HomeMy WebLinkAboutord2005-065WHATCOM COUNTY COUNCIL AGENDA BILL NO. zoos 72 C
CLEARANCES
Initial
Date
Date Received in Council Office
Agenda Date
Assigned to:
Originator.-
7/27/2005
�
FE C, E � V D
7/26/2-005
Introduction
Ow?sron Head.
JUL 2 7 2005
8/9/2005
Hearing
0e t. Head:
Prosecutor
WHATCOM COUNTY
Purchasrn !Bud et:
COUNCIL
Executive:
TITLE OF DOCUMENT.•
Interim ordinance additional regulatory protection for Lake Whatcom Watershed
A TTACIIMENTS:
SEPA review required? { ) Yes ( ) NO
Should Clerk schedule a hearing ? { x j Yes ( l NO
SEPA review completed? ( ) Yes ( ) NO
Requested Date: 81g12005
SUMMARY STATEMENT OR LEGAL NOTICE LANGUAGE: (If this item b an ordinance or requires apublic
hearing, you must provide the language for use in the required public notice Be specific and cite RCW or WCC as appropriate.
He clear in explaining the intent of the action.)
Interim ordinance amending Whatcom County Code, Title 20, Chapter 20 -71 - Water Resource Protection Overlay District, to provide additional
regulatory protection for the Lake Whatcom Watershed- This ordinance would adopt interim amendments to the provisions of Chapter 20.71 of the
Whatcom County Code -Water Resource Protection Overlay District to address the objectives of the interim moratorium on the acceptance of new
applications for subdivisions within the Lake Whatcom Watershed.
COMMITTEE ACTION:
COUNCIL ACTION:
7/26/2005: Introduced
8/9/2005: Adopted 6 -0, McShane absent,
Ord. #2005 -065
Related County Contract #:
Related File Numbers:
Ordinance or Resolution
Number: Ord_ #2005 -065
Please Note: Once adopted and signed, ordinances and resolutions are availahle for viewing andprinting
on the Coun 's website at: www.co.whalcom.wa.us /council.
SPONSORED BY: Consent
PROPOSED BY: Consent
INTRODUCTION DATE: 7/26/2005
ORDINANCE NO. 2005 -065
AN INTERIM ORDINANCE AMENDING WCC, TITLE 20, CHAPTER 20.79 - WATER RESOURCE
PROTECTION OVERLAY DISTRICT TO ADDRESS THE OBJECTIVES OF THE INTERIM
MORATORIUM ON THE ACCEPTANCE OF NEW APPLICATIONS FOR SUBDIVISIONS WITHIN
THE LAKE WHATCOM WATERSHED AND PROVIDE ADDITIONAL REGULATORY
PROTECTION FOR THE LAKE WHATCOM WATERSHED
WHEREAS, Lake Whatcom is the drinking water source far approximately half the residents
of Whatcom County; and
WHEREAS, the preservation and protection of drinking water is a priority of the Whatcom
County Council; and
WHEREAS, the Whatcom County Comprehensive Plan, updated in January 2005,
establishes the Lake Whatcom Watershed as a Special Study Area; and
WHEREAS, there are a variety of land use related pollutants that can adversely impact lake
water quality which may lead to violations of the Safe Drinking Water Act (SDWA); and
WHEREAS, Whatcom County Code, Chapter 20.71 establishes the Lake Whatcom
Watershed as a Water Resource Protection Overlay District; and
WHEREAS, Whatcom County Code, Sections 20.80 .635 and 20.80,735 designate the Lake
Whatcorn watershed as a Water Resource Special Management Area and a Stormwater Special
District; and
WHEREAS, priority actions to protect the drinking water supply should include strategies
to address existing development, future development, and emergency or spill response; and
WHEREAS, the Whatcom County Council adopted an interim moratorium on the
acceptance of new applications for subdivisions and new building permits within the Lake
Whatcorn watershed on February 8, 2005 [ORD2005 -027]; and
WHEREAS, the Whatcom County Council adopted an interim moratorium on the
acceptance of new applications for subdivision within the Lake Whatcom watershed on April 26,
2005 [ORD2005 -042]; and
WHEREAS, interim Ordinance No. 2005 -042 will expire in October 2005; and
WHEREAS, absent the adoption of any interim official controls the purpose of the interim
moratorium will be thwarted; and
Page 1
WHEREAS, it is anticipated that the Whatcom County SEPA Official will issue a
determination on the proposed interim amendments prior to official Council action; and
WHEREAS, RCW 36.70.790 and RCW 36.70.795 permits adoption of interim official
controls as long as a public hearing is held within 60 days of adoption; and
WHEREAS, RCW 36.70.795 requires the adoption of findings of fact which justify
Council action, the Council makes the following findings of fact:
The Washington State Department of Ecology (DOE) has listed portions of Lake Whatcom
as an "impaired water body" on the 303(d) list, under the Clean Water Act, of waterbodies
not attaining water quality criterion for dissolved oxygen.
