and accommodate heavy vehicle traffic. Service to through movement is
discouraged.
Local Non-Residential streets are typically constructed to accommodate two (2) lanes
of traffic with an operating speed of twenty-five miles per hours (25 mph). The design
year ADT is 400 to 1,200 vehicles per day.
10.01.3.3 Rural Residential See Standard Detail TRAFFIC-34
The Rural Residential streets primarily provide access to the adjacent land and
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 streets are typically constructed to accommodate two (2) lanes of
traffic with gravel shoulders on both sides and an operating speed of twenty-five miles
per hour (25 mph). The design year ADT is 100 to 1,000 vehicles per day.
10.01.3.4 Private Street
Community street requirements are usually best served by public streets, owned and
maintained by the City. Private streets may be appropriate for some local accesses in
very limited usage. Private streets shall provide a direct access to City streets and
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
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
travel from one public street to another. The design of a private street shall be such
that it will discourage any through traffic of non-residents. A private street will not be
allowed if it will result in land locking present of planned parcels.
Private streets shall be in conformance with the street standards that most closely
reflects their intended use, with a minimum of thirty-four feet (34’) of pavement width
or twenty-eight feet (28’) of pavement width with a marked fire lane on one side.
Private street networks shall be configured to deter speeding. Traffic calming
measures may also be required to deter speeding.
Private streets shall be located within permanently established tracts or easements. A
capable, legally responsible owner or homeowners’ association shall be established to
maintain private streets. A plat or short plat with private streets requires an executed
recorded Private Street Maintenance Agreement and a Storm Water Easement and
Maintenance Agreement that obligate the future property owners to maintain the
infrastructure indefinitely.
10.01.4 Alleys
Alleys afford a secondary means of vehicular access to abutting property and are not
intended for general traffic circulation. Dead-end alleys are generally unacceptable;
however, where dead-end alleys are determined suitable by the City Engineer, for short
term or temporary applications, they shall be provided with adequate turnaround facilities
at the dead-end. All new alleys shall be private.
Alleys shall incorporate the design criteria used in designing local streets with the
following exceptions:
A. All new alleys shall have a minimum width of twenty feet (20’) of asphalt
pavement.
B. Developments that generate four (4) or greater PM peak hour trips and have
direct access to existing alleys are required to pave the alley to a width of
twenty feet (20’) along the frontage of the property and between the nearest
property line and the public street that provides the City preferred travel path.
If adequate right-of-way does not exist to provide the required twenty feet (20’)
of pavement adjacent to the property, the appropriate dedication of right-of-
way shall be required. Such dedication shall be equally apportioned from both
sides of the alley, when feasible, as determined by the City Engineer. If
adequate right-of-way does not exist to provide the required twenty feet (20’) of
pavement along the alley between the nearest property line and public street,
the alley shall be paved to the width of the existing right-of-way.
C. The pavement section for alleys located in non-single family zones shall be
consistent with a local non-residential street standard.
D. Curb and gutter, sidewalk, lighting, and landscaping are not required along
alleys.
E. Alleys may be paved with either a crown at centerline with asphalt wedge
curbs on both sides to control drainage or be sloped to one side with an
asphalt wedge curb on one side to control drainage. When necessary, storm
drainage conveyance systems shall be installed along the alley to address
storm drainage runoff from the paved surface.
F. Alleys shall connect to City streets via a commercial driveway apron.
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Alleys serving alley loaded lots shall include provisions for unimpeded vehicular
circulation along the alley, and provisions for adequate sight distances along both the
alley at driveways and at intersections with public streets.
10.01.5 Private Access Roads on Access Tracts or Easements (Shared Driveways)
Access roads provided on access tracts or easements, also known as shared driveways,
provide access for up to six (6) residential units on panhandle/flag lots and rear lots that
do not have direct access to public street frontage. They will be private roads that shall
be maintained by the property owners who use them to access their property.
All access roads shall meet the following general standards:
1. Access roads shall be limited to six hundred feet (600’) in length.
2. 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.
3. 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 either a residential or commercial driveway apron commensurate with the
use of the property.
4. Access roads shall meet the geometric design standards for local residential
streets.
5. 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 two (2) residential units shall meet the
following additional standards:
6. The minimum pavement width shall be twenty-four feet (24’). The pavement
width may be reduces to twenty feet (20’) if the new residential unit using the
access road has a residential fire sprinkler system installed or a fire hydrant
exists within four hundred and fifty feet (450’) of the residences measured as
the fire vehicle lays its hose.
Existing access roads serving three (3) or more residential units when only one additional
residential unit is being created or developed shall meet the following additional
standards:
7. The minimum pavement width shall be twenty-four feet (24’) and be marked as
a fire lane per ACC 15.36A. The pavement width may be reduced to twenty
feet (20’) if the new residential unit using the access road has a residential fire
sprinkler system installed or a fire hydrant exists within four hundred and fifty
feet (450’) of the residences measured as the fire vehicle lays its hose.
8. An additional five foot (5’) wide pedestrian pathway along one side of the
paved access road separated by a four-inch (4”) wide painted line.
9. Access roads exceeding one hundred and fifty feet (150’) in length shall also
include an adequate turnaround at the end of the road.
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New access roads serving three (3) to six (6) residential units shall meet the following
additional standards:
10. Access roads seventy-five feet (75’) or less in length shall have a minimum
pavement width of twenty feet (20’) and shall be marked as a fire lane per ACC
15.36A.
11. Access roads exceeding seventy-five feet (75’) in length shall have a minimum
pavement width of thirty-four feet (34’). The pavement width may be reduced
to twenty-four feet (24’) if one side of the access road is marked as a fire lane
per ACC 15.36A.
12. Access roads exceeding one hundred and fifty feet (150’) in length shall also
include an adequate turnaround at the end of the road.
13. An additional five foot (5’) 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 sidewalk.
New access roads serving non-residential properties shall meet the following additional
standards:
14. The minimum pavement width shall be twenty-four feet (24’) for access roads
servicing commercial properties and thirty feet (30’) for access roads serving
industrial properties.
15. The access road will be marking as a fire lane per ACC 15.36A.
16. Access roads exceeding one hundred and fifty feet (150’) in length shall also
include an adequate turnaround at the end of the road.
10.01.6 Half-Streets
A Half -Street could be comprised of any one of the above mentioned street
classifications. Half -Streets require, at a minimum, the construction from one side of the
street, including the curb and gutter, storm drainage, sidewalk, lighting, conduits, and
landscape strip, to the street centerline. Half -Streets will need to be constructed when a
proposed new development or redevelopment of a property is located on a public street
that 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.
When Half-Street construction is required on an existing paved street, the design of the
Half-Street shall be consistent with the existing street conditions. This could require
construction of more than half the street for safety and drainage reasons.
When Half-Street construction is required on unpaved streets or unimproved areas, a
minimum of twenty-four feet (24’) of pavement will be required. In these cases, the street
should be designed to provide drainage for the constructed portion of the street.
Provisions shall be made to allow for extension of the storm drainage system to the
undeveloped portion of the street for future construction.
The construction of a Half-Street may require the dedication of additional right-of-way. If
a Half-Street does not connect at both ends to other streets, construction of a cul-de-sac
will be required.
Where Half-Streets are connected to existing streets, transition tapers will be required
when edges of pavement do not match. The following formula provides the information
necessary to determine the length of the tapers for a specific situation:
For street design speeds of less than forty miles per hour (40mph)
W = the width of the pavement offset
= L S = the design speed in mph
L = the length of the taper
For street design speeds of greater than or equal to forty miles per hour (40 mph)
W = the width of the pavement offset
WS = L S = the design speed in mph
L = the length of the taper
All required utilities located within the portion of the street being built, shall be installed
during construction. Half-Street construction may also require the upgrading of existing
utilities if said upgrading was necessary for the proposed development.
The unfinished side of the Half-Street shall be finished with temporary curbing, shoulders,
clear zones, guardrail, slope treatments, and drainage accommodations to assure proper
drainage, bank stability, and traffic safety.
When Half-Streets connect to an intersection, the nearest corner of the intersection on
the side being improved shall be designed and constructed for the full build-out of the
street. The intersection design and construction shall include adequate improvements to
insure safe use by pedestrians, bicycles, and vehicles.
WS2
60
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
10.02 Street Geometry
For in-depth design information on the following criteria, please reference the AASHTO
Manual “A Policy on Geometric Design of Highways & Streets,” latest adopted edition.
10.02.1 Minimum Horizontal Curve Radius
Horizontal curves shall be designed to provide the minimum radii required for vehicles to
safely negotiate a turn without leaving their driving lane and shall in no case violate
minimum sight distance requirements. Minimum radii are established by the design
speed of the street on which the curve is located and are listed in Table 10-1. On
arterials and rural collectors these radii may be reduced by superelevating the road
cross-section.
10.02.2 Tangents Between Reverse Curves
Sections of straight roadway must be designed between curves to avoid quick left-right
transitions that could potentially lead to loss of vehicular control. The length of these
straight sections should be a minimum of one hundred fifty feet (150’) for arterials and
collectors and one hundred feet (100’) for local residential streets. Where reversing
curves are superelevated, tangents between curves shall be of sufficient length to
accommodate transitions into and out of the superelevated sections.
10.02.3 Superelevations
The process of superelevating a street provides a constant cross slope from one edge of
the roadway to the other. This allows vehicles to travel around a turn at a higher speed
than would be possible if the road were a normal crown cross section. Superelevations
are allowed only on arterials and rural collectors. The maximum superelevation rate
allowed for these streets is eight percent (8%) and requires a design speed of thirty-five
miles per hour (35 mph) or greater.
10.02.4 Vertical Grades
Vertical Grades, the amount of slope of a street in the direction of travel, is limited to a
maximum of six percent (6%) for Arterials and eight percent (8%) for all other streets. All
street sections shall maintain a minimum of one-half percent (0.5%) vertical grade.
Vertical grades may be increased up to ten percent (10%) for non-arterials upon approval
of the City Engineer. The City Engineer shall consider the public benefit of any deviation
request including the classification of the roadway, traffic circulations, traffic congestion,
emergency access, adjacent property access, length of grade, impact to public utilities, or
any operational or safety factors. Deviations to the vertical street grade of a classified
roadway shall generally not be granted unless it can be demonstrated that the public
benefits significantly outweigh any potential detriments. If approved, grades between
eight percent (8%) and ten percent (10%) may trigger the additional following design
considerations:
• Increased travel lane widths
• Enhanced Paving Section
• Incorporation of Separated Multi-use trail
• Incorporation of Median Islands
• Enhanced Intersection/Signal Improvements
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
10.02.5 Vertical Curves
Vertical curves are required where a change in vertical alignment equals or exceeds a
one percent (1%) algebraic grade difference. Crest vertical curves shall be designed to
provide the required minimum stopping sight distance for the streets design speed as
listed in Table 10-2 of Section 10-03. Sag vertical curve lengths shall be designed to
provide headlight sight distance equal to or greater than the design speed stopping sight
distance. All vertical curves must be symmetrical, parabolic, and meet AASHTO
standards. The following formula provides the information necessary to calculate
minimum lengths for sag vertical curves.
A = algebraic grade difference, %;
L = ⎟⎠
⎞⎜⎝
⎛+−A
SS5.34002 S = stopping sight distance, ft;
L = length of sag vertical curve, ft
10.02.6 Cross Slopes
City streets shall be crowned in the middle to provide drainage to the gutter line or
roadside ditches. The cross slopes created by this crown shall be two percent (2%) for
local streets and three percent (3%) for collectors, arterials, and roads with vertical
grades of greater than six percent (6%). Collectors and arterials shall have steeper cross
slopes since the higher speeds associated with these roads require that water drain more
quickly from the roadway to avoid hydroplaning.
10.02.7 Posted and Design Speed
For design purposes, the “Posted Speed” for any given street segment shall be as
designated in Table 10-1 or the existing signed speed limit, whichever is greater.
For design purposes, the “Design Speed” for any given street segment shall be ten miles
per hour (10 mph) greater than the Posted Speed for arterials and five miles per hour (5
mph) greater than Posted Speed for non-arterials as designated in Table 10-1.
10.02.8 Right of Way
The required right-of-way will depend upon the width of the street and other
improvements. Excluding cul-de-sacs, the typical requirement is for the right-of-way to
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 storm facilities,
for example. Right-of-way requirements may be variable within a street corridor due to
intersections, turn lanes, bus loading zones, and other street features.
Right-of-way shall be conveyed to the City on a recorded plat or by a right-of-way
dedication or separate instrument.
The minimum right-of-way requirements for the various street classifications are listed in
Table 10-1.
10.02.9 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. Special cases
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.
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
10.02.9.1 Inside Through Lanes and Curb Lanes
The street classification and the amount of existing and projected traffic will determine
the number of lanes required for a street.
Curb lanes or outside lanes on all streets excluding residential collectors and local
and rural residential streets shall be a minimum of fourteen feet (14’) wide. Streets
will be widened to include inside through lanes based on street classifications and/or
projected traffic volumes. The minimum width for inside through lanes shall be eleven
feet (11’).
10.02.9.2 Center Turn Lanes
Center turn lanes will be required on principal and minor arterials. They may also be
required on collectors depending upon the nature of the roadway and the number of
left turn movement opportunities along the corridor. Center turn lanes shall be a
minimum of eleven feet (11’) wide.
10.02.9.3 Other Lanes
Acceleration and deceleration lanes may be required for sites located on arterials
where heavy volumes and/or heavy truck movements into and out of the site would
impact the speed and safety of the arterial.
Left turn and right turn pockets may be required at intersections with large numbers of
left and/or right turns. Left turn pockets shall be a minimum of eleven feet (11’) wide
with right turn pockets a minimum of fourteen feet (14’) wide.
