HomeMy WebLinkAbout3314 ORDINANCE NO. 3 3 14
AN ORDINANCE OF THE CITY OF AUBURN, WASHINGTON, ESTABLISHING A NEW CHAPTER OF THE AUBURN CITY CODE AND REQUIRING A DRAINAGE PLAN TO BE SUBMITTED
IN CONJUNCTION WITH CERTAIN PERMITS, SPECIFYING THE CONTENTS THEREOF.
WHEREAS, an expanding population and increased development of land,
coupled with inadequate drainage controls, has led to drainage and runoff
problems; and
WHEREAS, these drainage and runoff problems contribute to increased
sedimentat;on in ponds, creeks, and streams, thereby degrading water quality;
and
WHEREAS, these drainage and runoff problems also contribute to water
quality degradation through excessive discharge of nutrients, metals, oil
and grease, toxic materials, and other detrimental substances; and
WHEREAS, inadequate surface and subsurface drainage planning and practices
lead to crosion and property damage, and risk to life; and
WHEREAS, excess water runoff on streets and highways poses a safety
hazard to both lives and property; and
WHEREAS, the Auburn City Council finds that future problems could be
avoided if developers, both private and public, provide for adequate drainage
of their property.
NOW, THEREFORE, THE CITY COUNCIL OF THE CITY OF AUBURN, WASHINGTON,
DO ORDAIN AS FOLLOWS:
There is hereby created a new chapter of the Auburn City Code entitled
"Drainage Plans."
Section 1. PURPOSES. The Auburn City Council finds that this chapter
is necessary in order to promote sound development policies and construction
procedures which respect and preserve the City of Auburn's water courses; to
minimize water quality degradation and control the sedimentat;on of creeks,
streams, ponds, lakes and other water bodies; to protect property owners adjacent
to devleoping and developed land from increased runoff rates which could cause
crosion of abutting property; to protect downstream owners; to preserve and
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enhance the suitability of waters for contact recreation and fishing; to preserve
and enhance the aesthetic quality of the waters; to maintain and protect valuable
groundwater resources; to minimize adverse effects of alterations in goundwater or
quantities, locations, and flow patterns; to ensure the safety of City of Auburn
roads and rights of way; and to decrease drainage related damage to public and
private property.
Section 2. DEFINITIONS.
(1) "Procedures Manual" shall mean the manual of technical and
administrative procedures established by the Engineering and Planning Departments
which delineates methods to be used, the level of detail of analysis required,
and other details for implementation of the provisions of this Ordinance.
(2) "Comprehensive Drainage Plan" refers to a detailed analysis for
each drainage basin which compares the capabilities and needs for runoff
accomodation due to various combinations of development, land use, structural
and nonstructural management alternatives. The plan recommends the form,
location and extent of quantity and quality control measures which optimally
would meet the legal constraints, water quality standards, and community standards,
as well as identifying the institutional and funding requirements for plan
implementation.
(3) "Computations" shall mean calculations, including coefficients and
other partinent data, made to determine the frainage plan with rates of flow of
water given in cubic feet per second and cubic meters per second (cms).
(4) "Design Storm" shall refer to that rainfall event which is selected
by the Engineering Department for purposes of design, specifying both the return
period in years and the duration in hours.
(5) "Detention facilities" shall mean facilities designed to hold runoff
while gradually releasing it at a predetermined maximum rate.
(6) "Developer" shall mean the individual(s) or corporation(s) applying
for the permits or approvals described in Section 3 (1) of this chapter.
(7) "Developmental coverage" shall mean all developed surface areas
within the subject property including, but not limited to, rooftops, driveways,
carports, accessory buildings, parking areas, and any other impervious surfaces.
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During construction, "developmental coverage" shall include the above
in addition to the full extent of any alteration of previously occurring soils,
slope or vegetation due to grading, temporary storage, access areas, or any
other short-term causes.
