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E it U= :T,R=3 OR IIVHD, by the Mason County Board of
nereby adopt the Hoodspoat RLra Actavaty Center S'cornnwater
ADOPTED this 7 dayof November 2008.
ATTEST:
La
Rebecca S. Rogers, Clerk of the hoard
BOARD OF COUNTY COMMISSIO
ASON COUNTY, WASHINGTON
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ORDINANCE NO. 119-08
ATTACHMENT
HOODSPORT RURAL ACTIVITY CENTER STORMWATER MANAGEMENT PLAN
Mason County
Update of County's
Stormwater Policies/Regulations and
Development of Comprehensive
Stormwater Management Plan
Hoodsport Rural Activity Center
Stormwater Management Plan
Submitted to:
Mason County
Department of Public Works
411 N. Fifth Street
Shelton, WA 98584
Submitted by:
Otak, Inc.
10230 NE Points Drive
Suite 400
Kirkland, WA 98033
Otak Project No. 30784
September, 2008
Mason County
Update of County's Stormwater Policies/Regulations and
Development of Comprehensive Stormwater Management Plan
Hoodsport Rural Activity Center
Stormwater Management Plan
Submitted to:
Mason County
Department of Public Works
411 N. Fifth Street
Shelton, WA 98584
Prepared By
Otak, Inc.
Joe Simmler, Ph.D.
Project Manager
Larry Grimm, PE
Project Engineer
Maureen Knutson, PE
Regulatory Compliance Engineer
Laura Ruppert, PE
Water Resources Engineer
Acknowledgements
Mason County
Update of County's Stormwater Policies/Regulations and
Development of Comprehensive Stormwater Management Plans
Hoodsport Rural Activity Center
Stormwater Management Plan
Mason County Board of Commissioners
Lynda Ring Erickson District 1
Tim Sheldon District 2
Ross Gallagher District 3
Mason County Department of Public Works
Charlie Butros, PE, Director
Mason County Department of Community Development
Barbara Robinson, Director
Mason County Department of Utilities and Waste Management
Emmett Dobey, AICP, Director
Mason County Department of Health Services
Debbie Riley, RS, Environmental Health Manager
Preface / Acknowledgements
Hoodsport Rural Activity Center Stormwater Management Plan
This document, entitled Hoodsport Rural Activity Center (RAC) Stormwater Management
Plan (SWMP), has been prepared as part of the County's proposed stormwater management
strategy to protect and enhance the County's natural resources by addressing the stormwater
management (SWM; issues in the urban, and urbanizing areas of the County. This County
wide strategy includes the development of a Comprehensive Countywide SWM Plan, with
more in-depth technical studies in the areas of Allyn, Belfair, and Hoodsport. The County's
Comprehensive SWM Plan and technical studies assume a watershed based management
philosophy for the protection of natural resources and the establishment of effective
stormwater management throughout the County using a phased implementation strategy.
The County is committed to enhancing water quality and promoting effective stormwater
management especially in its urban and urbanizing areas, which are often located within and
adjacent to sensitive natural resource areas. This SWM planning strategy, as documented in
the Countywide Comprehensive SWM Plan currently under development, is intended to
address the drainage related impacts of existing and future development, and to protect and
enhance water quality, shellfish, habitat and groundwater. (The draft Comprehensive Countywide
SWM Plan is scheduled foi release to the public later thisyear.) Developing a Comprehensive
Countywide SWM Plan at this time allows the County to address the requirements of the
Puget Sound Water Quality Management Plan, as well as begin to prepare the County to
come into compliance with a future National Pollution Discharge Elimination System
(NPDES) Phase II Municipal Stormwater Permit.
Allyn and Belfair UGA SWM Plans (completed summer 2007) complement and support the
development of the Comprehensive Countywide SWM Plan. Shellfish protection and
recovery plans are currently under development for the Oakland and Annas Bay areas These
SWM technical documents (including the Hoodsport SWMP) will be reviewed by the public,
approved by the BOCC, and included as technical appendices to the County's
Comprehensive SWM Plan.
Acknowledgement of Combined State and Local Funding
The development of the StormwaterManagement Plan for the Hoodsport Rural Activity Center (RAC) has
been funded in part by a grant to Mason County by the Washington State Department of rcology, and is
also supported by a local match from Mason County.
Mason County—Hoodsport RAC Stormwater Management Plan
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Table of Contents
Hoodsport Rural Activity Center Stormwater Management Plan
Preface / Acknowledgements
Executive Summary
Section I —Introduction 22
Section 2—Characterization of the Hoodsport RAC 27
Section 3 Existing Stormwater Facilities 41
Section 4—Future Conditions 5I
Section 5—Regulatory Criteria 55
Section 6—SWM Impacts, Analysis and Strategies 67
Section 7 SWM Plan: Capital Projects 72
Section 8 SWM Plan• Programmatic Elements and Regulatory Compliance 77
Section 9—Costs, Funding and Implementation 94
Section I0—Public Review and Approval 102
List of Tables
Table E- I Recommended Maintenance
Table E-2 Hoodsport RAC Six Year Capital Improvement Program
Table E-3 Recommended SWM Programmatic Elements and Costs
Table E-4 Financial Plan for the Hoodsport SWM Plan Annualized Revenue Needs
Over the Planning Period
Table E-5—Potential SWM Funding Sources and Estimated Revenues
Table 2-1—Hoodsport RAC Subbasin Characteristics
Table 2 2—Subbasin Slope Characteristics
Table 2-3—Hydrologic Soil Groups
Table 4-I—Hoodsport RAC Zoning
Table 5-I—Ecology 2005 Manual: Minimum Stormwater Management Requirements
Table 7- I —Recommended Maintenance
Table 7-2—Hoodsport RAC Six Year Capital Improvements Program
Table 8-I—Recommended SWM Programmatic Elements and Costs
Table 9- I —Financial Plan for the Hoodsport Stormwater Management Plan
Annualized Revenue Needs Over the Planning Period
Table 9 2—Potential SWM Funding Sources and Estimated Annual Revenues
Mason County — Hoodsport RAC Stormwater Management Plan
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TOC-i
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Table of Contents
Continued
Figures
Figure E-I—Location Map
Figure E-2 Existing Drainage Basin Boundaries
Figure I - I Location Map
Figure 2-1—Existing Drainage Basin Boundaries
Figure 2 2 Site Soils
Figure 2-3 Hydric Soils
Figure 2-4—Sensitive Areas
Figure 3- I —Existing Conditions
Figure 3=2 Drainage Deficiency Map
Figure 4-I—Existing Land Use — Zoning
Figure 7 I —Six Year CIP Program
Appendices
Appendix A —Culvert Inventory Data
Appendix B—Stormwater Questionnaire
Appendix C Low Impact Development Techniques
Appendix D Capital Project Construction Cost Estimates
Appendix E — Master Comment Response Matrix for the Draft Hoodsport RAC
SWM Plan
Mason COUPE] Hoodsport RAC Stormwater Management Plan
TOG-ii
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Hoodsport Stormwater Management Plan
Executive Summary
Purpose
Hoodsport is one of three urbanizing areas within Mason County, along with Allyn and
Belfair that have been selected by the County for the development of comprehensive
stormwater management plans (SWM Plans). These SWM Plans are needed to protect the
water quality of Hood Canal by managing existing stormwater runoff and by guiding
continued growth within the region The following SWM Plan presents an evaluation of the
drainage system within the area, including capital projects needed to address local drainage
problems, and suggests a series of SWM activities to begin to address the elements of the
Puget Sound Water Quality Management Plan and prepare the County for the receipt of a
National Pollution Discharge Elimination System (NPDES) Permit within the next few
years.
Study Area
The Hoodsport Rural Activity Center (RAC) is one of three RACs within the Mason County
Growth Management Plan, along with Taylor Town I and II. The Hoodsport RAC contains
about 605 acres and is located at the north end of lower Hood Canal, as shown in Figure
F-1 The majority of the area (95%) is zoned residential, with only about 20% of the area
currently being developed. A small commercial area exists along both sides of Highway 101,
which generally follows the shoreline along Hood Canal. A number of relatively short
residential streets connect the residential areas with the highway and local business
community. The total number of miles of road within the RAC is estimated to be about
twelve, with the County routinely maintaining about four miles of the local transportation
system, and Washington Department of Transportation (WSDOT) maintaining the four
miles associated with Highway 101 and State Route 119 (SR 119) (North Lake Cushman
Road). The remaining four miles of roads are privately owned and maintained
Land Use and Growth
The majority of land within the Hoodsport RAC is currently zoned as rural residential
(RR2 5) which allows one dwelling unit per two and one-half acres. (See Title 17 Zoning of
the Mason County Code for a more detailed explanation of the zoning.) Small amounts of
the RAC are zoned for rural commercial (RR3) rural multi -family (RMF), and rural tourist -
campground (RT). As a result of this zoning, the Hoodsport RAC consists primarily of low -
density residential, vacant/rural, and forested areas with a small commercial area along
Highway 101.
Mason County—Hoodsport RAC Stormwater Management Plan 1
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9-16-08.doc
HOODSPORT RURAL
ACTIVITY CENTER
__,
Annas
Bay
HOOD
CANAL
Legend
b
S. Highway
flea nil
Street Centerline
Parcel Boundary
Admi �os,tra ive Boundary
Hoodsport RAC Boundary
TO BELFAIR
Source: GIS data provided by Mason County 2006.
Washington State Department of Natural Resources
provided Mason County with the stream data used in
this report . Disclaimer: This map is not to survey accuracy
and is meant for planning purposes only.
Figure h-
eat:ors Map
Hoodsport Stormwater Management Plan
0
5,100
Feet
411 North 5th, P.O. Box 279
Sllton, Washington 98584
Prone: (360)427-9670
Fax: (360)427-8425
10230 NE Points Drive, Suite 400
Kirkland, Washingbn 98033
Phone: (425) 822-4446
Fax: (425) 827-9577
K:/project/30700/30784/GIS/mxds/Hoodsport/Figures/LocationMap.mxd
Executive Summary
Continued
Currently, there are approximately 258 residential homes within the Hoodsport RAC, which
support an estimated population of about 642 individuals, including seasonal residents.
Existing lots range in size from about one -quarter to five acres, with much of the
undeveloped land within the RAC zoned for 5 acre minimum lot sizes. The current rate of
growth is about 3.5%, or about nine new homes per year, along with an occasional
commercial development. At this rate, and with a substantial amount of the area yet to be
developed, it will take 20 or more years for the area to fully develop.
A small amount of commercial land use is located within the Hoodsport RAC and is
concentrated principally along I Iighway 101 and along SR 119 near I Iighway 101.
Approximately 38 businesses are located in the Hoodsport RAC, with some industrial land
occurring along Highway 101 near Hill Creek
Development within the RAC is subject to the Mason County New Development and
Redevelopment — Minimum Standards (Mason County Code 14.48 140), which applies to
both residential and commercial development and redevelopment. If development within the
Hoodsport RAC continues to follow the Mason County's existing and proposed
development and drainage codes, there should be little increase in stormwater runoff due to
the large lot sizes, retainage of natural vegetation, and relatively less dense levels of
development.
Hydrology
The Hoodsport area average annual precipitation is about 90 inches per year based on the
Cushman Powerhouse 2 precipitation stations. These are the closest rain gauges to the
Hoodsport area. The 90 inch average is based on the period of record from July 1973
through June 2007, as reported by the Western Regional Climate Center. Average monthly
precipitation from November through January exceeds 14 inches per month. The lowest
rainfall month is July, with an average monthly rainfall of about 1.1 inches.
Natural and Environmental Characteristics
•
•
Topography —ranges from 0-5% slope near the shoreline to 15-30% within the
upland areas; most available land is located within the upper, steeper areas
Drainage —area is served by nine subbasins, with 43% of the land draining to Finch
Creek
Soils —fine grained, closely packed with little to no infiltration capabilities
Sensitive Areas —are numerous and consist of wetlands, shorelines, steep slopes,
highly erodible areas, forested wetlands, and streams with regulated buffers.
Fish Bearing Streamsallfive of the streams in the planning area are fish bearing,
Mason County Hoodsport RAC Stormwater Management Plan 3
otal<
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•
t
•
Executive Summary
Continued
including Finch and Hill Creeks and the smaller three unnamed creeks; a dam 0.25
miles up on Finch Creek limits access.
Fish Hatcheries —two hatcheries are located in the area, including a salmon hatchery
at the mouth of Finch Creek and a trout hatchery upstream along Hill Creek
Fish and Wildlife Habitat Conservation Areas —are numerous and include
shorelines, streams, shellfish beds, kelp and eel grass beds, and wetlands.
Water Quality —water quality standards are reported being violated for fecal
coliforms in the lower reaches of Finch Creek and along the shoreline of Hood
Canal; low dissolved oxygen levels occur just north of the area, and shellfish beds
have been contaminated since the late 1980s.
Shellfish —shellfish harvesting has been prohibited within the area for the last 20
years, and those prohibitions are still in effect today.
Character of Natural and Man -Made Drainage System
The Hoodsport RAC generally slopes from west to east downward towards Hood Canal.
Slopes range from nearly flat (0-5%) along the creek valley and shoreline, to over 30% in
hills to the west of the urban areas and along the shoreline bluffs directly above the salt
water. There are five creeks, including Finch Creek, Hill Creek, and three smaller unnamed
creeks that convey water from west to east to Hood Canal, as shown in Figure E-2
The RAC is made up of almost entirely Group C soils which have limited infiltration
capacity. Most rain falling on this area generally flows across the surface, with some
infiltration occurring along the way, follows the contours and collects in small natural ravines
that lead downstream into a system of larger ravines and smaller creeks and ultimately into
Hood Canal. Much of the stormwater runoff from streets and roadways collects in shallow
ditches and is conveyed directly into Hood Canal or downstream via a system of larger
ditches along Highway 101 and SR 119, passing the runoff along and under the highways via
culverts into Hood Canal.
The drainage system operated by the County within the Hoodsport RAC is made up
primarily of road side ditches and culverts that collect and convey runoff to creeks or directly
into Hood Canal, as shown in Figure F-2 County culverts typically range from 12 to 18
inches in diameter. The Washington State Department of Transportation (WSDOT) also
maintains a system of ditches and culverts along US 101 and SR 119 (N Lake Cushman
Road) within the Hoodsport RAC. Combined with the natural drainage system, the system
of ditches and culverts operated by the County and WSDOT comprise the region's drainage
system.
Mason County — H o o d s p o r t RAC S t o r m nr a t e r Management Plan
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4
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Source: GIS data and Aerial photography provided by
Mason County 2006. Washington State Department of
Natural Reources provided Mason County with the stream
data used in this report. Disclaimer: This map is not to survey
accuracy and is meant for planning purposes only.
Figure E-2
Existing Drainage Basin Boundaries
Hoodsport Stormwater Management Plan
— N_ N_O.R.T_H__H_I Lam.
411 North 5th, P.O. Box 279
Shelton. Washington 98584
Phone: (360) 427-9670
lax: (360)427-8425
10230 NEPoints Drive
Kirkland Wa>hington 98033
Phone: t425)822-i446
Fax: (425) 827.9577
Legend
Parcel Boundary
Flow Direction
20 Basin Boundary with ID
County Owned Road
State\Federal Owned Road
t Privately Owned Road
Stream
200 Ft Contour with label
40 Ft Contour
0
500 1,000 2,000
Feet
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Executive Summary
Continued
SWM Plan: Elements, Priorities and Costs
The Stormwater Management Plan for the Hoodsport RAC includes two main elements,
infrastructure/facility needs and programmatic needs. Addressing the facility needs ensures
the drainage system has adequate capacity to reduce local flooding, address water quality, and
protect property and public safety. Addressing the programmatic needs gives the County the
tools and funding needed to guide future development and comply with existing and future
regulatory and financial requirements.
The following is a summary of the stormwater management plan developed for the
Hoodsport RAC. A five/six year implementation plan presents a strategy to phase in the
various elements of the proposed SWM Plan over time as future revenues allow.
Stormwater Management Program: Existing/Future Facilities and Costs
Enhanced Maintenance
The primary focus of the stormwater management plan for the Hoodsport RAC is to
enhance maintenance of the existing drainage system to avoid blockages and maintain the
existing capacity and continue in to allow continued development and redevelopment in
regard to new impervious area, zoning and lot sizes. Recommended locations for more
frequent maintenance are provided in Table E-1
Table
E-
I
Recommended
Maintenance
Facility
in need
of
Function when
Responsible
Deficiency
not maintained
when
Jurisdiction
maintenance
maintained
Ditches
and
N.
Schoolhouse
Hill
Road
Capacity
results
is reduced
in
flooding
when
along
clogged;
N.
Mason
Culverts
County
Schoolhouse
Hill
Rd
conveyance
Capacity
is reduced
when
clogged;
Bypasses
Finch
Creek
water to
results
in
flooding
along
N
Finch
WDFW
Intake
structure
the
Hatchery
Creek
Rd.
SR
119
(Lake
Capacity
is reduced
when
clogged;
Ditches
and
increased
runoff
to
N.
Finch Creek
Cushman
Road)
WSDOT
Rd.;
in
flooding
along
Finch
Culverts
results
conveyance
Creek
Rd.
Mason County—Hoodsport RAC Stormwater Management Pion 6
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Executive Summary
Continued
Capital Infrastructure Improvements
Along with enhanced annual maintenance, a few capital improvement projects (CIP) have
also been recommended for those areas where the existing drainage systems are insufficient,
as reported by local residents and Mason County Staff. A total of four CIP projects have
been identified and are discussed below in Table F-2 The total cost of these projects is
$423,000, and they are intended to be constructed over a six year period, as local funding
allows.
Program
Project Cost
Table
E-2
Hoodsport
RAC Six Year Capital
Improvement
$ 185,000
# 1
N.
North
Hill
Drainage
Improvements
$ 121,000
# 2
N.
Schoolhouse
Hill
Road
Ditch
Improvements
$ 56,000
# 3
Replace
Half
-Pipe
with
18-inch
Diameter Culvert
$ 61,000
# 4
Filterra
Device
for WQ
Retrofit
(retrofits
0.8 ac)
Total
Cost of
Six Year CIP
Program
$ 423,000*
*Note that these capital costs do not include any water quality treatment retrofit projects.
Effective operation of the capital SWM facilities within the Hoodsport RAC also assume
routine coordination with WSDOT to ensure an adequate level of maintenance is being
continually provided to optimize existing culvert capacity along and underneath Highway
101 and SR 119.
Future Emphasis on Water Quality Treatment
It is important to mention the discussions currently underway within Mason County to
develop a Countywide SWM Program initiative to design, fund, andbuild a series of water
quality treatment facilities within the more urban areas of the County, including the
Hoodsport RAC. The request. has been made by Ecology and the Puget Sound Partnership
to treat all existing runoff from the more urban areas of the County in order to protect
sensitive receiving waters.
Under this initiative, low impact development (i.e. bio-retention facilities within County road
right-of-ways) would be used to treat runoff prior to discharge to Hood Canal and Puget
Sound These facilities will cost approximately $40K each, if construction on County owned
land.
It is likely that one or two of these facilities may be built within the Hoodsport RAC over
the next two to six years. Funding may initially come from a $750K grant that the County
recently received from H cology. Later, additional local funding, possibly including the
Mason Count]]— Hoodsport RAC S to rm zva to r Management Plan 7
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Executive Summary
Continued
formation of stormwater utility, may be needed to continue to fund the SWM Program
within the Hoodsport RAC.
(Note that the cost of these potential water quality retrofit facilities has not been included in the funding needs
identified in Section 9 of the Hoodspori SWMP, and am assumed to be part of the County's eme►ping
program to retrofit drainage facilities within existing urban areas throughout the County for water quality
treatment.)
Programmatic Overview
The County's existing annual SWM Program within the Hoodsport RAC consists primarily
of annual maintenance (of about $25K per year) and development related review,
construction, and inspection/enforcement services, as paid for through developer permit
fees. Additional SWM activities provided on an as needed basis include:
•
•
•
•
•
Response to spills and complaints
Comprehensive land use planning
Participation in local and regional planning
Annual maintenance
Public education and involvement
One of the purposes of this study is to review the County s existing levels of funding and
staffing to determine its effectiveness and adequacy to address local drainage issues and
regulatory compliance. As defined in this SWMP, it is anticipated that the Hoodsport SWM
Program will be enhanced and incorporated into the County's larger comprehensive SWM
Program. It is anticipated that the SWM Program for Hoodsport RAC will be one of the
elements of the Countywide SWM Program, and will benefit from future county funding and
staffing appropriations. Increased funding for SWM throughout the County is currently
being considered to support the County's growing SWM obligations and regulatory
compliance needs.
Need for Regulatory Compliance
Compliance with the Puget Sound Water Quality Management Plan
There are a series of existing regulatory requirements related to stormwater management,
water quality, and habitat that apply to the Hoodsport RAC. The most significant are the
municipal stormwater elements of the Puget Sound Water Quality Management Plan
(PSWQMP), and its associated 2007-2009 Conservation Plan. Compliance with these
requirements consists of addressing thirteen different municipal stormwater management
program elements including:
1. Stormwater controls for new development and redevelopment
2. Stormwater site plan review
Mason County Hoodsport RAC Stormwater Management Plan 8
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3. Inspection of construction sites
4. Maintenance of permanent facilities
5. Source control
6. Illicit discharges and water quality
7. Identification and ranking of problems
8. Public involvement and education
9. Low impact development practices
10. Watershed or basin planning
11. Funding
12. Monitoring
13. Schedule for implementation
Executive Summary
Continued
Other requirements of the PSWQMP include compliance with local water quality TMDLs,
which for the receiving waters in and around the Hoodsport RAC do not currently exist.
There are, however, concerns about the impacts of continued and increased stormwater
discharges to the local water quality of Hood Canal and the shellfish beds in nearby natural
and commercial rearing areas. hlevated concentrations of coliforms have been documented
by Ecology in nearby Annas Bay.
National Pollution Discharge Elimination System Phase II Municipal Stormwater Permit
Preparing the County for compliance with a future Phase II NPDES Municipal Stormwater
Permit requires the County to add stormwater programmatic elements to its existing annual
SWM Program, many of which are the same as those required under the PSWQMP. Future
compliance with the NPDES Phase II Permit will include:
•
•
•
•
•
•
Developing and conducting a public education program.
