Ordinance 30130006.170.045
WSS:are
11/30/94
R: 2/17/95
ORDINANCE NO. 3013
AN ORDINANCE OF THE CITY OF EDMONDS,
WASHINGTON, AMENDING THE COMMUNITY
DEVELOPMENT CODE TO ADOPT A NEW CHAPTER 18.30
STORM WATER MANAGEMENT AND FIXING A TIME
WHEN THE SAME SHALL BECOME EFFECTIVE.
THE CITY COUNCIL OF THE CITY OF EDMONDS, WASHINGTON, DO
ORDAIN AS FOLLOWS:
Section 1. The Edmonds Community Development Code is hereby amended by
the repeal of Chapter 18.30 and the enactment of a new Chapter 18.30 Storm Water
Management to read as follows:
CHAPTER 18.30
STORM WATER MANAGEMENT
18.30.000 PURPOSE. The purposes of this chapter are:
A. To protect creeks, streams, ponds, wetlands, lakes and
other bodies of water from pollution associated with surface
storm water including sediments, petroleum products,
pesticides, fertilizers, pet wastes or other damaging
substances.
B. To protect land and the ecological balance of the receiving
water bodies near development sites from increased surface
water runoff rates that could cause flooding or erosion,
scouring, and deposition of sediment due to the
development.
C. To protect private and public property and City streets and
rights -of -way from flooding or erosion.
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D. To preserve and enhance the suitability of all bodies of
water for contact recreation, fishing, and a wide diversity
of wildlife habitat.
E. Provide for inspection and maintenance of storm water
facilities in the City so that they will perform as designed
to prevent or remove pollution and /or reduce flooding.
F. To require that all public and private storm water facilities
be operated, maintained, and repaired in conformance with
this chapter.
G. To establish the minimum standards that must be met for
compliance.
H. To provide guidelines for all who conduct inspections and
perform maintenance of storm water facilities.
I. To promote development practices that will ensure that the
above purposes are met.
J. To meet the requirements of RCW 90.70.080.
18.30.010 DEFINITIONS. For the purposes of this chapter,
the following definitions shall apply:
A. "Approval" means the proposed work or completed work
conforming to this chapter as approved by the Community
Services Director or designee.
B. 'Basin plan" means a plan, along with all regulations and
procedures including, but not limited to, land use
management elements adopted by ordinance for managing
surface and storm water management facilities and features
within individual sub - basins.
C. 'Best Management Practice" or "BMP" means physical,
structural, and /or managerial practices that, when singly or
in combination, prevent or reduce pollution of water.
BMPs are listed and described in the Manual.
D. 'Buffer" is as defined in Chapter 20.15B of the Edmonds
Community Development Code (ECDC).
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E. "Civil engineer" means a professional engineer licensed in
the State of Washington in Civil Engineering.
F. "Civil engineering" means the application of the knowledge
of the forces of nature, principles of mechanics and the
properties of materials to the evaluation, design and
construction of civil works for the beneficial uses of
mankind.
G. "Clearing" means the act of . cutting and /or removing
vegetation including grubbing.
H. "Critical areas" is as defined in Chapter 20 of the Edmonds
Community Development Code.
I. "Design storm" means a rainfall event or pattern of events
for use in analyzing and designing drainage facilities.
J. "Detention" means detaining the runoff after development
for a prescribed design storm and thus releasing the storm
water from the facility at a prescribed predeveloped rate.
K. "Director" means Community Services Director or a
designee with an appropriate background in engineering or
another related discipline.
L. "Detention facility" means an above or below ground
facility, such as a pond or storage tank, that temporarily
stores storm water runoff without infiltration and
subsequently releases at a prescribed rate.
M. "Earth material" means any rock, natural soil or fill and /or
any combination thereof.
N. "Ecology" means the Washington State Department of
Ecology.
O. "Erosion" means the displacement of any land surface by
rainfall, storm water, runoff, and seepage.
P. "Erosion and Sediment Control Plan" or "ESC Plan" means
a plan to implement BMPs to control pollution generated
during land disturbing activity. Guidance for preparing an
ESC Plan is contained in the manual.
88948.4 -3-
Q. "Excavation" means the removal of any earth material.
R. "Fill" means a deposit of earth material placed by artificial
means.
S. "Grade" means the slope of anything such as a road,
channel, or natural ground.
T. "Ground water" means water in the earth below the
surface.
U. "Hydroperiod" means the seasonal pattern of surface runoff
and /or soil saturation; encompassing depth, frequency,
duration, and seasonal pattern of inundation.
V. "Impervious surface" means a constructed hard surface area
that either prevents or retards the entry of surface water
into the soil. Impervious surfaces include, but are not
limited to, roof tops, patios, storage areas, concrete,
asphalt, brick, gravel, oiled, packed earthen or other
surfaces that similarly impede the natural infiltration of
storm water. Open, uncovered retention /detention facilities
shall not be considered as impervious surfaces.
W. "Illicit discharge" means all non approved discharges to
surface waters, ground waters, sewer systems, or storm
water drainage systems in violation of City codes or state
and federal laws including; but not limited to, sanitary
sewer cross connections, injection into ground water,
interior floor drains, car washing and gray water systems.
X. "Land disturbing activity" means any activity that results in
a change in the existing soil cover (both vegetative and non
vegetative) and /or the existing soil topography. Land
disturbing activities include, but are not limited to,
demolition, construction, clearing, grading, filling and
excavation.
Y. "Manual or Storm Water Management Manual" means the
Manual adopted by reference and prepared by Ecology that
contains BMPs to prevent or reduce pollution.
Z. "Mitigation ", in the following order of preference, means:
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1. Avoiding the impact altogether by not taking a
certain action or part of an action.
2. Minimizing impacts by limiting the degree or
magnitude of the action and its implementation, by
using appropriate technology, or by taking
affirmative steps to avoid or reduce impacts.
3. Rectifying the impact by repairing, rehabilitating or
restoring the affected environment.
4. Reducing or eliminating the impact over time by
preservation and maintenance operations during the
life of the action.
5. Compensation for the impact by replacing,
enhancing, or providing substitute resources or
environments.