2. It has been recommended by the State Department of Ecology that Lake Whatcom also be
placed on the 303(d) list for impairments resulting from the toxic pollutants PCB -1254, PCB -
1260 and mercury, and that Austin Creek, Park Place Drain, and Cable Street drainage be
placed on the 303(d) list as impaired for not attaining water quality criteria for bacteria.
1 Interim amendment of WCC, Title 20, Chapter 20.71 — Water Resource Protection Overlay
District is necessary to avoid future degradation of the Lake Whatcom Watershed and any
associated harm to the health, safety and welfare of the public.
4. Without the imposition of additional interim official controls, impacts from development and
stormwater may cause harm to the Lake Whatcom Watershed and may thereby cause harm
to the health, safety and welfare of the public.
5. The Whatcom County Council desires the opportunity to evaluate the impacts of future
development in relation to reducing phosphorous loads to Lake Whatcom and meeting the
Total Maxium Daily Load (TMDL) goal of reversing the declining oxygen trends in Lake
Whatcom.
6. Meeting the TIVIDL goals and improving oxygen levels in Lake Whatcom will require a variety
of comprehensive planning, pollution prevention, pollution reduction and technical
approaches.
7. The Whatcom County Council desires the opportunity to review and evaluate existing
development codes and regulations to permanently address these health and safety
concerns.
NOW, THEREFORE, BE IT ORDAINED by the Whatcom County Council that Whatcom
County Code, Title 20, is hereby amended as indicated in Exhibit A to this ordinance.
BE IT FURTHER ORDAINED by the Whatcom County Council, pursuant to RCW
36.70.795, that this ordinance shall be effective for not longer than six months following its
effective date, but may be renewed for one or more six -month periods if subsequent public
hearings are held and findings of fact are made prior to each renewal.
Page 2
ADOPTED this 9th_ day of August , 2005.
�.• H A 7- WHATCOM COUNTY COUNCIL.
CD WHATCOM COUNTY, WASHINGTON
Cp.;NTY .
1�9 n a
Cl'6ic of to &'Co%cil
` +,//111118 I 1I* I%000
APPROVED as to form
Karen Frakes, Civil Depu y Prosecutor
Laurie Caskey - Schreiber, Council Chair
pproved } Denied
ete Kre n, County Executive
Date: '< yr j
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Whatcom County Council
Lake Whatcom Watershed Moratorium Response
Chapter 20.71
WATER RESOURCE PROTECTION OVERLAY DISTRICT
Sections:
20.71.010 Purpose.
20.71.020 Application.
20.71.021 Area and applicability.
20.71.050 Permitted uses.
20.71.100 Accessory uses.
20.71.150 Conditional uses.
20.71.200 Prohibited uses.
20.71.300 Open space and impervious surfaces.
20.71.350 Cluster subdivisions.
20.71, 351 Cluster design standards.
20.71.352 Open space reserve tract.
20.71.400 Building setback /buffer areas.
20.71.600 Development criteria.
20.71.601 Parking space dimensions.
20.71.602 Parking requirements.
20.71.503 Alternative surfacing methods.
20.71.604 Vehicular access.
20.71.700 Roads, curbs, gutters and sidewalks.
July 26, 2005
20.71.010 Purpose.
The Water Resource Protection Overlay District is an overlay zone which is intended to impose
additional controls to preserve and protect unique and important water resources within
Whatcom County. This district is designed to protect the unique character of the Lake Whatcom
and Lake Samish watersheds while creating opportunities not available in the underlying zone
districts to address the needs of these watersheds.
20.71.020 Application.
20.71.021 Area and applicability.
(1) The Water Resource Protection Overlay District is an overlay zone which covers the
entire geographic area of the Lake Whatcom and Lake Samish watersheds within Whatcom
County's jurisdiction. For purposes of this title, the Lake Samish watershed shall consist of that
portion of the Friday Creek sub -basin of the Samish River watershed that lies within Whatcom
County.