Implementing a public involvement program.
Initiating an illicit discharge detection and elimination program.
Adopting the 2005 Manual and maintaining effective and responsive development
review program, that includes inspection and enforcement, especially for erosion
control
Conducting annual maintenance consistent with the protocols and frequencies listed
in the Phase II Permit.
Setting up a comprehensive stormwater management program, and conducting
annual reporting and assessments of program effectiveness using adaptive
management.
Mason County — Hoodsport RAC Stormwater Management Plan 9
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Executive Summary
Continued
SWM Activities Needed for Compliance with PSWQMP and NPDES Phase II Permit
Due to the similarities of the PSWQMP and the Phase II NPDES Permit, and the likelihood
of the County will be receiving an I\PDES Phase II Permit within the next few years, the
following regulatory gap, or programmatic, analysis has been performed and will be used to
develop the comprehensive SWMP for the Hoodsport RAC. These I\PDES Phase II
requirements were issued in January of 2007 to most, smaller municipalities (with
populations less than 100,000) throughout the State.
The various existing regulatory requirements have been grouped into nine stormwater
management program (SWMP) elements, to form the primary elements of the Hoodsport
SWMP A listing of each regulatory requirement and recommended actions for compliance
are provided below.
SWMP Element #I —Public Education and Outreach
Develop and distribute a County -wide brochure for the public that addresses stormwater
pollution issues and what homeowners can to do to help solve them. Ensure it covers those
issues specific to the Hoodsport RAC, including the benefits of low impact development
(LID) Consider the use of the Puget Sound Partnership's recently updated general education
brochure on LID, which is available on its web site.
SWMP Element #2—Public Involvement and Participation
Engage the local stakeholders of the Hoodsport in SWM planning and implementation
within the Hoodsport RAC. Organize volunteers to assist in the development of a Stream
Team for Finch Creek and Hill Creek, regional surface water management water quality
monitoring, and facility inventory and mapping.
SWMP Element #3—I1licit Discharge Detection and Elimination (IDDE)
Illicit discharge and spill education is a topic that should be incorporated into products
developed under SWMP Public hducation hiement #1 An element of the IDDE
requirement that would be useful in the short-term is an accurate inventory of facilities and a
survey of key drainage facilities electronically recorded in the County's GIS/mapping system.
This could be done in annual increments over the next few years.
SWMP Element #4—Controlling Runoff from New Development, Redevelopment and
Construction Sites
For the Hoodsport RAC, the County needs to update its current SWM ordinance and adopt
standards that are consistent with the requirements of the 2005 Ecology Manual, and
support the use of LID for new development. To do this, additional training on 2005
H cology Manual and LID, will likely be required for both County staff and local developers.
Mason County Hoodsport RAC Stormnvater Management Plan 10
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Executive Summary
Continued
The County's existing design criteria for stormwater are based largely on the 1992 Ecology
Manual. When the County was more rural that level of treatment may have been adequate,
however, as urban centers have emerged throughout the County pollutant loadings have
increased and impacts to water quality fish habitat and shellfish rearing areas have been
documented It is widely understood that untreated or inadequately treated surface water
runoff, particularly from the more intensely developed areas, may be a major contributor to
these problems in local receiving waters. Adoption of the 2005 Ecology Manual and LID
ordinance is strongly recommended to address both local flow and potential water quality
related problems.
SWMP Element #5 Pollution Prevention &Operations/Maintenance for Municipal Operations
Review the adequacy of current annual maintenance practices and their effectiveness.
Annually review and update their effectiveness to improve water quality. Maintain the
County s existing level of maintenance effort within the Hoodsport RAC, enhance frequency
of inspection and maintenance of known problem areas, as discussed in Section 7.
SWMP Element #6 Stormwater Management Program Implementation
Develop and implement a routine tracking system for County SWMP implementation that
includes the SWM activities associated with the Hoodsport SWM Plan Evaluate annually
using adaptive management and make annual refinements as needed, involving local citizen,
stakeholder, and regulatory input.
SWMP Element #7—Total Maximum Daily Load (TMDL) Allocations
At the present time, there are no TMDLs established within the Hoodsport RAC, however,
strategies to protect surface waters from water quality degradation are included in
recommended actions of other SWMP elements, including the adoption of the 2005 Ecology
Manual and development/adoption of an LID ordinance.
Local water quality monitoring of major outfalls has been recommended in SWM Element
#12 to assess impacts of stormwater and the effectiveness of existing SWM controls and
practices, as future funding allows. (The future Phase II permit requires compliance with established
TMDLs. These would be identified in Appendix 2 of the permit, if the County had been issued one.
Note that current discussions are underway for the County to develop, fund, and implement a countywide
program to retrofit the runoff from existing development using bio-retention and other T ID types of facilities.
The Hoodsport RAC, along with the GMA areas of Allyn and Belfair are being targeted as high priorty
areas for this type of water quality enhancement program. (Constructing one of these types of T ,ID facilities
within the Iloodsport RAC would cost about .i$40K per year; the design and construction of a couple of these
11
Mason County —I -Ioodsport RAC Storm»vater Management Plan
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Executive Summary
Continued
facilities within Hoodsport RAC may be possible using the funds within the 8750Kgrant recently received by
the County from P cology.)
SWMP Element #8 Monitor ng (of SWM Program)
As the Countywide SWM Program is established over the next several years, an annual
monitoring program to review the effectiveness of individual SWMP activities should be
established, the should be SWMP modified as needed on an annual basis using the principals
of adaptive management.
SWMP Element #9—Reporting
Develop and implement an annual internal reporting system for County SWM Program
implementation that includes the SWM activities contained within the recommended
Hoodsport SWM Plan. As mentioned in Element #8, documenting and evaluating the
effectiveness of the proposed SWMP should be clone annually in order to review and refine
the program and continue to address the high priority needs.
SWM Programmatic Elements Required for Consistency between NPDES II and
PSWQMP
Note that the requirements of the NPDES II Permit are similar in many ways to the
requirements of the PSWQMP. However, there are elements that are specifically stated in
the PSWQMP that are not specifically spelled out in the Phase II Permit. These include
conducting watershed or basin planning, creating adequate local funding, and implementing
annual water quality monitoring to assess program effectiveness. To ensure consistency of
the County's response to the various stormwater requirements, the following three elements
from the PSWQMP should also be included in the recommended Hoodsport SWM Plan.
SWMP Element #IO—Watershed or Basin Planning
The PSWQMP calls for the use of watershed or basin planning processes to identify and
rank existing problems that degrade water quality aquatic species, habitat, and natural
hydrological processes; this element of the Plan also calls for the development of action
plans/schedules, along with the identification of funding strategies to fix local drainage
problems. This Hoodsport SWM Plan and the County's larger evaluation of its SWM needs
and funding is consistent with this requirement.
Note that the County plans on taking the initiative to develop a comprehensive stormwater management
program for the Hoodsport RAC that involves a programmatic approach to stormwater management, as
described in the PSWQMP. Thzs approach includes the enhancement of development criteria (by the adoption
of the Ficology 2005 Manual and an T JD Ordinance, as well as the enhancement of annual maintenance
procedures and practices, as described in this SIYIM Plan. The County will continue to participate in regional
Mason C o u n t y —Hood s p o r t RAC S t o r m w a. t e r Management Plan 12
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Executive Summary
Continued
coordination efforts and in making additional SlVM program enhancements in a phased approach, as more
knowledge of the relationship of stormwater discharges to local and regional receiving waters is acquired.
SWMP Element #I 1—Funding
The PSWQMP calls for the creation of funding capacity, such as a utility, to ensure adequate,
permanent funding for SWM program activities and regional stormwater projects.
It will be important for the County to work with local citizens to create a stormwater
management utility throughout the Hoodsport RAC (and urban areas throughout the
County). Also explore the development of a system development charge for new
development and redevelopment to help the County off -set some of the costs of bl ilding
the future conveyance systems and water quality treatment systems that will be needed in the
future.
SWMP Element #I2—Water Quality Monitoring
The PSWQMP calls for monitoring of program implementation and environmental
conditions and trends over time to measure the effectiveness of program activities and to
share the results with others.
At this point in time, consistent with the Allyn and Belfair SWM Plans, water quality
monitoring will consist primarily of documenting the effectiveness of LID retrofit facilities
that are being designed to treat existing runoff. Implementation of an annual monitoring
program (programmatic in nature; i.e. not involving any water quality monitoring) to track
progress and assess effectiveness is recommended.
In the future, as funding allows, water quality monitoring of major outfalls, as well as the
effectiveness of annual maintenance and new development review practices, should be
considered by the County. This monitoring program should be annually tailored to focus on
local flooding problems and water quality and habitat priorities, especially if local TMDLs
have not been established by Ecology.
Stormwater Management Program: Summary of Elements and Costs
Recommended SWM Programmatic elements listed above have been summarized along with
annual costs in Table F-3 These activities, presented as SWM Program Elements, represent
an enhancement of the County's existing SWM Program within the Hoodsport RAC They
emphasize the need to control/guide new development, enhance maintenance where needed,
repair/enhance existing facilities, conduct annual program monitoring, and initiate a local
public involvement/education program, along with other a series of other activities. The
annual costs for these SWM Programmatic Flements averages about $70,000
Mason Count] Hoodsport RAC Stormwater Management Plan 13
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Executive Summary
Continued
E-3
Recommended
SWM
Programmatic
Elements
and
Costs
Table
SWMP
Element
Recommended
Action
Satisfies
Program
Needs
Costs ($
I ,000's)
PSWQMP
NPDES
Phasell
Permit
Habitat
Shellfish
WQ
Yr
I
Yr 2
Yr 3
Yr 4
Yr 5
Yr 6
Total
I
Public
- SWM
Education*
(LID)
Brochure
X
X
X
$5
$5
$5
$5
$5
$5
$30
2
Public
-
Organize
Involvement*
Volunteers/Mtgs
X
X
X
$10
$10
$10
$10
$10
$10
$60
3
Illicit
-
Facility
Discharges
Inventory
(IDDE)
&
Mapping
X
X
X
$0
$10
$10
$10
$0
$0
$30
4
New
-
-
Ordinance
Ordinance
Development
-
-
DOE
Manual
X
X
X
$0*
$0*
$0*
$0*
$0*
$0*
$0*
05
LID
-
-
Training
Training
-
-
05
LID
Manual
X
X
$0*2
$0*2
$0*2
$0*2
$0*2
$0*2
$0*2
5
Maintenance
-
Annual
(Inc.
Enhancements)
X
X
X
$25
$25
$25
$25
$25
$25
$150
6
SWM
-
Develop
Program*
Tracking
Implementation
System
X
X
$5
$5
$5
$5
$5
$5
$30
- Annual
Program
Evaluation
X
X
$5
$5
$5
$5
$5
$5
$30
7
TMDLs
X
X
$0
$0
$0
$0
$0
$0
$0
8
SWM
(Addressed
Program
in
Monitoring
#6)
X
X
$0
$0
$0
$0
$0
$0
$0
Element
9
Reporting*
(Internal)
X
$5
$5
$5
$5
$5
$5
$30
10
Basin
Planning
of
Co -wide
study.)
X
X
$0*
$0*
$0*
$0*
$0*
$0*
$0*
current
(Part
II
Funding
-
Develop
SWM
Utility
X
$0*
$0*
$0*
$0*
$0*
$0*
$0*
- SDC Feasibility
Study
X
$0*
$0*
$0*
$0*
$0*
$0*
$0*
12
WQ
- Annual
Monitoring
Monitoring
X
X
$5
*3
$5
*3
$5
*3
$5
*3
$5
*3
$5
*3
$30
WQ
Total.
$60
$70
$70
$70
$60
$60
$390
*Future
County
Staff
(-- 0
FTE)
$0*4
$0*4
$0*4
$0*4
$0*4
$0*4
$0
Outside
Services
$5
$5
$5
$5
$5
$5
$30
Total
Annual
Budget
$65
$75
$75
$75
$65
$65
$420
* - Activity included in the development and implementation of the Countywide SWM Program; no
additional funding needed at the local planrung level.
Mason Countyy—Hoodsport RAC Stormwater Management Pion
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14
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Executive Summary
Continued
*2 — Development Review labor is paid by developer fees; no additional county funding is required
*3 — The emphasis of the water quality monitoring program is to evaluate the effectiveness of water quality
retrofit bio-retention facilities installed in road right of ways to treat existing runoff. Labor for WQ
monitoring of these facilities to determine their effectiveness will be provided by volunteers; costs included
are primarily for laboratory related analyses.
*4 — County staffing required to administer the Hoodsport annual SWM Program will be included in the
administration and management of the County -wide SWM Program; approximately $15K, (or about 0 20
1 "1 E, equivalent to 400 hours, or about 10 weeks per year), has been set aside for annual tracking, program
evaluation, and reporting in SWM Elements #6 and #9.
per year. These resources are addition to those resources the County is planning to spend
within the Allyn and Belfair UGA areas, as part of the initial phase of the development.
Recommended SWM Plan: Summary of Elements and Costs
It is suggested that the programmatic SWM elements identified above be developed and
integrated with the proposed capital improvements proposed to create a Comprehensive
Stormwater Management Plan for the Hoodsport RAC Total SWMP costs for the next six
years, including both capital and programmatic needs, amount to $843,000. Annual SWM
costs are about $140,000, $70,000 per year for the SWM programmatic elements, as shown
in Table E-3, and $70,000 per year for the capital elements, as shown in Table 1-4,-2 Annual
costs and funding are presented in the implementation plan presented in the following
section.
Recommended SWM Plan: Integration with Countywide SWM Program
The funding and implementation of the Hoodsport SWMP is only one aspect of a much
larger, integrated countywide SWM Program that is currently under consideration. The
concept of the County is to develop a comprehensive SWM Program throughout the County
over the next five years The program would initially focus on the most urbanized areas,
including the Allyn and Belfair Growth Management Areas and the rural activity centers of
Hoodsport and Taylor Town I and II.
The program, complete with the adoption of the 2005 Manual and a Low Impact
Development Ordinance, along with the generation of local funding, such as a stormwater
utility, would be implemented by phasing in stormwatet management requirements annually,
according to the following five phases:
• Phase I — Allyn and Belfair Urban Growth Areas — Year 1, 2008
• Phase II — Defined Marine Recovery Areas — Year 2, 2009
• Phase III — Defined Shellfish Protection Areas — Year 3, 2010
• Phase IV — Defined Rural Activities Centers and Limited Areas of more Intense
Rural Development (LAMIRD) —Year 4, 2011
Mason County—Hoodsport RAC Stormuvater Management Pion 15
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Executive Summary
Continued
• Phase V — Countywide, excluding Designated Forest Lands, Year 5 - 2012
As noted above in the listing and estimate of SWM Programmatic costs for the Hoodsport
SWMP, many of the administrative and management costs of the Hoodsport SWMP will be
supported by the larger, centrally funded Countywide SWM Program. The Countywide
SWM Program would be supported by dedicated SWM staff that would be responsible for
the Hoodsport SWMP, as well as the administration and implementation of SWM planning
throughout the County. According to the above schedule, the Hoodsport SWM Plan,
stormwater utility, and design and LID standards would be implemented in Year 4, 2011.
SWM Plano Funding and Implementation
Hoodsport SWM Plan: Program Elements, Priorities, Schedule and Costs
Annual Revenue Needs
The Comprehensive SWM Program for the Hoodsport RAC has been created by integrating
the capital needs/costs identified in Section 7 with the programmatic and regulatory
compliance needs/costs presented in Section 8. The recommended plan includes a
combination of programmatic activities and capital improvement projects over the next six
years, 2009 to 2012.
• Total SWMP costs for the next six years, including both capital and programmatic
needs, amounts to $840,000 or about $140,000 annually.
• Capital projects consist of four projects that total $423,000 (rounded to $420,000), or
about $70K annually. (Note that these costs do not include water quality tetrofitprojects; the
retrofit projects will be included in the County -wide Storawater Management Program.
• Programmatic and regulatory compliance needs include various activities ranging
from public education/involvement to SWM Program monitoring, and include the
adoption of new ordinances, development of new funding mechanisms, completion
of inventory and GIS mapping of existing drainage facilities, along with a number of
other SWMP activities. Programmatic costs have been estimated to be $420,000 over
the six years or about $70,000 annually.
The funding/revenue needed to implement the recommended SWMP for the Hoodsport
RAC is presented below in Table F-4
Mason County Hoodsport RAC Stormwater Management Plan 16
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Executive Summary
Continued
Stormwater
Management
Plan
Table
E-4—Financial
Plan
for
the
Hoodsport
Period
Annualized
Revenue
Needs
Over the
Six Year
Planning
Relative
Implementation
Priority
for
Schedule
& Costs
by Years
($1000s)
1
2
3
4
5
6
Total
$65
$65
$420
SWM
Deeds
Programmatic
$65
$75
$75
$75
SWM
Capital
Needs
$70
$420
$70
$70
$70
$70
$70
Total*
$135
$145
$145
$145
$135
$135
$840
*Average Annual SWM cost for years tf1 6 is $420K/6 years = $140K per year.
Funding Analysis
Presented in Table E-4 is an estimate of the cost of the recommended SWM Plan for the
Hoodsport RAC. New revenue is needed over the next six years to support programmatic
initiatives, as well as over the next 20 or more years to support both future programmatic
and capital projects that will be needed to support ultimate buildout.
SWM Policies Guide Selection of Financial Options
The SWM management policies and approaches preferred by the County, as presented in
this plan, play a large role in determining the funding strategies to implement the proposed
SWM Plan for the Hoodsport RAC. In general the proposed funding strategy has been
guided by the following policies and technical decisions that have been created to manage
stormwater within the Hoodsport RAC
•
•
•
•
•
Low impact development will be required for all new development and
redevelopment.
N o regional detention facilities will be created to accommodate either existing or
future development; if needed, detention will be provided onsite by each new
developer on an as needed basis.
N ew development/redevelopment will pay for the cost of onsite water quality
treatment (per the adoption of the 2005 Manual by the County).
N ew development/redevelopment may help pay for future regional conveyance
facilities, as/if needed to support future growth through the establishment of SI1,PA
mitigation and system developer charges.
There are currently no major flooding or maintenance problems associated with the
current drainage system within the Hoodsport RAC.
Retrofitting existing homes and businesses for detention or water quality treatment
has not been included at this time, but is currently being considered as part of the
County's new stormwater grant from Fcology.
Mason C o u n t j— Hoodsport RAC Stormwater Management Plan 17
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Executive Summary
Continued
As the County builds new roads within the RAC the County will design and pay for
some new water qualities retrofit systems that will be located within the County road
right-of-ways to collect and treat road runoff.
Review and Evaluate Potential Funding/Revenue Options
Discussions with the County suggest that there are several financial options that should be
considered to fund stormwater management within the Hoodsport RAC. A preliminary
review of these potential funding sources suggests that multiple sources of funding will likely
be needed; no single source of funding will likely be adequate by itself. Funding sources that
are currently being considered include:
• Formation of a Local Drainage/Stormwater Improvement District, which
would have an annual assessment usually based on assessed property value, or some
other equitable means of establishing value and/or benefit to the various rate payers.
• Real Estate Excise Tax (REET) Funding, which currently amounts to about
$750K per year for the County, and is currently being used to pay for a number of
capital projects throughout the County. Securing periodic appropriations from
RE1-i,T funding for either capital or program needs may be available on an annual
basis depending on other County project priorities.
® Annual County Portion of State Sales Tax, which has recently been raised from
.08% to .09%0 this will amount to about $450K per year for the County with the
recent increase to 0.09 per cent.
• Public Sector Funding, such as giants and low interest loans from the State
(Ecology or the Puget Sound Partnership) or federal government, including federal
319 Water Quality Grants, and the State Public Works Trust Fund and State
Revolving Fund. While available, they potential funding sources are generally limited
m duration and amount. They are also very competitive and have limitations
regarding timing, applicability reporting, and administrative costs.
® Formation of a Local Stormwater Utility throughout the Hoodsport RAC where
a monthly service fee is assessed to rate payers, often based on the amount of
impervious area per parcel.
• Continued collection and use of developer fees to review and approve plans for
new development and re -development, as well as conducting inspection and
enforcement in the field
• System Development Charges (SDCs), where any person moving into an
upstream drainage area by the purchase of a home would be required to pay for a
portion of the downstream collection, conveyance, detention, treatment, and outfall
facilities that may be needed to support continued development within the drainage
Mason County — Hoodsport RAC S t o r m m a t e r Management Plan 18
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Executive Summary
Continued
basin. These would be assessed to the developer prior to the construction of the
home during the County's permitting process.
® SEPA Mitigation Funds, which would be established on a per development basis
as a project enters and is ultimately approved through the State SEPA review
process. This has historically been used very successfully by the County for
additional infrastructure that has directly resulted from new proposed development/
redevelopment.
® Partnering with prospective developers, land owners and other State agencies can
be especially effective in establishing funding for larger regional drainage facilities.
These are usually project -specific types of funding agreements based on use or
contribution of stormwater runoff.
® Other potential, but less likely sources of direct internal county funding,
include the General Fund Road Fund, Park Fund and the Utility (Sewer) Fund;
however, these funds are perhaps best used as potential sources for the joint funding of
projects with common community purposes.
From this list of potential sources of funding, the most likely sources of new future
funding for SWM within the Hoodsport RAC, in relative order of priority, are the following:
1. Forming a Stormwater Utility to support programmatic SWM activities.
2. Ensuring developer and permit fees are adequate to support development review,
inspection, and enforcement services.
3. Using project related SEPA mitigation funding to support capital projects,
especially those required by an increase in capacity within a regional conveyance
system.
4 Establishing System Development Charges for new growth -related capital
drainage projects; this is also another good source of funding for regional
conveyance and/or treatment systems.
5. Annually appropriating a portion of Annual State Sales Tax Returns.
6. Securing periodic appropriations from REET funding for either capital or program
needs.
7. Obtaining capital project funding, from Future Road, Park, and/or Utility
Projects, with common objectives that include stormwater management
opportunities.