AA. "Natural drainage course" means the location of the
channels, swales, and other non - manmade conveyance
systems as defined by the earliest documented topographic
contours existing for the subject property, either from maps
or photographs, or such other means as appropriate.
BB. "New development" shall mean any land disturbing
activities, structural development, including construction,
installation or expansion of a building or other structures;
creation of impervious surfaces or subdivision and short
subdivision of land as defined in RCW 58.17.020.
CC. . "One- hundred year, twenty -four hour storm" means a 3.0
inch, twenty -four hour rainfall event over a twenty -four
hour period with a SCS type lA rainfall distribution.
DD. "Person" means any individual, partnership, corporation,
association, organization, cooperative, public or municipal
corporation, agency of the state, or local government unit,
however designated.
EE. "Pollution" means contamination or other alteration of the
physical, chemical, or biological properties, of waters of
the state, including change in temperature, taste, color,
turbidity, or odor of the waters; or such discharge of any
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liquid, gaseous, solid, radioactive, or other substance into
any waters of the state as will or is likely to create a
nuisance or render such waters harmful, detrimental or
injurious to the public health, safety or welfare, or to
domestic, commercial, industrial, agricultural, recreational,
or other legitimate beneficial uses, or to livestock, wild
animals, birds, fish or other aquatic life.
FF. "Predeveloped site condition" means meadows or young
second growth as defined in the Manual.
GG. "Redevelopment" means, on an already developed site, the
creation or addition of impervious surfaces, structural
development including construction, installation or
expansion of a building or other structure, and /or
replacement of impervious surfaces that are not part of a
routine maintenance activity and land disturbing activities
associated with structural or impervious development.
HH. "Site" means the property that is subject to the new
development or redevelopment.
II. "Six- month, twenty-four hour storm" means a 1.0 inch
rainfall event over a twenty-four hour period with a SCS
type lA rainfall distribution.
H. "Slope" means the degree of slant of a surface measured as
a numerical ratio, percent, or in degrees. Expressed as a
ratio, the first number is the horizontal distance (run) and
the second is the vertical distance (rise), as 2:1. A 2:1
slope is a 50 percent slope. Expressed in degrees, the
slope is the angle from the horizontal plane, with a 90
degree slope being vertical (maximum) and 45 degrees
being a 1:1 or 100 percent slope.
KK. "Soil" means the unconsolidated mantle of the earth that
serves as a natural medium for the growth of land plants.
LL. "Source control BMP" means a BUT that manages a
potential pollutant and prevents pollutants from entering
storm water. Examples of source control BMPs include
but are not limited to erosion control practices covering
storage and working areas and directing wash water and
similar discharges to treatment facilities.
88948.4 -6-
MM. "Storm water" means that portion of precipitation that does
not naturally percolate into the ground or evaporate.
NN. "Storm water drainage system" means constructed and
natural features that function together as a system to
collect, convey, channel, hold, inhibit, retain, detain,
infiltrate, divert, treat or filter storm water.
00. "Storm water facility" means a constructed component of
a storm water drainage system, designed and constructed to
perform a particular function, or multiple functions. Storm
water facilities include, but are not limited to, pipes,
pumping systems, swales, ditches, culverts, street gutters,
catch basins, detention basins, wetlands, infiltration
devices, and pollutant removal devices.
PP. " "Storm Water Quality Control (SQC)" means permanent
BMPs for the control of pollution from storm water runoff
after construction and /or any land disturbing activity has
been completed.
QQ. "Storm Water Site Plan" means a plan that includes an
Erosion and Sediment Control (ESC) Plan and storm water
quality control elements if applicable. Guidance on
preparing a Storm Water Site Plan is contained in the
Manual.
RR. "Ten -year, twenty -four hour storm" means a 2.0 inch
rainfall event over a twenty -four hour period, with a SCS
type lA rainfall distribution.
SS. "Treatment" means to remove pollutants from storm water.
A few examples of treatment are detention ponds, oil /water
separators, biofiltration swales and constructed wetlands.
TT. "Two -year, twenty -four hour storm" means a 1.5 inch
rainfall event over a twenty-four hour period with a SCS
lA rainfall distribution.
UU. "Vegetation" means all organic plant life growing on the
surface of the earth.
VV. "Water body" means surface waters including rivers,
streams, lakes, marine waters, estuaries, and wetlands.
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WW. "Watershed" means a geographic region within which
water drains into a particular river, stream, or body of
water as identified and numbered by the State of
Washington Water Resource Inventory Areas (WRIAs) as
defined in Chapter 173 -500 WAC.
XX. "Wetlands" are as defined in Chapter 20.15B of the
Edmonds Community Development Code (ECDC)..
18.30.020 STORM WATER BEST . MANAGEMENT
PRACTICES BMPS). BMPs shall be used to control and treat
the quantity and quality of storm water before it leaves the site.
BMPs shall be used -to comply with the standards of this chapter.
Guidance for the design, implementation and maintenance of BMPs
are provided in the latest edition of the Washington State
Department of Ecology Storm Water Technical Manual for the
Puget Sound Basin (The Technical Manual) and hereinafter
referred to as the Manual.
18.30.030 APPLICABILITY
A. Abrogation and Greater Restrictions. When any provision
of any other chapter of the ECDC conflicts with this
chapter, that which provides greater environmental
protection shall apply.
B. Governed Activities. Consistent with the minimum
requirements contained in this chapter, the City of
Edmonds shall approve or disapprove new development and
redevelopment activities.
18 30 040 GENERAL REQUIREMENTS FOR
DEVELOPMENT
A. Illicit Discharges. Illicit discharges to storm drainage
systems are prohibited.
B. Required Plans and Permitting.
1. Governed activities shall be conducted only after the
City approves a Storm Water Site Plan, which
includes one or both of the following:
88948.4 -8-
a. Erosion and Sediment Control (ESC) Plan,
and /or
b. Storm Water Quality Control (SQC)
Elements.
2. No approval to conduct any regulated activity shall
be granted until required plans have been approved
pursuant to the criteria adopted in this chapter.