10.02.9.4 Road Edge
All urban roads within the City of Auburn shall be designed using concrete curb and
gutter (WSDOT Plan F-10.12-00, Traffic Curb & Gutter). Rural roads within the City
may be designed with a gravel shoulder (minimum of 2⅝” Crushed Surfacing Top
Coarse (CSTC) over eight inches (8”) of “gravel base”; eight feet (8’) wide for rural
collectors and three feet (3’) wide for rural residential) and a ditch for drainage. Rural
roads shall also meet AASHTO standards for a clear zone between the edge of
pavement and any obstructions.
10.02.9.5 On-Street Parking
On-Street parking requirements shall be as designated in Table 10-1. For Local
Residential streets where parking is allowed on one side only, the City shall require
the parking to be placed on the side of the street that can accommodate the most
parking.
Parking is not allowed at any of the following locations:
1. Within 20 feet of an uncontrolled intersection measured from the point of
tangency on the entering curb radius.
2. Within 30 feet of a stop, yield or signal controlled intersection measured from the
point of tangency on the entering curb radius.
3. Within any intersection. For “T” intersections, the no parking limits shall apply to
both sides of the through street (top of the “T”). See Figure 10-0.
4. In front of or within 15 feet of each side of a fire hydrant.
5. In front of or within 5 feet of each side of a driveway.
6. Where mid-block crosswalks are installed, no parking shall be allowed on either
side of the street within 50 feet in advance of the nearest edge of the crosswalk
12/21/2009............................................Design Standards ............................................Page 10-10
REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
and within 20 feet past the furthest edge of the crosswalk. In no case shall the
advance parking restriction for crosswalks be less than the minimum stopping
sight distance of the roadway.
Additional parking restriction may be required depending upon roadway geometrics,
adjacent land use, and the proximity to bridges and railroads.
10.02.9.6 Intersection Curb Radii
The minimum right-of-way requirements for the various curb radii shall be as
designated in Table 10-1. At intersections with two different street classifications, the
highest classification for curb radii shall be used except at intersections with
residential streets where the lowest order street.
10.02.10 Street Layout
An efficient transportation system seeks to spread vehicle movements over a series of
planned streets. The goal of the system is to encourage connectivity while preventing
unacceptably high traffic volumes on any one street. Ample alternatives should exist to
accommodate access for emergency vehicles. For these reasons the City will continue
to plan a series of arterials and collectors designed to national standards to provide
efficient service to the community. Ample alternatives should also exist to accommodate
non-motorized transportation on arterials, collectors and local roads within and between
subdivisions.
10.02.10.1 Local Residential Streets
The internal local residential street network for a subdivision should be designed to
discourage regional through traffic and non-residential traffic from penetrating the
subdivision or adjacent subdivisions. Local residential streets shall not exceed one
thousand three hundred feet (1,300’) in length between intersections and shall not
serve more than 75 dwelling units.
Residential subdivisions should be planned in a manner that minimizes the number of
local street accesses to arterials and collectors. Residential subdivisions with greater
than 75 lots shall have a minimum of two accesses to either an arterial or collector.
Residential subdivisions developments with less than 75 lots shall have at least one
access to an arterial or collector. Residential subdivisions with between 25 and 75
lots shall also provide a second emergency vehicle access route to an arterial or
collector.
10.02.10.2 Other Streets
New streets and/or new street systems, other than local residential streets serving
residential subdivisions, shall be configured in conformance with the City’s
comprehensive plan guidelines and policies. Where the comprehensive plan lacks
clear guidance to address a particular situation, the City may require traffic studies
and other supporting analysis to help define the configuration and nature of the
planned street system.
10.02.10.3 Cul-de-sacs
Where possible, streets shall be planned, designed and constructed to connect to
future developments. All dead-end streets shall end in either a temporary or
permanent cul-de-sac. Permanent dead-end streets or cul-de-sacs will only be
allowed where a through street to connect adjacent properties and/or other streets is
not needed or possible. Dead-end streets shall not be more than six hundred feet
(600’) in length as measured from the center of the nearest intersection, unless the
city determines that due to topography or existing development patterns there are no
12/21/2009............................................Design Standards ............................................Page 10-11
REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
feasible alternatives and emergency services can be effectively provided. Dead end
streets ending in permanent cul-de-sacs shall serve a maximum of 25 dwelling units.
When applicable, non-motorized paths shall be provided at the end of the street to
shorten walking distances to an adjacent arterial or public facilities including, but not
limited to, schools or parks. Existing stub-end streets that are greater than eight
hundred feet (800’) in length shall be linked to other streets whenever the 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’) as measured from the center
of the nearest intersection shall not be allowed to serve substantial new development.
10.02.10.3.1 Temporary Cul-de-sacs
Temporary cul-de-sacs may be provided only when there is a plan for extending
the street.
Temporary cul-de-sacs shall have a paved surface with a diameter of sixty-five feet
(65’).
A sign shall be posted at the back of the temporary cul-de-sac stating that the road
is planned to be extended in the future and to contact the City of Auburn Public
Works Department for further information.
10.02.10.3.2 Permanent Cul-de-sacs
Permanent cul-de-sacs shall have a paved surface with a diameter of seventy-five
feet (75’) unless otherwise directed by the City.
Permanent cul-de-sacs right-of-way shall have diameter of ninety feet (90’) unless
otherwise directed by the City.
10.02.10.4 Traffic Volumes
Projected trip generation shall be calculated based on the current edition of the
Institute of Transportation Engineers (ITE) Trip Generation Manual.
Stub end streets shall not be linked to a new street if the connection is likely to result
in traffic volumes that will exceed acceptable volumes for the road’s classification.
These volumes are defined in Table 10-1 of these standards. Consideration may also
be given to the character and nature of the neighborhoods proposed to be connected.
10.02.11 Figure 10-0 - T-Intersection Parking Restrictions
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
10.03 Sight Distance
Sight distance is defined as the length of roadway ahead that is visible to the driver. All
roads, intersections, and access pointes should be designed to provide sight distance of
sufficient length that drivers can control the operation of their vehicles to avoid striking an
unexpected object in the traveled way.
10.03.1 Sight Distance Design
The requirements for stopping sight distance and intersection sight distance listed in this
section were taken from AASHTO’s “A Policy on Geometric Design of Highways and
Streets” manual as a quick reference guide and are for passenger cars on level
roadways. Deviations from City design standards may require additional sight distance
study and documentation. Sight distance design calculations will also be required for
design grades not listed in the tables below.
10.03.1.1 Stopping Sight Distance
Stopping sight distance is the distance required at every point along a roadway for a
vehicle traveling at or near the road’s design speed to come to a stop before reaching
a stationary object in its path. Table 10-2 contains the minimum design values that
shall be used for stopping sight distance.
In calculating stopping sight distance, the driver’s eye is assumed to be three and a
half feet (3.5’) above the roadway and the height of the object to be seen by the driver
is assumed to be two feet (2’) above the roadway.
10.03.1.2 Intersection Sight Distance
Intersection sight distance is the clear sight distance necessary for a driver entering a
controlled or uncontrolled intersection to proceed safely without impeding traffic.
Table 10-2A contains the minimum design values that shall be used for intersection
sight distance. The City Engineer may require the use of single unit of combination
trucks as the design vehicle for minor road approaches with five percent (5%) or
greater heavy vehicle volumes.
10.03.1.2.1 Major Road and Minor Road
For the purposes of intersection sight distance analysis, the Minor Road shall be
defined by any of the following criteria:
1. The controlled approaches of a Two-Way Stop Controlled Intersection.
2. The roadway with lower classification, lower design speed of lower traffic
volumes.
3. For uncontrolled intersections of similar classification, design speed and
volume roadways, the City Engineer shall designate the minor roadway.
4. Minor Roads include driveways, alleys, access tracts or any other location
accessing a public road.
10.03.1.2.2 Sight Triangles
Intersection, driveway, and access point sight distances are analyzed using the
applicable sight triangles per Figures 10-1 and 10-2. These sight triangles shall be
provided on site plans including landscaping and other potential sight obstructions
for all projects where intersections, driveways or access points are being installed
12/21/2009............................................Design Standards ............................................Page 10-13
REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
or modified. Additionally, the City Engineer may require supporting documentation
for vertical sight distance profile analysis on street grades over three percent (3%).
10.03.1.2.2.1 Measurements
Horizontal: Horizontal legs of the sight distance triangles on the major road are
measured along the roadway centerline. Major road vertex points are placed at
the midpoint of the traveled lane closest to the approach being analyzed. Minor
road vertex points are placed in accordance with following applicable sections
for uncontrolled and controlled intersections.
Vertical: In calculating vertical sight distance at intersections the driver’s eye is
assumed to be three and a half feet (3.5’) above the roadway surface and the
object to be seen is three and a half feet (3.5’) above the surface of the
intersecting road.
10.03.1.2.2.2 Restrictions
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 objects include but are not limited to: buildings, parked
vehicles, signs, fences, and landscaping.
10.03.1.2.2.3 Right-of-Way Requirements
The sight distance triangle shall be located completely within the City right-of-
way. The City will require a right-of-way dedication as a condition of
development approval to ensure the sight distance triangle is contained
completely within the City right-of-way. If the City Engineer determines that this
is not practical a “Sight Distance Easement” shall be required.
10.03.1.2.3 Uncontrolled Intersections
For uncontrolled intersections (intersections without signals, stop signs or yield
signs) the sight distance triangle dimensions are determined by applying the
applicable distances listed in Table 10-2A to the respective legs of the sight
distance triangle as shown on Figure 10-1.
10.03.1.2.4 Two Way Stop Controlled Intersections
In calculating intersection sight distance for Two Way Stop Controlled intersections
the vertex (decision point) of the sight triangle on the minor road shall be measured
fourteen and a half feet (14.5’) back from the nearest edge of the traveled roadway.
Where parking is allowed on the major road this distance shall be measured from
the far edge of the parking lane.
Left turns from the minor road: Using Figure 10-2 sight triangles for traffic
approaching from both the left and right should be provided using the value in
Table 10-2A that corresponds to the major road design speed.
Right turns from the minor road: Using Figure 10.2 a sight distance triangle for
traffic approaching from the left should be provided using the value in Table 10-2A
that corresponds to the major street design speed.
10.03.1.2.5 All Way Stop Controlled Intersections
At All Way Stop Controlled intersections, the first stopped vehicle on one approach
should be visible to the drivers of the first stopped vehicles on each of the other
approaches.
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
10.03.1.2.6 Signalized Intersections
At signalized intersections the first stopped vehicle on one approach should be
visible to the drivers of the first stopped vehicles on each of the other approaches.
Left-turning vehicles should have sufficient sight distance to complete left turns.
Additionally, if right turns on a red signal are permitted from any approach then the
appropriate sight triangle should be provided to accommodate right turns on that
approach.
10.03.1.3 Decision Sight Distance
Decision sight distance is used in cases where the driver is required to detect
unexpected or confusing situations and then make appropriate changes in their
driving style or method. This could mean changing lanes, slowing down, or coming to
a complete stop. Decision sight distance will need to be addressed when designing
roads with tight turns and unexpected driveway and street connections. When
decision sight distance requirements are applicable, the guidelines presented in the
latest edition of AASHTO shall be used.
10.03.1.4 Passing Sight Distance
Passing sight distance should be addressed when designing two (2) lane roads where
vehicle speeds can differ by a considerable amount depending on the driver. When
passing sight distance requirements are applicable, the guidelines presented in the
latest edition of AASHTO shall be used.
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
10.03.2 Table 10-2 Stopping Sight Distance
Stopping Sight Distance (ft)
Downgrades*
(Equation 10-2)
Upgrades*
(Equation 10-2)
Design
Speed
(MPH)
Level
Roads
(Equatio
n 10-1) 3% 6% 8% 10
% 3% 6% 8% 10%
15 80 80 82 84 86 75 74 73 72
20 115 116 120 124 128 109 107 105 104
25 155 158 165 170 176 147 143 141 139
30 200 205 215 223 232 200 184 181 178
35 250 257 271 282 294 237 229 225 220
40 305 315 333 347 363 289 278 272 267
45 360 378 400 418 438 344 331 324 317
50 425 446 474 495 520 405 388 379 370
55 495 520 553 579 609 469 450 438 428
60 570 598 638 669 705 538 515 501 489
Equation 10-1: (Grades < 3%)
a
VVtd
2
075.147.1+=
Equation 10-2 (Grades ≥ 3%)
⎟⎟⎠
⎞⎜⎜⎝
⎛±⎟⎠
⎞⎜⎝
⎛+=
Ga
VVtd
2.3230
47.1
2
d = stopping sight distance, ft.
V = design speed, mph
a = deceleration rate of 11.2ft/s2
t = brake reaction time, 2.5s
G = percent grade divided by 100
Data for this table was taken from the 5th edition of AASHTO’s “A Policy on
Geometric Design of Highways and Streets” manual, Exhibit 3-1 Stopping Sight
Distance and Exhibit 3-2 Stopping Sight Distance on Grades.
*Use Equation 10-2 above to calculate appropriate stopping sight distances for
grades not shown.
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
10.03.3 Table 10-2A Intersection Sight Distance
Intersection Sight Distance, (ft)
Uncontrolled
Intersections*
Use Figure 10-1
Two Way Stop Controlled Intersections**
Use Figure 10-2
(Equation 10-3)
Design Speed (mph) Dimensions “a” and
“b”
Dimension “a” for Left
Turns
(Table10-2C)
Dimension “a”
for Right Turns
(Table 10-2D)
15 70 170 145
20 90 225 195
25 115 280 240
30 140 335 290
35 165 390 335
40 195 445 385
45 220 500 430
50 245 555 480
55 285 610 530
60 325 665 575
Equation 10-3:
gmajortVISD47.1=
ISD = intersection sight distance (length of the leg of
sight distance triangle along the major road) (ft)
majorV = design speed of major road (mph)
gt = time gap for minor road vehicle to enter the major
road(s)
Data for this table was taken from the 5th edition of AASHTO’s “A Policy on Geometric
Design of Highways and Streets” manual’s Exhibit 9-51 Length of Sight Triangle Leg-No
Intersection Control, 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.