(2) This district may be expanded to include other areas through the annual zoning text
amendment process.
(3) The Lake Whatcom and Lake Samish watersheds are also designated as stormwater
special districts under the stormwater regulations contained in WCC 20.80.635 and as water
resource special management areas under the clearing regulations contained in WCC
20.80.735.
(4) If the provisions of this chapter conflict with the provisions of the Shoreline Management
Program, the Critical Areas Ordinance, the Whatcom County Development Standards, or the
provisions of the underlying zoning district, then the most restrictive shall apply, with the
exception of the setback provisions established in WCC 20.71.401.
Whatcom County Council
Lake Whatcom Watershed Moratorium Response
July 26, 2005
20.71.050 Permitted uses.
All permitted uses in the underlying zone districts are permitted except as expressly prohibited
or made conditional, or further conditioned by this chapter.
..
..
0512 Private noncommercial greenhouses less than 250 square feet.
20.7 1.100 Accessory uses.
All accessory uses in the underlying zone districts are permitted except as expressly prohibited
or made conditional, or further conditioned by this chapter.
20.71.150 Conditional uses.
All conditional uses in the underlying zone districts shall remain conditional uses unless
expressly prohibited, made conditional, or further conditioned by this chapter. In addition, the
following uses shall only be conditionally permitted:
.151 On -site storage facilities for hazardous wastes associated with outright permitted uses or
approved conditional uses, other than cottage industries as defined in WCC 20.71.215, subject
to the most current siting criteria under Chapter 173 -303 WAC within the Rural, Rural Forestry,
Commercial Forestry, Neighborhood Commercial and Resort Commercial Zone Districts only.
_.
.1524 Retail or wholesale plant nurseries or greenhouses for storage, propagation and culture of
plants, provided:
(1) Greenhouses shall not be larger than 1,000 square feet,
(2) Greenhouses and cultivated ground shall not be located within 250 feet of Lake
Whatcom, Lake Samish, or streams subject to the Shoreline Management Program, 200 feet
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Whatcom County Council
Lake Whatcom Watershed Moratorium Response July 26, 2005
from fish bearing streams, or 150 feet from other streams, and their tributaries, which flow into
Lake Whatcom or Lake Samish.
(3) A monitoring program has been established to ensure that chemical and pesticide
quantities in stormwater runoff do not exceed state water quality standards. Complete control of
drainage from the operation shall be in effect. Such runoff will be tested for pollutants bimonthly
for pollutants and there will be q aFterly unannrti in.+ d spot nheGk by a licensed water quality
testing agency. All requirements will be met at the owner's expense.
(4) No person shall apply a commercial fertilizer, either liquid or granular, that is labeled as
containing more than 0% phosphorous or other compound containing phosphorous, such as
phosphate.
.185 Type I solid waste handling facilities, except:
(1) Moderate risk waste facilities; and
(2) Facilities in the Recreation and Open Space District,
20.71.200 Prohibited uses.
In addition to the uses prohibited in the underlying zone districts, the following uses are
prohibited:
.201 Dry cleaning establishments.
.202 Gas stations, service stations, combustion engine repair garages and automotive wrecking
yards.
.203 Sod farming.
.204 Aquaculture and mariculture projects.
.205 The operation of fur farms.
.206 Confinement feeding operations.
.207 Asphalt and concrete batch plants.
.208 Gravel bar scalping projects within the jurisdiction of the Shoreline Management Program.
.209 Utilization of sewage sludge on land.
,210 On -site treatment facilities for hazardous wastes.
.211 Type I solid waste handling facilities, except those specified in WCC 20.71.185.
.212 Type 11 and Type III solid waste handling facilities.
.213 Golf courses.
.214 Cemeteries.
.215 Cottage industries which would require on -site hazardous waste storage facilities.
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Whatcom County Council
Lake Whatcom Watershed Moratorium Response July 26, 2005
.216 Surface mining outside of designated Mineral Resource Lands (MRL) Special Districts,
provided that surface mining, rock crushing, washing and sorting subject to the Forest Practices
Act (Chapter 76.09 RCW) is permitted.
.217 Major passenger intermodal terminals.
.218 Freight railroad switching yards and terminals.
.219 Agriculture including animal husbandry, horticulture, viticulture, floriculture, and the
cultivation of crops.
.220 Animal hospitals and accessory kennels and stables.
.221 Commercial kennels and stables.