18.30.050 DEVELOPMENT APPROVAL STANDARDS FOR
EROSION AND SEDIMENTATION CONTROL OC) PLAN
A. ESC Minimum Requirements. All activities necessitating
a clearing or grading permit- and all utility projects
consisting of more than 500 lineal feet of trench excavation
shall be required to control erosion and sediment during
construction and to permanently stabilize exposed soil
resulting from construction. Projects involving a critical
area may also be required to comply with any combination
of the ESC minimum requirements. Compliance will be
demonstrated through the implementation of an approved
ESC Plan. Guidelines for preparing ESC Plans are
provided in the manual. The plan must address the
following requirements:
1. ESC Minimum Requirement - Construction Access
Route. Construction vehicle access shall be,
whenever practical, limited to one route. Access
points shall be stabilized with quarry spalls or
crushed rock to minimize the tracking of sediment
onto public roads. If sediment is transported onto
a road surface, the roads shall be cleaned
thoroughly at the end of each day. Sediment shall
be removed from roads by shoveling or sweeping
and be transported to a controlled sediment disposal
area within twenty-four (24) hours. Street washing
shall be allowed only after sediment is removed in
this manner.
2. ESC Minimum Requirement - Stabilization of
Exposed Areas. All soils exposed by land
disturbing activities shall be stabilized by suitable
application of BMPs, including, but not limited to,
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sod, hydroseeding, or other vegetation, plastic
covering, or mulching. All BMPs shall be selected,
designed, and maintained in accordance with the
Manual. The exposed soils shall be stabilized
according to an approved timetable. (Typically, no
soils shall remain exposed for more than two (2)
days from October 1 through April 30 and no more
than seven (7) days from May 1 through September
30).
3. ESC Minimum Requirement - Protection of
Adjacent Properties. Adjacent properties shall be
protected from sediment deposition by appropriate
use of vegetative buffer strips, sediment barriers or
filters, dikes or mulching, or by a combination of
these measures and other appropriate BMPs.
4. ESC Minimum Requirement - Maintenance. All
erosion and sediment control BMPs shall be
regularly inspected and maintained by the owner to
ensure continued performance of their intended
function. All maintenance and repair shall be
conducted in accordance with the manual.
5. ESC Minimum Requirement - Other BMPs. As
required by the City, other appropriate BMPs to
mitigate the effects of increased runoff shall be
applied.
6. Erosion and Sediment Control Requirement -
Underground Utility Construction. The
construction of underground utility lines shall
specifically address the following:
a. Erosion control for excavated and stockpiled
materials.
b. The placement of excavated material where
consistent with safety and space
considerations shall be placed on the uphill
side of trenches.
88948.4 -10-
C. Trench dewatering systems (must discharge
into sediment traps, sediment ponds, or
other acceptable means).
d. Tracking and spilling of materials on streets
due to hauling.
e. Daily cleanup and street maintenance.
7. Additional ESC Minimum Requirements for Larger
Developments. All new development and
redevelopment that includes land disturbing
activities of greater than, or equal to, one acre in
addition to meeting the minimum requirements set
forth above shall comply with ESC Requirements
listed below.
8. ESC Minimum Requirement - Delineate Clearing
and Easement Limits. In the field, mark clearing
limits and /or any easements, setbacks,
sensitive /critical areas and the buffers, trees and
drainage courses.
9. ESC Minimum Requirement - Sediment Trapping.
Prior to leaving the site, storm water runoff shall
pass through a sediment pond or sediment trap, or
other appropriate BMPs. Sediment ponds and
traps, perimeter dikes, sediment barriers, and other
BMPs intended to trap sediment on -site shall be
constructed as a first step in grading. These BMPs
shall be functional before land disturbing activities
take place. Earthen structures, such as dams,
dikes, and diversions shall be seeded and mulched
according to an approved timetable.
10. ESC Minimum Requirement - Cut and Fill Slopes.
Cut and fill slopes shall be designed and constructed
in a manner that will minimize erosion. In
addition, slopes shall be stabilized in accordance
with ESC Requirement No. 2.
11. ESC Minimum Requirement - Controlling Off- -Site
Erosion. Properties and water ways downstream
from development sites shall be protected from
88948.4 -11-
erosion due to increases in the volume, velocity,
and peak flow rate of storm water runoff from the
project site.
12. ESC Minimum Requirement - Stabilization of
Temporary Conveyance Channels and Outlets. All
temporary on -site conveyance channels shall be
designed, constructed and stabilized to prevent
erosion from the expected velocity of flow from a
two -year, twenty-four hour frequency storm for the
developed condition. Stabilization adequate to
prevent erosion of outlets, adjacent stream banks,
slopes and downstream reaches shall be provided at .
the outlets of all conveyance systems.
13. ESC Minimum Requirement - Storm Drain Inlet
Protection. All storm drain inlets made operable
during construction shall be protected so that storm
water runoff shall not enter the conveyance system
without first being filtered or otherwise treated to
remove sediment.
14. ESC Requirement - Removal of Temporary BMPs.
All temporary erosion and sediment control BMPs
shall be removed within thirty (30) days after final
site stabilization is achieved or after the temporary
BMPs are no longer needed. Trapped sediment
shall be removed or stabilized on site. Disturbed
soil areas resulting from removal shall be
permanently stabilized.
15. Erosion and Sediment Control Requirement -
Dewatering Construction Sites. Dewatering systems
shall discharge into a sediment trap or sediment
pond.
16. Erosion and Sediment Control Requirement
Control of Pollutants other than Sediment on
Construction Sites. All pollutants other than
sediment that occur on site during construction shall
be handled and disposed of in a manner that does
not cause contamination of storm water.
88948.4 -12-
17. , Erosion and Sediment Control Requirement -
Financial Liability. Performance bonding, or other
appropriate financial instruments, shall be required
for all projects to ensure compliance with the
approved erosion and sediment control plan.
18.30.060 DEVELOPMENT APPROVAL STANDARDS FOR
STORM WATER QUALITY CONTROL
A. Any new development or redevelopment with more than
2,000 square feet of new impervious surfacing shall be
required to provide storm water quality control.
Compliance - will be demonstrated by implementing an
approved Storm Water Site Plan. Guidelines for Storm
Water Site Plans are provided in the manual. The plan
must address the following requirements, in addition to
ESC requirements.