* Where grade along an uncontrolled intersection approach exceeds 3%, the leg of the clear
sight triangle along that approach should be adjusted by multiplying the sight distance listed
in this table by the appropriate adjustment factor in Table 10-2B.
** 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 () will need to be adjusted per Tables 10-2C /10-2D and the sight distance
recalculated.
gt
*** Refer to the latest edition of the AASHTO manual for sight distance requirements on
major street left turns and at yield controlled intersections.
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
10.03.4 Table 10-2B Uncontrolled Intersection Sight Distance Adjustment Factors
Adjustment Factors
Design Speed (mph) Approach
Grade (%) 15 20 25 30 35 40 45 50 55 60
-10 1.1 1.1 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2
-8 1.1 1.1 1.1 1.1 1.1 1.2 1.2 1.2 1.2 1.2
-6 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.2 1.2 1.2
-5 1.0 1.0 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1
-4 1.0 1.0 1.0 1.1 1.1 1.1 1.1 1.1 1.1 1.1
-3 to 3 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0
4 1.0 1.0 1.0 1.0 1.0 0.9 0.9 0.9 0.9 0.9
5 1.0 1.0 0.9 0.9 0.9 0.9 0.9 0.9 0.9 0.9
6 1.0 1.0 0.9 0.9 0.9 0.9 0.9 0.9 0.9 0.9
8 1.0 0.9 0.9 0.9 0.9 0.9 0.9 0.9 0.9 0.9
10 0.9 0.9 0.9 0.9 0.9 0.9 0.9 0.9 0.9 0.9
Note: Apply adjustment factor to sight distance measurement for each approach.
Data for this table was taken from AASHTO Exhibit 9-53.
10.03.5 Table 10-2C Time Gap for Left Turns
Design Vehicle Time gap() (seconds) at design speed of major road gt
Passenger Car 7.5
Single Unit Truck 9.5
Combination Truck 11.5
Note: Time gaps are for a stopped vehicle to turn left onto a two-lane roadway with no
median and grades 3 percent or less. Table 10-2A values require adjustments
as follows:
For Multilane roads:
For left turns onto two-way highways with more than two lanes add
0.5 seconds for passenger cars and 0.7 seconds for trucks for each
additional lane, from the left, in excess of one, to be crossed by the
turning vehicle.
For minor road approach grades:
If the approach grade is an upgrade that exceed 3 percent; add 0.2
seconds for each percent grade for left turns
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
10.03.6 Table 10-2D Time Gap for Right Turns
Design Vehicle Time gap() (seconds) at design speed of major
road
gt
Passenger Car 6.5
Single Unit Truck 8.5
Combination Truck 10.5
Note: Time gaps are for a stopped vehicle to turn right onto or cross a
two-lane roadway with no median and grades 3 percent or less.
Table 10-2A values require adjustments as follows:
For Multilane roads:
For crossing a major road with more than two lanes add 0.5
seconds for passenger cars and 0.7 seconds for trucks for
each additional lane to be crossed and for narrow medians
that cannot store the design vehicle.
For minor road approach grades:
If the approach grade is an upgrade that exceed 3 percent;
add 0.1 seconds for each percent grade for left turns
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
10.03.7 Figure 10-1 Intersection Sight Triangles for Uncontrolled Intersections
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
10.03.8 Figure 10-2 Intersection Sight Triangles for Two-Way Stop Controlled Intersections
12/21/2009............................................Design Standards ............................................Page 10-21
REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
10.04 Street Access Points
All access points to and from City streets, including intersections and driveways, shall be
approved by the City prior to construction. These access points shall meet all the
requirements contained throughout this chapter for sight distance, spacing, and other safety
considerations.
The following section contains design criteria on all access points including street
intersections and driveways. These criteria are minimum values and may need to be
modified according to safety factors, traffic volumes (existing and/or projected), topography,
design speed, design vehicle requirements, drainage, and other conditions, both existing
and projected.
10.04.1 Public Street Intersections
Public Street Intersections are intersections where two (2) or more City streets intersect.
These intersections shall be designed using the following criteria:
10.04.1.1 Intersection Spacing
Public street intersections shall meet the minimum centerline spacing requirements as
shown in Table 10-3.
10.04.1.2 Horizontal Approach Angle
The horizontal approach angle of public street intersections shall be between 85° and
95° at the centerlines of intersecting streets.
10.04.1.3 Intersection Approach Offsets
Public Street intersections shall be aligned so that opposing single left turn lanes and
through lanes are not offset more than four feet (4’) as measured from the lane
centerline approach tangent.
10.04.1.4 Curb and Right-of-Way Radius
A minimum curb radius is required at intersection corners for vehicles to safely
execute a right turn at a reasonable rate of speed without crossing lanes or
encroaching onto the adjacent curb. At intersections of differing street classification,
the higher classification street curb radius requirements shall be used. The exception
to this rule is for local residential streets where the minimum radii listed in Table 10-1
shall be used. The right-of-way radius is the additional radius required to install
sidewalks, landscape strips, and other roadway appurtenances. Additional right-of-
way may be required near intersections to accommodate auxiliary traffic lanes and
equipment for existing or future traffic signals and street lights. These minimum
values and listed in Table 10-1.
10.04.1.5 Landing Approach
The landing approach is a defined segment of the street before the intersection and is
measured back from the point of tangency of the curb radius on each approach to the
intersection. The requirements for minimum landing approach length and maximum
landing approach grade are listed in Table 10-1.
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
10.04.1.6 Street Crowns
Public street intersections shall be designed to drain away from the higher classification
street. Grades shall match at the center of intersections for equal classification streets.
At intersections of differing classification streets the crown shall be carried through the
intersection for the higher classification.
10.04.2 Private Street Intersections
Private street intersections are those intersections where a private street intersects a City
street. These intersections shall be designed in the same manner as public street
intersections, except that the private streets will be stop-controlled.
10.04.3 Table 10-3
Minimum Intersection Spacing from Centerline to Centerline (ft)
PRINCIPAL
ARTERIAL
MINOR
ARTERIAL
RESIDENTIAL
& NON-
RESIDENTIAL
COLLECTORS
RURAL
COLLECTOR
LOCAL
STREETS
5001 5001 250 250 125 LOCAL
STREETS
1320 1320 500 500 250 RURAL
COLLECTOR
2640 1320 500 500 250
RESIDENTIAL
& NON-
RESIDENTIAL
COLLECTORS
2640 2640 1320 1320 5001 MINOR
ARTERIAL
2640 2640 2640 1320 5001 PRINCIPAL
ARTERIAL
Notes:
1. Local streets shall generally not be allowed to access directly onto arterials.
2. Refer to section 10.03 for intersection sight distance requirements.
3. Refer to section 10.05 for intersection pedestrian accessibility requirements.
12/21/2009............................................Design Standards .........................................Page 10-23
REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
10.04.4 Driveways See Standard Detail TRAFFIC-07 through TRAFFIC-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 except single
family residential.
C. Temporary Driveways – Driveways to property allowed prior to and during
construction only.
D. Emergency Driveways – Driveways required by the fire department to provide
an alternative emergency-only access to the property.
E. Signalized Driveways – For special circumstances when no other option is
available, the City may allow signalized access to a public street from a private
access. In such situations, dedication to the City of any right-of-way necessary
for maintaining and operating the intersection will be required. Additional
mitigation measures may be required to ensure safe and efficient access to the
public street. The private leg of the intersection within the right-of-way shall be
designed to the applicable public street standard as determined by the City.
10.04.4.1 Driveway Locations
Most properties shall be limited to one driveway access to a City street (or alley).
Multiple driveway accesses to a street (or alley) shall only be allowed when the City
determines that the second access does not create a safety concern or impede traffic
flow.
To address safety or to mitigate impacts of traffic flow, the City may require two or
more contiguous non-single family properties to share a single driveway, and/or
require the driveway to be located on the lowest classification of street (or alley) when
a property has frontage on two or more streets (or alleys).
Driveway accesses within the “Functional Intersection Boundary” shall be either
prohibited or restricted in conformance with Section 10.04.4.1.1 below. The City may
also impose driveway restrictions at other locations when a safety hazard is identified
or to mitigate impacts of traffic flow along a classified street. Such restrictions shall be
incorporated into the design of the driveway in conformance with the provisions of
Section 10.04.4.5 in a manner that strives to maintain existing access turning
movements to other properties in the vicinity.
Redeveloped properties are not guaranteed that their existing driveways will be
retained. Redeveloped properties that meet the requirements for half street
improvements, have more than one access point, or do not meet current City
standards may be required to eliminate, relocate or modify existing driveway
access/accesses.
Except for Local Residential Streets the spacing of driveways and their separation
from intersections shall meet the minimum “Functional Intersection Boundary”
distances of this Chapter.
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
10.04.4.1.1 Function Intersection Boundary See Table 10-4 and Figure 10-3
The functional intersection boundary is the portion of the street leading up to the
intersection required to allow vehicle movements and storage. This is the area
within which drivers identify the situation, change lanes, come to a stop, and wait
before proceeding through the intersection. Driveways shall be either prohibited or
restricted within the functional intersection boundary in accordance with Table 10-4
and Figure 10-3.The functional length of an intersection is measured from the point
of curvature/point of tangency (PC/PT) of the curb return. Driveway restrictions
include prohibiting either all left turn movements, left turns out of, or left turns into
the subject driveway.
10.04.4.1.2 Table 10-4 *Distance Requirements for Functional Intersection Boundaries
Speed
mph
Speed
ft/sec
Reaction
Time
(sec)
Decision
Distance
(ft)
”d1”
Lane
Change
Distance
(ft)
”d2”
Braking
Distance
(ft)
”d3”
Storage
Length
(ft)
”d4”
Functional
Intersection
Boundary
Length
d1+d2+d3+d4
(ft)
25 mph 37 1 37 25 60 50 222
30 mph 44 1 44 40 86 50 270
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
10.04.4.1.3 Figure 10-3 Functional Length Diagram of an Intersection with Right and/or
Left-Turn Lane
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
10.04.4.1.4 Figure 10-4 Functional Intersection Boundary Restricted Access Diagram
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
10.04.4.2 Driveway Lay Out See Standard Detail TRAFFIC-11
Driveways shall be designed in such a manner as to allow for efficient and safe
ingress and egress from the City streets. Driveways and on-site parking, other than
that for single-family residences on unclassified roads or alleys, shall be designed
such that vehicle-backing maneuvers will not occur onto the street. A properly
designed driveway shall allow the largest typical vehicle that will use the driveway (i.e.
tractor-trailers at large warehouses, delivery trucks at mini marts) to enter and exit the
site without encroaching into opposing traffic.
Driveways for adjacent properties should be separated by a minimum of ten feet (10’)
for residential and fifty feet (50’) for commercial/industrial. This distance should be
measured from the outside edge of the driveway apron. When this separation is not
obtainable, a single driveway centered on the property line may be required.
When designing site layout and driveway access, internal circulation shall be such
that on-site traffic will not backup the driveway impeding vehicles in the public street.
The City may require sites with internal traffic congestion to design driveways with
long throat lengths to provide extra storage to avoid impacting City streets.
10.04.4.3 Driveway Alignment (Horizontal and Vertical)
The angle of driveway throats to the City streets shall not be less than eighty-five
degrees (85°) unless a “pork chop” or other access control device is allowed to be
utilized per Section 10.15.
The vertical grade behind the driveway shall not exceed five percent (5%) for a
distance of 12 feet (12’) beyond back of sidewalk or right of way line. Driveways shall
be designed to preclude vehicles from dragging when entering or exiting the site.
Driveways shall meet all sight distance requirements per Section 10.03.
10.04.4.4 Driveway Widths
10.04.4.4.1 Residential See Standard Detail TRAFFIC-07 & 08
Residential driveways shall be used when serving four (4) or fewer living units.
Driveway widths shall be a minimum of ten feet (10’) and a maximum of twenty-four
feet (24’). Residential driveways shall be constructed using a minimum thickness of
six inches (6”) of non-reinforced concrete.
10.04.4.4.2 Commercial/Industrial See Standard Detail TRAFFIC-09 & 10
Commercial and industrial driveway widths shall be based on the number of lanes
used on the driveway and the type of use. Commercial driveways shall be
constructed using a minimum thickness of eight inches (8”) of reinforced concrete
The three categories described below will be determined based on the vehicles
expected to use the site.
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, and small apartment buildings. Driveways
will have one entering lane and up to two exiting lanes with the lane
widths restricted to a maximum of twelve feet (12’).
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
B. Medium commercial/industrial driveways should be used for sites
where the average vehicle use will range from medium to high
volumes of passenger vehicles to multiple medium delivery trucks per
day and the occasional large tractor/trailer delivery truck. Examples
included supermarkets, large outlet stores, shopping malls, large
apartment buildings, and busy retail stores located on arterials.
Driveways will have one entering lane and up to two exiting lanes
with the lane widths restricted to a maximum of fourteen feet (14’).
C. Heavy commercial/industrial driveways should be used for sites
where high volumes of medium to large tractor/trailer trucks enter
and exit every day. Examples include manufacturing and storage
warehouses. Driveways will have one entering lane and one exiting
lane with the lane widths restricted to a maximum of sixteen feet
(16’).
Driveway uses discussed above may be subject to change based on the street
classification on which they are located. For example: a site use that may normally
fall under the light commercial/industrial classification may be upgraded to a medium
commercial/industrial classification if it is located on a principal or minor arterial to
facilitate moving vehicles off the right-of-way in a more efficient manor.
10.04.4.5 Restricted Access Driveways
Restricted Access Driveways are used to restrict turning movements out of or into
driveways. Turning restrictions at driveway locations shall be by one of the following
methods as deemed appropriate by the City.
