HomeMy WebLinkAbout2444 Adopting Volumes II through IV, State Department of Ecology (DOE) Stormwater Management Manual for Puget Sound BasinOrdinance No. ,~'q'q~
AN ORDINANCE OF THE CITY OF PORT TOWNSEND AMENDING
CHAPTER 16.12 OF THE PORT TOWNSEND MUNICIPAL CODE,
ADOPTING VOLUMES II THROUGH IV OF THE DEPARTMENT OF
ECOLOGY "STORMWATER MANAGEMENT MANUAL FOR THE
PUGET SOUND BASIN" TO SUPPLEMENT THE PUBLIC WORKS
PROCEDURES MANUAL
WHEREAS, in Chapter 16.12 PTMC, the City of Port Townsend has adopted regulatory
standards and procedures for the purpose of preserving the City's watercourses, and minimizing
water quality degradation and control of sedimentation of creeks, critical drainage corridors,
ponds, wetlands, and other water bodies, and promoting sound development policies and
construction procedures defined within the Code; and
WHEREAS, Section 16.12 PTMC, empowers the Public Works Department to adopt
a "Procedures Manual" of technical and administrative procedures to delineate methods to be
used, the level of detail of analysis required, and other details for the implementation of the
provisions of Section 16.12 PTMC; and
WHEREAS, pursuant to RCW 90.70.070, and as part of the City's compliance with the
Growth Management Act, RCW 36.70A et. seq., the City is required to "evaluate, and
incorporate as applicable, subject to the availability of appropriate funds or other funding
sources," the provisions of the 1991 Puget Sound Water Quality Management Plan (Revised),
February, 1992, including any guidelines, standards, and timetables contained in the Plan; and
WHEREAS, as a component of the Puget Sound Water Quality Management Plan, the
City is required to adopt a stormwater management manual that is substantially equivalent to the
Department of Ecology's "Stormwater Management Manual for the Puget Sound Basin," dated
February, 1992, (hereinafter the "DOE Manual"); and
WHEREAS, Volumes II through IV of the DOE Manual contain procedural and
technical standards for the review of stormwater drainage plans, and "best management
practices" used uniformly throughout the State of Washington, in compliance with RCW
90.70.070; and
WHEREAS, the Department of Public Works, pursuant to its authority contained within
Section 16.12 PTMC, has designated the DOE Manual as a component of, and supplementing
the "Procedures Manual" defined within PTMC 16.12.020(M), (the "Interim Procedures
Manual," dated June 5, 1992); and
WHEREAS, the Washington state Department of Ecology has conducted SEPA review
of the DOE Manual and has issued a Determination of Non-Significance (published in the SEPA
Registry, March 16-20, 1992). EcOlogy's Determination of Non-Significance pertaining to the
DOE Manual .is hereby formally adopted by the City of Port Townsend for the purpose of this
Ordinance; and
WHEREAS, the City Council intends on interim basis to amend Section 16.12 PTMC,
in a manner consistent with the mandate contained within RCW 90.70.070, and consistent with
the requirements of the 1991 Puget Sound Water Quality Management Plan, to adopt volumes
,II: through IV of the DOE .Manuat as a component of, and to supplement the Public Works
Department's "Interim Procedures Manual" for :the control of stormwater within the City of Port
Townsend,
NOW, THEREFOR, the City Council of the City of Port Townsend does ordain as
follows:
Section 1. Chapter 16.12 Section 020 of the Port Townsend Municipal Code is hereby
amended to read as follows:
Chapter 16.12
DRAINAGE PLANS
16.12.020 Definitions.
For purposes of this chapter, the following words shall have the following meanings:
A. "Comprehensive drainage plan" means a detailed analysis for each drainage basin
which compares the capabilities and needs for runoff accommodations due to various
combinations of development, land use, structural and nonstructural management alternatives.
B. "Computations" means calculations, including coefficients and other pertinent data,
made to determine the drainage plan with rates of flow of water given in cubic feet per second
and cubic meters per second (cms).
C, ',Design storm" means that rainfall event which is selected by the public works
department for purposes of design, specifying both the return period in years and the duration
in hours.
D. "Detention facilities" means facilities designed to hold runoff while gradually releasing
it at a predetermined maximum rate.
E. "Developer" means the individual(s) or corporation(s) applying for the permits of
approvals described in PTMC 16.12.030A.
F. "Developmental coverage" means 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. During construction "development 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.
G. ,,Drainage area" means the watershed contributing water runoff to and including the
subject property.
H. "Drainage plan" means a plan for collection, transport, treatment, and discharge or
recycle of water within the subject property.