1. SQC Minimum Requirement - Storm Water
Detention /Streambank Erosion Control. Storm
water discharges shall control stream bank erosion
and flooding of the downstream storm system by
limiting the peak rate of runoff from the site. The
predevelopment condition for all cases other than
open water bodies shall be considered meadows or
young second growth forest. As the first priority to
meet this requirement, BMPs shall utilize
infiltration to the fullest extent practicable only if
site conditions are appropriate and ground water
quality is protected. Due to high ground water
tables in large portions of the City and a landslide
complex in the Meadowdale area (where high
ground water increases the slide hazard), there are
few sites within the City where infiltration should
be considered. Exhibit B delineates the areas where
infiltration may be feasible for this requirement if
the site satisfies the requirements outlined in the
Manual. BMPs shall be selected, designed, and
maintained according to the Manual. The minimum
diameter orifice size used for control shall be 5/8 of
an inch. In the case of redevelopment, this
requirement shall apply only to that portion of the
site that is being redeveloped. Any development or
redevelopment that has less than 5,000 square feet
88%8.4 -13-
of impervious surfacing, other than a road
constructed for the purpose of permitting new
development, can comply with this requirement by
using the guidelines outlined in the City of
Edmonds' drainage systems handout (Exhibit A).
a. All development sites less than one (1) acre
that discharge directly or indirectly to a
stream shall be required to limit the peak
rate of runoff to the predeveloped condition
two -year, twenty -for hour design storm,
while maintaining the predeveloped
condition peak runoff rate for the ten -year,
twenty -four hour and one - hundred year,
twenty -four hour storms.
b. All developments greater than or equal to
one (1) acre that discharge directly or
indirectly to a stream shall be required to
limit the peak rate of runoff to fifty percent
(50 %) of the predeveloped condition, two -
year, twenty -four hour design storm, while
maintaining the predeveloped condition peak
runoff rate for the ten -year, twenty -four
hour and one - hundred year, twenty -four
hour storms.
C. All other developments required to comply
with this requirement shall maintain the
predeveloped condition peak runoff rate for
the ten -year, twenty -four hour and 100 -year,
twenty -four hour design storms.
d. Development of an access road, private or
public streets for the purpose of permitting
new development, shall be required to meet
this minimum requirement for both the street
or road and the new development it is
intended for.
e. Storm water detention /streambank erosion
control BMPs shall not be built within a
natural vegetated buffer, except for
88%8.4 -14-
necessary conveyance systems as approved
by the local government.
f. An adopted and implemented basin plan
(Minimum Requirement No. 8) may be used
to develop stream bank erosion control or
detention requirements that are tailored to a
specific basin.
B. The following developments will be required to comply
with Storm Water Quality Control Requirements 2 through
10:
1.
a. All new developments that include the
creation or addition of 5,000 square feet or
greater of new impervious surface.
b. Any access road, private or public street
constructed for the purpose of permitting
new development.
C. Any land disturbing activity within a critical
area.
d. Any land disturbing activity of one (1) acre
or greater.
2. SQC Minimum Requirement - Preservation of
Natural Drainage Systems. Natural drainage
patterns shall be maintained, and discharges from
the site shall occur at the natural location to the
maximum extent practicable. Where significant
changes are necessary downstream, drainage
facilities shall be improved to allow them to
accommodate the increased drainage without
damage to the drainage facilities, nearby property,
or water quality.
3. SQC Minimum Requirement - Source Control of
Pollution. Source control BMPs shall be applied to
all projects to the maximum extent practicable.
Source control BMPs shall be selected, designed,
88948.4 -15-
and maintained according to an approved manual.
In the case of redevelopment, source control'BMPs
shall be applied to the entire site.
An adopted and implemented basin plan
(development pursuant to minimum requirement
No. 8 below) may be used to develop source
control requirements that are tailored to a specific
basin, however, in all circumstances, source control
BMPs shall be required for all sites.
4. Minimum Requirement - Runoff Treatment BMPs.
Projects shall provide treatment of storm water.
Runoff from roof tops, pervious areas and other
areas the Director determines to be uncontaminated
may be exempted from runoff treatment. Treatment
BMPs shall be sized to capture and treat the water
quality design storm defined as the six- month,
twenty-four hour return period storm. Due to
inappropriate soil conditions throughout the City,
infiltration is not feasible for runoff treatment.•
Direct discharge of untreated storm water to ground
water is prohibited. All treatment BMPs shall be
selected, designed, and maintained according to an
approved manual. Runoff treatment BMPs are not
necessary where all business activities, including
parking, loading or unloading of liquids, or
temporary storage of liquid or solid wastes are
totally enclosed within a building.
5. SQC Minimum Requirement - Wetlands. The
requirements below apply only to situations where
storm water discharges directly or indirectly
through a conveyance system into a wetland and
must be met in addition to meeting the requirements
in SQC Minimum Standard No. 4 - Runoff
Treatment BMPs.
a. Storm water discharged to wetlands must be
controlled and treated to the extent
necessary to meet the State Water Quality
Standards, Chapter 173 -201 WAC, or
Ground Water Quality Standards, Chapter
173 -200 WAC, as appropriate.
88948A -16-
b. Discharges to wetlands shall maintain the
hydroperiod and flows of predeveloped site
conditions to the extent necessary to protect
the characteristic uses of the wetland. Prior
to discharging to a wetland, alternative
discharge locations shall be evaluated and
natural water storage and infiltration
opportunities outside the wetland shall be
maximized.
C. Created wetlands that are intended to
mitigate for loss of wetland acreage,
function and value shall not be designed to
also treat storm water.
d. In order for constructed wetlands to be
considered treatment systems, they must be
constructed on sites that are not wetlands
and they must be managed for storm water
treatment. If these systems are not managed
and maintained in accordance with an
approved manual for a period exceeding
three (3) years, these systems may no longer
be considered constructed wetlands.
Discharges from constructed wetlands to
waters of the state (including discharges to
natural wetlands) are regulated under
Chapter 90.48 RCW, Chapter 173 -201
WAC, and Chapter 173 -200 WAC.
e. Storm water treatment BMPs shall not be built
within a natural vegetated buffer, except for
necessary conveyance systems as approved by the
local government.