A. Median Islands (Per Section 10.15.1)
B. Traffic (“C”) Curbs (Per Section 10.15.2)
C. Pork Chops (Per Section 10.15.3)
D. Signing (Per Section 10.15.4)
E. Pavement Markings (Per Section 10.15.5)
12/21/2009............................................Design Standards .........................................Page 10-28
REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
10.05 Sidewalks
Sidewalk requirements vary by street classification and corridor/area specific standards as
determined by the City. Sidewalks are required along both sides of all street classifications
except for rural streets.
10.05.1 Sidewalk Widths See Standard Details TRAFFIC-23 & 24
Sidewalks shall be a minimum of five feet (5’) in width for all local residential and
residential collector streets. Sidewalks shall be a minimum of ten feet (10’) in width for all
principal arterials, minor arterials, non-residential collectors, and local non-residential
streets. Non-standard widths of sidewalk greater than the standards identified above
may be required to maintain continuity on existing corridors. All sidewalks shall have a
minimum of five feet (5ft) of unobstructed width.
10.05.1.1 Downtown Auburn
Sidewalk widths in the Downtown Urban Center Zone shall be a minimum of ten feet
(10’) in width as measured from face of curb to face of building or Right-of-way. All
sidewalks in the downtown zone shall maintain a minimum walking zone of five feet
(5’) in width, free of all obstructions including utilities, signage, street trees, furniture or
other elements, permanent or temporary.
10.05.2 Structural Section See Standard Details TRAFFIC-23 & 24
Sidewalks shall be a minimum of four inches (4”) thick concrete over two inches (2”) of
Crushed Surface Top Course (CSTC). At driveway crossings the sidewalk section shall
match that required for the driveway. When sidewalks are installed at the back of the
curb, a thickened edge shall be provided as shown in City of Auburn Standard Details
TRAFFIC 23 & 24.
10.05.3 Meandering Sidewalks
The City Engineer may approve meandering sidewalks along a corridor when the sidewalk,
landscaping, lighting, signing, right-of-way, and other surface features are integrated into
the design of the improvements. Additional right-of-way (or an easement) may be required
to accommodate the meander of the sidewalk and other surface features.
10.05.4 Accessibility
All sidewalks shall be designed according to the Americans with Disabilities Act (ADA)
guidelines. Cross slopes shall not exceed two percent (2%). Sidewalk grade shall not
exceed the grade of the adjacent street centerline.
10.05.4.1 Curb Ramps See Standard Details TRAFFIC-25 & 26
Curb ramps shall be provided at all intersections and pedestrian crossings having
vertical curb sections. Every curb ramp shall have at least one receiving ramp. In
special conditions, curb ramps shall also be provided to enable passage across
curbed radius return access points. All curb ramps shall have detectable warning
patterns formed with manufactured truncated domes painted yellow.
12/21/2009............................................Design Standards .........................................Page 10-29
REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
10.06 Bikeways
The City of Auburn bikeway standards are designed to ensure that bikeways are constructed
in a manner that provides a safe and convenient network of interconnected routes for
bicycling.
Bikeways are any road, street path or way which in some manner is specifically designated for
the exclusive use of bicycles or are to be shared with other transportation modes. Bikeway
facilities shall be incorporated into development and transportation projects in accordance with
the Future Trail and Bicycle Network plan adopted by the City of Auburn Comprehensive
Transportation Plan.
Bikeways shall be designed in accordance with AASHTO’s “Guide for the Development of
Bicycle Facilities 1999,” the latest adopted edition of FHWA’s Manual on Uniform Traffic
Control Devices (MUTCD), this section, and applicable City of Auburn standard details.
10.06.1 Bikeway Classifications
The City of Auburn’s Future Trail and Bicycle Network consists of various classification
bikeways. Typically, these bikeways are shared with other transportation modes, although
they may be provided exclusively for bicycle use. Bikeways are categorized as follows:
10.06.1.1 Class I Bikeway
Class I Bikeways are facilities shared with other non-motorized modes and are
physically separated from motorized vehicle roadways. For the purposes of this
section, Class I Bikeway design standards are for bicycle facilities that generally
parallel a roadway with minimal crossflow by motor vehicles. It is designed and built
primarily for use by bicycles, but may also be used by pedestrians, joggers, skaters,
wheelchair users (both non-motorized and motorized), equestrians, and other non-
motorized users. When required, Class I Bikeways shall be designed for two-way
traffic and meet the following minimum design criteria:
10.06.1.1.1 Width
Standard Class I Bikeways shall include a fourteen foot (14’) paved section in
accordance with Section 10.06.1.1.2. Minimum ten foot (10’) paved width.
10.06.1.1.2 Structural Section
Minimum pavement section of six inches (6”) of gravel base, two inches (2”) of
Crushed Surface Top Course (CSTC), and two inches (2”) of Class “B” asphalt
concrete pavement. When the California Bearing Ratio (CBR) of the existing soil is
less that five (5), an additional six inches (6”) of gravel base shall be required. When
the trail is also utilized as a service road, the Class “B” asphalt concrete pavement
section shall be increased to three inches (3”).
10.06.1.1.3 Geometrics
Class I Bikeways shall closely conform to the grades of the adjacent street and meet
the geometric design standards of AASHTO’s “Guide for the Development of Bicycle
Facilities 1999”.
10.06.1.1.4 Buffer
Class I Bikeways shall have a minimum five foot (5’) landscape buffer located
between the bikeway and any adjacent street.
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
10.06.1.1.5 Driveway Crossings
Where Class I Bikeways are intersected by driveways appropriate signing and
pavement markings shall be provided consistent with MUTCD requirements for
midblock crossings.
10.06.1.1.6 Ownership
Class I Bikeways that are part of the City’s Future Trails and Bicycle Network shall be
public and shall be located within the public right-of-way, tracts or easements.
10.06.1.2 Class II Bikeway
Class II Bikeways, or “Bike Lanes,” are incorporated within the street right-of-way.
Bike lanes are established on streets in corridors where there is a current of
anticipated bicycle demand and where it would be unsafe for bicyclists to ride in travel
lanes. Bike lanes shall be provided in accordance with the Future Trail and Bicycle
Network plan pursuant to the City of Auburn Comprehensive Transportation Plan.
Bike lanes are exclusive one-way bicycle facilities delineated by pavement markings
and signing. Bicycle traffic is carried in the same direction as the adjacent motorized
vehicle traffic. When required, bike lanes shall meet the following minimum design
criteria:
10.06.1.2.1 Width
Minimum six foot (6’) paved width as measured from nearest edge of the travel way
to face of curb, edge of pavement, or edge of parking lane.
10.06.1.2.2 Structural Section
Bike lanes shall have the same pavement cross-section as the adjacent street.
10.06.1.2.3 Geometrics
Class II Bikeways, as part of the street section, shall follow the same geometric
design standards.
10.06.1.3 Class III Bikeway
Class III Bikeways, or “Shared Lane,” are facilities shared by bicyclists and motorized
vehicles. Class III Bikeways will be utilized, in accordance with the Future Trail and
Bicycle Network plan, on existing streets as interim bike corridors until a Class I or
Class II facility can be provided. Class III Bikeways may or may not be delineated
with shared use pavement markings and signage. Generally, lower-speed/lower-
volume streets are adequate for bicycle travel, so additional signing and pavement
markings for bicycle use are unnecessary. When required, Class III Bikeways shall
meet the following minimum design criteria.
10.06.1.3.1 Width
Minimum fourteen foot (14’) paved width as measured from laneline to face of curb,
edge of pavement, or edge of parking lane.
10.06.1.3.2 Structural Section
Class III Bikeways shall have the same pavement cross-section as the adjacent
street.
10.06.1.3.3 Geometrics
Class III Bikeways, as part of the street section, shall follow the same geometric
design standards.
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
10.06.1.4 Class IV Bikeway
Class IV Bikeways consist of all improved roadways unless otherwise designated as
Class I, Class II, or Class III Bikeways.
10.06.2 Bikeways at Railroad Crossings
Railroad-Bikeway grade crossings shall be designed as near perpendicular as possible. If
rail crossing is less than forty-five degrees (45°), an additional paved shoulder of sufficient
width shall be provided to permit the bicyclist to cross the track at a safer angle. Where this
is not possible and train speeds are low, compressible flangeway fillers will be required.
When not under City control the railroad owner shall be responsible for bicycle crossings.
10.06.3 Bikeways at Roundabouts
Class I Bikeways at roundabouts shall be combined with the adjacent sidewalk, if
applicable; to create a single shared use crossing through the roundabout zone.
Class II and Class III Bikeways shall be terminated a minimum of sixty-five feet (65’) in
advance of roundabouts using appropriate signing and striping with transitions to the
adjacent pedestrian facilities which shall be enhanced through the roundabout zone,
consistent with a Class I Bikeway, to accommodate the shared use with bicycles.
10.06.4 Bikeways at Signalized Intersections
Class I Bikeway crossings at signalized intersections shall be combined with the adjacent
sidewalk, if applicable, to create a single shared facility utilizing the protected pedestrian
crossing at traffic signals.
Class II and Class III Bikeways shall be provided an optional transition to the adjacent
pedestrian facilities a minimum of fifty feet (50’) in advance of traffic signals using
appropriate signing and striping. The adjacent pedestrian facility shall be enhanced to
Class I Bikeway standards in advance of the transition point to accommodate the shared
use through the intersection.
10.06.5 Bikeways at Unsignalized Intersections
Class I Bikeway crossings at unsignalized intersections shall be combined with the
adjacent sidewalk, if applicable, to create a single shared use crossing. Class II Bikeways
shall be delineated in accordance with City of Auburn standard details and MUTCD bike
lane requirements for intersections.
10.06.6 Bikeway Pavement Markings, Signing, and Striping
Pavement markings, signing, and striping for bikeways shall be designed in accordance
with City of Auburn standard details and Manual of Uniform Traffic Control Devices
(MUTCD) requirements.
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
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 will ensure that
paved transportation corridors are adequately built or improved in a uniform and consistent
manner.
The information contained in Table 10-5 has been established to minimize the structural
failures in streets, due to traffic loadings and/or existing soils conditions. Engineers will be
allowed to do their own pavement designs in accordance with the current AASHTO design
procedure and the minimum City requirements supplied in Section 10.07.3.
The pavement design information contained herein was established for a complete range of
street and traffic conditions excluding principal arterials. It has been simplified so that
extensive data and computer analysis is not necessary for developing pavement designs for
most projects. A separate design study will be required for principal arterials and streets
where the daily average traffic count is expected to exceed 15,000 vehicles per day and
streets where unusually heavy truck and bus traffic is expected or encountered, such as
freight routes and bus routes.
Freight routes are defined in the “City of Auburn Comprehensive Transportation Plan”.
Studies should be performed along the freight route to determine the vehicle mix and
volumes. Pavement sections for freight routes are not defined in the following tables and
need to be designed to accommodate anticipated volumes.
10.07.1 Design Requirements
10.07.1.1 Street Classification
The classification of a particular street, (i.e. Residential Collector), can be obtained
from the City of Auburn. The classification of a street will be required to determine the
volume and mix of vehicles for which it is designed.
In some cases where a street has yet to be designated a specific classification, street
pavement should be designed based on the anticipated traffic volume. An anticipated
daily traffic count can be obtained from the City of Auburn for the street in question or
a similar street that functions in the same manner. The City may, however, require
the applicant to obtain additional traffic information, as warranted.
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
ability to provide CBR data. 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.
The subgrade under the proposed street shall have its CBR evaluated by an
independent testing laboratory or geotechnical firm. The existing subgrade shall then
be classified as determined in the soils classification section (Section 10.07.3). The
proposed roadway shall have a minimum of one CBR test for every 1,000 feet of road
and/or for every obvious change in subgrade material (minimum of two (2) tests per
street).
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
Prior to placing any street base material, the subgrade shall be rolled and compacted
to a minimum of 95% of the maximum density as determined by ASTM D-1557
(Modified Proctor).
Any sections of a roadway that exhibit “pumping” shall be removed to a depth where
the pumping ceases and replaced with granular imported material that can be
compacted to the required 95% of the maximum density as determined by ASTM-
1557 without pumping, or as directed by a Geotechnical Engineer licensed in the
State of Washington.
If the existing subgrade is classified as a poor subgrade, then a geotextile fabric may
be required on the subgrade prior to placing any subbase or base materials. The
geotextile fabric shall be a woven, permeable fabric produced for placement in road
bases.
Other requirements for subgrade grading, including slopes and retaining wall, are
covered in Chapter 5.
10.07.1.3 Street Pavement Sections
Street pavement section requirements can be determined by using the pavement
design chart in Section 10.07.2. The CBR obtained from the testing or geotechnical
firm, the type and class of road from the City of Auburn, will assist in determining the
appropriate chart column.
A civil engineer licensed in the State of Washington may also design street pavement
sections. However, the minimum allowable thickness of asphalt will be a two inch (2”)
leveling course with a two inch (2”) overlay of class “B” asphalt. The maximum
allowable thickness for a single lift of asphalt shall be two inches (2”) for Class “B” and
four inches (4”) for Class “E”. Section 10.07.3 provides additional information on
pavement design requirements.
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
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.