20.71.300 Open space and impervious surfaces.
.301 Open space requirements shall be as follows:
(1) For uses in the TC and NC Zones, at least 25 percent of the parcel shall be reserved as
open space.
(2) For uses in the RC Zone, at least 40 percent of the parcel shall be reserved as open
space.
(3) Open space areas shall be maintained in natural vegetation or landscaped per WCC
20.80.325.
(4) For properties within the jurisdiction of the Shoreline Management Program (WCC Title
23), submerged lands and/or tidelands within the boundaries of any waterfront parcel that are
located waterward of the ordinary high water mark shall not be used in open space calculations.
.302 Impervious surface requirements shall be as follows*
(1) For uses in the UR, URM and RR Zone Districts, at least 80 percent of the lot or parcel
shall be kept free of structures and impervious surfaces.
(2) For uses in the R Zone District, at least 90 percent of the lot or parcel shall be kept free
of structures and impervious surfaces.
(3) For lots or parcels where the applicable formulas in subsections (1) and (2) of this
section would not allow a 2,500 square -foot impervious surface area, 2,504 square feet of
impervious surface shall be allowed. Two or more lots of record consolidated pursuant to the
provisions of WCC 20.83.070 shall be treated as one undivided parcel for the purpose of
calculating total allowable impervious surface. Where two or more lots or parcels are
consolidated and are not subject to the provisions of WCC 20.83.070;; and are not subject to a
restrictive covenant which precludes development of buildings, structures or other
improvements not otherwise identiffied by said covenant, 4,000 square feet of impervious
surface shall be allowed.
(4) Pre - existing nonconforming impervious surfaces may be maintained or redeveloped.
However, if 50 percent, or greater, of the pre- existing nonconforming impervious area is to be
redeveloped, then the applicable impervious surface limitations shall apply per subsections (1),
(2) and (3) of this section. However, if a structure is destroyed, the pre - existing nonconforming
use may be reconstructed using the pre - existing footprint. Expansion of nonconforming
impervious surfaces shall be prohibited.
(5) A mobile home within an existing mobile home park may be replaced with a larger mobile
home (not to exceed a maximum of 1,500 square feet) provided there is not an increase in the
overall number of mobile homes in the park or any increase in other impervious surfaces
beyond the new mobile home footprint.
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Whatcom County Council
Lake Whatcom Watershed Moratorium Response July 26, 2005
(6) For properties within the jurisdiction of the Shoreline Management Program (WCC Title
23), submerged lands and/or tidelands within the boundaries of any waterfront parcel that are
located waterward of the ordinary high water mark shall not be used in impervious /pervious
surface calculations.
(7) Any portion of a roof overhang or other overhanging architectural feature which projects
further than three feet from the footprint of a structure shall be calculated as impervious surface.
(8) GFavel swfaGeS shall be given a 50 PBFGent redu6tion On imperviOur, suFfaGe value.
Alternative surface methods described in WCC 20,71.603 may be used.
20.71.350 Cluster subdivisions.
The purpose of cluster subdivision is to provide a method of creating building lots with
spatially efficient sizes. Clustering is intended to consolidate development and associated
infrastructure, reduce development costs, and increase infrastructure efficiency. Clustering is
also intended to help preserve open space and the character of areas, reduce total impervious
surface area, and minimize development effects on critical areas and associated buffers, as
defined in WCC 16.16, and resource lands. Preservation of open space is thereby intended to
reduce potential stormwater runoff and associated impacts while assuring protection of viable,
undeveloped, and naturally vegetated corridors for wildlife habitat, protection of watersheds,
preservation of critical areas, PF0t8.. },. R of watersheds preservation of aesthetic values
including view corridors, and preservation of trail and/or recreation areas.
20.71.351 Cluster design standards.
The creation of new building lots within Water Resource Protection Overlay Districts shall be
subject to the following design standards:
(1) Cluster subdivisions shall be required for all land divisions resulting in lots less than five
acres in size, with the exception of boundary line adjustments.
(2) A cluster subdivision shall include a permanent open space reserve area meeting the
criteria established in WCC 20.71.352.
(3) The minimum cluster lot size requirements of the underlying zone district shall apply.
(4) The maximum number of building lots in a lot cluster shall be 10.
(5) Clusters containing two or more lots of less than one acre within a proposed
development shall be separated by at least eighty feet.
(6) Clustered building lots may only be created through the subdivision, short subdivision or
binding site plan process pursuant to WCC Title 21.