(8) "Drainage area" shall mean the watershed contributing water runoff
to and including the subject property.
(9) "Drainage plan" shall mean a plan for collection, transport, treatment,
and discharge or recycle of water within the subject property.
(lO) "Drainage treatment/abatement facilities" shall mean any facilities
installed or constructed in conjunction with a drainage plan for the purpose of
treatment or abatement of urban runoff, excluding retention or detention facilities.
(11) "Natural location" of drainage systems shall refer to the location
of those channels, swales, and other non-man-made conveyance systems as defined
by the first documented topographic contours existing for the subject property,
either from maps or photograps, or such other means as appropriate.
(12) "Peak discharge" shall mean the maximum surface water runoff rate
(cfs and cms) determined for the design storm.
(13) "Planned unit development" shall 'refer to residential developments
which are planned and/or developed in several stages but submitted together for
approvals, and which typically consist of clusters of multi-unit structures
interspersed with areas of common open space.
(14) "Receiving bodies of water" shall mean creeks, streams, lakes and
other bodies of water into which waters are directed, either naturally, in man-
made ditches, or in closed conduit systems.
(15) "Retention facilities" shall mean facilities designed to hold water
for a considerable length of time and then consume it by evaporation, plant
transpiration, or infiltration into the soil.
(16) "Subject property" shall mean the tract of land which is the subject
of the permit and/or approval action, as defined by the full legal description of
all parcels involved in the proposed development.
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Section 3. SUBMISSION OF A DRAINAGE PLAN.
(1) All developers applying for any of the following permits and/or
approvals shall submit for approval a drainage plan with their application and/or
request:
(a) Grading permit.
(b) Substantial development permit required under RCW
90.58 (Shoreline Management Act).
(c) Subdivision approval.
(d) Short subdivision approval. (Industrial and Commercial)
(e) Conditional Use Permits.
(f) Building permits where the permit relates to 5,000
or more square feet of development coverage within
the property, or where development is in a critical area.
(g) Planned unit development.
(2) Commencement of construction work under any of the above permits
or applications shall not begin until such time as final approval of the
drainage plan is obtained in accordance with Section 7 of this chapter.
(3) The same plan submitted during one permit/approval process may be
subsequently submitted with further required applications. The plan shall be
supplemented with such additional information that is requested by the Engineering
Department or required by the provisions of the Compliance Manual.
(4) The plan requirement established in this section shall apply except
when the developer demonstrates to the satisfaction of the Engineering and
Planning Departments that the proposed activity or development:
(a) Will neither seriously nor adversely impact the water
quality conditions or any affected receiving bodies of water, and
(b) Will not alter the surface discharge location, alter the
drainage pattern on adjoining properties, alter drainage patterns,
increase the discharge, nor cause any other adverse effects in the
drainage area, and
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(c) Will not alter the subsurface drainage patterns, flowrates,
and discharge points, nor result in any significant adverse effects
to property or residents..
Section 4. CONTENTS OF A DRAINAGE PLAN.
All persons applying for any of the permits and/or approvals contained
in Section 3 of the Auburn City Code shall provide a drainage plan for surface
and pertinent subsurface water flows entering, flowing within, and leaving
the subject property both during and after construction. The detailed form
and contents of the drainage plan shall be prepared by a registered professional
Civil Engineer and shall be prepared in accordance with procedures established
by the Engineering and Planning Departments, or in the Procedures Manual. The
Procedures Manual will set forth the manner of presenting the following required
information:
(a) Background computations for sizing drainage facilities:
(1) Depiction of the drainage area on a topographical map
of approved scale and contour interval, with acreage of the site,
development, and developmental coverage indicated.
(2) Indication of the peak discharge and volume of surface
water currently entering and leaving the subject property due to the
design storm.
(3) Indication of the peak discharge and volume of runoff which
will be generated due to the design storm within the subject property
if the development or proposed activity is allowed to proceed.