Summary of New Potential Annual Revenue Sources
(Creation of Multiple Funding Sources to Realirce Needed Revenue
By optimizing the revenue potential of the proposed SWM funding mechanisms,
approximately $110,000 - $130,000 may be realized on an annual basis to support the
development and implementation of the Hoodsport RAC SWM Plan, as shown in
Mason County Hoodsport RAC Stormuater Management Plan 19
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Continued
Table hi-5 Approximately $67,000 in annual programmatic funding and $100,000 to
$120,000 in annual capital funding could be realized from these sources.
Table
E-5
Potential
SWM
Funding
Sources and
Estimated
Annual
Revenues
Potential
Estimated
Annual
Revenue
Funding
Source
Capital
Amount
Programmatic
X
Ok
for either
111:
S
Stormwater
Utility
$27,000
$0
---
___
#2:
Developer
and
Permit
Fees
X
$20,000
#3• SEPA
Mitigation
$12,000
---
X
#4:
System
Development
Charges
$20,000
X
Ok
for either
#5: Sales
Tax
Returns
Ok
for
$20,000
X
either
11-6:
RENT
Funding
X
#7:
Project
-Specific
Funding
$10K
-
$30K
Annual
Total•
—$110K-$130K
—$67K
�$100K-$120K
Adequacy of Potential Future Funding Mechanisms
(Matching Available Funding with the Revenue Needs of the Implementation Plan)
Assessment of Proposed Stormwater Management Funding Strategy
The proposed Hoodsport SWM Plan totahng averaging $140,000 over each of the next six
years is a reasonable level of funding that matches the local drainage needs, as well as the
County's and community's ability to pay.
As shown in Table E-5, estimated annual revenues from the above listed funding sources
totals about $110K to $130K per year With the annual capital appropriation of $70,000, the
total average annual level of funding needed over the next six years is $140,000, and closely
matches available resources, projected in above in Table E-5
While the overall funding is about $10K-$20K short per year, it is suggested that there is
adequate funding for the $70K needed per year for the programmatic SWM activities, and
about $50K-$60K per year for capital projects If the four capital projects are completed
over an eight year period rather than a six year period, the proposed level of funding would
be adequate to meet the needs of the proposed Hoodsport SWM Program and this
I Ioodsport SWM Plan. Alternatively, in order to build the proposed capital projects within
the next six years, the County may choose to prioritize the $70K to the capital projects and
appropriate the $50K to programmatic SWM activities.
(Note that this initial funding analysis has not estimated any annual increases in the amount of annual
funding available from each of the seven proposed funding mechanisms. It is likely that future funding from
Mason County Hoodsport RAC Stormwater Management Plan 20
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Executive Summary
Continued
these sources will increase along with the increased annual funding needs of the Hoodsport SIVM Program.
Also, new funding mechanisms may present themselves as the SI /M Program is implemented. For example,
future grants would be an excellent way to augment these local funding mechanisms and should be actively and
aggressively pursued. Additional funding analyses may be needed to substantiate and further refine this
conceptual fundingplan, as the various proposed funding mechanisms are developed, approved, and
implemented.)
SWM Plan: Findings and Conclusion
The Hoodsport RAC area is a unique geographic environmental, and cultural area of Mason
County. This SWMP has been prepared to fix deficiencies within the drainage infrastructure,
assess proposed land uses and develop guidelines for new development, and assist the
County in addressing existing and future regulatory requirements In the course of doing this
a financial plan has been developed to facilitate implementation with the primary intent of
protecting and maintaining the unique water quality and habitat functions of the region
Consistent with the State's Growth Management Planning process, this Stormwater
Management Plan for the Hoodsport Rural Activity Center demonstrates that here is
adequate local funding to develop and maintain the needed drainage infrastructure and
associated SWM Program as required to support continued economic development within
the Hoodsport RAC.
Mason County — Hoodsport RAC Stormwater Management Plan 21
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Section I —Introduction
1.1 Purpose
Mason County currently has a Stormwater Management (SWM) Program that does not
address current federal, state, regional, and local stormwater related regulatory requirements.
The purpose of this report is to present a Stormwater Management Plan (SWM Plan) for the
Hoodsport Rural Activity Center (RAC) that is consistent with the County's SWM Program
and the Puget Sound Water Quality Management Plan, begins to address required
stormwater related program responsibilities, and prepares the County for the receipt of a
Phase II I\PDFS Municipal Stormwater Permit. The Hoodsport RAC is located at the north
end of lower Hood Canal along Highway 101, as shown in Figure 1-1, just east of the
Skokomish River junction with Hood Canal.
1.2 Authorization
This study has been authorized by the Mason County Board of Commissioners and is being
jointly implemented by the Departments of Public Works and Community Development.
The Mason County Department of Health Services has also been invited to participate. The
development of the Hoodsport RAC Stormwater Management Plan has been funded in part
by a grant to Mason County by the Washington State Department of Ecology.
This study is part of a larger county -wide, stormwater and regulatory compliance planning
effort, currently being undertaken by the County entitled: Update of County s Stormwater
Policies/Regulations and Development of Comprehensive Stormwater Management Plan for Mason County
and the Communities of Belfair, Allyn, and Hoodsport. This larger county -wide stormwater
management planning program is expected to be completed in the summer of 2008 and
includes the development of a comprehensive stormwater management program for the
County and stormwater management plans for the areas of Allyn, Belfair, and Hoodsport. It
includes the development and adoption of updated design criteria, policies, and funding
mechanisms for stormwater management throughout the County.
1.3 Countywide Stormwater Mission Statement Goals/Objectives
Listed below are excerpts from the Mason County Vision Statement, as documented in the
Mason County Comprehensive Plan (2005). These statements document the County's intent
to "protect the environment in a way which is compatible with the needs of a growing
population."
Mason County Vision Statement
Mason County will remain a primariy rural county where residents will enjoy peace and quiet, privacy,
natural views, and rural enterprise. Although rural character means diffirent things to different people, aspects
of it include: natural vistas, wildlife, and natural ecosystems; fewer restrictions and moreprivaey than
Mason Count' Hoodsport RAC Stormmater Management Plan
K:\project\30700\30784\Reports\Hoodsport\Final Rpt\H SWIvMP 9-16-08.doc
22
otak
,t.
-•' i
. 1 1'
1
'11
•
1--
K \f C) '!
of CY
M T
vaet1
HOODSPORT RURAL
ACTIVITY CENTER
1,
71
t
S.FCO_K 0 1\4
Annas
Bay
CANAL
-r
f
r
i
Legend
U.S Highway
Stream
Street Centerline
Parcel Boundary
rr fr 1
O BFAIR`n
;(11EL
treci,-:
"ere
Source: GIS data provided by Mason County 2006.
Washington State Department of Natural Resources
provided Mason County with the stream data used in
this report . Disclaimer: This map is not to survey accuracy
and is meant for planning purposes only.
/ 7.1 r+' 1 �7 1 , ) fie
/
Figure 1-
Location Map
Hoodsport Stormwater Management Plan
0
5,100
Feet
411 North 51h, P.O. Box 279
Stelton, Washington 98584
Fiore: (360)427.9670
Fax: (360) 427-8425
10230 NE Points Drive, Suite 400
Kirkland, Wast>ngbn 98033
Phore: (425) 822-4446
Fax (425) 827-9577
K:/project/30700/30784/GIS/mxds/Hoodsport/Figures/LocationMap.mxd
Section I —Introduction
Continued
in an urban area; the easy operation of resource based industries such as timber, mining and agriculture; and
the close ties of family and community to the land.
The Rural Areas
Natural resources will continue to provide the foundation of the County'. economy. Forestry, agriculture,
aquaculture including shellfish and other fisheries industries, Ch; stmas tree fanning and mining will provide
employment for County residents. The County's abundance of natural amenities including mountains, lakes,
rivers, and wildlife will continue to support the county's thriving tourist industries, including Master Planned
Resorts. The county's land use regulations will protect natural resource lands and industries against
encroachment from incompatible, competing uses.
The Environment and Open Space
Mason County will protect the environment in a way which is compatible with the needs of a growing
population. One focus will be watersheds and their water quality. The County will also conserve an open space
network that will include wildlife habitat and corridors, greenways, estuaries, parks, trails and campgrounds.
This system will help preserve the county's environment and the rural character, support the County's tourism
industry, and meet the recreation needs of County residents.
1.4 Scope of the Hoodsport SWM Planning Project
The Hoodsport RAC SWM Plan has been prepared as part of a County -wide stormwater
management strategy. The County -wide strategy aims to protect and enhance the County's
most sensitive natural resources by addressing the SWM issues in the urban and urbanizing
areas of the County.
The scope of this Stormwater Management Plan includes:
1. Characterization of existing stormwater conditions within the Hoodsport RAC.
2. The location and reduction of flooding and drainage related problems.
3. An estimate of future conditions based on continued development allowed by
current zoning, as defined in the County's 2005 Comprehensive Plan engineering
analyses to •determine the size and location of facilities needed to accommodate
existing and future growth.
4. The identification and creation of development of design standards, consistent with
the 2005 I i cology stormwater design manual for Western Washington
5. The development of a comprehensive stormwater management plan that addresses
regulatory requirements, protects habitat and water quality, and protects the health,
safety, and property of its inhabitants, including projects and activities, costs,
priorities, permitting, financing, and implementation considerations over a six and
twenty year planning period.
Mason Conanty—Hoodsport RAC Stormwater Management Plan 24
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K:\project\30700\30784\Reports\Hoodsport\Final Rpt\H SWMF' 9-16-08.doc
Section I —Introduction
Continued
1.5 Other Planning Efforts within the Region
In addition to comprehensive land use and stormwater management, several other planning
and monitoring initiatives within the region have identified a number of stormwater related
issues concerning water quality, habitat, and shellfish. A brief overview is provided below,
with additional information provided in Section 8.
• Water quality monitoring is conducted by the Washington State Department of
Ecology, Mason County Department of Health, and the Washington State
Department of Health, Office of Shellfish Programs.
• Salmon recovery planning has been conducted by the Shared Strategy for Puget
Sound and the Hood Canal Coordinating Council, in conjunction with the National
Marine Fisheries Service (NMFS) of the National Oceanic and Atmospheric
Administration (NOAA) Responsibilities for salmon recovery planning by the
Shared Strategy for Puget Sound have been recently transferred to the Puget Sound
Partnership.
• The Watershed Planning Act (RCW 90.82) provides local governments a framework
and resources for developing local solutions to watershed issues on a watershed
basis. As a component of this process, the WRIA 16 Planning Unit was formed, and
is comprised of a variety of public and non -governmental stakeholders in the Hood
Canal region, including the Port of Hoodsport. The Planning Unit has prepared
reports that assess water quality, quantity, fish habitat, and instream flow conditions
within the WRIA 16 watershed (Golder Associates, 2002; EnviroVision, 2005)
adjacent to Hood Canal. Furthermore, the Planning Unit has consolidated the WRIA
16 data and a series of recommendations into a broad -based and comprehensive
watershed plan for WRIA 16 (WRIA 16 Planning Unit, 2006).
• Washington State has also developed the 2000 Puget Sound Water Quality
Management Plan, which presents the State's long-term strategy for managing and
protecting the Sound, and coordinating the roles and responsibilities of federal, state
and local governments.
•
The Puget Sound Partnership defines, coordinates and implements Washington
State s environmental agenda for Puget Sound and has been providing leadership in
the area of low impact development (LID) and regional watershed planning.
Mason County Hoodsport RAC Stormwater Management Plan 25
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K:\project\30700\30784\Reports\Hoodsport\Final Rpt\H SWMP 9-16-08.doc
•
•
•
Section I —Introduction
Continued
The Hood Canal Coordinating Council (HCCC) was established in 1985, with the
mission to improve regulatory decision making by providing a forum for discussion
of regional water quality issues affecting Hood Canal.
The Hood Canal Dissolved Oxygen Program (HCDOP) is a partnership of 28
organizations that conducts monitoring and analysis and develops potential
corrective actions to address the low dissolved oxygen problem in Hood Canal.
Gray & Osborne, Inc. has developed a Wastewater Facility Plan (Plan) for the
community of Hoodsport, Mason County Washington. This Plan evaluates
wastewater treatment and disposal alternatives for the Hoodsport RAC and develops
cost estimates. The intent of this plan was to address the on -site treatment system
problems identified in the Hood Canal Low Dissolved Oxygen Preliminary
Assessment and Corrective Action (PACA) Plan. The PACA plan was developed
through a collaborative and cooperative arrangement between the Puget Sound
Action Team, the State's Partnership for Puget Sound, Mason County, and the
council of governments within the Hood Canal watershed.
1.6 Regulatory Requirements
This stormwater management plan has been prepared to be consistent with the requirements
set forth in the N cology 2005 Stormwater Management Manual for Western Washington
(Ecology 2005 Manual) and existing Mason County codes and regulations. These design
criteria are also consistent with the 2000 Puget Sound Water Quality Management Plan and
its 2007-2009 biennial work plan. Additional discussion of the design criteria used to develop
the Hoodsport Stormwater Management Plan is presented in Section 5.
1.7 Report Content and Organization
The Hoodsport RAC Stormwater Management Plan is presented in a series of sections that
generally follow the flow of work, culminating in the presentation of recommended capital
projects and costs. The report is composed of the following ten sections:
Section 1—Introduction
Section 2—Characterization of the Hoodsport RAC
Section 3—Existing Stormwater Facilities
Section 4--Future Conditions
Section 5—Regulatory Criteria
Section 6—SWM Impacts, Analysis and Strategies
Mason County —Hoodsport RAC Stormwater Management Plan 26
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Section I —Introduction
Continued
Section 7—SWM Plan: Capital Projects
Section 8 SWM Plan: Programmatic Elements and Regulatory Compliance
Section 9—Costs, Funding and Implementation
Section 10—Public Review and Approval
Mason Coirntj'—Hoodsport RAC Stormwater Management Plan 27
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K:\project\30700\30784\Reports\Hoodsport\Final Rpt\H SWVIP 9-16-08.doc
Section 2—Characterization of the Hoodsport RCA
2. I Study Area
The Hoodsport RAC is one of three rural activity centers (RACs) identified within the
Mason County GMA Plan. It contains about 605 acres and is located at the north end of
Hoods Canal, as shown in Figure 2-1. The majority of the area is zoned for residential, with
the vast majority of the area currently in an undeveloped state The Hoodsport RAC is about
1.3 miles long north to south and averages about 1 2 miles wide east to west. Of this area,
less than five percent is currently developed as commercial -industrial, with the entire RAC
being less than about 15% developed
The area is unique in that it is zoned primarily for residential within the uplands area, with a
thin strip of commercial area located along Highway 101, directly adjacent to Hood Canal.
All surface water runoff from the Hoodsport RAC flows directly into Hood Canal. Existing
conditions relating to stormwater management within the Hoodsport RAC are described in
the following paragtaphs.
2.2 Topography and Drainage Subbasins
The majority of the land within the Hoodsport RAC, approximately 43-percent, drains to
Finch Creek, which flows into Hood Canal via a narrow channel that discharges next to the
State Fish Hatchery just on the southern side of State Highway 101. The Hoodsport RAC
generally slopes from west to east, and is characterized by the Finch/T,illiwaup drainage
basin that conveys surface water runoff from west to east, as shown in Figure 2-1. Slopes
range from relatively flat (0 to 5 percent) in the lower creek valleys and low lying areas and
beaches adjacent to Hood Canal to over 30-40 percent in the steeper portions of the
upstream drainage basins and the bluffs along the shoreline.
A total of nine drainage subbasins, identified as Subbasins 10 through 90, have been
delineated within the Hoodsport RAC. These are shown in Figure 2-1, together with
principal directions of flow and contours. Subbasin delineations are based on County -
provided GIS topography, site visit observations, and discussions with County staff.
Significance of Local Soils to Surface Water Management.
The challenge of continued development within the Hoodsport RAC will be the steep slopes
and the almost uniform presence of soils with limited infiltration capacity. Due to these
unique natural conditions, it will be important to limit future development to lower densities
and require the preservation of 65% or more of the native vegetation on site, along with the
use of numerous types of on -site low impact development (LID) techniques.
Mason County Hoodsport RAC Stormwater Management Plan 28
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K:A project \30700\30784\Reports \Hoodsport \Final Rpt\H SWMP 9-16-08.doc
Source: GIS data and Aerial photography provided by
Mason County 2006. Washington State Department of
Natural Reources provided Mason County with the stream
data used in this report. Disclaimer: This map is not to survey
accuracy and is meant for planning purposes only.
Figure 2-1
Existing Drainage Basin Boundaries
Hoodsport Stonnwater Management Plan
411 North 5th. P.O. Box 279
Shelton. Washington 93584
Phone: (3601427-9670
Far. (360)427-3425
10230 NE Points Drive
Kirkland. Washington 93033
Phone: (425) 322-3416
Fax: (425) 827.9577
Hood
Canal
Legend
Hoodsport RAC
Parcel Boundary
Fiow Direction
20 Basin Boundary with ID
--- County Owned Road
State\Federal Owned Road
Privately Owned Road
Stream
200 Ft Contour with label
40 Ft Contour
0 500
1,000
2,000
Feet
K:/project/30700/30784/GIS/mxds/Hoodsport/Figures/ExDraingeBasinBound.mxd
Section 2—Characterization of the Hoodsport RCA
Continued
2.3 Existing Drainage Basin Characteristics Summary
The existing characteristics of the Hoodsport RAC subbasins are summarized in Tables 2-1
and 2-2. Table 2-1 includes subbasin areas, subbasin discharge location, and primary and
secondary h5 drologic soil groups. Table 2-2 characterizes subbasins by topographic slope
information. This information has been used in part to develop stormwater management
strategies for each subbasin, as presented in Section 6.
Characteristics
Table
2-
I
Hoodsport
RAC Subbasin
Area
Hydrologic
Soil
Group
Total
Within
Discharge
Subbasin
ID
#
Area
RAC
Location
Primary
Secondary
(ac)
(ac)
Group
(%)
Group
(%)
5
4.5
4.5
Hood
Canal
C
100%
---
---
10
743.3
16.8
Hill
Creek
C
82%
B
18%
20
42.5
42
5
Hood
Canal
C
89%
B
10%
C
100%
30
58.1
41.6
Creek
1f1
C
100%
---
40
216.7
56.9
Creek
#2
50
28.9
28.9
Hood
Canal
C
99%
---
---
C
100%
---
---
60
277 2
133.9
Creek
#3
C
94%
B
6%
70
15.5
15.5
Hood
Canal
80
2248
2
257.8
Finch
Creek
C
81%
B
13%
90
141.1
7.0
Hood
Canal
C
75%
A
25Vo
Totals*
3776.0
605.3
C
90%
B
8%
*The remaining 2% of the area is made up of hydrologic Soil Groups A and ll.
Mason County Hoodsport RAC Stormwater Management Plan 30
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Section 2-Characterization of the Hoodsport RCA
Continued
2-2 Subbasin
Slope
Characteristics
Table
Subbasin
ID
Within
RAC
Slope
<
15%
1
5%<
Slope
<30%
Slope
> 30%
(ac)
(ac)
(%)
(ac)
(%)
(ac)
(%)
#
5
4.5
1.9
42%
0.6
14%
2.0
44%
10
16.8
7.3
43%
2.2
13%
7.4
44%
20
42.5
20.5
48%
10.8
25%
11.2
26%
30
41.6
24.4
59%
11.9
29%
5.2
13%
40
56.9
37.2
65%
13.6
24%
6.1
11%
50
28.9
15.6
54%
8.6
30%
4.7
16%
60
133.9
86.6
65%
24.4
18%
22.9
1
7 %
70
15.5
11.5
75%
2.7
18%
1.2
8%
80
257.8
107.4
42%
51.3
20%
99.1
38%
90
7.0
3.4
49%
1.1
16%
2.5
36%
Totals
605.3
315.8
52.2%
127.2
21.0%
162.3
26.8%
Note: Totals may not equal 100% due to rounding.
2 4 Soils
The soils within the Hoodsport RAC are generally relatively shallow, fine wined in nature
and allow only a minimum amount of infiltration The soils of the RAC as mapped by the
Natural Resources Conservation Service (FRCS) (formerly the U.S. Soil Conservation
Service (SCS)), are shown in Figure 2-2. The soils groups, shown in Figure 2-2, are generally
classified based on their ability to infiltrate surface water runoff, and are listed in Table 2-3.
They are dominated by Group C soils, which provide little infiltration
Mason County-Hoodsport RAC Stormnvater Management Plan 31
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K:Aproject\30700\30784\Reports \Hoodsport \Final Rpt\H SWMP 9-16-08.doc
Map Unit
Symbol
Gh
Gk
Hd
He
Hf
Soil Description
Jd
Ra
lb
M
4
Cloquallum silt loam, 5 to 15 percent slopes
Grove gravelly sandy loam, 0 to 5 percent slopes
Grove gravelly sandy loam, 5 to 15 percent slopes
Hoodsport gravelly sandy loam, 5 to 15 percent slopes
Hoodsport gravelly sandy loam, 15 to 30 percent slopes
Hoodsport gravelly sandy loam, 30 to 45 percent slopes
Juno sandy loam, 0 to 3 percent slopes
Riverwash, 0 to 3 percent slopes
Tanwax peat, 0 to 2 percent slopes
-
O
URA
NTER
••
Source: GIS data and Aerial photography provided by
Mason County 2006. Washington State Department of
Natural Reources provided Mason County with the stream
data used in this report. Disclaimer: This map is not to survey
accuracy and is meant for planning purposes only.