(7) Building lots shall be designed and located to be compatible with, and avoid disturbance
of, critical areas or other valuable or unique natural resources featUFes or known archaeological
sites, as well as physical constraints of the site.
(8) Building lots shall be arranged in a cluster /concentrated pattern.
(3) A cluster subdivision shall have no more than two common encroachments on existing
county roads unless site constraints require additional road access. The arrangement of
clustered building lots shall be designed to avoid development forms commonly known as
linear, straight line or highway strip patterns.
(10) As applicable, interior streets shall be designed to allow future vehicular access to any
portion of the reserve tract which may be divided into future building lots, provided that the
required permanent open space reserve area, pursuant to 20.71.352, shall not be further
subdivided.
20.71.352 Open space reserve area.
(1) For purposes of this title, an "open space reserve area" shall be defined as that portion of
a subdivision or short subdivision set aside in accordance with this chapter, and permanently
dedicated for active or passive recreation, critical area protection, natural resource or
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Whatcom County Council
Lake Whatcom Watershed Moratorium Response July 26, 2005
archaeological site preservation, wildlife habitat and/or visual enjoyment, and shall be consistent
with the definition of "open space" pursuant to WCC. 20,97.275.
(2) The open space reserve area shall be subject to the following provisions:
(a) The minimum open space reserve area shall be determined by the minimum cluster
subdivision reserve area requirements of the underlying zone district.
(b) A permanent open space reserve area shall be protected using one of the following
mechanisms-
(i) Placement in a separate non - building tract owned in common by all lots within
the subdivision; or
(ii) Covered by a protective easement or public or private land trust
dedicationwhich protects at least the minimum required cluster reserve area specified in the
underlying zone district; or
{iii} Preserved through an appropriate permanent protective mechanism that
provides the same level of permanent protection as subsection (i) of this section as determined
by the County Zoning Administrator or Hearing Examiner which applies to at least the minimum
required cluster reserve area specified in the underlying zone district.
(c) The boundaries of the open space portion of the reserve area may be altered only if
the county finds that in dedicating adjacent reserve areas it would further the objectives listed in
WCC 20.71.350 by altering the reserve area and increasing the area of reserve proportionately
on the adjacent land being subdivided so that there is no net reduction in open space reserve
area.
(d) The purpose of the open space reserve area as defined in subsection 20.71.352(1)
shall be recorded on the face of the final plat or short plat.
(e) The remaining unused development density and /or impervious surface allowances
remaining on the parcel containing the open space reserve area, based on the gross density of
the parent parcel, may be assigned to that portion of the reserve tract not subject to the
minimum area requirements of 20.71.352(2 )(b). The density shall be recorded on the face of
the final plat or short plat. The development rights assigned to the reserve tract in accordance
with this subsection may not be transferred if the pervious surface area associated with the
reserve tract has been transferred to the other building lots within the subdivision.
(f)i The requirements stated in subsections (c) and (d) of this section shall be recorded as
a restriction on the face of the final plat or short plat, and shall constitute an agreement between
Whatcom County and the current/future owner(s) of record that shall run with the land. Said
restriction(s) may be amended by mutual agreement between said parties after review for
consistency and compliance with the official Whatcom County zoning ordinance, the Whatcom
County subdivision ordinance, and the Whatcom County Comprehensive Plan.
(g) For cluster subdivisions approved after December 7, 1999, that portion of the reserve
tract which is kept in pervious open space may be counted toward pervious surface area
requirements for the building lots in the subdivision on a prorated basis.
20.71.400 Building setbackibuffer areas.
.401 Setbacks for all properties within the overlay district shall be as follows: Class I and Class II
roads shall have a minimum setback of 30 feet; and Class III, IV and V roads shall have a
minimum setback of 20 feet; provided, that the road right -of -way meets the minimum standard
for road rights -of -way pursuant to the Whatcom County Development Standards.
.402 Roof overhangs or other overhanging architectural features shall not project further than 18
inches into the side or rear yard setbacks. Such overhangs may extend three feet into the front
yard setback; however, in no case shall they extend more than one -half the depth of the front
yard setback.
C.
Whatcom County Council
Lake Whatcom Watershed Moratorium Response July 26, 2665
20.71.600 Development criteria.
20.71.601 Parking space dimensions.
A standard parking space shall have the rectangular dimensions of 10 feet in width and 20
feet in length; provided, however, that for any parking area of six or more spaces, 50 percent of
all spaces may have the rectangular dimensions of eight feet in width and 15 feet in length;
provided, that these spaces are marked for use by compact automobiles. Except in single - family
residential areas, all dimensions shall be exclusive of driveways, aisles and other circulation
areas required under WCC 20.80.560 and 20.80.570.