An adopted and implemented basin plan
(Minimum Requirement No. 8) may be used
to develop requirements for wetlands that
are tailored to a specific basin.
6. SQC Minimum Requirement - Water Quality
Sensitive Areas. Where local governments
determine that the minimum requirements do not
provide adequate protection of water quality
88948.4 -17-
sensitive areas, either on -site or within the basin,
more stringent controls shall be required to protect
water quality.
Storm water treatment BMPs shall not be built
within a natural vegetated buffer, except for
necessary conveyance systems as approved by the
local government.
An adopted and implemented basin plan (developed
pursuant to Minimum Requirement No. 8 below)
may be used to develop requirements for water
quality sensitive areas that are tailored to a specific
basin.
7. SQC Minimum Requirement - Off -Site Analysis and
Mitigation. All development projects shall conduct
an analysis of off -site water quality impacts
resulting from the project and shall mitigate these
impacts. The analysis shall extend a minimum of
one -fourth of a mile downstream from the project.
The existing or potential impacts to be evaluated
and mitigated shall include, at a minimum, but not
be limited to:
a. Excessive sedimentation
b. Stream bank erosion
C. Violations of water quality standards
d. Spills and discharges of priority pollutants
8. SQC Minimum Requirement - Basin Planning.
Adopted and implemented watershed -based basin
plans may be used to modify any or all of the
minimum requirements, provided that the level of
protection for surface or ground water achieved by
the basin plan will equal or exceed that which
would be achieved by the minimum requirements in
the absence of a basin plan. Basin plans shall
evaluate and include, as necessary, retrofitting of
BMPs for existing development and /or
redevelopment in order to achieve watershed -wide
88948.4 -18-
pollutant reduction goals. Standards developed
from basin plans shall not modify any of the above
requirements until the basin plan is formally
adopted and fully implemented by local
government. Basin plans shall be developed
according to an approved manual.
9. SQC Minimum Requirement - Operation and
Maintenance. An operation and maintenance
schedule shall be provided for all proposed storm
water facilities and BMPs and the party (or parties)
responsible for maintenance and operation shall be
identified.
10. SOC Minimum Requirement - Financial Liability.
Before beginning construction on the site and before
the City issues any construction permits for any
site, the owner or builder shall post a performance
bond or other suitable security in accordance with
Chapter 17.10. A maintenance bond may be
required before final approval of the drainage
system.
18 30 065 EXCEPTIONS TO MINIMUM REQUIREMENTS
Exceptions to the ESC and SQC minimum requirements may be
granted prior to permit approval and construction. An exception
may be granted after following the procedures outlined in Chapter
20.105 of the ECDC provided that a written finding of fact is
prepared that addresses all of the following criteria for approval:
A. The exception provides equivalent environmental protection
and is in the overriding public interest; and that the
objectives of safety, function, environmental protection and
facility maintenance, based upon sound engineering, are
fully met.
B. There are special physical circumstances or conditions
affecting the property which the strict application of these
provisions would deprive the applicant of all reasonable use
of the parcel of land in question, and every effort to find
creative ways to meet the intend of the minimum standards
has been made.
88948.4 -19-
C. The granting of the exception will not be detrimental 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.
D. The exception is the least possible exception that could be
granted to comply with the intent of the minimum
requirements.
18.30.070 DEVELOPMENT ACTIVITY ADMINISTRATION
A. Director. The Community Services Director or a designee
shall administer this ordinance and shall be referred to as
the Director. The Director shall have the authority to
develop and implement administrative procedures to
administer and enforce this ordinance.
1. The Director shall review all plans for compliance
with this chapter. Revision and resubmittal may be
required.
2. A review fee as set in Chapter 15.00 shall be paid.
3. Enforcement Authority. The Director shall enforce
this ordinance.
4. Inspection. All activities regulated by this
ordinance, except those exempt under Section
18.30.030 shall be inspected by the Director. The
Director shall inspect projects at various stages of
the work requiring approval to determine that
adequate control is being exercised. Stages of work
requiring inspection include, but are not limited to,
preconstruction, installation of BMPs, land
disturbing activities, installation of utilities,
landscaping, retaining walls, and completion of
project. When required by the Director, a special
inspection and /or testing shall be performed. The
drainage system shall be installed concurrently with
site development and shall be completed as shown
on the approved plan before City approval of an
occupancy permit or final inspection.
88948.4 -20-
18.30.080 ENFORCEMENT ACTION
A. General. Enforcement action shall be in accordance with
this ordinance whenever a person has violated any
provision of this ordinance. The choice of enforcement
action and the severity of any penalty shall be based on the
nature of the violation, the damage or risk to the public or
to public resources, and /or the degree of bad faith of the
person subject to the enforcement action.
B. Stop Work Order. The Director shall have the authority to
serve a person a stop work order if an action is being
undertaken in violation of this ordinance.
1. Content of order - the order shall contain:
a. A description of the specific nature, extent,
and time of violation and the damage or
potential damage.
b. A notice that the violation or the potential
violation cease and design, and, in
appropriate cases, the specific corrective
action to be taken within a given time.
C. A civil penalty under Section 9.3 below may
be issued with the order.
2. Notice - a stop work order shall be imposed by a
notice in writing, either by certified mail with
return receipt requested, or by personal service, to
the person(s) shown on the rolls of the Snohomish
County Assessor as the owner of the site, noted as
the applicant on any application for development
approval or observed doing regulated activity on the
site.
3. Effective date - the stop work order issued under
this Section shall become effective immediately
upon receipt by the person to whom the order is
directed.
4. Compliance - failure to comply with the terms of a
stop work order shall result in enforcement actions
88948.4 -21-
including, but not limited to, the issuance of a civil
penalty.
C. Civil Penalty. A person who fails to comply with the
requirements of this ordinance, who fails to conform to the
terms of an approval or order issued, who undertakes new
development without first obtaining approval, or who fails
to comply with a stop work order issued under these
regulations shall be subject to a civil penalty as outlined in
Chapter 20 of the Edmonds Community Development
Code.
18.30. 100 MAINTENANCE REQUIREMENTS .