Figure 2-2
Site Soils
Hoodsport Stormwater Management Plan
111 North 5th, P.O. Box 279
Shelton. Washington 98584
Phone: (360)427-9670
Fax: (3t0).127-8425
F-INC14.CREEK F
10230 NE Points Drive
Kirkland. Washincl.m 981)33
Phcne: (425) 8224416
Fax: (425) 827-9577
Hood
Canal
Parcel Boundary
Soil Boundary
20 Basin Boundary with ID
— County Owned Road
State\Federal Owned Road
Privately Owned Road
Stream
200 Ft Contour with label
40 Ft Contour
0
500 1,000 2,000
le I Feet
K:/project/30700/30784/GIS/mxds/Hoodsport/Figures/SiteSoi IsV2.mxd
Section 2—Characterization of the Hoodsport RCA
Continued
Table
2-3
Soil
Groups
Hydrologic
Infiltration
Characteristic
Area Within
RAC
Percent of
RAC area
Soil
Group
(ac)
(%)
High
infiltration,
low runoff, as for
A
deep
loess,
15
acres
2%
sand
or
aggregated
silts
B
moderately
Moderate
infiltration,
coarse -textured
as for
soils
such
42
acres
8%
as sandy
loam
Slow
infiltration,
as for
fine
-textured
90%
C
soil
loam,
such
as
soils
clay
low
loam, shallow
in organic
sandy
content
547
acres
Very slow infiltration,
such
as swelling
D
and
plastic
clay
-pan
< 1
acre
< 1%
The distribution of soils within the RAC by their hydrologic soil group is shown in Figure 2-
3. The RAC is made up of almost entirely Group C soils, with minor areas of Group A,
Group B, and Group D soils. Group A and B soils, which are located in the lower flatter
areas, generally promote the infiltration of runoff. In these areas, infiltration would be a
preferred method of stormwater disposal.
Significance of Local Soils to Surface Dater Management:
Group C soils, which cover almost the entire study area, particularly the more steeply sloped
upland areas, have limited infiltration capacity. As a result, constructed stormwater facilities
will be needed to support increased development in these areas, and eventually a regional
conveyance system to safely convey peak runoff may be needed to convey excess surface
water flows directly to Hood Canal.
2.5 Land Use
The majority of land within the Hoodsport RAC is currently zoned as rural residential
(RR2 5) which allows one dwelling unit per two and one-half acres (see Title 17 Zoning of
the Mason County Code for a more detailed explanation of the zoning). Small amounts of
the RAC are zoned for rural commercial (RR3) rural multi -family (RMF), and rural tourist -
campground (RT). As a result of this zoning, the Hoodsport RAC consists primarily of low -
density residential, vacant/rural, and forested areas with a small commercial area along State
Highway 101.
Mason County — Hoodsport RAC S t o r m n a t e r Management Plan 33
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K:\project\30700\30784\Reports\Hoodsport\Final Rpt\H SWMP 9-16-08.doc
Source: GIS data and Aerial photography provided by
Mason County 2006. Washington State Department of
Natural Reources provided Mason County with the stream
data used in this report. Disclaimer: This map is not to survey
accuracy and is meant for planning purposes only.
Figure 2-3
Hydric Group
Hoodsport Stormwater Management Plan
411 North 5th, P.O. Dux 279
Shelton. Washington 98584
Phone: (360)427-9670
Pas: (360)427-8425
10230NE Points Drive
Kirkland. Washington 98033
Phone: (425) 822-4446
Fm: (425) 827-9577
r
WDFW DAM
Hood
Canal
Legend
Hydric Group
A
B
D
Hoodsport RAC
Parcel Boundary
20 Basin Boundary with ID
County Owned Road
State\Federal Owned Road
Privately Owned Road
Stream
200 Ft Contour with label
40 Ft Contour
0 500 1,000 2,000
Feet
K:/project/30700/30784/GIS/mxds/Hood sport/Figures/HydricGrou p. mxd
Section 2—Characterization of the Hoodsport RCA
Continued
The Wastewater Facility Plan prepared for the Hoodsport RAC in 2007 recorded 258
residential housing units in the Hoodsport RAC and estimated a population within the RAC
of 642 individuals (in 2005; estimate also includes seasonal residents). A small amount of
commercial land use is located within the Hoodsport RAC and is concentrated principally
along Highway 101 and SR.119, near Highway 101. According to the Wastewater Facility
Plan, approximately 38 businesses are located in the RAC, with a small amount of industrial
land use located along Highway 101 near Hill Creek
2.6 Hydrology
The Hoodsport area average annual precipitation is about 90 inches per year based on the
Cushman Powerhouse 2 precipitation stations. These are the closest rain gauges to the
Hoodsport area. The 90 inch average is based on the period of record from July 1973
through June 2007, as reported by the Western Regional Climate Center. Average monthly
precipitation from November through January exceeds 14 inches per month. The lowest
rainfall month is July, with an average monthly rainfall of about 1.1 inches.
2.7 Sensitive or Critical Areas
Sensitive areas within the RAC (as provided by Mason County) are delineated in Figure 2-4.
These sensitive/critical areas have been identified and defined in Mason County Code
8.40.020 and Chapter 17 (of Mason County Resource Ordinance 77-93) and include
frequently flooded areas, critical aquifer recharge areas, wetlands, geologic hazards, which
include landslide, seismic and erosion hazards, and fish and wildlife habitat conservation
areas. (Refer to Mason County Resource Ordinance Adopted 12-27-06 for information on
Geological Hazardous Areas.)
Frequently Flooded Areas: Frequently flooded areas are defined by Mason County as areas
occurring within the 100-year floodplain, as defined bs the Federal Emergency Management
Agency (1-ibMA) and the Washington State Department of F,cology s Coastal Zone Atlas.
Within the Hoodsport RAC, frequently flooded areas are limited and are primarily associated
with the lower reaches of Finch Creek and the marine shoreline along Hood Canal.
Development and land uses in frequently flooded areas are subject to provisions and
requirements outlined in Chapter 17 of the Mason County Code. Note that during the
December 2-4, 2007 storm event, the bridge over Finch Creek above the Highway 101
bridge was washed away.
Critical Aquifer Recharge Areas: Aquifer recharge areas are defined by Mason County as "those
areas which are determined to have an important recharging effect on aquifers usedas a
Mason County—Hoodsport RAC Star/tinter Management Plan 35
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K:Aproject \30700\30784\Reports \Hoodsport \Final Rpt\H SW)vIP 9-16-08.doc
Wetland
E2AB/FLN
E2BBN
PFO4Y
PSS1Y
Description
Estu_arine, Intertidal, Aquatic Bed/ Flat, Regularly Flooded
Estuarine, Intertidal, Beach/Bar, Regularly Flooded
Palustrine, Forested, Needle -Leaved Evergreen, Saturated/Semipermanent/Seasonal
Palustrine, Scrub -Shrub, Broad -Leaved, Saturated/Semipermanent/Seasonal
Upland — - -- -
PSSlY
j* i,s�-. t',��' w 44 i. #. VileAtk:
•f• ry 1
t
. - J
Source: GIS data and Aerial photography provided by
Mason County 2006. Washington State Department of
Natural Reources provided Mason County with the stream
data used in this report. Disclaimer: This map is not to survey
accuracy and is meant for planning purposes only.
Figure 2-4
Sensitive Areas
Hoodsport Stormwater Management Plan
411 North 5th. P.O. Box 279
Shelton. Washington 98584
Phone: (3(0)427.9670
Fag (360) 427.8125
10230 NE Points Drive
Kirkland. Washington 98033
Phone: (425) 822-1446
Pax: (425)827-9577
N_o-R.T_E-l__U 1 L L_R
/21
101
WDFW DAM
Hoo,�
Canal
Legend
Hoodsport RAC
Wetland Type
E2AB/FLN
E2BBN
PFO4Y
PSS1Y
Percent Slope
Stream Type
Fish
Non -Fish
D O I
- .. • a
Unknown
Stream Buffer (ft)
Basin Boundary with ID
County Owned Road
State\Federal Owned Road
Privately Owned Road
200 Ft Contour with label
0
500 1,000
2,000
Feet
K:/project/30700/30784/GIS/mxds/Hoodsport/Figures/SensitveAreasV2.mxd
Section 2—Characterization of the Hoodsport RCA
Continued
source for potable water and are vulnerable to contamination from recharge (MCC,
17.01.080). ' This classification of aquifer recharge areas is based on their potential for use
as potable groundwater, and their susceptibility to contamination, ranging from Category I
(highly susceptible) to Category IV (low susceptibility). Note that no critical aquifer recharge
areas have been identified within the Hoodsport RAC.
Wetlands: Wetlands are also present in the RAC, based on data from the National Wetlands
Inventory (ma) database. These consist of estuarine, inter -tidal, regularly flooded wetlands
and are located along the shoreline (Wetland data provided by Mason County.), as shown in
Figure 2-4. No other NWI-identified wetlands are present within the Hoodsport RAC;
however, numerous other, unmapped wetlands are likely present throughout the RAC.
These are likely to consist of smaller wetlands associated with springs and hillside seeps,
riparian habitat, and topographical depressions across the landscape.
Details concerning wetland delineation and categorization are provided in Mason County
Code 17.01.070, and associated buffer widths, development and land use regulations, and
mitigation approaches are likewise provided in that chapter.
Geologic Haards: Geologic hazards, per Mason County Code (MCC) Chapter 17, consist of
three hazard subtypes landslide hazards, seismic hazards, and erosion hazards.
Landslide hazard areas are defined as the following per MCC:
• Areas with any indications of earth movement such as debris slide earthflows, slumps
and rock falls.
• Areas with artificial over -steepened or un-engineered slopes, i.e. cuts or fills.
• Areas with slopes containing soft or potentially liquefiable soils.
• Areas over -steepened or otherwise unstable as a result of stream incision, stream
bank erosion, and undercutting by wave action
• Slopes greater than 15-percent (8.5 degrees) and having the following:
o Hillsides intersecting geologic contacts with a relatively petineable sediment
overlying a relatively impermeable sediment or bedrock (e.g. sand overlying
clay) and
o Springs or groundwater seepage.
• Any area with a slope of forty percent or steeper and with a vertical relief of ten or
more feet except areas composed of consolidated rock. A slope is delineated by
establishing its toe and top and measured by averaging the inclination over at least
ten feet of vertical relief.
Mason County Hoodsport RAC Stormwater Management Plan 37
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Section 2—Characterization of the Hoodsport RCA
Continued
Landslide hazard areas within the Hoodsport RAC with slopes greater than 15% and having
either permeable soils underlain with impermeable sediment or a prevalence of
springs/seeps, include portions of the steep slopes of Finch Creek. Provisions regulating the
designation of landslide hazard areas, their development and buffers, and associated
requirements for geotechnical reports may be found in MCC 17.01.100.
Seismic hazard areas are prone to severe disturbance from seismic events, and per the MCC
include the following:
• Areas with geologic faults;
• Deep road fills and areas of poorly compacted artificial fill;
• Areas with artificially steepened slopes (i.e. old gravel pits);
• Postglacial stream, lake or beach sediments;
• River deltas;
• Areas designated as potential Landslide Hazard Areas;
• Bluff areas; and
• Areas underlain by potentially liquefiable soils
According to the 2007 Hoodsport Wastewater Plan, the areas within the Hoodsport RAC
designated as seismic hazard areas are associated with the interface between shoreline and
Hood Canal, along Highway 101 from Potlatch to 1 illiwaup. Provisions regulating the
designation of seismic hazard areas and their development may be found in MCC 17.01.100.
Frosion hazard areas are defined as areas that are susceptible to severe erosion as a result of
disturbance Soils that are relatively unconsolidated and/or are associated with steep slopes
may meet the criteria for being considered erosions hazard areas. Within the Hoodsport
RAC, erosion hazard areas are associated with the steep, relatively unconsolidated slopes
along Finch Creek Development standards for erosion hazard areas are outlined in MCC
17.01.104.
Fish and Wildlife Habitat Conservation Areas (FWHCAs): According to Mason County Code,
FWHCAs are defined as areas managed 'for maintaining species in suitable habitats within
their natural geographic distribution so that isolated populations are not created (MCC
17.01.110).'
Areas designated as FWHCAs in Mason County include the following habitat types and
categories:
•
•
Commercial and recreational shellfish areas.
Kelp and eelgrass beds; herring, sand lance, and smelt spawning areas.
Mason County Ho o dsp o rt RAC S to rrrr wa to r Management Plan 38
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Section 2—Characterization of the Hoodsport RCA
Continued
® Naturally occurring lakes and ponds under twenty acres and their submerged aquatic
beds that provide fish or wildlife habitat.
Streams.
Saltwater shorelines, and lakes 20 acres and greater in surface area.
• Lakes, ponds, streams, and rivers planted with game fish by a governmental or tribal
entity.
State Department of Natural Resources natural area preserves and natural resource
conservation areas.
Areas with which Federal or State endangered, threatened and sensitive species of
fish and wildlife have a primary association. Protection of species habitats is
determined by the State or Federal listing, and their actual presence near the site
subject to review.
Other areas that contain habitats and species of local importance (which include
juvenile salmon migration areas). Species of local importance may include, but are
not limited to, Washington State Candidate and Monitor species.
Details concerning protection and management of FWHCAs, including buffer
establishment, allowable activities stewardship activities, permitting and habitat
management plans are found in MCC 17.01.110.
Marine habitat FWHCAs (commercial/recreational shellfish areas, kelp and eelgrass beds,
saltwater shorelines, etc) are associated with the shoreline and shallow tidal areas to the east
of the Hoodsport RCA The following Section 2.8 provides detail on one type of FHWCA
mapped within the Hoodsport RCA: stream habitat —specifically, fish -bearing stream
habitat.
•
•
2.8 Fish Bearing Creeks
There are five creeks located within the RAC, as graphically shown in Figure 2-4, including
Finch and Hill Creeks, along with three unnamed smaller streams. The largest and most
productive from both a flow and a fish perspective is Finch Creek, which has the largest
contributing drainage area
As shown in Figure 2-4, the lower reaches and much of the main stem of all five creeks have
been classified as fish bearing by the WDNR. Only the upper reaches and very small
tributaries have been classified as Non -Fish creeks
The creek locations are from Mason County's GIS database which uses the Washington
State Department of Natural Resources (WDNR) stream location data. The permanent water
type classification associated with these streams is also taken from the WDNR. The
Mason Countji—Hoodsport RAC Stormwater Management Plan 39
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Section 2—Characterization of the Hoodsport RCA
Continued
classification definitions are provided below. Note that since the non -fish RAC streams have
not been differentiated as "Np" or "Ns" by WDNR, "N" has been used for non -fish creeks.
•
•
Type "F"—Fish-bearing or containing habitat suitable for fish
Type "S" Waterbodies or streams designated as Shorelines of the State
Type "Np"—Non-Fish-bearing; Perennial
Type "Ns" —Non -Fish -bearing; Seasonal
Letter "N" Non -Fish -bearing
Letter "U"Unknown, untyped
Washington State Department of Fish and Wildlife (WDFW) operate two fish hatcheries
within the Hoodsport RAC: a salmon hatchery at the mouth of Finch Creek, east of
Highway 101, and a trout hatchery on Hill Creek west of Highway 101. Currently, Finch
Creek supports populations of spawning Coho salmon, fall run Chinook salmon, fall run
Chum salmon, pink salmon, and winter steelhead runs, as well as sea -run cutthroat. The
upper reaches of Finch Creek are generally inaccessible to anadromous salmonids, due to the
presence of the WDFW-operated diversion dam exists approximately 0 25 miles upstream of
Hood Canal.
Each of the five creeks that flow through the Hoodsport RAC has a stream buffer (150-feet
by ordinance on either side of the creek at most locations) and steep slopes that are within
the stream buffer and extend outside of the buffers these sensitive areas will limit
development adjacent to streams per MCC 17.01.110.
2 9 Receiving Water Quality
The Hoodsport RAC is located in Ecology's Water Resources Inventory Area (WRIA) 16,
Skokomish-Dosewallips. The receiving water for Hoodsport RAC runoff is Hood Canal.
Runoff reaches Hood Canal directly or via Finch Creek, Hill Creek, or one of the other three
unnamed creeks within the RAC which discharge to Hood Canal.
DOE considers Finch Creek impaired due to fecal coliform bacterial loading in the system.
Impaired water hstings from hcology s 2002/2004 303(d) list within WRTA 16 include a
Category 5 listing for fecal coliform contamination in the lower reaches of Finch Creek
Category 5 listings denote that the water body is impaired for the parameter in question and
that the water body does not have a Total Maximum Daily Load (TMDL) or other adequate
pollution control plan in place to address the contamination. Fecal coliform contamination
within Finch Creek is likely due to a combination of failing on -site sewage (septic) systems
Mason Count) Hoodsport RAC Stormuvater Management Plan 40
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Section 2—Characterization of the Hoodsport RCA
Continued
and animal waste, with septic system contribution providing the primary input of
contamination.
Areas of the Hood Canal, just to the north of the Hoodsport RAC, are listed by DOE as
Category 5 for low dissolved oxygen (no) concentrations. Other portions of the Hood
Canal to the south and east have likewise been given a Category 5 listing by DOE for low
DO concentrations Ecology staff do not know the reason for the low DO concentrations in
this portion of the canal. Both natural and anthropogenic sources are hkely causes.
WDFW considers shellfish in this area to be unfit for human consumption at any time. The
Washington State Department of Health (DOH) has prohibited shellfish harvesting in the
marine waters of the Hood Canal within the immediate vicinity of Hoodsport and the
Hoodsport Hatchery (Hood Canal Area #6), due to fecal coliform contamination. These
restrictions have been in place since the late 1980's, and remain in place today.
Mason County — Floor/sport RAC S t o r nr n' a t e r Management Plan 41
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Section 3—Existing Stormwater Facilities
3.1 Introduction
The Hoodsport RAC relies heavily on the use of its natural drainage systems to collect,
convey, treat, and infiltrate surface water runoff. These natural facilities have been
augmented by a series of man-made systems consisting of ponds, ditches, culverts, outfalls,
and conveyance pipes. As the RAC continues to develop, it will be critical to retain these
natural areas and continue to integrate new man made facilities with these natural systems in
order to maintain the hydrology and hydraulics of the region and support habitat areas.
3.2 Existing Stormwater Facilities
Stormwater facilities within the Hoodsport RAC, consist of a series of drainage facilities
owned and operated by three different agencies. Mason County constructs and maintains the
public drainage facilities, consisting primarily of ditches and culverts, within County road
right-of-ways. The Washington State Department of Transportation also builds and
maintains a system of drainage ditches and culverts that keep surface water off of state
highways, while the Washington State Department of Fish Wildlife has modified the natural
drainage system of Finch Creek to provide clean, clear, cool water to support their local
hatchery. At the present time, there are no County, WSDOT, WSDFW or private
stormwater treatment and few detention/retention facilities located in the Hoodsport RAC.
County Drainage Facilities
The County drainage system in the Hoodsport RAC consists of a series of road side ditches
and culverts that collect and convey runoff from about four miles of County roads to local
creeks and Hood Canal. Most of these drainages are along:
• N Finch Creek Road,
• N Schoolhouse Hill Road,
• N North Hill Road,
• N Ol mpic Road, and
• N Old Mill Hill Road.
Within these roadside systems, County culverts typically range from 12 to 18 inches in
diameter, as shown in the culvert inventory data provided in Appendix A
In addition to roadside ditch/culvert conveyances, the County has installed a drainage
system to collect surface water resulting from spring activity along the north side of Finch
Creek Road at the base of the hill between Highway 101 and the bridge over Finch Creek
Installed approximately four or five years ago, this drainage system includes a series of catch
basins connected by 12-inch diameter perforated pipes in drain rock with outfalls to Finch
Mason County Hoodsport RAC Stormwater Management Plan 42
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Section 3 Existing Stormwater Facilities
Continued
Creek. These drainage improvements address both the surface and subsurface water
problems that were historically plaguing this area. County identified culvert and catchbasin
locations are shown in Figure 3-1.
WSDOT Drainage Facilities
The Washington State Department of Transportation (WSDOT) also maintains a system of
ditches and culverts four about four miles along Highway 101 and SR 119 (N Lake Cushman
Road) within the Hoodsport RAC. Like the County, WSDOT culverts typically range from
12 to 18 inches in diameter, except where larger drainage pipes are needed at the crossings at
Finch Creek and Hill Creek/Highway 101. WSDOT also maintains the associated bridge
where Highway 101 crosses Finch Creek and the 3' x 3' box culvert where Highway 101
crosses Hill Creek. WSDOT culverts along Highway 101 are shown in Figure 3-1, with a
culvert inventory data provided in Appendix A.
WDFW Drainage Facilities
The Hoodsport WDFW salmon hatchery, receives water diverted from Finch Creek via an
intake structure diversion dam, located approximately one -quarter mile upstream from the
hatchery. The intake structure provides water for the hatchery and helps reduce flooding in
the lower reach of Finch Creek during smaller storm events.
i
tR�1 Y LII• ,j,� _ ,
\I
•
Mason County Hoodsport RAC Stormwater Management Plan 43
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GRESTHILL WY
Source: GIS data and Aerial photography provided by
Mason County 2006. Washington State Department of
Natural Reources provided Mason County with the stream
data used in this report. Disclaimer: This map is not to survey
accuracy and is meant for planning purposes only.
Figure 3-1
Existing Conditions
Hoodsport Stormwater Management Plan
411 North 5th, P.O. Box 279
Shelton, Washington 98584
Phone: (360)427-9670
Fax: (360) •127-8125
10230 NE Points Drive
Kirkland, Washington 98033
Phone: (425) 822-4446
Fax: (425) 827-9577
tiffct
t ••
WDFW DAM
0
Hood
Canal
Legend
WDOT Culverts
O County Culvert/CB
[_-_ j Hoodsport RAC
Parcel Boundary
20 Basin Boundary with ID
County Owned Road
State\Federal Owned Road
Privately Owned Road
Stream
200 Ft Contour with label
40 Ft Contour
500 1,000
2,000
Feet
K:/project/30700/30784/GIS/mxds/Hoodsport/Figures/ExistingConditionsV2.mxd
Section 3—Existing Stormwater Facilities
Continued
3.3 Local Drainage Issues and Deficiencies
Existing localized problem areas were defined from a variety of sources including, County
staff, WSDOT maintenance staff, and public input from the comments received via a
stormwater questionnaire distributed throughout the Hoodsport postal service area.
County Identified Drainage Deficiencies
Citizen drainage complaints submitted to the County are routinely recorded on "green
sheets" and stored within County's Road maintenance files. However, within the Hoodsport
area, no citizen complaints were recorded. So drainage deficiency areas were determined
primarily from interviews with County Staff [personal communication with Allan Eaton,
Assistant Road Operation and Maintenance Manager]. These interview were supplemented
by the use of a special drainage questionnaire that was mailed out to each resident, as
described in Section 3.4. Those reported by the County road maintenance crew are shown in
Figure 3-2 and described below.