20.71.602 Parking requirements.
Parking shall conform to the requirements of WCC 20.80.500 through 20.80.590 unless
otherwise specified in this section. Minimum parking requirements may be reduced through any
of the following methods:
(1) A shared parking agreement has been filed with the county auditor establishing a shared
parking lot for land uses with noncompeting hours of operation, or for multitenant retail and
commercial facilities; provided, the parking lot is not located further than 700 feet from any of
the uses it is intended to serve.
(a) The minimum required parking in shared facilities shall be based on the land use with
the highest parking demand.
(b) Mixed use developments with similar operating hours may be required to submit a
parking demand study to determine if parking can be combined.
(2) A 20 percent reduction may be approved if an establishment is located within 1,000 feet
of any regularly scheduled bus stop.
(3) The zoning administrator determines that a reduced requirement will reduce overall
impervious surfaces while maintaining consistency with this title.
20.71.603 Alternative surfacing methods.
Alternative surfaces including, but not limited to: bark or wood mulch, washed
ravel tuff bleG grid /lattice systems, permeable interlocking pavers, pervious concrete, porous
asphalt, and other similar approved materials are encouraged. Alternative surfacing methods
may be approved for fringe or overflow parking areas, emergency parking areas, private roads,
fire lanes, road shoulders, bike paths, walkways, patios, driveways, and easement service roads
in residential or commercial zones unless site constraints make use of such materials
detrimental to water quality. '�^�.��u! tilization of alternative surfacing methods shall be
subject to review and approval by the Whatcom County public works department, fire marshal
and/or the county ADA coordinator for compliance with other applicable regulations and
development standards. Surfaces that comply with this section shall not be considered
impervious surfaces under WCC 20.71.300 if the following conditions are met:
(1) Bark, wood mulch, and washed gravel shall be designed and installed so that all rain
water falling upon the alternative surface will be infiltrated directly beneath the alternative
surface without generating surface runoff based on the one -year, 24 -hour storm event.
(2) Other alternative surface methods shall be designed and installed in accordance with the
guidelines in the 2005 Low Impact Development Technical Guidance Manual for Puget Sound,
prepared by the Puget Sound Action Team (Publication No, PSAT 05 -03), as applicable. No
pervious surface credit shall be given for projects utilizing an underdrain system.
20.71.604 Vehicular access.
Driveways and curb cuts shall be minimized along all arterial and collector roads. Each
existing lot shall be allowed only one driveway or curb cut; adjacent lots are encouraged to
share access points. In new developments, lots or leased sites shall be oriented toward internal
driveways, parking areas, or roads, with limited access to arterial or collector roads.
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Whatcom County Council
Lake Whatcom Watershed Moratorium Response
July 26, 2005
20.71.700 Roads, curbs, gutters and sidewalks.
The intent of this section is to reduce impervious surfaces and stormwater ru
noff. Innovative street sections, which do not compromise public safety, shall be encouraged in
the watershed. Narrow streets and reduced sidewalk standards that satisfy pedestrian and
vehicular circulation requirements may be implemented with the approval of the Whatcom
County public works department. Unless specifically required, roads shall not be wider than the
minimum applicable standard. A rural road standard may be approved by the Whatcom County
public works department for urban density residential areas where the developer provides
adequate off - street parking and pedestrian walkways.
Chapter 20.97 - DEFINITIONS
20.97.187 Impervious surface.
"Impervious surface" means a hard surface area which either prevents or retards the entry of
water into the soil mantle as under natural conditions prior to development, and/or a hard
surface area which causes water to run off the surface in greater quantities or at an increased
rate of flow from the flow present under natural conditions prior to development. Common
impervious surfaces include, but are not limited to, roof tops, walkways, patios, driveways,
parking lots or storage areas, concrete or asphalt paving, gravel roads, and oiled macadam or
other surfaces which similarly impede the natural infiltration of stormwater. Natural surface
waters and open, uncovered detention /retention facilities shall not be calculated when
determining total impervious surfaces.
6hall he given a 69 PBFG Rt Feductinn in imnorteirti S G, PfaGe Y ,o Alternative surface methods
as set forth in WCC 20.71.603 shall not be considered impervious surfaces.
M.