A. Maintenance Required. All storm water facilities shall be
maintained in accordance with this ordinance and the
Storm Water .Management Manual. Systematic, routine
preventive maintenance is preferred.
B. Minimum Standards. The following are the minimum
standards for the maintenance of storm water facilities:
1. Facilities shall be inspected annually and cleared 'of
debris, sediment and vegetation when they affect the
functioning and /or design capacity of the facility.
2. Grassy swales and other bioiilters shall be inspected
monthly and mowed or replanted as necessary.
Clippings are to be removed and properly disposed
of.
3. Where lack of maintenance is causing or
contributing to a water quality problem, immediate
action shall be taken to correct the problem.
Within one (1) month, the Director shall revisit the
facility to assure that it is being maintained.
C. Disposal of Waste from Maintenance Activities. Disposal
of waste from maintenance activities shall be conducted in
accordance with the minimum Functional Standards for
Solid Waste Handling, Chapter 173 -304 WAC, guidelines
for disposal of waste materials from storm water
maintenance activities, and where appropriate, the
Dangerous Waste Regulations, Chapter 173 -303 WAC.
88948.4 -22-
D. Compliance. Property owners are responsible for the
maintenance, operation or repair of storm water drainage
systems and BMPs. Property owners shall maintain,
operate and repair these facilities in compliance with the
requirements of this ordinance and the Storm Water
Management Manual.
18.30.120 MAINTENANCE INSPECTION PROGRAM
A. Inspection and Enforcement Authority. The Director is
directed and authorized to develop an inspection program
for storm water facilities in the City that are designed for
developments with greater than 5,000 square feet of
impervious surface, and shall enforce the program.
B. Inspection. Whenever implementing the provisions of the
inspection program or whenever there is cause to believe
that a violation of this ordinance has been or is being
committed, the inspector is authorized to inspect during
regular working hours and at other reasonable times all
storm water drainage systems within the City to determine
compliance with the provisions of this ordinance.
C. Procedures. Prior to making any inspections, the inspector
shall present identification credentials, state the reason for
the inspection and request entry.
1. If the property or any building or structure on the
property is unoccupied, the inspector shall first
make a reasonable effort to locate the owner or
other person(s) having charge or control of the
property or portions of the property and request
entry.
2. If after reasonable effort, the inspector is unable to
locate the owner or other person(s) having charge
or control of the property, and has reason to believe
the condition of the storm water drainage system
creates an imminent hazard to persons or property,
the inspector may enter.
3. Unless entry is consented to by the owner or
person(s) in control of the property or portion of the
property or unless conditions are reasonably
88948.4 -23-
believed to exist which create imminent hazard, the
inspector shall obtain a search warrant prior to
entry, as authorized by the laws of the State of
Washington.
4. The inspector may inspect the storm water drainage
system without obtaining a search warrant provided
for in Subsection 3 above, provided the inspection
can be conducted while remaining on public
property or other property when permission to enter
has been obtained.
D. Inspection Schedule. The Director shall establish a master
inspection and maintenance schedule to inspect appropriate
storm water facilities that are not owned by the City.
Inspections shall be annual. Critical storm water facilities
may require a more frequent inspection schedule.
E. Inspection and Maintenance Records. As existing storm
water facilities are encountered, they shall be added to the
master inspection and maintenance schedule. Records of
newly constructed storm water facilities shall include the
following:
1. As -built plans and locations.
2. Findings of fact from any exemption granted by the
local government.
3. Operation and maintenance requirements and
records of inspection, maintenance actions and
frequencies.
4. Engineering reports, as appropriate.
F. Reporting Requirements. The Director shall report
annually to the City Council about the status of the
inspections. The annual report may include, but need not
be limited to, the proportion of the components found in
and out of compliance, the need to upgrade components,
enforcement actions taken, compliance with the inspection
schedule, the resources needed to comply with the
schedule, and comparisons with previous years.
88948.4 -24-
18.30.130 MAINTENANCE ENFORCEMENT
A. General. Enforcement action shall be taken whenever a
person has violated any provision of this ordinance. The
choice of enforcement action taken and the severity of any
penalty shall be based on the nature of the violation, the
damage or risk to the public or to public resources, and /or
the degree of bad faith of the persons subject to the
enforcement action.
B. Orders. The Director shall have the authority to issue to
an owner or person an order to maintain or repair a
component of a storm water facility or BMP to bring it in
compliance with this ordinance, the manual, and the
ECDC. The order shall include:
1. A description of the specific nature, extent and time
of the violation and the damage or potential damage
that reasonably might occur;
2. A notice that the violation or the potential violation
cease and desist and, in appropriate cases, the
specific corrective actions to be taken; and
3. A reasonable time to comply, depending on the
circumstances.
C. Civil Penalty. A person who fails to comply with the
requirements of this ordinance or who fails to conform to
the terms of an approval or order issued shall be subject to
a civil penalty as outlined in Chapter 20 of the ECDC.
D. The remedies provided for in this section shall not be
exclusive. The City may also use other civil and
administrative remedies available to it, including but not
limited to, these remedies provided in Title 19 and the
State Building and Dangerous Building Code.
Section 2. Exhibits A and B to Chapter 18.30 are adopted by reference as fully
as if herein set forth. Copies of such documents shall be maintained by the City Clerk and in
88948.4 -25-
the Community Services Department for reference by the public. Copies shall be available for
purchase at the cost of reproduction.
Section 3. Severability. If any section, sentence, clause or phrase of this
ordinance should be held to be invalid or unconstitutional by a court of competent jurisdiction,
such invalidity or unconstitutionality shall not affect the validity or constitutionality of any other
section, sentence, clause or phrase of this ordinance.
Section 4. Effective Date. This ordinance, being an exercise of a power specifi-
cally delegated to the City legislative body, is not subject to referendum, and shall take effect
five (5) days after passage and publication of an approved summary thereof consisting of the
title.
APPROVED:
C.