## 1 o Finch Creek
Erosion/Sedimentation Maintenance of Hatchery Intake by WSDFW
Finch Creek flows full during most storm events, but normally does not flood Finch Creek
Road, Highway 101, or other nearby roads. When it flows full, it is highly erosive and
carrying and depositing large amounts of sediment within the lower reaches of the stream,
especially within the channel adjacent to the WSDFW hatchery just before the stream
discharges into Hood Canal. To stop bank erosion that was threatening a nearby home, the
County has installed some rock armoring along the north bank of the creek under the bridge.
Mason County Hoodsport RAC Stormwater Management Plan 45
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-HOODSPORTR
Source: GIS data and Aerial photography provided by
Mason County 2006. Washington State Department of
Natural Reources provided Mason County with the stream
data used in this report. Disclaimer: This map is not to survey
accuracy and is meant for planning purposes only.
Figure 3-2
Drainage Deficiency Map
Hoodsport Stormwater Management Plan
411 North 5th, P.O. Box 279
Shelton, Washington 98584
Phone: (360)427-9670
Fax: (360)427-8425
10230 NE Points Drive
Kirkland, Washington 98033
Phcnc: (425)822-1446
Fay: (4251 827-9577
North
NORTH-HILL .:_RD.
Drainage
Lumbermans
School House
- South
0
Drainage
Hood
Canal
Legend
O County Culvert/CB
Drainage Deficiency Data
Recent Drainage Improvement
Localized Flooding
[— —j Hoodsport RAC
Parcel Boundary
re\ Bridge
20 Basin Boundary with ID
County Owned Road
State\Federal Owned Road
Privately Owned Road
Stream
200 Ft Contour with label
40 Ft Contour
300
600
1,200
Feet
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Section 3—Existing Stormwater Facilities
Continued
Finch Creek requires routine maintenance following major storm events, but generally does
overflow and create local damage property. This maintenance usually takes the form of
debris and sediment removal needed to protect the dam structure and maintain the diversion
to the Hoodsport Salmon Hatchery. WDFW hatchery personnel routinely remove this
sediment and debris that deposits at the intake structure.
#2 Finch Creek Road
Most Systems Adequate with Some Localized Flooding During Large Storms
There is spring activity along the north side of Finch Creek Road at the base of the hill
between Highway 101 and the bridge over Finch Creek Approximately four or five years
ago, Mason County installed a drainage system to collect this water and discharge it into
Finch Creek The drainage system includes a series of catch basins connected by 12-inch
diameter perforated pipe in drain rock with outfalls to Finch Creek The drainage
improvement addressed both the surface and subsurface water that was collecting in this
area
At the Forest service property, there is a storm drainage system on the west side of the
building comprised of French drains, three catch basins, and three culverts that discharge to
Finch Creek There is also a drainage system on the east side of the building. There are no
reported problems at this location, but the County's drainage inventory should be updated to
include this system.
Localized flooding can occur near the west end of Finch Creek road where two culverts
cross under the road from north to south, then drain through a culvert system to Finch
Creek. The capacity of this system is exceeded during larger storm events and can cause
localized drainage problems.
#3 - Double, I8-inch Diameter Culverts
Localized Flooding if SR 1 19 System Is Not Adequately Maintained by WSDOT
Flooding on Finch Creek Road has been reported in the vicinity of where two, eighteen inch
culverts cross under Finch Creek Road, near Lumberman's and the bridge. According to
County staff, flooding does not usually occur here unless the storm drainage system along
SR 119 (I\ Lake Cushman Road) becomes plugged with debris. When the SR 119 system
becomes restricted, stormwater runs down SR 119, and crosses under SR 119 towards the
two, eighteen inch culverts. This stormwater from SR119 can result in flooding at the ditch
between SR 119, along Finch Creek Road, and within the Lumberman parking lot. This
drainage deficiency is more of a routine maintenance issue than a capacity issue since
flooding only occurs when the SR 119 system becomes plugged.
Mason County—Hoodsport RAC Sto rm ovate r M a n aR em e n t Plan 47
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Section .3. 'Existing Stormwater Facilities
Continued
Culverts at SR 119
#4 - North Hill
Small Undersized System along Baskin Lane
During the larger rain events, drainage from the upper areas of North Hill exceeds the
capacity of the 12-inch diameter Baskin Lane drainage system. When the system capacity is
exceeded, stormwater runs down Basin Lane, and North Hill Road, then flows over the
hillside down towards homes along Finch Creek Road, where soils are already saturated by
spring activity. The 12-inch drainage system is likely undersized for the amount of
development that has taken place within the drainage subbasln. Although there were no
reported problems during the winter of 2006-2007, but there have been drainage problems
here during several of the past several winters.
#5 - Old Mill Hill
Large Amount of Runoff into Canyon But No Major Flooding Problems
There is a large amount of runoff from the Old Mill Hill area, according to the County's
maintenance crew, however the existing canyon system seems to be able to handle it. The
lower portion of the road (i.e. the west end of the road) has catch basins that collect runoff
and route water down the hill towards Highway 101. There are no reported problems in this
drainage area.
Mason County Hoodsport RAC Stormwater Management Plan 48
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Section 3—Existing Stormwater Facilities
Continued
#6 - School House Road
Localized System Has Limited Capacity but No Major Flooding Problems
Runoff from the west, along School House Road, crosses the road from south to north via a
culvert located near the Quest telephone building; there are no reported problems with this
system. Drainage from that culvert and areas to the east, collect along the north side of the
road and enter the WSDOT drainage system Stormwater from the south side of the road
does not have a collection system and can flow onto adjacent properties.
#7 Future Road Improvements
County Currently Considering Local LID Projects to Treat Road/Development Runoff
Roadway improvement projects are important because they provide an opportunity to make
drainage improvements and apply low impact development drainage improvements. The
County currently does not have any County road improvements planed for the next six years
within the Hoodsport RAC, although they are currently considering the use of LID bio-
retention facilities within the County road right-of-ways to treat runoff from existing
development.
3.4 Public Identified Drainage Deficiencies from Drainage Survey
Mason County conducted a mail -in drainage survey for the Hoodsport RAC and
surrounding area using a questionnaire. The surveys were sent out to all Hoodsport
addresses and covered a few areas that were lust outside of the RAC. Participation in this
survey was voluntary
The County received 103 completed questionnaires. The results of the survey were reviewed
and used in the development of this Stormwater Management Plan. A copy of the
questionnaire and a summary of the responses received are included as Appendix B.
Results of Questionnaire
When
•
asked if they had experienced flooding in Hoodsport:
Eighty eight percent of respondents reported no flooding.
Within the Lake Cushman area, west of the Hoodsport RAC, not only reported very
little flooding but responded by saying that 'We have great drainage here in Lake
Cushman."
Nine percent responded "yes," indicating that they had experienced flooding within
Hoodsport area. While some of these responses came from outside of the RAC,
flooding was reported primarily within the RAC, along both North Finch Creek
Road and North Schoolhouse Hill Road.
Mason County—Hoodsport RAC Stormwater Management Plan 49
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Section 3—Existing Stormwater Facilities
Continued
® Three percent gave no response and did not return their survey questionnaire.
Summary and Conclusions of Survey Questionnaire
In general, flooding was described as occurring mostly in yards along and driveways. Some
flooding along Highway 101 was reported; however, the flooding was located outside of the
RAC near SR 106 and is associated with the Skokomish River. While the dates of the
reported flooding varied, most people agreed that flooding follows a "long, heavy rain."
Opinions as to what is causing the flooding included a variety of answers such as: clogged
drains, clear cutting and development within the watershed, alterations made to Finch Creek,
poor infiltrating soils, and "Mother Nature." It is recommended that the County focus on
the factors that they can control such as maintenance, and development in addressing
localized drainage issues within the Hoodsport RAC.
3 5 December 2-3, 2007 Flooding
Mason County incurred a significant amount of damage resulting from flooding that
occurred during December 2-3, 2007 rainfall event. This event was significant because it was
a rain -on -snow event, which created a large amount of surface water runoff over a relatively
short period of time. At the Cushman Powerhouse precipitation gage, 7 inches of rain fell on
the snow that had fallen the previous day resulting in a tremendous amount of stormwater
runoff (precipitation data is provided by the Office of the Washington State Climatologist).
Although other areas of the County were much harder hit, Hoodsport experienced some
damage along Finch Creek The Finch Creek County Bridge on North Finch Creek Road
was washed away during the storm. Another Finch Creek Bridge located at the upper, west
end of North Finch Creek Road was damaged where high flows were hitting the bridge
abutment; fortunately this bridge was repairable. The bridge were Highway 101 crosses
Finch Creek was not damage during the storm and water did not overtop Highway 101 at
this location or anywhere else within the Hoodsport RAC.
Holiday Beach, located approximately one mile north of the RAC, experienced water over
Highway 101, as did other areas of the County. Other than the Finch Creek bridges, there
was no major or permanent damage to the Hoodsport drainage system according to Mason
County maintenance personnel. Mason County considers this as evidence that the drainage
system in Hoodsport is in good working order and of the appropriate size to be able to
handled sucha large storm with relatively few major flooding problems or major damage to
property or infrastructure.
Mason Countj'—Hoodrport RAC Storn/wwater Management Plan 50
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Section 3—Existing Stormwater Facilities
Continued
3.6 Areas Needing Routine Maintenance
Enhanced maintenance is suggested to address the two following drainage problem areas
within the Hoodsport RAC.
North Finch Creek Road
Enhanced Maintenance by WSDFW at the Intake Structure on Finch Creek
Flooding along this road is reported to coincide with high tides that occur when the creek is
flowing full following a large rain. It was also reported that flooding is less frequent when
the hatchery clears out the gravel and sediment that accumulates at the intake structure.
Based on these reports, a more frequent maintenance regime by WSDFW at the intake
structure would be expected to reduce the frequency of flooding along IN Finch Creek Road.
North Schoolhouse Hill Road
Enhanced Ditch Maintenance by County along the Road
Another maintenance issue are the ditches along North Schoolhouse Hill Road. Clogged
ditches have been reported as the source of flooding at the west end of this road. More
frequent maintenance to clean out the ditches should reduce the frequency of flooding along
North Schoolhouse Hill Road.
Technical Information to Local Residents
At the east end of North Schoolhouse Hill Road, there are no ditches and water has been
reported to run down the road and down peoples' driveways. To improve this situation, the
County may want to offer information to residents on how they can improve the drainage in
their yards and driveways. For example, diagonal driveway berms could be use to direct
runoff to trench infiltration systems that residents could build in their yards. hxamples of
these drainage features are available in the County's small parcel ordinance and in the 2005
King County Surface Water Manual, Appendix C — Small Project Drainage Requirements.
Mason County—floodsport RAC Stormwater Management Plan 51
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Section 4-Future Conditions
4.1 Future Conditions
The future land use conditions assume that as population growth occurs in the RAC, any
currently undeveloped land will be developed or existing developments may be redeveloped
according to the current County zoning.
4.2 RAC Zoning
There are four different zoning classifications used in the Hoodsport RAC as shown in
Figure 4-1. These classifications are:
1. Rural Residential (RR2.5)
2. Rural Commercial (RC3)
3. Rural Multi Family (RMF)
4. Rural Tourist -Campground (RT,
The majority of land within the Hoodsport RAC is zoned as rural residential (RR2 5-one
dwelling unit per two and one-half acres). A small amount of the RAC is zoned for rural
commercial (RR3), rural multi -family (RMF), andrural tourist -campground (RT). As a result
of this zoning, the Hoodsport RAC consists primarily of low -density residential,
vacant/rural, and forested areas with a small commercial area. A summary of zoning
classification by subbasin is in Table 4-1.
4-
RAC
Table
Zoning
I Hoodsport
Subbasin
ID
#
Area
within
RAC
(acre)
Zoning
RR2.5
RC3
RMF
RT
(acre)
(%)
(acre)
(%)
(acre)
(%)
(acre)
(%)
5
4.5
4.5
100%
0.0
0%
0.0
0%
0.0
0%
10
16.8
8.1
48%
8.7
52%
0.0
0%
0.0
0%
20
42.5
41.2
97%
1.3
3%
0.0
0%
0.0
0%
30
41.6
41.6
100%
0.0
0%
0.0
0%
0.0
0%
40
56.9
56.5
99%
0.3
1%
0.0
0%
0.0
0%
50
28.9
27.3
94%
1.6
6%
0.0
0%
0.0
0%
60
133.9
124.5
93%
8.0
6%
0.0
0%
1.4
1%
70
15.5
12.4
80%
3.1
20%
0.0
0%
0.0
0%
80
257.8
245.7
95%
10.1
4%
2.0
1%
0.0
0%
90
7.0
6.3
90%
0.3
5%
0.0
0%
0.4
6%
Totals
605.3
568.0
94%
33.5
6%
2.0
0%
1.8
0%
Mason County Hoodsport RAC Stormuwater Management Plan
K:\protect\30700\30784\Reports\Hoodsport\Final Rpt\H SWMP 9-16-08.doc
52
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Source: GIS data and Aerial photography provided by
Mason County 2006. Washington State Department of
Natural Reources provided Mason County with the stream
data used in this report. Disclaimer: This map is not to survey
accuracy and is meant for planning purposes only.
Figure 4-1
Existing Land Use - Zoning
Hoodsport Stormwater Management Plan
411 North 5th, P.O. Box 279
Shelton. \'.'ashin tton 98584
Phone: (360)427.9670
lay (360)427.8425
t
WDFW DAM
10230 NE Points Drive
Kirkland. Washington 98033
Phone: (425) 822-1446
Fax: (425) 827-9577
0
Hood
Canal
Legend
ZONING
Rural Commercial 3 (RC3)
Rural Multifamily (RMF)
r Rural Residential (RR 2.5)
Rural Tourist -Campground
G J Hoodsport RAC
Parcel Boundary
20 Basin Boundary with ID
County Owned Road
State\Federal Owned Road
Privately Owned Road
--- Stream
500 1,000 2,000
Feet
K:/project/30700/30784/GIS/mxds/Hoodsport/Figures/ExistingLandUse Zoning.mxd
Section 4—Future Conditions
Continued
4.3 Future Growth Over the Next Six Years
Projected Population Growth
In the Hoodsport RAC Wastewater Faczlity Plan «uly 2007), an annual population growth rate of
3.5 percent was suggested by Mason County. Based on the 2005 population of 642 persons
and the 3.5-percent growth rate, about 9 new building permits will be received next year
supporting a population of about 690 in 2007 and an additional40 50 resident in 2008. The
population is estimated to be 840 at the end of the six year planning period in 2013.
Assessment of Growth and its Drainage Related Impacts
Development and redevelopment in Hoodsport that adheres to Mason County Code should
not increase runoff in the future. As the County phases in the use of the low impact
development and the 2005 Ecology Manual within the County's most urban areas, including
urban growth areas and rural activity centers like Hoodsport, those developments that
generate 5,000 square feet or more of new impervious surface will be subject to the
treatment and discharge requirements of the 2005 Manual. Developments that generate
fewer then 5,000 square feet of new impervious surface will be subject to Mason County
Code Chapter 14.48, which is based on the 1992 Ecology Manual and includes the Small
Parcel Development Requirements and New Development and Redevelopment — Minimum
Standards (Mason County Codes 14.48.130, and 14.48.140 respectively).
As development continues throughout the Hoodsport RAC, increased runoff is not
expected because low density development such as RR2.5 leaves enough undeveloped land
(with un disturbed native vegetation) on each site that stormwater runoff from the new
structures can be treated and infiltrated on site through the use of Low Impact Development
(LID) techniques, resulting in no increase in surface water runoff from the site.
Where this may not apply, is where parcels zoned RR2 5 but are less than 2.5 acres. Such
parcels are the result of previous subdivisions which are no longer allowed. The issue is with
those parcels that are currently undeveloped. If parcels are too small, then setting aside
enough open space to treat and infiltrate stormwater on site through the use of LID
techniques becomes more difficult Sites that are too small to infiltrate all of their runoff on
site will need to provide on -site water quality treatment and rate control before stormwater is
discharged from their site.
Redevelopment is also subject to the New Development and Redevelopment - Minimum
Standards (Mason County Code 14.48.140); therefore, any redevelopment that occurs in
Hoodsport will likely result in a reduced amount of stormwater runoff leaving the site
Mason County Hoodsporto rt RAC S to rm wa t e r M a n aR em e n t Plan 54
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Section 4—Future Conditions
Continued
compared to existing conditions. The Counts's New Development and Redevelopment
Minimum Standards apply to both residential and commercial redevelopment.
Mason Co
y
Hoodsport RAC Stormwater Management Plan 55
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Section 5—Regulatory Criteria
5.1 Introduction
Existing Development Criteria
Within the Hoodsport Rural Activity Center (RAC) the growth rate is approximately 3.5%,
which accounts for about 9 new building permits per year. Most of these permits are for new
residents, with the occasional commercial permit request. To guide new development within
the Hoodsport RAC the County uses a series of land use, design manuals, and development
codes and ordinances.
The general develop guidance document for the Hoodsport RAC is the County's
Comprehensive Land Use Plan (2005). This global planning document is supplemented by
the use of more detailed development guidance that takes the form of Stormwater Design
Criteria and Development Regulations, as described in Sections 5.2 and 5.3 below.
Need for New Development Guidelines
While these existing development guidance practices have served the County well for many
years, the County is now considering additional design criteria to address the more intense
and cumulative impacts of development. As rural densities begin to make the transition to
form rural activity centers, and then to continue to evolve into even more densely developed
urban areas, described as growth management areas in the County's Comprehensive Land
Use Plan, impacts to the County's sensitive natural systems are occurring. Streams are being
impacted by higher flows, increasing erosion and sedimentation, and the destruction of
habitat and critical spawning areas. Continually elevated pollutant loadings are affecting
receiving waters causing water quality violations, which result in low dissolved oxygen levels
creating fish kills and contaminating sensitive shellfish rearing areas throughout Hood Canal
and the most sensitive areas of south Puget Sound (i.e. North Bay and Oakland). (Reference:
Addenda to Allyn and Belfair Stormwater Management Plans; September, 2007.)
To address these more intense and accumulative impacts of continued, increasingly dense
urban development, the County is considering the requirement of the use of low impact
development (LID) techniques and the establishment of new, more effective stormwater
design criteria. LID techniques are currently being used throughout the Puget Sounds basin
to improve the protection and retention of natural systems and natural functions on
development sites and to limit the impacts of new impervious areas. These LID techniques
are being coupled with the use of more defined stormwater design criteria (i.e. the 2005
Ecology Stormwater Deign Manual for Western Washington (2005 Fi cology Manual)) in
order to reduce the impacts of peak flows and improve water quality by managing and
treating the runoff from new development on site, enhancing treatment and infiltration on
site as local soils allow, and making sure that post development rates of runoff do not exceed
those of the predeveloped site.
Mason County — Hoot/sport RAC Stormwater Management Plan 56
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Section 5—Regulatory Criteria
Continued
(Note # 1: It should be noted that the adoption and routine use of the 2005 Ecology Manual is also one of
the requirements for all municipalities that discharge into Puget Sound, as described in the Municipal
Stormwater section of the 2000 Puget Sound Water0Quality Management Plan and 2007 Conservation
Plan.
(1\Tote #2: It should also be noted that the engineering analyses and capital _project recommendations presented
in this Stormwater Management Plan for the Hoodsport RAC have been based on the application of the
2005 Ecology Manual for Western Washington, per the requirements of Ecology's grant to Mason Counti.)
5.2 Existing Development and Redevelopment Criteria
Requirements for Small and Large Parcels
The minimum requirements for new and redevelopment are triggered at different amounts
of impervious surface for both residential and non-residential developments. The two
existing Countywide stormwater management ordinances one for parcels with greater than
2,000 square feet of impervious area or land disturbing activities of one acre or greater, and
one for the smaller parcels with less than 2,000 square feet impervious are located in
Chapter 14.48, Article VII, of the Mason County Municipal Code, and are summarized
below. (For the complete text of these ordinances, refer to the Mason County web site:
http://www.co.mason.wa.us/codeicommissionerstindex.htm.)
Small Parcel Minimum Requirements for New Development/Redevelopment (Mason County
Code I4.48.130)
Due to the large number of relatively small residential sites that were continually being
developed throughout the County, a special ordinance was recently created and approved by
the County Board of Commissioners (CBOC) to address the special needs of the smaller,
more rural sites. Many other counties within the Puget Sound region have similar ordinances.
This new small parcel ordinance imposes stormwater management requirements on
developments, and redevelopments, with less than 2,000 square feet of impervious surface
and land disturbing activities of less than one acre. This ordinance is significant because prior
to its adoption, there were no stormwater management requirements to reduce the amount
of erosion and sedimentation from the new impervious area resulting from these smaller
developments.
Requirements for Small Parcels: Impervious Area T iess Than 2,000 Square Feet for Residential Sites
Prepare a small parcel erosion and sediment control plan that complies with the small parcel
minimum requirements #1 - #4 described in this section 14.48.130. These small parcel
Mason County Hoodsport RAC Stormwater Management Plan 57
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Section 5—Regulatory Criteria
Continued
requirements are designed to control erosion and sediment during construction and to
permanently stabilize soils that were exposed during construction.
1. Construction Access Route.
2. Stabilization of Potentially Erodible Denuded Areas.
3. Protection of Adjacent Properties.
4. Maintenance of Best Management Practices (BMP's).
New Development/Redevelopment Requirements (Mason County Code 14.48.140)
All residential sites and nonresidential sites fall under this ordinance. This ordinance
addresses special stormwater requirements for small and larger residential sites as well as
non-residential sites when the triggers mentioned below are reached
Requirements For All Sites Of New Residential Development Or Redevelopment With An Impervious
Area Of 2,000 Square Feet Or Greater.