(b) Proposed measures for handling the computed runoff at the detail
level specified in the Procedures Manual.
(c) Proposed measures for controlling runoff during construction.
The requirements of this section may be modified at the discretion of the
Auburn City Engineering Department in special cases requiring more information,
with the concurrence of the Planning Department.
Section 5. MANDATORY REQUIREMENTS FOR DRAINAGE IMPROVEMENTS.
(1) (a) Surface water entering the subject property shall be received
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at the naturally occurring locations and surface water exiting the subject
property shall be discharged at the natural locations with adequate energy
dissipators within the subject property to minimize downstream damage and
with no diversion at any of these points; and
(b) The design storm peak discharge from the subject property may
not be increased by the proposed development; and
(c) Retention/detention facilities must be provided in order to
maintain surface water discharge rates at or below the existing design
storm peak discharge; and
(d) Where open channel construction is used to handle drainage
within the subject property, a minimum of fifteen (15) feet will be
provided between any structures and the top of the bank of the defined
channel.
(1) In open channel work the water surface elevation
will be indicated on the plan and profile drawings. The con-
figuration of the finished grades constituting the banks of
the open channel will also be shown on the drawings.
(2) Proposed cross section of the channel will be shown
with stable side slopes as approved by the Engineering Department.
(3) The water surface elevation of the flow for the design
storm will be indicated on the cross section.
(c) When a closed system is used to handle drainage within the
subject property, the system will be a minimum of ten (10) feet from
all structures.
(2) To the extent possible, approved measures for controlling runoff
during construction should comply with the above provisions.
(3) Variances from the requirements of Section 5 (1) may be permitted
only after a determination by the Engineering and Planning Departments, using the
Comprehensive Drainage Plan (if available) and/or employing the following criteria:
(a) Sufficient capacity of downstream facilities under design
conditions.
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(b) Maintenance of the integrity of the receiving waters;
(c) Possibility of adverse effects of retention/detention;
(d) Utility of regional retention/detention facilities;
(e) Capability of maintenance of the system; and
(f) Structural integrity of abutting foundations and structures.
Request for variances shall be filed in writing with the Engineering
Department and shall adequately detail the basis for granting an exemption.
Section 6. DEVELOPMENT IN CRITICAL AREAS.
Development which would increase the volume or rate of discharge due to any
storm from the subject property shall not be permitted in areas designated as
critical areas by the Engineering and Planning Departments. Critical areas
are those in which existing flooding, drainage, erosion, and/or instability
conditions present an imminent likelihood of harm to the welfare and safety
of the surrounding community, or to the integrity of the surface or groundwater
system. Development shall not be permitted in these critical areas until such
time as the existing community hazard is alleviated and it is adequately demonstrated
that the proposed development will not cause a recurrence of the problem nor the
occurrence of any new drainage-related problem. The Engineering and Planning
Departments may also designate as critical any area in which comparable problems
would occur in the future due to any increase in volume or peak discharge. The
requirements of this section shall apply regardless of any variance under Section
3, item (3). Where applications of the provisions of this section will deny all
reasonable uses of the property, the restrictions on development contained in this
section may be waived for the subject property, provided that the resulting
development shall be subject to all the remaining terms and conditions of the
chapter. All decisions based on the provision of this section shall be compatible
with the Comprehensive Drainage Plan (if available) for the basin in which the
subject property is located. For development in areas designated as critical, the
developer shall provide information regarding volume and rate of discharge for a
range of storms as specified in the Procedures Manual.
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Section 7. REVIEW AND APPROVAL OF THE PLAN.
All storm drainage plans prepared in connection with any of the permits
and/or approvals listed in Section 3 shall be submitted for review by and
approval of the Engineering and Planning Departments, in accordance with the
procedures established in the Procedures Manual.
At the time of approval of the drainage plan for the subject property,
a schedule for inspection of construction and facilities will be established
by the Engineering Department.