ATTEST /AUTHENTICATED :
i - L./• - •
.� •
APPROVED AS TO FORM:
OFFICE OF THE CITY ATTORNEY:
I. 4
FILED WITH THE CITY CNJRK: 2/17/95
PASSED BY THE CITY COUNCIL: 3/21/95
PUBLISHED: 3/26/95
EFFECTIVE DATE: 3/31/95
ORDINANCE NO. 3 013
88948.4 -26-
SUMMARY OF ORDINANCE NO. 3013
of the City of Edmonds, Washington
On the 21st day of March , 1995_, the City Council of the City of Edmonds,
passed Ordinance No. 3013 . A summary of the content of said ordinance, consisting
of the title, provides as follows:
AN ORDINANCE OF THE CITY OF EDMONDS, WASHINGTON, AMENDING THE
COMMUNITY DEVELOPMENT CODE TO ADOPT A NEW CHAPTER 18.30 STORM
WATER MANAGEMENT AND FIXING A TIME WHEN THE SAME SHALL BECOME
EFFECTIVE.
The full text of this Ordinance will be mailed upon request.
DATED this 21st day of March , 199 5
C Y CLERK, ONDA J. MARCH
city of edmonds
development information
EXHIBIT A
Drainage System Standards
The Edmonds Community Development Code (Chapter 18.30) requires special
drainage control on all developments with over 2000 square feet of new
impervious covering. Development means:
1. A building or other construction permit for a
development with more than 2000 square feet
of impervious surfacing.
2. A grading, rockery or retaining wall permit.
3. Final approval of a subdivision or PRO.
Before issuance of any development permit, and before development
begins on any site, the developer shall submit a drainage plan and
obtain approval from the Engineering Department. The drainage system
shall be installed concurrently with site development, and shall be
completed as shown on the approved plan.
Development exceeding 5000 square feet of impermeable surface must have
the drainage plan prepared and stamped by a licensed civil engineer.
Any plan for a project located in a critical drainage area, in an
environmentally sensitive area, or on a site presenting special
problems,.must be prepared and stamped by a licensed civil engineer,
regardless of the impervious area on that site. All other developments
not exceeding 5000 square feet of impermeable surfacing may use
standard plans.
The remainder of this document describes the standard plans.
Pre - printed sheets for preparing standard plans are included in this
packet. If you have questions of a technical nature, please call the
Hydraulics Engineer (206) 771 -0220.
Standard /Preferred Plan Approach
The standard plan approach uses an enclosed sub - surface detention
system discharging at an acceptable outfall location. Any other type
of plan must be prepared by a licensed engineer. There is
no assurance that the proposal you submit will be subsequently
approved.
REV 2/18/92
BASIC DRAINAGE REQUIREMENTS
Submit four (4) drainage plans to scale, preferably at a scale of
1 " =10' or 1" =20' on an 11" x 17" or larger drawing sheet. Most
applicants use the grading or plot plan submitted with their building
permit. The following elements must be included with the drainage plan:
1. Show all locations where concentrated surface water enters
the property, the route it now takes through the property,
and the locations where it leaves the property. A
description of the type and magnitude of flow should be noted
on the plan. For example, "intermittent flow during storms
in shallow grass swale". Show all other surface waters.
2. Show locations and scaled dimensions of all existing and
proposed buildings and other impervious surfaces.
3. Show the route and the type of channel to be
provided for any concentrated flow which is to be
changed. Note that structures are to be set back at least
10 feet from any closed drainage facility and 15 feet from
the top of bank of any channel, pond, or stream. Additional
setbacks or native growth protection easements may be
required through the SEPA process. Structures must be at
least one foot above the maximum water level in the channel.
Work in streams, ponds, or channels require a State
Department of Fisheries or Department of Wildlife hydraulics
permit.
4. Profile the elevations of the existing utilities and proposed
drainage system (inverts, pipe sizes and ground cover).
S. Topography shall be shown:
If surface water enters the property from off site. Plan
must show all drainage areas that contribute surface water to
the site. Contour interval shall be two (2) feet. (However,
five (5) feet may be acceptable in some cases; aerial photos
with five (5) foot intervals are available from the City.)
6. Show all improvements or other methods of handling surface
water runoff in accordance with the requirements of Section
18.30.040 of the Edmonds Community Development Code and this
handout (see Standard Plan Detention System).
7. A temporary sediment and erosion control plan is required.
The location of the sediment and erosion control practices or
devices and the limits of disturbed area must be shown on the
plan view. Examples of temporary sediment and erosion
control practices and devices include:
a) Earth dike diversion to route clean offsite water around
the disturbed area.
b) Filter fabric fence.
REV 2/18/92 Page 2 of 6
c) Straw bale barriers.
d) Stabilized construction entrance.
e) Temporary seeding practices.
f) Practices used to minimize soil exposure.
Details of the sediment and erosion control devices are to be
provided with the drainage plan.
8. A sequence of construction must be provided. The sequence
must stipulate that the temporary sediment and erosion
measures will be in place and inspected prior to any
construction or site clearing. Furthermore, it must
address the requirement for the sediment and erosion control
practices and /or devices to be maintained until the permanent
vegetation is established.
9. Calculations must be submitted when plans are prepared by a
civil engineer. The detention worksheet must be completed
and submitted when standard plans are used.
STANDARD PLAN DETENTION SYSTEM
1. Select the outflow location. It must be low enough to allow
the detention pipe to drain completely.
a. If a public storm drain or public drainage ditch is
within or adjacent to the property, direct the outflow
pipe to these facilities.
b. When there is no public system available, direct the
outflow to a well defined drainage channel that drains
through the area to be developed. The outlet pipe and
the channel at the discharge location must be within the
property.
2. Locate the underground detention pipe. The detention pipe
must be placed downhill so that all impermeable surface on
site can be detained.
3. Indicate tightlines from roof drains and driveway drains
through the system to the outflow location. Roof drains
shall not be piped into footing drains. Roof drains or
footing drains shall not be connected to the sanitary sewer.
Footing drains should not connect to the surface water system
except in unstable slope areas where groundwater recharge is
discouraged. (Discharging groundwater through footing drains
to storm water systems can impact fish resources by reducing
the low flow volumes of water in streams.)
4. Complete detention worksheet.
a) Compute the impermeable surface area that will drain to
the detention system and enter on the detention
worksheet.