Any residential development that creates or adds more than 2,000 square feet of impervious
surface area is to:
• Prepare a small parcel erosion and sediment control plan that complies with the
small parcel minimum requirements described section 14.48.130. These small parcel
requirements are designed to control erosion and sediment during construction and
permanently stabilize soils that were exposed during construction
• Small parcels are also required to prepare a residential site improvement plan that
includes a description of the proposed development and construction process.
• Some sites, located on steeper slopes or adjacent to sensitive areas, may also be
required to prepare small parcel drainage plans (examples of which are available from
the County upon request)
Requirements For Non -Residential Development With An Area Greater Than 5,000 Squa? e Feet
Impervious Or Land Disturbing Area Of One Acre Or More OR Residential Development With One
Acre Or More Of T and Disturbing Activity.
Under the current Mason County Code, non-residential developments and redevelopments,
exceeding five thousand square feet of impervious surface area and/or land disturbing
activities of one acre or more and residential sites with one acre or more of land disturbing
activity, are required to comply with the following eleven minimum requirements (or
requirements 2 — 11 and the small parcel minimum requirements in section 14.48.130):
1. Perform erosion and sediment control during pre and post construction activities.
2. Conduct basin planning.
3. Preserve and protect the natural drainage systems.
4. Provide source controls.
5. knhance water quality leaving the site using BMPs
Mason County—Hoodsport RAC Stormzvater Management Plan 58
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Section 5—Regulatory Criteria
Continued
6. Maintain and protect stream banks from erosion
7. Preserve and protect wetlands, maintaining natural hydroperiods.
8. Protect and preserve aquifer recharge and water quality sensitive areas.
9. Provide offsite downstream analysis and mitigation.
10. Perform routine operation and maintenance during construction.
11. Provide financial securities to ensure liabilities are addressed.
5 3 Discussion of Existing County SWM Design Criteria for Large Parcels
Compliance with the large parcel minimum requirements, listed in Section 5.2 above, is to be
demonstrated through the development and implementation of an approved stormwater site
plan that includes a large parcel erosion and sediment control plan and a permanent
stormwater quality control plan.
The existing stormwater design criteria for Mason County are generally based on the
F cology 1992 Manual, as further refined by County Ordinance 14.48, which emphasizes the
use of onsite detention to mitigate the impacts of site development and the addition of new
impervious areas. In general, non-residential developments must address the Ecology 1992
Manual requirements. Smaller residential parcels have a series of flow, erosion, and treatment
requirements specifically tailored to the construction impacts associated with smaller, more
isolated construction sites. Highlights of the County's existing stormwater design criteria for
new development include the following:
•
•
•
Thresholds: The use of stormwater design criteria is required for all new
development or redevelopment that exceeds 5,000 square feet of new impervious
area or one acre of land disturbance. A stormwater and erosion mitigation plan is
required for 2,000 of more square feet of new impervious area for smaller residential
developments. This would include all new residences as well as any new commercial
developments. (Note that the County's small parcel development ordinance applies
to the smaller residential developments.)
Hydrologic Analysis Methodology: The },cology 1992 Manual requires the use of the
Santa Barbara Unit Hydrograph methodology which generally selects a unit
hydrograph that represents the rainfall and estimates the amount and duration of
one-half of the 2, 10, and 100 year design rainfall events. Resulting flows are
estimated and required volumes of onsite detention/retention are estimated. Usually,
required peak flow detention is achieved with the design and construction of onsite
detention/retention ponds The treatment of runoff is designed for the 6 month, 24
hour storm event and erosion controls are usually designed for 0.64 of the 2 year, 24
hour event.
Flow Control: According to the h cology 1992 Manual, post -development discharges
from the site must matchthe pre-existing conditions. Flow control requirements are
Mason County— Hoodsport RAC Stormwater Management Plan 59
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Section 5—Regulatory Criteria
Continued
usually achieved via onsite detention/retention facilities. As local soil conditions
allow, much if not all of the new runoff can often be infiltrated onsite.
Downstream Analysis: If the runoff from the site is not directly flowing into a major
water body a downstream analysis is required to ensure the peak flows are conveyed
safely and that they enter into the natural drainage system without significant erosion
or sedimentation, or habitat or water quality damage.
Water Quality Treatment° In the Ecology 1992 Manual, water quality treatment is
achieved through the use of one or more best management practices (BMPs) A
common site water quality BMP is the grass -lined swale or the design of a wet pond
in the bottom of the required detention/retention facility
Frosion Control: Frosion control is required on all new development sites. On most
of the smaller residential and commercial sites erosion control consists of an erosion
control plan for during construction as well as a permanent site stabilization plan.
The County has created a small parcel stormwater application package to help
facilitate the permitting process.
Other additional special stormwater design criteria: In general, the main concern of
any new development in Mason County with regard to stormwater, is the
downstream impacts which include water quality, erosion/sedimentation, increased
flow rates, and impacts to habitat areas.
These stormwater design criteria work in conjunction with the County's other land use
practices and development controls that include:
® Following the allowed building densities allowed per the zoning rules in the County's
Comprehensive Plan.
e Consistency with the County's flood plain protection and set back guidelines.
® Adherence to the various setbacks and buffers described in the County's Shoreline
Management Plan and Sensitive/Critical Areas Ordinance that provides additional
protection and preservation of lakes, streams, steep slopes, wetlands, and aquifer
infiltration areas.
• Routine onsite inspection of construction to ensure that erosion control and proper
construction practices are being performed and regularly enforced
5.4 Future County SWM Design Criteria Using Low Impact Development
Use of the above stormwater design criteria have served the County well for mans years,
particularly in the more rural locations and for the smaller less intensely developed sites,
however additional stormwater design criteria and techniques are going to be needed to
continue to protect and preserve the sensitive natural resources of Mason County.
Mason C o u n t y— H o o d s p o r t RAC S t o r m w a t e r Management Plan 60
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Section 5 Regulatory Criteria
Continued
Ecology encourages the use of LID techniques for stormwater management where
appropriate. The Low Impact Development Technical Guidance Manual for the Puget
Sound describes LID as follows: Low impact development (LID) is a stormwater strategy that
enaphasites conservation and use of natural site features integrated with distributed, small --scale stormwater
controls to more closely mimic natural hydrologic patterns in residential, commercial, and industrial settings.
LID methods are presented in Appendix C. Design guidance for LID methods are also
available from:
• The 2005 Ecology Manual
www.ecy.wa.gov/programs/wq/stormwaterimanual.html
• The Puget Sound Partnership
http://www.psp.wa.govidownloads/LID/LLD manua12005.pdf
LID techniques have been considered in the development of the stormwater alternatives for
the Hoodsport RAC. LID techniques may reduce or eliminate the size of stormwater
facilities and infrastructure. Even though the Hoodsport RAC has predominantly Type C
soils (which may not be suitable for infiltration), there is still a large variety of LID options
available. Descriptions of potential LID options are included in Appendix C.
The County currently uses a series of stormwater related codes, ordinances, and design
criteria. Their current design criteria for new development and re -development are patterned
after the 1992 Ecology Manual. Currently, the use of continuous modeling for flows is not
required and there is no requirement for water quality treatment or the use of best
management practices (BMPs). Adoption of the Ecology 2005 Manual will update these
requirements.
The County recently passed Ordinance No. 76-08 on June 10, 2008, that promotes the use
of LID techniques and makes the use of LID mandatory within the Allyn and Belfair UGAs.
In addition, the County recently passed Ordinance No. 80-08 on June 17, 2008, that
establishes a storm and surface water utility and a phased schedule for implementation
throughout the County over the next five years. The initial SWM utility boundary includes
the service areas of the Allyn and Belfair UGAs. RACs and other sensitive areas will be
phased into the utility boundary over the next five years. Recommendations for the County
to update their current ordinances and design standards for the Hoodsport RAC are
scheduled for Year 4, 2011, and are included as Stormwater Element ##4 in Section 8 of this
document.
Mason County Hoodsport RAC Stormwater Management Plan 61
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Section 5—Regulatory Criteria
Continued
5.5 Future County SWM Design Criteria: 2005 Ecology Manual
The County is currently considering whether larger developments exceeding five thousand
square feet of impervious surface area, should be required to comply with the Ecology 2005
Manual. Due to the likelihood of this occurring in the near future the minimum stormwater
requirements for new development, as described in the 2005 Ecology Manual, are
summarized below.
Minimum Stormwater Management Requirements
The regulatory requirements for stormwater management are contained in Kcology's 2005
Stormwater Management Manual for Western Washington (Ecology 2005 Manual) The
Ecology 2005 Manual sets forth ten minimum requirements for stormwater management.
These are required for both development and redevelopment and are listed in Table 5-1.
All stormwater plans must demonstrate compliance with the following applicable minimum
requirements.
Table
5-1
2005
Manual:
Minimum
Stormwater
Management
Requirements
Ecology
Requirement
Minimum
Requirement
All
meeting the
thresholds
[outlined
in the
Ecology
2005
projects
1.
Preparation
of
Manual]
shall
prepare
a
Stormwater
Site
Plan
for
local
government
Stormwater Site
Plans
review.
in
the
new,
replaced,
or new
plus
replaced
2 Construction Stormwater
—Projects
which
feet
disturb
7,000
impervious
surfaces
total
2,000 square
or
more, or
Pollution
Prevention
(SWPP)
square
feet
or more
of
land
Site
must
Plan.
prepare
a Construction
SWPP
Plan
as
part of
the
Stormwater
Best
Management
All
known available
and
reasonable
source control
3. Source Control
of
Pollution
Practices
according
(BMPs)
to
the
shall
Ecology
be selected,
2005
Manual.
designed,
and
maintained
discharges
from
Natural
drainage
shall
be maintained,
and
patterns
the
project
site shall
occur at the
natural
location,
to the maximum
4.
Preservation of
Natural
Then
manner
by which
runoff
is discharged
from
Drainage Systems and
extent
practicable.
impact
to
the
project
site must not cause significant
adverse
Outfalls
All
downstream
outfalls
require
receiving
energy
waters
dissipation.
and
down
gradient
properties
5. Onsite Stormwater
infiltrate,
Projects
should
disperse
employ
and
Onsite Stormwater
retain stormwater runoff
Management
onsite to
BMPs
the
to
feasible
flooding
or erosion
Management
maximum
impacts.
extent
without
causing
Mason County — H o o d s p o r t RAC Stormwater M a n a g e m e n t Plan
62
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Section 5—Regulatory Criteria
Continued
Direct discharge
of
untreated
stormwater
from
pollution
-generating
for the
impervious
surfaces
to
ground
water
is
prohibited,
except
by
dispersion
of
runoff
from
6.
Runoff
Treatment
discharge
achieved
infiltration
or
residential
sites through
use of
Onsite Stormwater
Management
is
BMPs,
the
construction of
stormwater treatment
facilities
required.
flow
the
impacts
of
Projects
stormwater
must
runoff
provide
from
impervious
control
to reduce
surfaces
and
land
that
cover
discharge
conversions.
This
requirement
applies
to
projects
7.
Flow
Control
stormwater
directly,
or indirectly
through
a conveyance system, into a
discharge
to
direct
fresh
for
that
an approved
water — except
projects
discharge
receiving water.
Discharges
to wetlands
shall
maintain the
hydrologic
conditions,
8. Wetlands
Protection
hydrophytic
vegetation, and
substrate
characteristics
necessary to
support
existing
conditions
9.
Basin/Watershed
Projects
may
be subject
to equivalent
or more stringent minimum
in
Basin/Watershed
Plans.
Planning
requirements...
as identified
be
for
l
10.
Operation
An operation
and
maintenance manual .. shall
provided
a
and
Maintenance
proposed
stormwater
for the
maintenance
facilities
and
and
BMPs,
operation
and
the
shall
party
(or
be identified
parties)
responsible
Minimum Requirements for New Development
As described in the Ecology 2005 Manual: All new development shall be required to comply with
Minimum Requirement #2, entitled Construction Stormwater Pollution Prevention.
New development shall comply with Minimum Requirements # 1 through #5 for the new and replaced
impervious surfaces and the land disturbed if the proposed new development:
1. Creates or adds 2,000 square feet, orgreater, of new, replaced, or new plus replaced impervious
surface area, or
2. Ilas land disturbing activity of 7,000 square feet orgreater.
The following new development shall comply with Minimum Requirements # 1 through # 10 for the new
impervious surfaces and the converted pervious surfaces if the proposed new development:
1. Creates or adds 5,000 square feet, or more, of new impervious surface area, or
2. Converts 3/4 acres, or more, of native vegetation to lawn or landscaped areas, or
3. Converts 2.5 acres, or more, of native vegetation to pasture.
Minimum Requirements for Redevelopment
As quoted from the 2005 Manual: All redevelopment shall be required to comply with Minimum
Requirement 1t2. In addition, all redevelopment that exceeds certain thresholds shall be required to comply
with additional Minimum Requirements as follows:
Mason County— H o o d sp o rt RAC Stormwater Management Plan 63
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Section 5—Regulatory Criteria
Continued
Redevelopment shall comply with Minimum Requirements # 1 through II5 for the new and replaced
impervious swfaces and the land disturbed if.
- The new, replaced, or total of new plus replaced impervious su;faces is 2,000 square feet or more,
OR
- The redevelopment involves more than 7,000 square feet or more land disturbing activities.
2. Redevelopment shall comply with Minimum Requirements # 1 through # 10 for the new impervious
surfaces and converted pervious areas if the new redevelopment:
- Adds 5,000 square feet or more of new impervious surfaces or,
- Converts % acres, or more, of native vegetation to lawn or landscaped areas, or
- Converts 2.5 acres, or more, of native vegetation to pasture.
3. If the runoff from the impervious surfaces and converted pervious surfaces is not separated from runoff
from other surfaces on the pr ject site, the stormwater treatment facilities must be sided for the entire
flow that is directed to them.
4. Also note that: The local government may allow the Minimum Requirements to be met for an
equivalent NOW and pollution characteristics) area within the same site. For public roads'projects,
the equivalent area does not have to be within the project limits, but must drain to the same receiving
water.
Flow Rate Control Requirements
Flow control stormwater compliance criteria used in this stormwater planning study are
taken directly from i~ cology's 2005 SWM Manual for Western Washington. The compliance
criteria, set forth in the 2005 SWM Manual for basins requiring rate control, are as follows:
1. Stormwater discharge shall match pre -developed conditions flow duration values from % of the 2-year
flow frequeng through the 50 year flow frequeng. (Matching flow durations ensures that any
potential erosion problems downstream of the development are not exacerbated by the proposed
development.)
2. Developed peak discharge rates shall match pre -developed conditions peak flows for the 2 , 10-, and
50-year return periods. (Matchingpeak flows ensures that the downstream system will continue to
have the capacity to carry the expected flow rates.)
Direct Discharges to Saltwater Do Not Require Detention
The Ecology 2005 Manual does not define flow control requirements for freshwater
discharges into salt water receiving water bodies Thus for the Hoodsport RAC, stormwater
discharges into salt water such as Hood Canal, do not need to meet any special detention
requirements and may be directly discharged into Hood Canal. However, the flow control
requirements of the 2005 Ecology Manual do apply to those stormwater discharges that
directly enter fresh water systems, such as streams, rivers, wetlands, and smaller lakes
Mason County — H o o d s p o r t RAC Stormwater Management Plan 64
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Section 5—Regulatory Criteria
Continued
Water Quality Treatment Requirements
The Ecology 2005 Manual presents two sets of requirements for the selection of water
quality treatment methods, depending on the type of development that is being constructed
The Basic Treatment Menu is the standard for most residential developments, including those
that discharge into salt water. However, there is also the 1-P nhanced Treatment Menu that applies
to developments with a more intense use of impervious areas and greater potential for
pollutants leaving the site, including new roads, highways, and commercial developments or
discharges to fish -bearing streams. These two menus are summarized below:
The Basic WWaterQuality Treatment Menu allows any of the following options to be use&
-Bio-infiltration Swale
- Infiltration
- Sand Filters
- Bio-filtration Swales
-Filter Strips
-Basic Wetpond
- Stormwater Treatment Wetland
-Combined Detention and Wetpool Facilities
-Bioretention/Rain Garden
-Ecology F mbankment
- `StormFilter' with ZPGTM media
- Wetvault
To meet the Basic requirements, it is common for a developer to use either bio-
infiltration/bio-filtration swales or some form of a wetpond, depending on the shape and
amount of space available on the site. Wetponds can be sized with continuous simulation
models to treat the volume associated with 91% of all flows during the period of simulation,
which is generally equivalent to 0.72 times the amount of precipitation of the 2-year, 24 hour
storm event.
The Enhanced WaterQuality Treatment Menu allows any of the following options to be utilized
- Infiltration with Appropriate Pretreatment
- Large Sand Filter
- Amended Sand Filter
- Stormwater Treatment Wetland
- Compost-amended Filter Strip
- Two Facility Treatment Train
-Bioretention/Rain Garden
- Ecology Embankment
To meet the Enhanced requirements, a developer will often use a two of the above facilities
connected in series to create a "treatment train" or to develop a constructed wetland Sand
filters may also be required for special pollutant removals such as nutrients, which are not
readily removed using the above listed techniques.
Mason County—Hoodsport RAC Stormwater Management Plan
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Section 5—Regulatory Criteria
Continued
5.6 Timing and Scope of Future SWM Design Criteria
(In Mason County and the Hoodsport RAC)
Due to the continuing documentation of the impacts of existing and proposed future
development on the health of the natural systems (i.e. streams, water quality, fisheries, and
shellfish) throughout the County, the Mason County Board of Commissioners has elected to
use additional stormwater design methodologies and techniques, as described above (i.e. use
of LID and the 2005 Ecology Manual), to both retrofit existing development and improve
the mitigation of the impacts associated with new development/redevelopment.
The approach to implementing these additional stormwater management strategies is to first
establish a storm and surface water utility with a phased implementation schedule that is
prioritized based on level of urbanization and sensitive areas with identified water quality
impairments. The concept is to apply the LID and 2005 Ecology Manual requirements
along with the formation of a stormwater utility within local areas, using a phased approach
over the next five years, until the entire County comes under the same set of development
guidelines.
On June 17, 2008, the County adopted Ordinance Nos. 80-08 and 81-08. Ordinance No.
80-08 creates Mason County Code (MCC) Chapter 14.46, Storm and Surface Water Utility,
which establishes the County's storm and surface water utility and a phased implementation
schedule for expansion of the utility boundaries over time as follows:
•
•
•
•
•
Belfair and Allyn UGAs — 2008
Defined Marine Recovery Areas — 2009
Defined Shellfish Protection Districts — 2010
Defined Rural Activity Centers and Limited Areas of More Intense Rira;
Development (LAMIRD) — 2011
Countywide, excluding Designated Forest Lands - 2012
Ordinance No. 81-08 amends MCC 14.48, Stormwater Management, and adopts the
minimum requirements of the 2005 Ecology Manual for the Allyn and Belfair UGAs intially
and other areas as defined or added pursuant to MCC 14.46.
On June 10, 2008, the County adopted Ordinance No. 76-08 to add a new Chapter 17 80,
Low Impact Development (LID), to the MCC. The Chapter applies to all new development
within all zones within the Allyn and Belfair UGAs.
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Section 5—Regulatory Criteria
Continued
Under the phased implementation schedule adopted by the County, application of LID and
the 2005 Ecology Manual minimum requirements will commence in 2011.
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Section 6—SWM Impacts, Analysis and Strategies
6.1 Introduction and Overview
Due to the relatively sparse and rural type of existing and projected development within the
RAC, the approach for stormwater management within the Hoodsport RAC has not been
on the development and use of large, expensive regional facilities. Rather, the recommended
approach for stormwater management has focused on;
® The identification and correction of the relatively small, localized deficiencies within
the existing drainage system
• The relatively minor impacts of the runoff associated with the development/
redevelopment of the remaining rural density parcels within the RAC, and
• The need to address the County s newly adopted goal of retrofitting existing
drainage facilities for water quality treatment prior to discharge into Hood Canal.
The following section presents the results of the engineering analysis and recommendations
for stormwater management throughout the Hoodsport RAC.
6.2 Engineering Approach and Methodology
Approach
The engineering approach used to develop stormwater management strategies for the
Hoodsport RAC was to identify the various categories of existing deficiencies, project future
development impacts, and to determine the appropriate method to deal with each.
Existing Identified Drainage Deficiencies
The approach used to identify existing drainage deficiencies included a site visit, interviews
with County and WSDOT road maintenance crews, discussions with planning/development
review staff, and the use of a local drainage questionnaire that was sent our to the public.
Once identified, the deficiencies were divided by whether they were on public or private
property and also if the source of the excess runoff was from road runoff and other public
properties.
New Development and Redevelopment
The drainage issues associated with new development and redevelopment were estimated
based on the type of development and the type of land use zoning. With so many of the.
future parcels being relatively large and being used primarily for residential development,
there would be less future runoff generated than from the smaller existing parcels that would
be developed or redeveloped in the future for either residential or commercial purposes.
In order to estimate the impacts of future, ultimate development based on the zoning and
land uses presented in the County s Comprehensive Plan, the following categories of future
Mason County—Hoodsport RAC Starmuiater Management Plan
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Section 6—SWM Impacts, Analysis and Strategies
Continued
land use were analyzed and the future amounts of stormwater runoff were estimated for each
different type of future land use.
•
•
•
•
•
•
•
•
Existing residential platted parcels less than 2.5 acres
Vacant parcel
Redevelopment on existing developed parcel
Redevelopment on existing commercial parcels
Vacant parcels — RR2 5 zoning
Vacant parcels — RC3 zoning
Vacant parcels — RMF zoning
Vacant parcels — RT zoning
Water Ouality Retrofit Existing Development
At the request of regulatory agencies (Ecology and the Puget Sound Partnership), the County
is undertaking a program to retrofit existing drainage facilities in some of the more urban
areas of the County in order to collect and treat the runoff from existing development,
especially County roads and right-of-ways. To accomplish this water quality treatment goal
within the Hoodsport RAC, opportunities to use LID type of retrofit using bio-retention
facilities were investigated both on public right-of-ways (i.e. along County roads) as well as in
association with commercial development.
Methodology
The methodology for each of the three major categories presented above is discussed below.
Drainage Deficiencies.