Poor Soils
(CBR 3-5)
Medium Soils
(CBR 6-10)
Good Soils
(CBR 11-20)
Excellent
Soils
(CBR >20)
Private Streets
Alleys
Access Roads
2” CL “B”
5” CL “E”
12” Gravel Base
2” CL “B”
2” CL “E”
8” Gravel Base
2” CL “B”
2” CL “E”
6” Gravel Base
2” CL “B”
2” CL “E”
4” Gravel Base
Local Residential
Rural Residential
2” CL “B”
5” CL “E”
12” Gravel Base
2” CL “B”
2” CL “E”
8” Gravel Base
2” CL “B”
2” CL “E”
6” Gravel Base
2” CL “B”
2” CL “E”
4” Gravel Base
Local Non-
Residential
2” CL “B”
5” CL “E”
12” Gravel Base
2” CL “B”
4” CL “E”
8” Gravel Base
2” CL “B”
3” CL “E”
6” Gravel Base
2” CL “B”
2” CL “E”
4” Gravel Base
Residential Collectors
Rural Collectors
2” CL “B”
5” CL “E”
12” Gravel Base
2” CL “B”
4” CL “E”
10” Gravel Base
2” CL “B”
3” CL “E”
8” Gravel Base
2” CL “B”
2” CL “E”
6” Gravel Base
Non-Residential
Collectors
2” CL “B”
6” CL “E”
12” Gravel Base
2” CL “B”
5” CL “E”
10” Gravel Base
2” CL “B”
4” CL “E”
8” Gravel Base
2” CL “B”
3” CL “E”
6” Gravel Base
Minor Arterials
2” CL “B”
8” CL “E”
12” Gravel Base
2” CL “B”
7” CL “E”
10” Gravel Base
2” CL “B”
6” CL “E”
8” Gravel Base
2” CL “B”
5” CL “E”
6” Gravel Base
12/21/2009............................................Design Standards .........................................Page 10-35
REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
10.07.3 Requirements for Engineered Pavement Sections
Engineered pavement designs should follow the latest “AASHTO Guide for Design of
Pavement Structures” for flexible pavements and be based on the following criteria:
10.07.3.1 Traffic Requirements
For projects where a traffic analysis report was not required, to determine the amount
of traffic for which a street should be designed, contact the City to obtain the most
recent street classification and traffic counts. Traffic counts are done assuming there
is a 50/50 split in the direction of traffic. One hundred percent of the 50/50 split must
be assumed 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
half percent (3.5%) for commercial/industrial streets and arterials streets. The one
and a half percent (1.5%) growth can be waived in closed subdivisions with City
approval.
10.07.3.2 Pavement Minimums
For designers, the minimum allowable thicknesses of pavement sections are as
follows:
CL.“B” CL.“E” Gravel Base
Minor Arterials 2” 5” 6”
Residential/Rural Collectors 2” 2” 6”
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 to three (every
two inches (2”) of asphalt may be replaced with three inches (3”) of crushed rock). At
no time however shall asphalt be placed in less than a two inch (2”) thick lift.
Geo-textile fabric may be required between the subgrade and the gravel base where
soil conditions are poor.
10.07.3.3 Soils Classifications
Prior to designing the pavement thickness, the soils condition of the area in which the
road or street is to be built shall be evaluated and classified into one of the following
four different categories in this Section. These classifications and the tested soil
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, ML, CL, OL,
MH, CH, or as OH as per the Unified Soils Classification System. The CBR values
for these materials range from 3 to 5.
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
10.07.3.3.2 Medium Soils
These soils are relatively firm when wet and may contain some amounts of silt.
These soils would be classified as SP, SM, or SC as per Unified Soils
Classification System. The CBR value would range from 6 to 10.
10.07.3.3.3 Good Soils
These soils retain a substantial amount of their load-bearing capacity when wet.
These soils would be classified as GM, GC, SW, or SM 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.
10.07.3.3.5 Unified Soils Classification Symbols
GW: Well graded or gravel-sand mixtures with little or no fines.
GP: Poorly graded gravels or gravel-sand mixtures with little or no fines.
GM: Silty gravels or gravel-sand mixtures.
GC: Clayey gravels or gravel-sand-clay mixtures.
SW: Well graded sands or gravelly sands with little or no fines.
SP: Poorly graded sands or gravelly sand mixtures with little or no fines.
SM: Silty sands or sand silt mixture.
SC: Clayey sands or sand-clay mixtures.
ML: Inorganic silts and very fine sands, rock flour, silty or clayey fine sands or
clayey silty that are slightly plastic.
CL: Inorganic clays of low to medium plasticity, gravelly clays, sandy clays, silty
clays, lean clays.
OL: Organic silts and organic silt clays of low plasticity.
MH: Inorganic silts, micaceous or diatomaceous fine sand or silty soils, elastic
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 analysis report to the City of Auburn, including a
narrative of the site conditions, the pavement sections, and applicable background
information for review and approval. The report must detail data on how the design
was achieved including information on the subgrade soils. (Note: The soils
classification in Section 10.07.3.3 is not a substitute for tests to support soil capacity.)
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
10.07.4 Materials Specifications
The following material requirements are referenced from the City of Auburn’s Engineering
Construction Standards Manual and WSDOT Standard Specifications and are subject to
change. For the most current definitions, please reference the Construction Standards
Manual.
10.07.4.1 Gravel Base
Gravel base shall be bank run gravel, defined as naturally occurring material having
characteristics such that when compacted in place on the roadway, it will provide a
course having greater supporting value than 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)
B. Crushed Surfacing Base Course (CSBC)
CSTC and CSBC shall be in accordance with Section 9-03.9(3) of the WSDOT
Standard Specifications.
10.07.4.3 Asphalt Concrete Pavement
Asphalt use in City street construction will typically fall under the following two
classifications:
A. HMA Class “E”
B. HMA Class “B”
Asphalt Concrete Pavement shall be in accordance with WSDOT Standard
Specifications and the City’s Engineering Construction Standards Manual.
10.08 Landscaping
10.08.1 General Landscaping Requirements
An area devoted to landscaping is included within the right-of-way of all street
classifications. This landscape strip is an integral part of the roadway cross-section. It
serves several important functions, including improving pedestrian safety by providing a
buffer between traffic and the sidewalk; providing the perception of a narrower travel
corridor, thereby slowing traffic; improving air quality; and improving the aesthetic
appearance of the street. Located between the sidewalk and the street, landscape strips
are frequently used by pedestrians, hence they should not contain shrubs for these can
create a tripping hazard. Shrubs with a mature height not greater than 3 feet are however
often appropriate in medians, entry features and other landscaped areas in the public
right of way not traversed by pedestrians.
The applicant shall design and install the landscape strip in accordance with these design
standards. The proposed design shall be reviewed and approved by the City.
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
Landscape strips are required for local residential streets and residential collector streets.
The minimum width required for landscape strips is five feet (5’). Landscape strips shall
be located between the back of the curb and the sidewalk. The applicant shall provide
for and plant street trees within the landscape strip in accordance with these design
standards.
Street trees are required for principal arterials, minor arterials, non-residential collectors,
and local non-residential streets. Street trees shall be placed within the sidewalk in tree
pits with tree grates and spaced in accordance with the standards identified in Section
10.08.5.1.
10.08.2 Landscape Strip Components
Landscape strips contain several components. These include soil, the plants
themselves, structural 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
The roadway sections designate either five-foot (5’) or five and half-foot (5½’) wide
landscape strips.
10.08.4 Plant Layers
In order to balance a safe walking environment and improved aesthetics and air quality,
a multilayer planting approach is recommended in the landscape strip. For instance,
grass or an approved ground cover should be used at the ground level. Properly spaced
trees form the upper or canopy level. Within this general framework are many choices,
outlined in the Plant Selection section below.
In summary, the landscape strip will contain the following layers:
1. Ground Cover(s) or Grass—Required
2. Trees—Required
10.08.5 Trees
10.08.5.1 Placement and Spacing
Trees shall be placed so that they do not obstruct the view of any street intersection,
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 placed in tree
wells with tree grates within the sidewalk per City of Auburn Standard Detail
TRAFFIC-64.
Nearby features such as street lighting, inground utilities, buildings or overhead wires
will also affect where trees should be located. Minimum size for street trees shall be a
two inch (2”) caliper, measured two feet (2’) above the root ball.
Minimum spacing for street trees should be 1 1/2 times the mature diameter of the
tree canopy as identified in Table 10-5A.
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
Planting Next to a Building: Where a building is placed close to the sidewalk, the
mature size of a tree should be considered when selecting species. Trees with a
pyramidal, columnar, or oval shaped canopy are preferable; a tree with a round head
is generally unsuitable in this situation.
Overhead Wires: When trees must be planted directly under or when the mature
canopy is within twelve feet (12’) of overhead utility lines, species with a mature
maximum height of twenty-five feet (25’) must be selected.
Street Lighting: Trees need to be located at least half their mature canopy width or
twenty feet (20’) from light standards, whichever is greater. Planting locations should
be coordinated with locations of lighting standards.
Street Signage: Trees shall be planted to avoid blocking the view of street signage.
Underground Utilities: Trees shall be planted so as to avoid impacts on
underground utilities.
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
roadway surfaces.
10.08.5.2 Tree Canopy Shape
Tree canopy shapes are an important factor in the selection of street trees. The
setting will often dictate which canopy shapes are most appropriate. This in turn will
aid in the selection of the most suitable species.
The guidance offered below includes information about which tree canopy shapes
work best under different conditions. Table 10-5A offers information about tree
species and their canopy shapes.
10.08.5.2.1 V-Shaped Trees
V-shaped (sometimes also called “vase shaped”) trees have canopies that are
narrow toward the bottom and broad at the top. The American Elm is a classic
street tree with this shape. V-shaped trees may have arching branches that form a
canopy over both street and sidewalk. They generally do not cause problems with
overhead power lines or traffic.
10.08.5.2.2 Pyramidal Trees
Pyramidal or cone-shaped trees are typically broad at the base of the canopy and
are somewhat pointed at the top. Planted close together, pyramidal trees can
screen unwanted views or create vistas. Lower branches sometimes droop with
age and may have to be limbed up in later years to provide the needed clearance.
10.08.5.2.3 Round Trees
These are generally wide spreading trees that need more space than other
shapes.
10.08.5.2.4 Oval Trees
Oval trees are taller than they are wide and cause less interference with traffic.
10.08.5.2.5 Columnar Trees
Columnar trees are useful in locations where there is little available room between
the street and buildings, awnings, or other features. Branches of columnar trees
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
tend to grow up rather than out. Many branch lower than other types of trees
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 shall use a root
direction device to deflect tree roots downward into the soil. Any tree planted on
public property within 10 feet or less of a sidewalk or curb shall be planted with a root
directional device. 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
and to the curb line. Under 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
In highly urbanized settings such as downtown, it may be necessary to install street
trees into an existing street and sidewalk setting. Where high levels of pedestrian
traffic is expected, it may be necessary to place trees into a paved area rather than a
landscape strip. In these situations planting wells and grates may be necessary. The
desirable size for a tree planting well is thirty-six square feet (36 sq.ft.) or greater. A
minimum of twenty-five square feet (25 sq.ft.) should be provided.
Where trees are within a heavily traveled pedestrian area, their roots can be easily
damaged. In these areas tree grates or other means such as pavers in sand will be
required to protect the health of the tree.
Where tree wells or grates are necessary, provide planting details, specifications, and
product sheets for proposed tree-planting wells and tree grates. See Standard Details
TRAFFIC-14.
10.08.6 Plant Selection
There are innumerable plant choices for each layer of the landscape strip. Selection is
based on:
Size of the landscape strip
Canopy shape of trees
Size and type of leaves
Root shape
Site environmental conditions, such as the amount of sunlight available or
moisture in the soil; and
Aesthetic qualities desired.
Needled evergreens shall NOT be used in landscape strips, unless the strips are very
wide.
10.08.7 Plant Selection Table
Table 10-5A provides several acceptable species of trees. Many other trees are
appropriate and alternative selections may be proposed if desired. Alternative plant
choices must be evaluated and approved by the City.
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
Column Headings: A short description of several of the column headings follows:
Height and Canopy Width (in feet):
Trees vary considerably in height and mature width and these dimensions are
identified per species to ensure that the right tree is being planted in the right
location.
Landscape Strips/Wells and Grates and Median:
This section identifies which species are appropriate to be planted in these locations
Sun:
Sun Needs full sun
Sun/Shade Takes sun to part shade; needs at least ½ day of sun
Shade Shade to part shade. Protect from full sun, especially in afternoon
H20 Req. (Requirement):
Low Drought tolerant after 1st year
Mod Moderate water need. May need supplemental watering during dry season.
High Requires irrigation
Canopy Shape:
“V” V-shaped Trees (sometimes also called “vase shaped trees”)
Pyramid Pyramidal trees or cone shaped trees
Round Round trees
Oval Oval trees
Col. Columnar trees
See Table 10-5A with Tree Matrix.
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
TABLE 10-5A (TREES FOR THE PUBLIC RIGHT-OF-WAY ENVIRONMENT)
Botanical
Name
Common
Name
Mature
Height
(ft.)
Mature
Canopy
Width
(ft.)
Min.
Landscape
Strip Width Planting OK?
Leaf
Size
Canopy
Shape
H20
Req Sun Remarks
5'-
6' >10'
Wells
&
Grates Median
Acer campestre
Queen
Elizabeth
Maple
'Evelyn' 35 30 x x x 2"-4" Oval Mod
Sun/
part.
sun Hardy tree
Acer freemanii
Autumn
Blaze Maple 50 40 x x 4"-8" Oval Mod Sun
Fast
Growing
Acer ginnala
Amur Maple
'Flame' 20 20 x x x
1.5"-
3" Round Mod
Sun/
part.
sun
Good
power line
tree.