REV 2/1,8/92 Page 3 of 6
b) Indicate the detention pipe diameter and specify the
required detention pipe length for impermeable surface
area using Table 1. Enter the pipe diameter and length
on the worksheet.
c) Indicate the required outlet orifice size for the
impermeable surface area using Table 2. Enter the
outlet orifice size on the worksheet.
MAINTENANCE OF DETENTION SYSTEMS
Material must be removed from the catch basins and detention pipe to
prevent clogging, especially at the outlet control system. Catch
basins should be cleaned at least twice per year. Frequent catch basin
cleaning will reduce the need for the more difficult task of cleaning
the detention pipe. The system should be kept clean during
construction. Material must be physically removed and not just flushed
downstream.
REV 2/18/92 Page 4 of 6
cable 1 - Detention Pipe Size
Impermeable
Required
Area So. Ft.
------- - - - - --
Vol Cu Ft
2000
---- - - - - --
50
2500
62)
3000
75
3500
87
4000
100
4500
112
5000
125
Note: Allowable
Pipe Materials:
Pipe Diameter
15" 18" V4.. 30"
------------------------
40 28 16 10
50 35 20 13
60 42 24 15 Required pipe
70 49 28 18 length in feet
80 56 32 21
90 63 36 23
100 70 40 25
Reinforced Concrete
Aluminized Steel
Aluminum
CMP Asphalt Coated
N -12 ADS (Not permitted on roads)
Table 2 - Outlet Orifice Sizes
Impermeable
Area Sq. Ft. Outlet Orifice Diameter (Inches)
-- --------------------------------
2000 5/8
2500 5/8
3000 3/4
3500 3/4
4000 7/8
4500 7/8
5000 7/8
Table 3 - Rectangular Catch Basin Requirements* ;
Detention
Max. size
Catch Basin
Pipe diameter
knockout
Type
< 18"
20"
---- - - - - --
Type I, CB
15
18" to 24"
26"
Type IL, CB
16
24" to 36"
36"
Type II, CB
19 (48" Basin)
36" to 42"
42"
Type II, CB
19 (54" Basin)
*Source: Assoc.
Sand & Gravel Co.
Standards
ADDRESS
STANDARD "RAINAGE DETENT /ON J YSTEM
WORKSHEET
CALC BY:
PHONE:
DATE:
* * * **DESIGNDATA * * ***
IMPERVIOUS AREA PIPE DIA
Rent *LEN
sC o
/Hv ELE%
e.s�N •� • co* ac C.UrN
SONS"
SYSTEM CROSS SEC71ON
PIPE LG ORIFICE
wa T GRAVEL
~ �011TFIAM/ 7R£NCH� MW e0' LONG
/ TOP ANO �'PERF PIPE TO 8E LEVEL
V FROM 8 _
CONTROL
OUTLET 1•
!'PERFMPE W/CAPS
RUNOFF SPREADER
OUTLET
a Z-G'OEEP, l'.6- QUARRY SPALLS
X2.3' DEEP, 3/4' CRUSHED ROCK
FROM COHTROL
OUTLET
RIPRAP OUTLET
FOOTING DRAINS SHAU NOT BE CONNECTED Tip DETENTION SYSTEM
NOTES:
L Call Engineering Division (771 -0220) for a tightline and detention system inspection
before backfiiliag and for final inspections_
2, Responsibility for operation and maintenance of drainage systems on private property is the
responsibility of the property owner. Material accumulated in the storage pipe must be flus
out and removed from the catch basins to allow proper operation. The outlet control orifice
must be kept open at all times.
APPROVED BY
DATE
EXHIBIT B
City
of Edmonds
Infiltration
Feasibility Map
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Scale: 1"=4000'
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LEGEND
SOC«,N1YT
5YMBOL
PARK
MEANING • vK
Sites where infiltration
®
may be feasible. , if if
conditions are met.
a
Sites where infiltration 88th
will not be permitted.
pp''
a
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205th Sl.
STATE OF WASHINGTON,
COUNTY OF SNOHOIVISH,
SUMMARY OF
ORDINANCE NO. 3013
of the City of
Edmonds, Washington'
On the 21st day of March,
1995..ihe City Council of the
City of Edmonds, passed
Ordinance No. 3013. A sum-
mary of the content of said
ordinance, consisting of the
title, provides as follows:
AN ORDINANCE OF THE
CITY OF EDMONDS: WASH-
INGTON, AMENDING THE
rr)mKAiINITY DFVFLOPMENT
The
fugi text of this
Ordinance will be mailed upon
request.
DATED this 21st day of
March, 1995.
RHONDAJ.MARCH -
Citv Clerk
B -2 -1
ss.
Affidavit of Publication
FZECE1vED
APR 0 4 1995
EDMONDS CITY IERK
The undersigned, being first duly sworn on oath deposes and says
that she is Principal Clerk of THE HERALD, a daily newspaper
printed and published in the City of Everett, County of Snohomish,
and State of Washington; that said newspaper is a newspaper of
general circulation in said County and State; that said newspaper
has been approved as a legal newspaper by order of the Superior
Court of Snohomish County and that the notice ......... ...............................
Summary of Ordina
.-'-' nce No. 3013 ...... .........................
City of Edmonds
....."""' -" ........................... .... ............ ............................... ............................... ........ .........
a printed copy of which is hereunto attached, was published in said
newspaper proper and not in supplement form, in the regular and
entire edition of said paper on the following days and times, namely:
March 26, 1995
"
........... .. ' "" ' "'............................-". ............................... . - ........_...._........
.............. ............................... ' -' ..._.........--'.................................... ...._........I.................
and that said newspaper was regularly distributed to its subscribers
durin 1✓�1 of said eriod.
U c�
...... .
:....:.:.......... ......_....................' - ". ::.. "
I r Principal Clerk
Subscribed and sworn to before me this...... 2.. t h
dayf ........................ March. ......................, - 19..9 5..
.._..._.__._.- .....i ...... .............____. ....... �..... _ _...... ..... - - - - - -_ -- ._._._......._._
Notary Public in and for the Stat of shington,
residing at Everett, Snohomish o
J g \
0 "SlIGN
cs �pTAAy-
�� Pu B O
�7 5.19 98
OF W ASM