As mentioned above, the analysis of the existing drainage problems within the Hoodsport
RAC began with a site visit, a tour of existing facilities, and the identification of problem
areas by local residents and County staff. A mail -in questionnaire to the public was also used
to help identify problem areas.
Those drainage facilities observed in the field were compared with inventories from the
County and WSDOT, along with previous studies and reports. Observed facilities and
existing problem areas are shown in Figure 3-2 Approaches to address the observed existing
problems were analyzed and capital projects and/or enhanced maintenance activities were
proposed to address these types of observed existing problem areas.
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Section 6—SWM Impacts, Analysis and Strategies
Continued
Development and Redevelopment.
The methodology used to address the drainage issues associated with new development and
redevelopment is defined in the County's zoning ordinances and stormwater regulations that
were in -place at the time of platting or submittal of the building permits application. The low
density nature of the zoning within the Hoodsport RAC will allow many of the low impact
development (LID) technique, such as dispersion, filtration and preservation of natural
vegetation to be used, as described in the County's small parcel ordinance. The use of LID
usually reduces the need for the more traditional and often more expensive and more land
intensive engineering approaches.
Water Quality Retrofit Projects.
The methodology for selecting and designing water quality retrofit projects within the RAC
will follow the approach contained it in the scope of work presented in the County's
October 2007 grant application to the Washington State Department of Ecology. This scope
includes an assessment of potential retrofit projects in the Belfair and Allyn UGAs, and the
Hoodsport RAC. Potential water quality retrofit sites within each of these three urban areas
will be selected, and those top ranked six to eight projects will be selected for design and
construction over the next few years, as local funding allows.
6.3 Engineering Analysis: Results
Engineering Results
The engineering analysis identified the need for increased maintenance at three critical
locations, as well as the design and construction of two small capital projects to reduce two
areas of localized flooding.
Need for Increased Routine Maintenance
Of the drainage deficiencies identified and recorded in Section 3, a number of those
deficiencies associated with the public drainage facilities can be corrected and/or reduced in
magnitude by increased maintenance. The most important of those facilities needing
increased maintenance include the following:
® The WSDOT drainage system along SR 119 needs regular removal of debris to avoid
becoming plugged and overflowing, impacting the County's downstream drainage
system,
® The Department of Fish and Wildlife hatchery dam on Fitch Creek requires the
regular and routine removal of accumulated gravel and sediment in order to avoid
overtopping and creating localized flooding, and
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Section 6—SWM Impacts, Analysis and Strategies
Continued
The County drainage ditches along the west end of North Schoolhouse Road could
benefit from increased routine maintenance due the limited conveyance capacity of
the system.
Need for Capital Projects
Those deficiencies identified in Section 3 for correction via capital improvement projects
include:
The construction of a stormwater collection and conveyance system in the public
right-of-way on the east end of North Schoolhouse Road to eliminate road runoff
from entering private properties, and
• The construction of replacement or supplemental conveyance capacity for the North
Hill area to eliminate drainage impacts to private properties along the east end of
Fitch Creek Road.
Results of the Public Drainage Questionnaire
The results of the public questionnaire process indicated limited and infrequent flooding of
private property throughout the Hoodsport RAC. Most problems were reported to result for
prolonged heavy rainfall, as is common with many urban drainage systems. The correction
of drainage problems on private property is generally considered to be the responsibility of
the individual property owners, unless the runoff originates from public properties and
facilities. For the two areas where runoff from public right -of way was impacting private
properties (i.e. along North Schoolhouse Road and within the North Hill area, additional
maintenance activities and two small CIP projects, as presented above, have been
recommended.
6.4 Summary of Stormwater Strategies and Recommendations
Summary of Findings and Recommendations
In general, due to the predominant rural character and relatively limited amount of existing
residential and commercial development within the Hoodsport RAC, the existing drainage
system is generally adequate and there are few drainage related problems. It is also likely that
there will be few future drainage problems as the RAC continues to develop due to the
County's proposed use of enhanced stormwater design criteria and the preservation and use
of the remaining larger rural types of lots within the RAC for future development. Specific
recommendations follow.
Mason Count]Hoodsport RAC Storrn,pater Management Plan 71
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Section 6—SWM Impacts, Analysis and Strategies
Continued
Existing Drainage System
Of the few, small localized drainage problems that were identified, they can be readily
addressed by either increased regular maintenance, or increased maintenance along with two
small local capital projects.
New Development/Redevelopment
A detailed engineering analysis was not performed to estimate the drainage related impacts
associated with ultimate buildout within the RAC; however, an engineering assessment based
on past professional engineering modeling and drainage design experience within the Allyn
and Belfair UGAs, was performed. This analysis estimated that future drainage problems
should be minimal and should be able to be adequately addressed on -site by individual
developers using the County's new proposed stormwater design criteria, involving the use of
LID and the 2005 Ecology Manual, on the larger rural density parcels remaining within the
RAC.
Retrofitting for Water Quality Treatment
Water quality retrofit opportunities within the more densely developed areas of the RAC
along US Highway 101 will be examined by the County in the near future and sites for water
quality retrofit projects will be identified for design and construction within the next few
years, as local funding allows.
Summary of Stormwater Strategies
Short -Term Strategy
The short-term strategy for the Hoodsport RAC is to:
•
•
Work with WSDOT and WDFW to increase the level of maintenance along SR 119
and the hatchery dam, respectively, and
To increase the level of maintenance performed by County crews on the ditches at
the west end of North School House Road.
Long -Term Strategy
The recommended long-term strategy is to:
•
•
Maintain existing rural land use zoning, adopt the new LID and 2005 Ecology
Manual standards for future development/redevelopment, and continue to monitor
conditions within the RAC drainage basins as development takes place, and
Identify and implement water quality retrofit projects for commercial areas along
Highway 101 and SR 119, using County and WSDOT rights -of -way, as the
availability of local funding allows.
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Section 7—SWM Plan: Programmatic and Capital Projects
7.1 Introduction and Overview
Based on the methodologies described in Section 6, stormwater management strategies
involving both enhanced maintenance and new capital projects have been proposed for the
Hoodsport RAC. These programmatic initiatives and projects presented below first focus on
maintaining the drainage systems that are currently functioning well (through enhanced
maintenance), upgrading those parts of the drainage system that are underperforming
(through capital improvements), and then enhancing the design criteria for new
developments so that currently functioning systems will not become overwhelmed by future
development.
7.2 Stormwater Management Recommendations: Programmatic
Two programmatic stormwater management methods are recommended for the Hoodsport
RAG enhanced maintenance and the adoption of the LID ordinance and the Ecology 2005
Manual. (These are also included in the discussion of the Programmatic SWM elements in
the following section, Section 8.)
Stormdrain System Maintenance
As discussed in Sections 3 and 6, there are areas within the Hoodsport RAC that experience
flooding when the capacity of the existing system is reduced due to the collection of
excessive amounts of debris. Recommended locations for more frequent maintenance were
discussed in Section 6 and are provided in Table 7-1.
Table
7-1
Recommended
Maintenance
Facility
in need
of
Function
Responsible
jurisdiction
when
maintained
Deficiency
when
riot maintained
maintenance
1.
Ditches
and
N.
Schoolhouse
Capacity
results
is
in
flooding
reduced
along
when
N.
clogged;
Mason
County
Hill
Road
Schoolhouse
Hill
Rd.
Culverts
conveyance
Capacity
is reduced
when
clogged;
2.
Finch
Creek
Bypasses
the
Hatchery
water
to
WDFW
res ilts
in
flooding
along
N.
Finch
Creek
Rd.
Intake
structure
3.
Ditches
and
SR
Cushman
conveyance
119
(Lake
Road)
Capacity
increased
is reduced
runoff
to
when
N.
clogged;
Finch
Creek
Rd
; results
in
flooding
along
Finch
WSDOT
Culverts
Creek
Rd.
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Section 7—SWM Plan• Capital Projects
Continued
Adoption of LID and the Ecology 2005 Manual
It is recommended that the County adopt and use LID along with the h cology 2005 Manual
within the Hoodsport RAC to address the drainage and related impacts associated with new
development and redevelopment. Adoption of the LID Ordinance and Ecology Manual will
impose detention and water quality treatment requirements on new development and re-
development and protect the existing stormdrainage systems from increased runoff in the
future. The facilities required to meet these requirements will be constructed and funded by
private developers, and have therefore not been included in this SWM plan or CIP program.
7.3 Stormwater Management Recommendations' Capital Improvements
CIP projects are recommended for areas where the existing drainage system is insufficient
according to site visits the public questionnaire, and reports from local residents and Mason
County Staff. Three CIP projects are recommended to address existing problem areas, along
with one project to begin to address the area's water quality treatment needs. The total cost
of this Six -year CIP is $423,000. Each proposed project is discussed below.
Project
Cost
Table
7-2 Hoodsport
RAC Six Year Capital
Improvement
Program
$ 185,000
# 1
N.
North
Hill
Drainage
Improvements
$ 121,000
11 2
North
Schoolhouse
Hill
Road
Ditch
Improvements
$ 56,000
# 3
Replace
Half
-Pipe
w. 18-inch
Culvert:
SR119
to
Finch
Creek
$ 61,000
# 4
Filterra
Device
for WQ
Retrofit
(retrofits
0.8 ac of
County road)
Total
Cost of
Six Year CIP
(Annual
CIP
cost is about
$70,000.)
$ 423,000*
*A detailed cost estimate for each CIP is included in Appendix D
CIP Project #I — North Hill Drainage Improvements
It is recommended that the County increase the capacity of the roadside ditch and driveway
culverts along N. North Hill Road. It is also recommended that the roadside ditches along
N. Baskin Lane and N. Olympic Drive be cleaned out. This system is currently undersized
and stormwater has been reported to run off the road towards Highway 101 and private
properties at the east end of N. Finch Creek Road. The runoff that flows towards Highway
101 appears to be contributing to an unstable hillside. With this CIP approximately 3,000
lineal feet of ditch will be cleaned out and 470 lineal feet of driveway culverts will be upsized
by 6-inches (from 12-inch to 18-inch, or from 18-inch to 24-inch culverts). The locations of
these improvements are shown on Figure 7-1, with an estimated construction cost of
$185,000.
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CIP Description
# 1 N. North Hill Drainage Improvements
# 2 North Schoolhouse Hill Road Ditch Improvements
# 3 Replace Half -Pipe w. 18-inch Culvert: SR119 to Finch Creek
# 4 Filterra Device for WO Retrofit (retrofits 0.8 ac of County Road
Maintenance 'Area # 2
Mainte.nance'.Area # 3
Maintenance Area # 1
Source: GIS data and Aerial photography provided by
Mason County 2006. Washington State Department of
Natural Reources provided Mason County with the stream
data used in this report. Disclaimer: This map is not to survey
accuracy and is meant for planning purposes only.
Figure 7-1
6-Year CIP Program
Hoodsport Stonnwater Management Plan
Er Or
411 North sth, P.O. Box 279
Shelton. Washington 98584
Phone: (360) 427-9670
Fax: (360)427-8425
N NORTH HILL RD
10230 NE Points Drive.
Kirkland Washington 98033
Phone: (425) 8224446
Fax: (425) 827-9577
O WDOT Culvert
0 County Culvert/CB
i ' .t CIP Area
Maintenance Area
El 1 Hoodsport RAC
Parcel Boundary
20 Basin Boundary with ID
County Owned Road
State\Federal Owned Road
Privately Owned Road
Stream
200 Ft Contour with label
40 Ft Contour
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Section 7—SWM Plan: Capital Projects
Continued
CIP Project #2 — North Schoolhouse Hill Road Ditch
It is recommended that the County construct a roadside ditch, with driveway culverts along
the east end of North Schoolhouse Hill Road. There are no ditches here and stormwater has
been reported to run off the road and down private driveways. With this CIP, approximately
1,000 lineal feet of new ditch will be created along one side of the road and 120 lineal feet of
18-inch diameter driveway culverts will be installed The location of this improvement is
shown on Figure 7-1, and has an estimated construction cost of $121,000.
CIP Project #3 — Replace Half -Pipe with 18-inch Diameter Culvert: SR 1 19 to Finch
Creek
It is recommended that the County replace the existing half pipe culvert that flows down the
hillside from SR 119 to Finch Creek with a closed, 18-inch diameter pipe. The closed pipe
will reduce the amount of debris entering the pipe The estimated length of this pipe is 200
lineal feet. This improvement is located near the fire station as shown on Figure 7-1, and has
an estimated construction cost of $56,000.
CIP Project #4 — Water Quality Retrofit
Consistent with the County's new water quality retrofit objective, it is recommended that the
County install Filterra water quality treatment devices (or its approved equivalent) for water
quality retrofit in roadway areas that currently have no water quality treatment. This CIP
project includes the installation of two water quality retrofit devices, each with the capacity
of treating up to 0.40 acres each for a total of 0.80 acres of water quality treatment. Surface
water quality retrofit options such as bioswales, were considered but were found to be less
feasible due to the tight, steep terrain of the Hoodsport RAC. Recommended locations for
water quality retrofit are at the downstream ends of N. North Hill Road and North
Schoolhouse Hill Road, as shown on Figure 7-1. The estimated construction cost of this CIP
is $61,000.
Note for Recommended Downstream Analysis
It is suggested that a downstream analysis be performed to verfy that the capacity of the existing downstream
systems are adequate to convey the increased peak flows that may result from these enhanced conveyance
improvements. Such an analysis has not been performed as part of this engineering analysis. A downstream
analysis should be performed when these CIPs are designed to ensure there will not be adverse downstream
impacts.
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Section 7—SWM Plan: Capital Projects
Continued
7.4 Countywide Stormwater Management Initiative to Retrofit Existing
Stormwater Runoff
It is important to mention the discussions currently underway within Mason County to
develop a Countywide SWM Program initiative to design, fund, and build a series of water
quality treatment facilities within the more urban areas of the County, including the
Hoodsport RAC. The request has been made by Fcology and the Puget Sound Partnership
to treat all existing runoff from the more urban areas of the County in order to protect
sensitive receiving waters.
Under this initiative, low impact development (i.e. bio-retention facilities within County road
right-of-ways) would be used to treat runoff prior to discharge to Hood Canal and Puget
Sound. These facilities will cost approximately $40K each, if construction on County owned
land.
It is likely that one or two of these facilities may be b»ilt within the Hoodsport RAC over
the next two to six years. Funding may initially come from a $750K grant that the County
recently received from Ecology. Later, additional local funding, including the formation of
stormwater utility, may be needed to continue to fund the SWM Program within the
Hoodsport RAC.
(Please refer to Section 9 for a more detailed discussion of funding needs and potential
revenue sources. Note that the cost of these potential water quality retrofit facilities has not
been included in the funding needs identified for the Hoodsport SWM Program in Section
9.)
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Section 8—SWM Plan: Programmatic Elements and
Regulatory Compliance
8.1 Introduction
For the last two years Mason County has been undertaking the development of a
comprehensive County -Wide Stormwater Management (SWM) Program. The elements of
this program include:
• Updating the County's SWM related Policies and Ordinances,
• Development of Stormwater Management Plans for the areas of Belfair, Allyn, and
Hoodsport, and the
• Development of a County -Wide SWM Program, with a dedicated funding
mechanism.
This report is the regional SWM Study for the Hoodsport RAC. The intent of this plan is to:
•
•
•
•
•
Assess the capacity of the existing drainage system,
Plan for growth by projecting the runoff from new development over the next six
years,
Provide guidance for new development and redevelopment to ensure future design
criteria support this SWM Plan and continue to support local economic
development,
Assist the County in achieving compliance with existing regulatory requirements,
including the Puget Sound Water Quality Management Plan (PSWQMP) and address
local water quality issues, as recorded in local TMDLs issued by Ecology,
Provide advance planning to the County in anticipation of its future NPDES Phase
II Municipal Stormwater Permit, that contains regulatory requirements similar to
those of the PSWQMP, and
Protect local and regional water quality, habitat, and groundwater functions and
resources.
8.2 Strategy to Manage Existing and Future Runoff
The recommended strategy and proposed programmatic initiatives and capital project to
manage existing and future runoff have been previously discussed in Sections 6 and 7. In
general the recommended SWMP for the Hoodsport RAC includes:
•
•
•
Enhanced maintenance at three locations,
The design and construction of two conveyance enhancements,
The construction of retrofit facilities to treat runoff from 0.8 acres of County road,
and
The adoption of an LID ordinance and the 2005 1-neology Manual.
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Section 8—SWM Plan: Programmatic Elements and
Regulatory Compliance
Continued
8.3 Review of County's Existing SWM Program
Programmatic Overview
Mason County is in the process of conducting a review of the existing stormwater
management program for the Hoodsport RAC, as well as for the entire County. This review
will document existing SWM activities, legal authorities, staffing, resources and equipment.
During this review a regulatory gap analysis will be preformed, comparing the existing
Hoodsport SWM Program with its existing SWM responsibilities and obligations.
The County's existing annual SWM Program within the Hoodsport RAC consists primarily
of annual maintenance (of about $25K per year) and development related review,
construction, and inspection/enforcement services, as paid for through developer permit
fees. Additional SWM activities provided on an as needed basis include:
• Response to spills and complaints,
• Comprehensive land use planning,
• Participation in local and regional planning,
• Annual maintenance, and
• Public education and involvement.
One of the purposes of this study is to review the County s existing levels of funding and
staffing to determine its effectiveness and adequacy to address local drainage issues and
regulatory compliance. Once defined, it is anticipated that the Hoodsport SWM Program will
be enhanced and incorporated into the County's larger comprehensive SWM Program. It is
anticipated that the SWM Program for Hoodsport RAC will be one of the elements of the
Countywide SWM Program, and will benefit from future County funding and staffing
appropriations. Increased funding for SWM throughout the County is currently being
considered to support the County's growing SWM obligations and regulatory compliance
needs.
Existing SWM Policies and Legal Authority
As part of the analysis of the County's existing SWM Program, a review was completed of
the County's stormwater management policies, as presented in the updated SWM policies
included in the County's Comprehensive Plan. These updated policies were presented to the
Planning Commission and adopted by the County BOCC in December 2006.
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Section 8—SWM Plan: Programmatic Elements and
Regulatory Compliance
Continued
In addition to these updated SWM policies, other existing legal authorities were also
reviewed, including the County's use of the 1992 hcology Manual, and the recently adopted
small parcel drainage requirements. The County is also considering adoption of an LID
ordinance, along with the adoption of the 2005 Ecology Manual.
Review of the County's existing code suggests that current legal authorities will not be
adequate to fully implement the proposed SWM Plans for Hoodsport, Belfair, and Allyn
Existing codes, design manuals and legal authorities will need to be expanded and updated to
satisfy exiting and future water quality and regulatory compliance needs, as well as develop
needed funding. Implementation of the Countywide Comprehensive Stormwater
Management Plan, and the associated specific SWM Plans for Allyn, Belfair, and Hoodsport,
will need updated legal authorities for the successful implementation The specific legal
authorities needed will be identified in the upcoming County -wide Regulatory and SWM
Program Gap Analysis, soon to be undertaken by the County as part of the broader county-
wide comprehensive stormwater management planning process that is currently underway.
8.4 Regulatory Compliance: Regulatory Gap Analysis
Overview
Compliance with the Puget Sound Water Quality Management Plan
There are a series of existing regulatory requirements related to stormwater management,
water quality, and habitat that apply to the Hoodsport RAC. The most significant are the
municipal stormwater elements of the Puget Sound Water Quality Management Plan
(PSWQMP), and its associated 2007-2009 Conservation Plan. Compliance with these
requirements consists of addressing thirteen different municipal stormwater management
program elements including:
1. Stormwater controls for new development and redevelopment
2. Stormwater site plan review
3. Inspection of construction sites
4. Maintenance of permanent facilities
5. Source control
6 Illicit discharges and water quality
7. Identification and ranking of problems
8. Public involvement and education
9 Low impact development practices
10. Watershed or basin planning
11. Funding
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Section 8—SWM Plan: Programmatic Elements and
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12. Monitoring
13. Schedule for implementation
Other existing requirements may include local water quality TMDLs, which for the receiving
waters in and around the Hoodsport RAC do not currently exist. There are, however,
concerns about the impacts of continued and increased stormwater discharges to the local
water quality of Hood Canal and the shellfishbeds in nearby natural and commercial rearing
areas. Elevated concentrations of coliforms have been documented by Ecology in nearby
Annas Bay.
National Pollution Discharge Elimination System Phase II Municipal Stormwater Permit
Preparing the County for comphance with a future Phase II NPDES Municipal Stormwater
Permit requires the County to add stormwater programmatic elements to its existing annual
SWM Program, many of which are the same as those required under the PSWQMP Future
compliance with the NPDES Phase II Permit will include:
•
Developing and conducting a public education program,
SWM Activities Needed for Compliance with PSWQMP and NPDES Phase II Permit
Due to the similarities of the PSWQMP and the Phase II NPDES Permit, and the likelihood
of the County will be receiving an NPDES Phase II Permit within the next few years, the
following regulatory gap analysis has been performed and will be used to develop the
comprehensive SWMP for the Hoodsport RAC. These NPDES Phase II requirements were
issued in January of 2007 to most, smaller municipalities (with populations less than 100,000)
throughout the State. The requirements are grouped into nine stormwater management
program (SWMP) elements. A brief summary of the requirements of each element, its
applicability to the County, and recommended actions for the Hoodsport RAC, are provided
below.
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Section 8—SWM Plan: Programmatic Elements and
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SWMP Element #I —Public Education and Outreach
Develop and implement a public education and outreach program designed to achieve
measurable improvements in stakeholders understanding of stormwater pollution sources
and impacts and what they can do to address these issues. The program needs to include
efforts to measure the results of any education activities as well as maintaining records of
activities undertaken.
Applicability:
Public education and outreach is an effective and low-cost method for addressing
stormwater pollution issues within the County and can be focused on those specific issues
relevant for the Hoodsport RAC, especially those related to existing water quality
impairments such as fecal coliform contamination and low dissolved oxygen levels.
Recommended Actions:
Develop and distribute a County -wide brochure for the public that addresses stormwater
pollution issues and what homeowners can to do to help solve them. Ensure it covers those
issues specific to the Hoodsport RAC, including the benefits of low impact development
(LID). Consider the use of the Puget Sound Partnership's recently updated general education
brochure on LID, which is available at no charge on its web site.