Acer
grandidentatum
Rocky Mt
Glow Maple
'Schmidt' 25+ 15 x x x x 4"-8" Round Mod
Sun/
part.
sun
Requires
pruning
for
clearance
Acer Nigrum
Green
Column
Maple
'Green
Column' 50 20 x x x x 4"-8" Col Mod
Sun/
part.
sun
Acer
platanoides
Norway
Maple
'Emerald
queen' 50 40 x x 4"-8" Oval Mod
Sun/
part.
sun
Popular
variety
Acer
platanoides
Norway
Maple
'Columnar' 40 15 x x x x 4"-8" Col Mod
Sun/
part.
sun
Good
street tree
Acer rubrum
Bowhall
Maple
'Bowhall' 40 15 x x x x 2"-4"
Upright/
round Mod
Sun/
part.
sun
tolerant of
wet soil
Acer rubrum
Scarlet
Sentinel
Maple
'Scarsen' 40 20 x x x x 2"-4" Col Mod
Sun/
part.
sun
tolerant of
wet soil
Acer rubrum
Karpick
Maple
'Karpick' 35-40 20 x x x x 2"-4" Col Mod
Sun/
part.
sun
Acer saccharum
Sugar Maple
'Green
Mountain' 45 35 x x 3"-6" Oval Mod
Sun/
shade/
part.
sun
Acer truncatum
x A. platanoides
Pacific
Sunset
Maple
'Warrens
Red' 30 25 x x x x 4"-8" Round Mod Sun
Good fall
colors
Amelanchier x
grandiflora
Serviceberry
'Princess
Diana' 20 15 x x x 2"-4"
Upright/
round Mod
Sun/
part.
sun
Small
tree, red
in fall
Amelanchier x
grandiflora
Serviceberry
'Autumn
brilliance' 20 15 x x x 2"-4"
Upright/
round Mod
Sun/
part.
sun
Resistanc
e to ice
breakage
Carpinus
betulus
Pyramidal
European
Hornbeam
'Fastigiata' 35 25 x x x x 2"-4" Col Low
Sun/
part.
sun
Very
urban
tolerant,
good
street tree
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
TABLE 10-5A (TREES FOR THE PUBLIC RIGHT-OF-WAY ENVIRONMENT) continued
Botanical
Name
Common
Name
Mature
Height
(ft.)
Mature
Canopy
Width
(ft.)
Min.
Landscape
Strip Width Planting OK?
Leaf
Size
Canopy
Shape
H20
Req Sun Remarks 5'-6' >10'
Wells
&
Grates Median
Carpinus
betulus
Frans
Fontain
Hornbeam 35 15 x x x x 2-4 " Col Mod Sun
Cercidiphyllum
Japonicum
"Rotfuchs"
Red Fox
Katsura 30 16 x x x x 4" Oval Mod Sun
Fagus sylvatica
Green
Beech 50 40 x x 5" Oval Mod
Sun/
part.
sun
Does not
like wet soil
Fagus sylvatica
Dawyck
Purple
Beech
'Dawyck
Purple' 40 12 x x x x 2"-4" Col Mod
Sun/
part.
sun
Purple
leaves
Fagus sylvatica Red Obelisk 35 12 x x x x
2 - 4
" Col Mod Sun
Fraxinus
americana
Ash 'Autumn
Applause' 40 25 x x x x 2"-4" Oval Low
Sun/
part.
sun
Deep red
fall colors
Fraxinus
oxycarpa
Raywood
Ash
'Raywood' 45 30 x x x x 2"-4" Oval Low Sun
Fraxinus
pennsylvanica
Leprechaun
Ash
'Johnson' 18 16 x x x x 2"-4" Round Mod Sun
Good
power line
tree.
Fraxinus
pennsylvanica Ash
'Urbanite' 50 40 x x 2"-4" Pyramid Low Sun
Fraxinus
pennsylvanica Patmore Ash
'Patmore' 45 35 x x x x 2"-4" Oval Low Sun
Very good
tree
Ginko biloba
Ginko
'Autumn
Gold' (Male
Trees Only) 45 35 x x x x 2"-4" Oval Mod
Sun/
part.
sun
Use males
only
Ginko biloba
Ginko
'Princeton
Sentry'
(Male Trees
Only) 40 15 x x x x 2"-4" Col Mod
Sun/
part.
sun
Use males
only
Liriodendron
tulipefera Tulip Tree 60 30 x x 4"-6" Oval Mod Sun
Extremely
large tree
Lirioendron
tulipifera
Tulip tree
'Arnold' 60 30 x x x 4"-8" Oval Mod Sun
Grows
extremely
large
Malus "Marilee" 24 10 x x x x 2"-4" Cone Mod Sun
No fruit.
Good
power line
tree.
Nothofagus
antartica
Southern
Beech 50 35 x x 2"-4" Round Mod Sun
Plantus x
acerifolia
Planetree
'Yarwood' 50 40 x 6"-7" Round Mod Sun
Bark
defoliates
Prunus
Mt. St.
Helens Plum
'Frankthrees' 20 20 x x x x 2"-3" Round Mod Sun
Hardy tree.
Good
power line
tree.
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
TABLE 10-5A (TREES FOR THE PUBLIC RIGHT-OF-WAY ENVIRONMENT) continued
Botanical
Name
Common
Name
Mature
Height
(ft.)
Mature
Canopy
Width
(ft.)
Min.
Landscape
Strip Width Planting OK?
Leaf
Size
Canopy
Shape
H20
Req Sun Remarks
5'-
6' >10'
Wells
&
Grates Median
Prunus
Snow Goose
Cherry
'Snowgoose' 20 20 x x x 2"-4"
Upright
spreading Mod Sun
Disease
resistant.
Good power
line tree.
Prunus
cerasifera
Flowering
Plum 'Krauter
Vesuvius' 30 15 x x x x 2"-4" Round Mod Sun
Prunus
sargentii
Cherry
'Columnarus' 35 15 x x x x 4"-8" Col Mod Sun
Fast
grower.
Prunus
serrulata
Flowering
Cherry
'Amanogowa' 20 6 x x x x 2"-4" Vase Mod
Sun/
part.
sun
Short lived.
Good power
line tree.
Prunus x hillieri Cherry 'Spire' 30 10 x x x x 2"-4" Col Mod
Sun/
part.
sun
Good fall
colors.
Prunus x
yedoensis
Flowering
Cherry
'Akebono' 25 25 x x x 2"-4"
Round/
vase Mod Sun
Best pick for
region.
Good power
line tree.
Pyrus
calleryana Pear 'Capital' 35 12 x x x 2"-4" Col Mod Sun
Susceptible
to fire blight.
Pyrus
calleryana
Pear
'Aristocrat' 40 28 x x x x 2"-4" Pyramid Mod Sun
Susceptible
to fire blight
Pyrus
calleryana
Pear
'Redspire' 35 25 x x x x 2"-4" Pyramid Mod Sun
Susceptible
to fire blight
Pyrus
calleryana
Pear 'Autumn
Blaze' 30 25 x x x 2"-4" Round Mod Sun
Susceptible
to fire blight
Quercus
Crimson
Spire Oak
'Crimschmidt' 45 15 x x x x 4"-8" Round Mod Sun
Quercus robur
Skyrocket
Oak
'Fastigiata' 45 15 x x x 4"-8" Oval Mod Sun
Good street
tree
Styrax
japonica
Japanese
Snowbell 25 25 x 2"-4" Round Mod
Sun/
part.
sun
Slow
growing.
Good power
line tree.
Tilia americana
Linden
'Redmond' 35 20 x x x x 4"-8" Pyramid Mod
Sun/
part.
sun
tolerant to
wet soil
Tilia cordata
Linden
'DeGroot' 30 20 x x x x 2"-4" Pyramid Mod
Sun/
part.
sun
Tilia cordata
Chancelor
Linden
'Chancole' 35 20 x x x x 2"-4" Pyramid Mod
Sun/
part.
sun
Good street
tree
Tilia cordata
Linden
'Greenspire' 40 30 x x x x 2"-4" Pyramid Mod
Sun/
part.
sun
Tolerant to
difficult
conditions
Zelkova
serrata
Zelkova
'Village
Green' 40 38 x x 1"-3" Vase Mod Sun Good tree
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
Table 10-5B provides several acceptable species of ground covers and, shrubs less than 3 feet
high. Many other types of plants may be appropriate and alternative selections may be
proposed if desired. Alternative plant choices must be evaluated and approved by the City.
See Table 10-5B.
TABLE 10-5B (GROUND COVER/LOW SHRUBS)
Botanical
Name Common Name
Mature Height
(ft.)
Minimum
Planting
Area Width
(ft.) Sun
Obvious
Flowers Remarks
Arctostaphylos
Una-Ursi
Kinnikinnick
Bearberry 0.5’ to 1’ 5 to 6'
Full sun
to partial
shade Yes
Useful on slopes, poor
or dry soils. Slow to
establish;
must be weeded early.
Ceanothus
Gloriosus
California Wild
Lilac 1.5’ 6' to 8' Full sun Yes
Cotoneaster
Dammeri
Bearberry
Cotoneaster < 2’ 5 to 6 ' Yes Fast growing
Euonymus
Fortunei
Coloratus
Purple Leaf Winter
Creeper 1.5’ 6' to 8'
Full sun
to light
shade Yes
Hypericum
Calycinum St. John's Wort 1’ to 1.5’ 2'
Full sun
to partial
shade Yes
Juniperus
Horizontalis
Blue Chip
Juniper/Hughes
Juniper 1’ 6' to 8' Full sun No
Microbiota
Decussata
Siberian Carpet
Cypress 1.5’ 7' to 8'
Full sun
to light
shade No
Rubus
Calycinoides
Evergreen
Bramble 1’ 6' Full sun Yes
Vinca Minor Periwinkle 0.5’ 1.5'
Full sun
to partial
shade Yes
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
10.08.8 Planting Methods and Maintenance
Good horticultural practice should be employed in the preparation of the soil and planting
pits. This will include:
1. Conserving topsoil and replacing it on the site.
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 the public
landscape strip, medians and entry features in a healthy condition for one (1) year after
acceptance of the project. Because landscape strips do not usually include irrigation,
maintenance will include providing water during dry periods. Weeds, diseases, and
insect pests must also be controlled.
10.08.10 Deviations from the Landscape Strip Standards
Site conditions may occasionally make adhering to the landscape strip standards difficult.
Deviations from the standards may be requested. The following paragraphs list
circumstances that may be appropriate conditions for requesting a departure from the
design standards:
Grass or Ground Cover: Where it is extremely difficult to maintain grass in a landscape
strip, heav y 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 is not acceptable.
10.09 Mailboxes See Standard Details TRAFFIC-16 thru TRAFFIC-19
Locating and installing mailboxes in connection with the construction or reconstruction of a
City street shall follow AASHTO and Post Office guidelines.
10.09.1 Mailbox Locations
Mailboxes shall be located a minimum of two feet (2’) back from the face of curb on
streets which have a curb. For streets without a curb, setbacks shall be determined
using ASSHTO standards. When locating mailboxes, access, sight distance, and
landscaping requirements shall be taken into account. Final locations shall be detailed
on the civil plans and approved by the serving Post Office and the City.
When mailboxes are located in the sidewalk, individually or in clusters, sidewalks shall be
widened to provide a minimum five feet (5’) of clearance around the mailboxes.
Widening of the sidewalk may require the dedication of additional right-of way.
10.09.2 Mailbox Installation
The owners or residents served by mailboxes will install and thereafter maintain their own
individual, clustered, or separated mailboxes as instructed by the U.S. Postal Service.
Mailbox installation shall follow City of Auburn Standard Details TRAFFIC-16, TRAFFIC-
17, TRAFFIC-18, and TRAFFIC-19.
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
10.10 Illumination
10.10.1 General
The City desires to have safe and uniform lighting standards for streets to allow safe
comfortable use by all users. The City has approved standard lighting infrastructure for
reliability and ease of parts inventory and maintenance. Roadway lighting is required
along all City owned streets except classified Rural Collectors and Rural Residential.
Street lighting design shall be in conformance with the design criteria in the most recent
edition of the IES Lighting Handbook (Illuminating Engineering Society of North America)
and applicable WSDOT and City of Auburn Construction Standards.
10.10.2 Design
The City of Auburn prefers staggered lighting on all Principal and Minor Arterials. Single
sided lighting may be acceptable if approved by the City. Local Residential streets will
have a choice between a standard light and an ornamental alternative. Table 10-6 has
been included as a general guideline for determining illumination sizing and location
requirements. Project specific lighting calculations shall be provided to insure minimum
illumination levels will be met. Light level calculations shall be done ignoring any existing
substandard luminares (PSE lights on wood poles, etc.).
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 ninety miles per hour (90 mph) with a gust factor of 1.3.
Special consideration shall be given for light levels at crosswalks, curves, conflict points
and street ends and shall be designed to meet the minimum light level of 0.2 foot candle.
Roadway lighting levels also are impacted by the type of pavement surfacing and special
consideration shall be given for surfaces like concrete roadways.
When pedestrian lighting is used the street light design shall be done independent from
the influence of the pedestrian lighting. Pedestrian light spacing shall not exceed five
times the mounting height. When pedestrian lighting is installed, sidewalk lighting shall
be designed for two foot (2’) candles.
All illumination plans shall include a lighting schedule. Each luminaire shall be numbered
such that the circuit number, the mounting height, davit length and wattage are clearly
indicated.
For Boulevard streets, streets with median islands, double arm street lights in the median
may be allowed meeting all applicable design criteria of these standards. In addition,
access accommodations allowing for light maintenance vehicles to park outside the travel
way must be incorporated into the median island design.
The locations of street lights shall take into consideration any obstacles which may screen
or impede lighting levels such as street trees and awnings. Street trees shall be located a
minimum of twenty feet (20’) from all streetlights.
10.10.3 Table 10-6 Lighting Schedule
The following Light Spacing is based on the roadway classifications for a typical straight
roadway section with a staggered lighting configuration. Wider road sections, curves,
intersections, cul-de-sacs and single sided lighting configurations must use a calculated
design meeting the criteria on Table 10-6 with the exception of the Spacing criteria.
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
TABLE 10-6
Street
Classification
Street
Width
(feet)
Lamp
Wattage
Average
Maintained
Light Level
(foot-
candle)
Required
Uniformity
Ratio
Minimum
Light Level
(foot-
candle)
Luminaire
Mounting
Height
(feet)
Light
Pattern
Davit
Arm
Length
(feet)
Spacing
(feet)
Principal
Arterial
61 400 1.4 3 To 1 0.2 35 40 M-C III 12 190
Minor Arterial
50/61 250 0.9 3 To 1 0.2 35 M-C III 10 190
Non-
Residential
Collector
44 250 0.9 3 To 1 0.2 35 M-C III 6 200
Residential
Collector
34 150 0.6 3 To 1 0.2 30 M-C III 6 175
Local Non-
Residential 34 150 0.6 3 To 1 0.2 35 M-C III 6 160
Rural
Collector*
Local
Residential 28 100 0.4 6 To 1 0.1 30 M-C III 8 185
Local
Residential
Ornamental
Alternative
28 100 0.4 6 To 1 0.1 12 M-C III N/A 140
*Illuminate Signalized Intersections only.