I. "Drainage treatment/abatement facilities" means 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.
J. "Natural location of drainage systems" means the location of those channels, swales,
and other nonmanmade conveyance systems as defined by the first documented topographic
contours existing for the subject property, either from maps or photographs, or such other means
as appropriate.
K. "Peak discharge" means the maximum surface water runoff rate (cfs and cms)
determined for the design storm.
L. "Planned unit development" means residential developments which are planned and/or
developed in several stages but submitted together for approvals, and which typically consist of
clusters of multiunit structures interspersed with areas of common open spaces.
M. "Procedures manual" means the manual of technical and administrative procedures
established by the public works department which delineates methods to be used, the level of
detail of analysis required, and other details for implementation of the provisions of this chapter.
"Procedures manual" shall also mean Volumes II through IV of the Washington State
Department of Ecology "Sto.rmwater Management Manual for the Puget Sound Basin," dated
February, 1992 (hereinafter the "DOE Manual"). The DOE Manual supplements and is a
component of the Procedures Manual.
N. "Receiving bodies of water" means creeks, streams, lakes and other bodies of water
into which waters are directed, either naturally, in manmade ditches, or in closed conduit
systems.
O. "Retention facilities" means facilities designed to hold water for a considerable length
of time and then consume it by evaporation, Plant transpiration,' or infiltration into the soil.
P. "Subject property" means 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.
(Ord. oq'qq'q § 1, 1995; Ord. 1957 § 2, 1983).
Section 2, Chapter 16.12 Section 040 of the Port Townsend Municipal Code is
hereby amended to read as follows:
16.12.040 Drainage plan - Contents.
All persons applying for any of the permits and/or approvals contained in PTMC 16.12.030
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 described in procedures established
by the public works department, or in the procedures manual~ including the DOE Manual.
The procedures manual~ including the DOE 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. Indications 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,
4. Determination of the peak discharge and volume of water that will be
generated by the design storm at various points on the subject property;
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.
4
The requirements of this section may be modified at the discretion of the city public works
department in special cases requiring more information.
(Ord. ~"Pq~ § 2, 1995; Ord. 1957 § 4, 1983).
Section 3, Chapter 16.12 Section 070 of the Port Townsend Municipal Code is
hereby amended to read as follows:
16.12.070 Review and approval of the plan.
All storm drainage plans prepared in connection with any of the permits and/or approvals
listed in PTMC 16.12.030 shall be submitted for review by and approval of the public works
department in accordance with the procedures established in the procedures manual:,
including the DOE 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
public works department. The public works department is authorized to require compliance
with the standards and criteria, including all "best management, practices,' set forth in the
DOE Manual.
(Ord. a2444 § 3, 1995; Ord. 1957 § 7, 1983).
Section 4. Chapter 16.12 Section 150 of the Port Townsend Municipal Code is
hereby amended to read as follows:
16.12.150 Permit - Fee.
After review and approval of the plan, a storm drainage permit will be issued at a cost
, ...... set by PTMC 3..36.020.
(Ord.,~,q~'q § 4, 1995; Ord. 1957 § 17, 1983).
Section 5. Chapter 16.12 Section 160 of the Port Townsend Municipal Code is
hereby amended to read as follows:
16.12.160 Establishment of procedures manual.
The public works department is authorized and directed to conduct studies, assemble data,
establish rules, regulations and procedures and take all other steps necessary to prepare the
procedures manual. The procedures manual includes and is supplemented by the DOE
Manual.
(Ord. o9'q4'q § 5, 1995; Ord. 1957 § 18, 1983).
Section 6. Severability. If any clause, sentence, paragraph, section or part of this
Ordinance or its application to any person or circumstance is held to be invalid or
unconstitutional by a court of competent jurisdiction, such order or judgment shall not affect
the validity or constitutionality of the remainder of any part of this Ordinance. To this end,
the provisions of each clause, sentence, paragraph, section or part of this law are declared
severable.
This ordinance shall take effect and be in force five days after the date of its
publication in the manner provided by law.
Read for the first, second, and third time~ssed by the City Council of the City
of Port Townsend, Wast~ington, at a regular n~ting th~eof, h~d this ._~ 'r-Hday of
F~/eoA~. ¥, 1995. ' ~~.~
~hn M. Clise~ Mayor
Attest: //
Michael Hildt, Acting CitY Clerk
Approved a~' t~ Form:
Ti ~no ~ .~t'~I~:Ma~C i ty Attorney
02/01/95 CA§ORD\Chl 612.doc