Section 8. ESTABLISHMENT OF REGIONAL FACILITIES.
In the event that public benefits would accrue due to modification of
the drainage plan for the subject property to better implement the recommendations
of the Comprehensive Drainage Plan, the Engineering Department or the Planning
Department may recommend that the City of Auburn should assume responsibility
for the further design, construction, operation, and maintenance of drainage
facilities on the subject property. Such decision shall be made concurrently
with review and approval of the plan as specified in Section 7. In the event
that the City decides to assume responsibility for design, construction, operation,
and maintenance of the facilities, the developer will be required to contribute
a prorata share to the construction cost of the facilities. The developer may
be required to supply additional information at the request of the Engineering
Department to aid in the determination by the City. Guidelines for implementing
this section will be defined in the Procedures Manual or by the Engineering
and Planning Departments.
Section 9. OPERATION AND MAINTENANCE PROCEDURES.
It will be the responsibility of the developer to make arrangements with
the occupants or owners of the subject property for assumption of operation and
maintenance in a manner subject to the approval of the Engineering Department
or in accordance with the Procedures Manual.
The City may inspect the facilities in order to ensure continued use of
the facilities for the purposes for which they were built and in accordance with
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these arrangements. Failure to maintain the facilities in good working order
shall be cause for a written request to maintain the retention/detention
facilities after inspection by City forces. If after 30 days, no remedial
measures are taken by the property owner, the City may initiate legal action
against the property owner.
Section lO. APPLICABILITY TO GOVERNMENTAL ENTITIES.
All municipal corporations and governmental entities shall be required to
submit a drainage plan and comply with the terms of this chapter when developing
and/or improving land including, but not limited to, road building and widening,
within the areas of the City of Auburn.
It is recognized that many other city, county, state, and federal permit
conditions may apply to the proposed action and that compliance with the provisions
of this chapter does not constitute compliance with such other requirements.
Section ll. APPEALS.
If the property owner feels the requirements imposed by the Engineering
Department are inconsistent with storm drainage handling procedures for the
area, they may appeal to the Street Committee of the Auburn City Council and
present in writing their reasons for a revision to the requirements as imposed
upon their development. The Street Committee's ruling shall be binding on the
property owner.
Section 12. PROTECTION OF PUBLIC/PRIVATE RIGHTS.
Implementation of any provision of this chapter shall not cause nor be
construed as an infringement of the rights of individuals, municipalities, or
corporations other than the developer seeking a permit or approval as described
in Section 3.
Section 13. EFFECTIVE DATE.
The requirements of this chapter shall apply to all plats receiving
preliminary approval subsequent to the effective date of this Ordinance.
In the case of all additional actions enumerated in Section 3 of this Ordinance,
the terms of this chapter shall apply where final action by the City has not
been taken prior to the effective date of this Ordinance.
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Section 14. SEVERABILITY.
If any provision of this chapter or its application to any person or
property is held invalid, the remainder of the chapter or the application of
the provision to other persons or circumstances shall not be affected.
Section 15. FEE SCHEDULE.
A storm sewer permit fee to cover plan checking, inspection, as-built
drawings and processing of permit information shall be charged for all develop-
ment except single family residential. The permit fee shall be based on the
amount of impervious area on the developed site and shall be as follows:
5000 square feet or less No fee
5000 to 10,000 square feet $ 50.00
10,001 to 50,000 square feet $ 75.00
50,001 square feet or more $100.00
Section 16. This Ordinance shall take effect and be in force five (5)
days from and after its passage, approval and publication, as provided by law.
INTRODUCED: OCTOBER 16, 1978
PASSED: OCTOBER 16, 1978
APPROVED: OCTOBER 16, 1978
mAYOR ~
ATTEST:
APPRO D A~/~T~~.FORM'~~
· City Attorney
PUBLISHED: OCTOBER 20, 1978
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