For downtown pedestrian lighting requirements, contact the City of Auburn.
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
10.10.4 Light Standard Foundations See Standard Detail TRAFFIC-49, TRAFFIC-61
& TRAFFIC-63
All light poles shall be placed on a foundation. Foundations for light standards shall
conform to Standard Detail TRAFFIC-49, or TRAFFIC-61 and TRAFFIC-63 for the
Downtown light standards.
Light pole foundations adjacent to sidewalks shall include a four inch (4”) concrete pad
and conform to Standard Detail TRAFFIC-48.
10.10.5 Service Cabinet See Standard Detail TRAFFIC-51
All new luminaires shall be connected on an electrical circuit that is connected to a power
source through a service cabinet. Service cabinets shall conform to Standard Detail
TRAFFIC-51 and shall be metered with a photocell installed for luminaire control. The
service cabinet shall be within fifty feet (50’) of the Puget Sound Energy (PSE) point of
service connection.
Service cabinets should be installed behind the sidewalk when possible at locations that
do not impede maintenance access. The cabinet should be located in the center of the
system so there are a near equal number of lights being served on separate circuits from
each side of the 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-51
The Service Cabinet foundation shall conform to Standard Detail TRAFFIC-51.
10.10.7 Conduit
Street light conduit shall be Schedule 40 PVC-ASTM D1785. All conduits for street
crossings shall be Schedule 80 PVC-ASTM D1785. All conduits installed under sidewalk
and driveway areas shall be Schedule 40 PVC-ASTM D1785. Conduit type shall not
change within a run. Conduits installed under paved roadway, not crossing the roadway,
shall be Schedule 80 PVC-ASTM D1785. Conduits shall have a minimum of twenty-four
inches (24”) of cover. The City requires that street light conduit be extended through a
property’s frontage for future expansion of the lighting system.
10.10.8 Junction Boxes See Standard Detail TRAFFIC-50
A. Street Junction boxes shall conform to Standard Detail TRAFFIC-50.
Junction boxes shall be of the type specified on the plans and shall conform
to the requirements of WSDOT Standard J-40.10-01. All junction boxes shall
be locking.
B. Type 1 junction boxes shall be located adjacent to the sidewalk within the
landscaping strip, if provided, or adjacent to the back of sidewalk if a
landscape strip does not exist, or within the shoulder of a non-curbed
roadway.
10.10.9 Light Standards
A. STANDARD LUMINARE See Standard Detail TRAFFIC-49
Lighting standards shall be tapered aluminum, davit-style units, with five feet
nine inch (5’9”) radius per Section 9-29.6(1)A (Lighting Standards and Davit
Arms, of the City of Auburn Engineering Construction Standards), and shall
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
be installed in conformance with City of Auburn Standard Detail TRAFFIC-48
and TRAFFIC-49.
B. DOWNTOWN STREET LIGHTING LUMINARE See Standard Detail
TRAFFIC-63
Light standards located within the Downtown Urban Center as depicted on
the Comprehensive Zoning Map shall be a 40 foot Concrete Ameron MBR.
C. DOWNTOWN PEDESTRIAN LUMINARE See Standard Detail
TRAFFIC-61 & 61a
Pedestrian light standards located within the Downtown Urban Center as
depicted on the Comprehensive Zoning Map shall be 18 ft concrete Ameron
VBR.
D. LOCAL RESIDENTIAL ORNAMENTAL ALTERNATIVE LUMINARE See
Standard Detail TRAFFIC-62
The Local Residential Ornamental Alternative light standard shall conform to
Standard Detail TRAFFIC-62 and shall be Holophane Wadsworth series
fluted shaft with seventeen-inch (17”) diameter base (W12F4/17CA/BK or
DG) and may be used in residential plats in place of the standard luminare.
E. ANCHOR BASES
Anchor bases per Section 9-29.6(2) (Anchor Bases, of the City of Auburn
Engineering Construction Standards) shall conform to the Standard Detail
TRAFFIC-49, TRAFFIC-61, TRAFFIC-62, or TRAFFIC-63.
10.10.10 Light Standard Handholes See Standard Detail TRAFFIC-49
Light Standards handholes shall be four inches by six inches (4”x 6”) nominal non-flush
type in accordance with Standard Detail TRAFFIC-49.
10.10.11 Photoelectric Controls
Photocells installed on the service cabinet shall be “SST” Series model “SST-IES” or
approved equal in conformance with Section 9-29.11(2) (Photoelectric Controls) of the
City of Auburn Engineering Construction Standards. A bypass switch shall be required
inside the service cabinet, clearly marked PE Bypass. One photocell will be required per
service cabinet.
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
10.10.12 Luminaires
A. Luminaires shall meet the general requirements of Section 9-29 (Illumination,
Signals, Electrical) of the City of Auburn Engineering Construction Standards
with the following modifications:
1. Clear burning high-pressure sodium light sources of the ratings shown
in the lighting schedule shall be used.
2. Street and Pedestrian Luminaires shall operate on 240 Volt AC and all
luminares shall be full cuttoff.
B. All luminaires and circuits shall conform to Table 10-7 below:
TABLE 10-7
Wattage Max. LuminairesPer Circuit
100 14
150 12
250 8
400 7
C. All luminaires shall be provided with markers for positive identification of light
source and wattage per Section 9-29.10 (Luminaires) of the City of Auburn
Engineering Construction Standards. A maximum of five percent (5%)
voltage drop across each circuit will be permitted. Voltage drop calculations
will be required for all non-standard illumination systems.
10.11 Survey Monuments Standard Details TRAFFIC-20 thru TRAFFIC-22
Survey monuments shall be placed or replaced in accordance with good practice in land
surveying. Monuments are required along the centerline of improvement of all new or
reconstructed streets. Monuments shall be placed at intersections, P.C. (points of
curvature), and P.T. (points of tangency).
All existing survey monuments that are disturbed, lost, or destroyed during construction shall
be replaced by a registered land surveyor registered in the State of Washington at the
expense of the responsible builder or developer.
10.12 Guardrail
Evaluation of embankments for guardrail installations shall be in accordance with Chapter
710 of the WSDOT Design Manual.
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.
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
10.13 Bollards Standard Detail TRAFFIC-06
When necessary to deny vehicle access to an easement, tract, or trail (except for
maintenance or emergency vehicles) the point of access shall be closed by a line of bollards.
These shall include one or more fixed bollards on each side of the traveled way and
removable, locking bollards across the traveled way. Spacing shall provide one bollard on
centerline of the trail and other bollards at a maximum spacing of three feet (3’) to preclude
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 concurrence of the Fire
Marshal. Bollards shall be ten feet (10’) from the paved edge of roadway.
10.14 Transit Stops
This section provides the minimum design standards to be used in the design of bus transit
facilities in the City of Auburn. Bus facilities shall be designed, located and installed in
cooperation with appropriate operating transit agency.
When determined appropriate by the City Engineer, or if comments are made by a transit
service agency, an applicant for new or expanded development is encouraged to consult
with King County METRO, or Pierce Transit to determine the practicality of how the site can
be served by transit oriented improvements such as bus pullouts, bus stops, or other
appurtenances.
10.14.1 Bus Pullout Requirements
Bus pullout lanes may be required where bus queuing or staging is required by the transit
agencies operations and at the discretion of the City Engineer. The following are
guidelines that would indicate pullouts would be appropriate:
A. Traffic and passenger boarding and debarking conditions warrant.
B. Traffic flow would be greatly hindered due to in lane stopping.
C. The posted speed limit is in excess of thirty miles per hour (30 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 far side of signalized intersections and
non-signalized intersections immediately following the intersection. Distance
between pullouts should not be less than one thousand feet (1000’).
B. If far side pullouts are not possible, nearside pullouts will be evaluated. Mid-block
pullouts are discouraged. If a situation arises where a mid-block bus pullout is the
only option, pullouts should be constructed on both sides of a two-way street in a
complementary pair.
C. Maintaining adequate separation between access points, intersections, and bus
pullouts can increase the safety and efficiency of both the roadway and the transit
service.
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
D. When locating a bus pullout consideration shall be given to existing access points
and where passengers have safe and direct access to sidewalks, crosswalks,
ramps, or other pedestrian facilities. Consideration shall also be given to trip
attractors, and activity centers.
E. Bus pullouts must meet sight distance requirements. See Section 10.03.
10.14.3 Design of Bus Pullouts
Bus Pullouts shall be designed in accordance with the applicable operating transit
agency’s guidelines. Designs must follow 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.
10.14.4 Bus Stop Requirements
Bus stops are located, designed and installed as part of a cooperative effort between the
City and the operating transit agency. Bus stops are managed as part of a right of way
use permit granted by the City to the operating transit agency. In general bus stop
location and design decisions should follow the facility design guidelines of the operating
transit agency. The King County Metro Transit Planning Office or Pierce County Transit
should be contacted for specific design questions.
10.14.5 Locations for Bus Stops
In general bus stop location and design decisions should follow the facility design
guidelines of the operating transit agency. The following are guidelines that indicate
where bus stops are appropriate:
A. Projected or existing passenger boarding and debarking demand warrant a stop.
B. Traffic characteristics and street design make the location safe to stop a transit
vehicle.
C. The location meets the facility guidelines and fleet specifications of the operating
transit agency.
D. The stop is required to be accessible to the physically challenged (Americans with
Disabilities Act).
10.14.6 Bus Stops Features
In general bus stop location and design decisions should follow the facility design
guidelines of the operating transit agency. The following are some guidelines that would
indicate what type of treatment would be appropriate by type of bus stop.
A. Shelters should be installed at bus stops with an existing or estimated 25 or more
boardings per day.
B. Benches should be installed at bus stops with an existing or estimated 15 or more
boardings per day.
C. Trash receptacles should be installed and maintained by the operating transit
agency at all bus shelters. A sign should be placed indicating that the shelter stop
is maintained by the operating transit agency and giving specific contact
information to report problems with the stop including a phone number.
D. At all bus stops experiencing 15 or more boardings per day trash receptacles may
be placed by the City or adopt a spot group and should be maintained by the City
or the adopt a stop group.
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
E. Information schedules and schedule holders shall be placed at all inbound stops
(stops where buses are headed toward a major Central Business District), at all
transfer points and at heavily used outbound stops.
F. Additional bus stop lighting should be provided at locations where lighting levels
are determined to be less than 3 foot candles.
G. The stop should be accessible to the physically challenged (meeting the
requirements of the Americans with Disabilities Act).
10.15 Traffic Control Devices
Traffic Control devices are all signs, signals, markings and other devices used to regulate,
warn, or guide traffic. All traffic control devices shall meet the requirements of FHWA’s latest
adopted version of the Manual on Uniform Traffic Control Devices (MUTCD) and the
standards herein.
10.15.1 Median Islands
Median Islands are raised barriers constructed between opposing lanes of travel. Median
Islands are generally restricted to classified roadways and may be required in order to:
1. Control access along a corridor, or
2. Provide a traffic calming element.
10.15.1.1 Median Island Design
Median Islands shall be designed using the same geometric criteria as the street on
which they will be constructed. Medians shall also meet the following requirements:
A. Median Ends: Median ends shall be flared at intersections and at breaks to
allow for transitioning traffic, ease of street sweeping and shall include signage in
accordance with MUTCD requirements.
B. Width: Median islands shall be a minimum curb to curb width of eight feet (8’)
when landscaped and a minimum of four feet (4’) in width when paved.
C. Shy Distance: One foot (1’) minimum shy distance shall be maintained from
face of median curbs to edge of travel lanes.
D. Landscaping/Paving: Landscaping in medians shall conform to the
requirements of Section 10.08. Median paving shall be stamped asphalt with
colors and patterns approved by the City.
E. Irrigation: Landscaped medians shall include irrigation systems.
F. Illumination: Street lights on streets with median islands eight feet (8’) in width
and greater shall be located in the medians using dual arm posts and shall meet
the minimum light level requirements of Section 10.10.
G. Maintenance Access: Median islands eight feet (8’) in width and greater shall
provide a paved maintenance staging area fifty feet (50’) in length with
mountable curbs. Median islands smaller than eight feet (8’) in width shall
include one fifty foot (50’) break in the median per block.
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
10.15.2 Traffic “C” Curbs
Traffic “C” Curbs are barrier curbs used for the restriction of turning movements and to aid
in the channelizing of traffic, Traffic “C” curbs may be required in order to control access
along a corridor within the restricted zones of any functional intersection boundary as
defined in Section 10.04.
10.15.2.1 Traffic “C” Curb Design
Traffic “C” Curb layout shall be designed using the geometric criteria for
channelization. An approved list of barrier curb products can be obtained from the
Public Works Department. Use of any Traffic “C” Curb products not on the approved
list must be approved by the City Engineer and meet the following requirements:
A. Shall be a National Cooperative Highway Research Program (NCHRP 350)
approved product.
B. Shall be constructed of all-weather, shatter and crumble resistant materials.
C. Shall not restrict the flow of street surface drainage.
D. Shall include MUTCD compliant reflective markings and vertical channelizing
devices.
10.15.3 “Pork Chop” Islands
“Pork Chop” Islands are barrier islands used to restrict turning movements at driveways.
They may be required at any driveway where left turns are restricted and Median Islands
or Traffic “C” Curb installation is not feasible. When required, Pork Chops shall be
accompanied by appropriate turn restriction signing and pavement markings.
10.15.4 Signing
All signing shall be per the “Manual on Uniform Traffic Control Devices” (MUTCD) and
City of Auburn Engineering Construction Standards.
Developments shall be responsible for providing and installing all traffic control signs,
including but not limited to street name signs, regulatory signs, warning signs, barricades,
and bicycle/pedestrian signs as required.
10.15.5 Pavement Markings See Standard Detail TRAFFIC-35
Pavement markings, raised markers, or striping shall be used to delineate channelization,
lane endings, crosswalks, and longitudinal lines to regulate, warn or guide traffic. The
City shall approve all channelization plans and crosswalk locations.
10.15.5.1 Crosswalks See Standard Details TRAFFIC-36 thru TRAFFIC-38
& TRAFFIC-58
Crosswalks shall be installed at all intersections controlled by traffic signals and other
areas approved by the City. Crosswalks shall be a piano key design consisting of
white thermoplastic material. The position of the crossbars should be spaced in such
a way as to allow the majority of wheel traffic to pass in the unpainted space.
10.15.5.2 Left-turn Channelization See Standard Detail TRAFFIC-40 & 42
Left-turn channelization shall include a minimum of one hundred fifty feet (150’) of full-
width lane to include storage and a reverse curve ninety feet (90’) in length for posted
speed up to forty-five miles per hour (45 mph). The reverse curve may be included in
the taper distance. The standard width of a left-turn lane will be eleven feet (11’).
Left-turn arrows per Standard Detail TRAFFIC-35 shall be installed twenty-five feet
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
(25’) behind the stop bar. Additional storage may be required for long vehicles or
anticipated left-turn queues longer than the minimum storage. If storage length
exceeds one hundred fifty feet (150’), auxiliary turn arrows will be installed at one
hundred foot (100’) intervals. Deviation requests from the minimum left turn lane
storage requirements will need a traffic study submittal and approval by the City
Engineer.
10.15.5.3 Left-turn Lane at End of Two-way Left-turn Lane See Standard
Detail TRAFFIC 39
Left-turn lane at the end of two-way left-turn lanes shall conform to Standard Detail
TRAFFIC-39.
10.15.5.4 Lane Division See Standard Detail TRAFFIC-43
All pavement markings used to separate or channelize traffic shall conform to
Standard Detail TRAFFIC-43.
10.15.5.5 Painted Islands
Painted islands will be allowed on a case-by-case basis with approval from the City
Engineer. Pavement markings for painted islands shall meet the MUTCD
requirements.
10.15.5.6 Two-way Left-turn Lanes See Standard Detail TRAFFIC-40 & -41
The installation of two-way left-turn lanes on City streets will be 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
(Single Broken Yellow) and a SSY (Single Solid Yellow) along the opposing lanes per
the MUTCD. Two-way traffic arrows shall be spaced every one hundred fifty feet
(150’) along this lane. The designer should pay special attention to the beginning and
endings of this type of lane and use clearly defined tapers or islands to maintain traffic
safety.
10.15.6 Construction Area Temporary Traffic Control
The contractor shall be responsible to provide and maintain all signs, barriers, warning
lights, striping, and flag control required for maintaining public safety in construction
areas. Traffic control shall be maintained at all times when construction is in progress on
all streets, and access points in the construction area.
Construction activities will not be allowed in the public right of way without an approved
traffic control plan.
10.16 Roadway Barricades Standard Detail TRAFFIC-05
Temporary and permanent barricades shall conform to the standards described in
Section 6C-8 of the Manual on Uniform Traffic Control Devices (MUTCD) and Standard
Detail TRAFFIC-05.
A. Type I or Type II barricades may be used when traffic is maintained through an area
being constructed/reconstructed.
B. Type III barricades may be used when streets are closed to traffic. Type III
barricades may extend completely across the street (as a fence). Where provision
must be made for access of equipment and authorized vehicles, the Type III
barricades may be provided with movable sections that can be closed when work is
not in progress, or with indirect openings that will discourage public entry. Where job
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REF. H\DEVELOPMENT\Design Standards\Chapter 10 (01-10)
site access is provided through the Type III barricades, 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.
10.17 Traffic Impact Analysis
The City of Auburn has established guidelines for Traffic Impact Analysis that are herein
adopted by reference. These guidelines are used to identify capacity and safety concerns,
to assist in the evaluation of site design as it relates to traffic engineering issues, and to
identify appropriate solutions and mitigation.
To adequately assess a development’s traffic impact, the City Engineer may require a Traffic
Impact Analysis. The requirement for a Traffic Impact Analysis will be based on the size of
the development proposed, existing street and intersection conditions, traffic volumes,
accident history, safety considerations, community concerns, and other pertinent factors
relating to traffic impacts attributable to the development.
10.17.1 When Traffic Impact Analyses are Required
The following is a list of some specific conditions that may dictate the requirement for
preparing a Traffic Impact Analysis.
The development generates more than 30 PM peak hour trips on a corridor.
The development may potentially affect the implementation of the street system
as outlined in the Comprehensive Transportation Plan and Six Year
Transportation Improvement Program (TIP), or of any other documented
transportation project.
The development proposes a rezone of the subject property.
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.
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10.17.2 Elements of a Traffic Impact Analysis
Each development traffic review is different and, as such, each traffic study should be
cooperatively designed to address the city’s specific concerns. Traffic impact analyses
are therefore required to be scoped by and with the City Engineer. They may include all
or some of the following elements:
Corridor Level of Service analyses,
Intersection Level of Service analyses,
Access point level of service analyses,
Critical gap analyses,
Horizontal and vertical sight distance analyses,
Roundabout analyses,
Traffic signal warrant analyses,
Stop control warrant analyses,
Turn lane warrant analyses,
Access management design,
Other analyses and information as required by the City Engineer.
10.17.3 Special Uses
Special event land uses which do not exhibit typical trip generation characteristics may
require unique analysis, including but not limited to weekend and off-peak scenarios, and
AM versus PM time frames. Examples of such uses would be concert stadiums,
racetracks or uses which exhibit substantial traffic peaking associated with special events
that are scheduled on a periodic basis.
The traffic analysis for such uses may include a traffic management plan to control traffic
impacts associated with the special events.
10.17.4 Mitigation Identification
In order to protect the public from potentially adverse impacts of the proposal, to fulfill an
identified need for public services within the impacted area related to the development, or
both, the Traffic Impact Analysis shall identify methods of mitigating on-site and off-site
deficiencies for present and proposed phases of the development. The analysis shall
make recommendations for improvements necessary for safe and efficient traffic flow and
bicycle, pedestrian, and transit movement and access proportional to the identified
impacts. Build-out Year, Long-Range Forecast Year, and project phasing impacts shall be
considered. All or some of the following items are to be included in the mitigation
identification:
Methods for mitigating on-site impacts and mitigation recommendations,
Methods for mitigating off-site impacts and mitigation recommendations,
Discussion of whether on-site and off-site improvements are justified,
reasonably related to, and proportional to the impacts of the proposed
development,
Any requirements or mitigation measures associated with the Area Circulation
Plan.
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10.17.5 Recommendations
The Traffic Impact Analysis report shall clearly state the mitigation measures
recommended by the analysis and shall summarize how the recommended mitigations
are proportional to the identified impacts. The recommended street and highway
mitigation measures shall be explained in sufficient detail in the analysis to allow them to
be understood and evaluated. The recommendation shall also include the following:
Clear statements of the applicant’s recommended mitigation measures.
Scaled drawings depicting recommended mitigation improvements and their
relationship to existing and proposed conditions if drawings are needed.
10.17.6 Area Circulation Plan
Area Circulation Plans are plans which support the development of a multi-modal
transportation network with safe, efficient and pleasant routes for pedestrians, bicyclists,
transit users, and motor vehicle occupants. The plan recognizes the link between land
use and transportation planning and promotes land use and development patterns that
encourage walking, bicycling, and transit use.
The goal of an Area Circulation Plan is to "provide a transportation system that will
facilitate the safe and efficient movement of people and goods throughout the community
while supporting the designated Land Uses in the Comprehensive Plan.” This goal
applies to all aspects of circulation including: vehicular, mass transit, bicycle, and
pedestrian. In order for the City of Auburn to successfully meet the vision set forth in the
Comprehensive Plan, the Area Circulation Plan will need to address a variety of
transportation modes to facilitate the convenient and efficient movement of people in and
near new development.
Area Circulation Plans are required for all new development of general commercial and
industrial property. They also may be required for land uses which do not exhibit typical
trip generation characteristics that require unique analysis, including but not limited to
weekend and off-peak scenarios, and AM versus PM time frames.
The Area Circulation Plan shall include sufficient information to adequately assess the
functionality of the proposed development and its impact on surrounding properties and
circulation systems, including but not limited to:
Mapping details, such as site boundaries and dimensions, site acreage, vicinity
map, north arrow, scale, title block, etc.;
Access to the site and interior site circulation;
Proposed lot layout;
Other items which may impact adjacent property, such as general parking
arrangement, delivery truck/dock locations, medians or traffic control devices,
median breaks, and other information as deemed necessary by the City
Engineer and Planning Director.
Any development or subdivision of the property shall generally be consistent with the
Area Circulation Plan as approved or amended. No plat, building permit, or certificate of
occupancy shall be issued for the property unless all construction and development
generally conforms to the Area Circulation Plan.
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10.18 Table 10-1 Summary Matrix of Minimum Street Design Requirements
CLASSIFICATION SECTION PRINCIPAL
ARTERIAL
MINOR
ARTERIAL RESIDENTIAL COLLECTOR NON-RESIDENTIAL
COLLECTOR
RURAL
COLLECTOR
LOCAL
RESIDENTIAL
LOCAL
NON-RESIDENTIAL
RURAL
RESIDENTIAL
Roadway Section Standard Detail No. TRAFFIC-27 TRAFFIC-28 TRAFFIC-29 TRAFFIC-30 TRAFFIC-31 TRAFFIC-32 TRAFFIC-33 TRAFFIC-34
Average Daily Traffic (ADT) 10.01 Over 15,000 10,000 –
15,000 2,500 – 10,000 2,500 – 5,000 1,000 – 5,000 Up to 1,200 Up to 1,200 Up to 1,000
RIGHT-OF-WAY
Width (ft) 10.02.9 876 71/826 556 65 60 50 55 50
Intersection Radii- Min. (ft) 10.02.9 39.5 29.5 19.5 24.5 17 9 24.5 7
TRAVELWAY
Roadway Width (ft) 10.02.9 616 50/616 346 44 28 28 34 24
Curb/Gutter 10.02.9.4 Y Y Y Y N Y Y N
Number Of Lanes 10.01 5 4/5* 2/3* 3 2 2 2 2
Inside Through Lane Width (ft) 10.02.9.1 11 11 N/A N/A N/A 10 N/A N/A
Curb Lane Width (ft) 10.02.9.1 14 14 11.5 16 14 10 17 12
Center Turn Lane Width (ft) 10.02.9.2 11 11 11 12 N/A N/A N/A N/A
Bikeway Class/Width (ft) 5 10.06 Cl. 1 / 10 Cl. 1 / 10 Cl. 2 / 6 N/A Cl. 3 N/A N/A N/A
Intersection Curb Radii (ft)1 10.02.9.6 50 40 30 35 30 20 35 20
Parking Allowed 10.02.9.5 N N N N N Y, one-side N Y/ two-sides4
ROADSIDE
Shoulder Width (ft) 10.02.9.4 N/A N/A N/A N/A 8 N/A N/A 3
Sidewalk Width (ft) 10.05.1 10 10 5 10 0 5 10 0
Street Trees with Grates 10.08 Y Y N/A Y N/A N/A Y N/A
Landscape Strip Width (ft) 10.08.1 5 w/ Cl. 1 trail5 5 w/ Cl. 1 trail 5 5 N/A N/A 5.5 N/A N/A
Illumination 10.10 Y Y Y Y Only at
Intersections Y Y Only at Intersections
INTERSECTION
Min/Max Horizontal Approach Angle 10.04.1.2 90° ± 5° 90° ± 5° 90° ± 5° 90° ± 5° 90° ± 5° 90° ± 5° 90° ± 5° 90° ± 5°
Minimum Landing Approach Length (ft) 10.04.1.5 30 30 20 20 20 20 20 20
Maximum Landing Approach Grade (%) 10.04.1.5 3 3 5 5 5 5 5 5
GEOMETRIC DESIGN CRITERIA
Posted Speed (mph) 2 10.02.7 45 40 35 35 30 30 30 40 35 30 25 30 25
Design Speed (mph) 2 10.02.7 55 50 45 45 40 35 35 45 40 35 30 35 30
Min. Horizontal Curve Radius (ft)2, 8
(For Standard Cross Section) 10.02.1 9720 8150 4930 1121 821 544 544 1125 821 544 333 510 333
Min. Tangent Between Reverse Curves (ft) 2 10.02.2 150 150 150 150 150 100 150 100
Maximum Rate of Superelevation, e (%) 10.02.3 8 8 0 0 8 0 0 0
Max. Vertical Grade (%)2, 3,7 10.02.4 6 6 8 8 8 8 8 8
Cross Slope (%) 10.02.6 3 3 3 3 3 2 2 2
DRAINAGE
Closed System 6.00 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 Comprehensive Plan designation.
Residential Collectors may be designed as either a two (2) (one lane in either direction) or three (3) (one lane in either direction and a center turn lane) lane road based on the configuration of access points to the collector system.
1 At intersections with two different street classifications, use the highest classification for curb radii.
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 Geometric Design of Highways & Streets.”
3 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 The construction of separated bikeways shall be required in conjunction with street projects when designated by the Comprehensive Plan.
6 Required pavement and right-of-way widths may be greater then that shown to accommodate medians and/or bike lanes as required to meet Comprehensive Plan designations or to address traffic calming. See Section 10.06.
7 Vertical grades may be increased to 10% for non-arterial streets upon approval of the City Engineer.
8 Minimum radii are for streets designed using the recommended cross slopes listed above. Minimum street radii for Arterials and rural Collectors may be reduced by superelevating the street section per the requirements above.
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
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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.
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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, -05a, -06 and -06a 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.
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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.
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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.
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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.
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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, left-
turning 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.
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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 (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
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 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.
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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.