SWMP Element #2—Public Involvement and Participation
Develop and implement a pubhc involvement and participation program to create ongoing
opportunities for the public to participate in the decision making processes involved in the
development, implementation and update of the SWyIP and make all program documents
available on the County website.
Applicability.
Public involvement and outreach is vital to the success of stormwater management and
compliance with regulations There is an increasing realization that government programs
with hmited resources cannot do the job alone and that citizens share the responsibility of
finding, funding, and implementing solutions to local stormwater problems. It is equally
important to keep the public informed about program goals, objectives, priorities, available
resources, and strategies.
Recommended Actions:
H ngage the local stakeholders of the Hoodsport in SWM planning and implementation
within the Hoodsport RAC. Organize volunteers to assist in the development of a Stream
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Section 8—SWM Plan: Programmatic Elements and
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Team for Finch Creek and Hill Creek, regional surface water management water quality
monitoring, and facility inventory and mapping.
SWMP Element #3—Illicit Discharge Detection and Elimination (IDDE)
Develop and implement an ongoing program to detect and remove illicit discharges and
spills to the County's stormwater system. The program needs to include system mapping, an
ordinance to prohibit such discharges that includes escalating enforcement procedures and
actions, field assessment procedures and activities, and procedures for characterizing
discharges, tracing sources, notifying the appropriate parties, and removing sources.
Applicabiliy:
Due to the small amount of stormwater infrastructure within the Hoodsport RAC and the
relatively high expense of program development and implementation, this element is not
being considered for the Hoodsport SMW Plan at this time. If spills or obvious pollution
does occur these should be reported to Ecology for cleanup and possible enforcement
activities.
Recommended Actions:
Illicit discharge and spill education is a topic that can be incorporated into products
developed under SWMP Public Education Element #1 An element of the IDDE
requirement that would be useful in the short-term is an accurate inventory of facilities and a
survey of key drainage facilities electronically recorded in the County's GIS/mapping system.
This could be done in annual increments over the next few years.
SWMP Element #4 Controlling Runoff from New Development, Redevelopment and
Construction Sites
Develop and implement a program designed to reduce pollutants in stormwater runoff. The
program needs to include a stormwater runoff control ordinance that allows the use of low
impact development (LID) and specifies site plan review and permitting processes. It also
needs to establish maintenance standards and regulations to enforce long term operations
and maintenance of facilities.
Applicabiliy:
The County currently operates under an existing stormwater runoff control ordinance and
conducts development review and inspection activities for new development, redevelopment
and construction sites. The County recently worked with the Puget Sound Partnership under
its LID Local Regulation Assistance Project to develop recommendations on how to
incorporate the use of LID into its existing regulations. A draft ordinance was developed and
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Section 8—SWM Plan: Programmatic Elements and
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is currently under internal County review The County is also considering the adoption of the
Ecology 2005 Manual using a phased approach that focuses on the more urban and
urbanizing areas of the County.
Recommended Actions:
For the Hoodsport RAC, the County needs to update its current SWM ordinance and adopt
standards that are consistent with the requirements of the 2005 F cology Manual, and
support the use of LID for new development. To do this, additional training on 2005
Ecology Manual and LID, will likely be required for both County staff and local developers.
SWMP Element #5—Pollution Prevention & Operations/Maintenance for Municipal Operations
Develop and implement an operations and maintenance program designed to prevent or
reduce pollutant runoff from municipal operations. The program needs to include
establishment of maintenance standards, policies and procedures, inspections, maintenance
practices, staff training, and recordkeeping.
Applicability:
Due to the small amount of stormwater infrastructure within the Hoodsport RAC and the
relatively high expense of program development and implementation, enhancement of the
County's existing level of maintenance is not being recommended for the Hoodsport SWM
Plan at this time, except at known problem areas such as;
• N. North School House Road, and
• North Finch Creek Road.
Recommended Actions:
Review the adequacy of current annual maintenance practices and their effectiveness.
Annually review and update their effectiveness to improve water quality.
Maintain the County s existing level of maintenance effort within the Hoodsport RAC;
enhance frequency of inspection and maintenance of known problem areas, as discussed in
Section 7.
SWMP Element #6—Stormwater Management Program Implementation
Develop and implement a stormwater management program (SWMP) consistent with permit
requirements. to the Hoodsport RAC The SWMP needs to include program cost tracking
and coordination mechanisms and be designed to reduce the discharge of pollutants to the
Maximum Fxtent Practicable (MEP), meet All Known, Available, and Reasonable methods
of prevention, control and Treatment (AKART).
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Section 8—SWM Plan: Programmatic Elements and
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Applicability:
The County is not yet subject to the NPDFS Phase II permit requirements however, it
understands the value of tracking SWMP implementation activities for the purposes of
annual reporting, so that the) can be used as part of an adaptive management strategy to
help annually measure the effectiveness of the SWM Program.
Recommended Actions:
Develop and implement a routine tracking system for County SW_VIP implementation that
includes the SWM activities associated with the Hoodsport SWM Plan Evaluate annually
using adaptive management and make annual refinements as needed.
SWMP Element #7—Total Maximum Daily Load (TMDL) Allocations
Th.e Phase II permit requires compliance with established TMDLs identified in Appendix 2
of the permit.
Applicability:
There currently are no established TMDLs for the receiving waters within the Hoodsport
RAC; however, there are depressed dissolved oxygen and elevated fecal coliform
concentrations along the shoreline of Hood Canal, according to Ecology and County
Department of Health reports.
Recommended Actions:
Strategies to protect surface waters from water quality degradation are included in
recommended actions of other SWMP elements, including the adoption of the 2005 Ecology
Manual and development/adoption of an LID ordinance Local water quality monitoring of
major outfalls has been recommended in SWM Element #12 to assess impacts of
stormwater and the effectiveness of existing SWM controls and practices.
Note that current discussions are underway for the County to develop, fund, and implement
a countywide program to retrofit the runoff from existing development using bio-retention
and other LID types of facilities. The Hoodsport RAC, along with the GMA areas of Allyn
and Belfair are being targeted as high priority areas for this type of water quality
enhancement program. (Constructing one of these types of LID facilities within the
Hoodsport RAC would cost about $40K per 3 ear; the design and construction of a couple of
these facilities within Hoodsport RAC may be possible using the funds within the $750K
grant recently received by the County from Ecology.)
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SWMP Element #8—Monitoring (of SWM Program)
The Phase II permit requires an assessment of the appropriateness of best management
practices (BMPs) in the SWMP and any changes made or proposed to those previously
selected It also specifies steps to be taken in preparation for future stormwater monitoring
in the next permit cycle, which starts in 2012.
Applicability:
Annual assessments of the appropriateness and effectiveness of the BMPs to be
implemented as part of the SWMP are recommended as part of the tracking and evaluation
activities identified in SWMP Element 6—Stormwater Management Program
Implementation Water quality monitoring is also addressed in SWMP Element #12.
Recommended Actions:
As the Countywide SWM Program is established over the next several years, an annual
monitoring program to review the effectiveness of individual SWMP activities should be
established, the SWMP modified as needed on an annual basis using the principals of
adaptive management.
SWMP Element #9—Reporting
The Phase II permit requires that permittees submit annual reports that include its SWMP,
formal report forms that summarize the status of implementation, progress toward meeting
minimum performance standards, and description of activities, an implementation schedule
and a summary of its SWMP evaluation.
Applicability:
The County is not -yet subject to these requirements of the Phase II permit, however, as
mentioned in SWMP Element #6—Program Implementation, there is value in the tracking
of SWMP implementation activities for the purposes of annually evaluating SWM Program
effectiveness. The annual SWM Program effectiveness evaluation could also be used as part
of an adaptive management strategy to help document the effectiveness of the existing SWM
Program. Annual reports are also useful for informing the public and elected officials of
implementation progress and results.
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Section 8—SWM Plan: Programmatic Elements and
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Recommended Actions:
Develop and implement an annual internal reporting system for County SWM Program
implementation that includes the SWM activities contained within the recommended
Hoodsport SWM Plan. Review and refine the program annually using adaptive management.
Required for Consistency Between NPDES II and PSWQMP
Note that the requirements of the NPD N S II Permit are similar in many ways to the
requirements of the PSWQMP However, there are elements that are specifically stated in
the PSWQMP that are not specifically spelled out in the Phase II Permit. These include
conducting watershed or basin planning, creating adequate local funding, and implementing
annual water quality monitoring to assess program effectiveness. To ensure consistency of
the County's response to the various stormwater requirements, the following three elements
from the PSWQMP should also be included in the recommended Hoodsport SWM Plan.
Similar to the above permit requirements, those listed below within SWMP Elements 10, 11,
and 12, should also be included in the recommended SWMP for the Hoodsport RAC.
SWMP Element #10—Watershed or Basin Planning
The PSWQMP calls for the use of watershed or basin planning processes to identify and
rank existing problems that degrade water quality aquatic species, habitat, and natural
hydrological processes; this element of the Plan also calls for the development of action
plans/schedules, along with the identification of funding strategies to fix local drainage
problems.
Applicability•
The development of the Hoodsport SWM Plan fulfills this requirement since it based on
both basin characterization and problem assessment within the Hoodsport RAC. Both
capital and programmatic recommendations are included in the recommended Plan, together
with implementation costs, schedule, and funding strategy to address regulator) SWM
obligations and water quality and habitat needs.
Recommended Actions:
This Hoodsport SWM Plan and the County's larger evaluation of its SWM needs and
funding is consistent with this requirement. Implementation of the recommended actions
described in the various SWMP Elements presented in Section 8 demonstrates the initial
benefits of conducting local basin planning.
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Section 8—SWM Plan: Programmatic Elements and
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Continued
SWMP Element # 11—Funding
The PSWQMP calls for the creation of funding capacity, such as a utility, to ensure adequate,
permanent funding for SWM program activities and regional stormwater projects.
Applicability:
Developing and maintaining an adequate level of annual local funding is the key to the long-
term success of the program and the support of an effective capital improvement program.
Creating adequate local funding is the focus of the financial analysis presented in the
following section
Recommended Actions:
Work with local citizens to create a stormwater management utility throughout the
Hoodsport RAC (and urban areas throughout the County). Also explore the development of
a system development charge for new development and redevelopment to help the County
off -set some of the costs of building the larger regional conveyance systems and water
quality treatment systems that will be needed in the future.
SWMP Element # 12—Water Quality Monitoring
The PSWQMP calls for monitoring of program implementation and environmental
conditions and trends over time to measure the effectiveness of program activities and to
share the results with others.
Applicability:
The need for program effectiveness and water quality monitoring within the Hoodsport
RAC is discussed in SWMP Elements #6 Program Implementation, #7—TMDLs, and
1# 8Monitoring as well as in Section 8.5 Water Quality, Habitat, and Shellfish Needs.
Recommended Actions:
Implementation of an annual monitoring program (programmatic in nature; i.e. not
involving any water quality monitoring) to track progress and assess effectiveness is
recommended, as described in the various SWMP Flements and as presented in Section 8, is
recommended.
At this point in time, consistent with the Allyn and Belfair SWM Plans, water quality
monitoring will consist primarily of documenting the effectiveness of LID retrofit facilities
that are being designed to treat existing runoff.
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Section 8—SWM Plan: Programmatic Elements and
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In the future, as funding allows, water quality monitoring of major outfalls, as well as the
effectiveness of annual maintenance and development review practices, should be
considered by the County. This monitoring pro:ram should be annually tailored to focus on
local flooding problems and water quality priorities, if local TMDLs have not been
established by Ecology.
8.5 Guidance for Future Development/Redevelopment
The County's existing design criteria for stormwater are based largely on the 1992 h,cology
Manual. When the County was more rural that level of treatment may have been adequate,
however as urban centers have emerged throughout the County pollutant loadings have
increased and impacts to water quality fish habitat, and shellfish rearing areas have been
documented. It is widely understood that untreated or inadequately treated surface water
runoff, particularly from the more intensely developed areas, may be a major contributor to
these problems in local receiving waters.
Adoption and the routine use of the most current design criteria are needed to reduce the
loadings of additional pollutants from new and redevelopment. This SWM Plan for the
Hoodsport RAC has been based on the latest stormwater management techniques, as
described in the 2005 Ecology Manual. It is strongly recommended that the County adopt
these same design standards for all future development and redevelopment within the
Hoodsport RAC, along with the County's proposed LID ordinance.
Recommended SIZM Plan: Programmatic Hlements
Adoption of the 2005 Ecology Manual and LID ordinance is strongly recommended to
address both local flow and potential water quality related problems.
8.6 Regional Water Resource Planning
As summarized in Section 1.5 there are a number of planning initiatives underway within the
region that collectively influence the development and implementation of policy and
regulation related to water resource management that are discussed below.
e The Washington State Department of Ecology conducts water quality assessments
and categorizes water bodies depending on water quality conditions. These
assessments are published in hcology's 303(d) list and generally show elevated
concentrations of coliforms and other pollutants being generated within urban areas
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•
Section 8—SWM Plan: Programmatic Elements and
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Continued
and being discharged directly into local receiving waters with little to no advance
water quality treatment.
The Washington Department of Health, Office of Shellfish Programs also conducts
water quality monitoring of shellfish growing areas for the purposes of classification.
Many historical shellfish rearing areas, both commercially and recreationally, are
being impacted by stormwater runoff, including the Annas Bay and Oakland Bay
areas where shellfish harvesting has been curtailed due to elevated coliform
concentrations.
• In the Hoodsport area, along with other areas of Puget Sound, salmon recovery
planning has been conducted by the Shared Strategy for Puget Sound This is a
voluntary coalition of federal, tribal, state and local governments and business and
environmental organizations that is working to protect and restore regional salmon
populations. The National Marine Fisheries Service (NMFS) of the National Oceanic
and Atmospheric Administration (NOAA) has worked with the Shared Strategy to
produce a recovery plan for Puget Sound Chinook that was adopted on January 19,
2007. The Puget Sound Salmon Recovery Plan is built on the foundation of fourteen
local watershed planning areas across Puget Sound, with a tailored approach for
recovery based on local characteristics.
To coordinate government actions for protecting and restoring Puget Sound, the
Washington State legislature enacted Chapter 90.71 RCW, Puget Sound Water
Quality Protection Under this authority, the state developed the Puget Sound Water
Quality Management Plan, which is the state's long-term strategy for managing and
protecting the Sound and coordinating the roles and responsibilities of federal, state
and local governments. Each biennium a work plan is developed (2007-2009 Puget
Sound Conservation Recovery Plan) that prescribes the necessary federal, state and
local actions needed to maintain and enhance Puget Sound water quality.
• The Puget Sound Action Partnership defines, coordinates, and implements
Washington State's environmental agenda for Puget Sound and has been providing
leadership in the area of low impact development (LID) LID is a more
environmentally sensitive approach to developing land and managing stormwater
runoff. Many jurisdictions in Puget Sound are turning to LID techniques to help
protect their waters and natural resources. Between 2005 and 2006, the Puget Sound
Action Team lead a project to help twelve cities and seven counties, including Mason
County, integrate low impact development into their regulations and development
standards. A draft ordinance was developed for Mason County and is currently under
review.
• The Watershed Planning Act (RCW 90.82) provides local governments a framework
and resources for developing local solutions to watershed issues on a watershed
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Section 8—SWM Plan: Programmatic Elements and
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Continued
basis. The watershed plans are required to address water quantity with optional
elements of water quality, habitat, and flood control. The Hoodsport RAC is located
within Water Resource Inventory Area (WRIA) 16, the Skokomish-Dosewallips
watershed A draft watershed plan for WRIA 16 has been developed, but has not yet
been approved by all parties, and is currently awaiting implementation.
Summary of Recommended SWM Plan: Programmatic Elements
The County plans on taking the initiative to develop a comprehensive stormwater
management program for the Hoodsport RAC that involves a programmatic approach to
stormwater management as described in the PSWQMP, that includes the enhancement of
development criteria (by the adoption of the Ecology 2005 Manual and an LID Ordinance),
as well as the enhancement of annual maintenance procedures and practices, as described in
this SWM Plan. The County will continue to participate in regional coordination efforts and
in making additional SWM program enhancements in a phased approach, as more
knowledge of the relationship of stormwater discharges to local and regional receiving waters
is acquired.
8.7 SWM Programmatic Elements: Priorities and Costs
Recommended SWM Programmatic elements listed above have been summarized along with
annual costs in Table 8-1. These activities represent an enhancement of the County's existing
SWM Program within the Hoodsport RAC. They emphasize the need to control/guide new
development enhance maintenance where needed, conduct annual program monitoring, and
initiate a local public involvement/education program. Annual costs for these SWM
Programmatic Elements averages about $70,000 per year, and are addition to resources the
County is planning to spend within the Allyn and Belfair UGA areas, as part of the initial
phase of the development, implementation, and funding of the County -Wide SWM
Program.
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8-1
Recommended
SWM
Programmatic
Elements
and
Costs
Table
SWMP
Element
Recommended
Action
Satisfies
Program Needs
Costs ($
I,000's)
PSWQMP
NPDES
Phasell
Permit
Habitat
Shellfish
WQ
Yr
I
Yr 2
Yr 3
Yr 4
Yr 5
Yr 6
Total
I
Public
- SWM
Education*
(LID)
Brochure
X
X
X
$5
$5
$5
$5
$5
$5
$30
2
Public
-
Organize
Involvement*
Volunteers/Mtgs
X
X
X
$
I 0
$
I 0
$10
$
I 0
$
I 0
$
I 0
$60
3
Illicit
-
Facility
Discharges
Inventory
(IDDE)
&
Mapping
X
X
X
$0
$
I0
$
I0
$
I0
$0
$0
$30
4
New
-
-
Ordinance
Ordinance
Development
-
-
DOE
Manual
X
X
X
$0*
$0*
$0*
$0*
$0*
$0*
$0*
05
LID
-
-
Training
Training
- 05
- LID
Manual
X
X
$0*2
$0*2
$0*2
$0*2
$0*2
$0*2
$0*2
5
Maintenance
-
Annual
(Inc.
Enhancements)
X
X
X
$25
$25
$25
$25
$25
$25
$150
6
SWM
-
Develop
Program*
Tracking
Implementation
System
X
X
$5
$5
$5
$5
$5
$5
$30
- Annual
Program
Evaluation
X
X
$5
$5
$5
$5
$5
$5
$30
7
TMDLs
X
X
$0
$0
$0
$0
$0
$0
$0
8
SWM
(Addressed
Program
in
Monitoring
#6)
X
X
$0
$0
$0
$0
$0
$0
$0
Element
9
Reporting*
(Internal)
X
$5
$5
$5
$5
$5
$5
$30
10
Basin
(Part
Planning
of
current Co. study.)
X
X
$0*
$0*
$0*
$0*
$0*
$0*
$0*
II
Funding
-
Develop
SWM
Utility
X
$0*
$0*
$0*
$0*
$0*
$0*
$0*
- SDC
Feasibility
Study
X
$0*
$0*
$0*
$0*
$0*
$0*
$0*
12
WQ
- Annual
Monitoring
WQ
Monitoring
X
X
$5
*3
$5
*3
$5
*3
$5
*3
$5
*3
$5
*3
$30
Total:
$60
$70
$70
$70
$60
$60
$390
*Future
County Staff
(— 0
FTE)
$0*4
$0*4
$0*4
$0*4
$0*4
$0*4
$0
Outside
Services
$5
$5
$5
$5
$5
$5
$30
Total Annual
Budget
$65
$75
$75
$75
$65
$65
$420
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* - Activity included in the development and implementation of the Countywide SWM Program; no
additional funding needed at the local planning level
*2 — Development Review labor is paid by developer fees; no additional county funding is required.
*3 — The emphasis of the water quality monitoring program is to evaluate the effectiveness of water
quality retrofit bio-retention facilities installed in road right of ways to treat existing runoff. Labor for
WQ monitoring of these facilities to determine their effectiveness will be provided by volunteers;
costs included are primarily for laboratory related analyses.
*4 — County staffing required to administer the Hoodsport annual SWM Program would be included
in the administration and management of the County -wide SWM Program; approximately $15K, (or
about 0.20 P1 E , equivalent to 400 hours, or about 10 weeks per year), has been set aside for annual
tracking, program evaluation, and reporting in SWM Elements #6 and #9.
Recommended SWM Plan: Summary of Elements and Costs
It is suggested that the programmatic SW_VI elements identified above be developed and
integrated with the proposed capital improvements proposed to create a Comprehensive
Stormwater Management Plan for the Hoodsport RAC Total SWMP costs for the next six
years, including both capital and programmatic needs, amount to $843,000. Annual SWM
costs are about $140,000, $70,000 per year for the SWM programmatic elements, as shown
in Table 8-1, and $70,000 per year for the capital elements, as shown in Table 7-2. Annual
costs and funding analysis are presented in the implementation plan presented in the
following section.
Recommended SWM Plan: Integration with Countywide SWM Program
The funding and implementation of the Hoodsport SWMP is only one aspect of a much
larger, integrated countywide SWM Program that is currently under consideration The
concept of the County is to develop a comprehensive SWM Program throughout the County
over the next five years The program would initially focus on the most urbanized areas,
including the Allyn and Belfair Growth Management Areas and the rural activity centers of
Hoodsport and Taylor Town I and II
The program, complete with the adoption of the 2005 Manual and a Low Impact
Development Ordinance, along with the generation of local funding, such as a stormwater
utility, would be implemented by phasing in stormwater management requirements annually,
according to the following five phases:
• Phase I — Allyn and Belfair Urban Growth Areas
• Phase II — Hoodsport and Taylor Town I and II Rural Activity Centers
• Phase III — Water Quality and Shellfish Sensitive Areas
• Phase IV — Shoreline areas
• Phase V — The remaining unincorporated areas of the County
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Section 8—SWM Plan: Programmatic Elements and
Regulatory Compliance
Continued
As noted above in the listing and estimate of SWVI Programmatic costs for the Hoodsport
SWMP, many of the administrative and management costs of the Hoodsport SWMP will be
supported by the larger, centrally funded Countywide SWM Program. The Countywide
SWM Program would be supported by dedicated SWM staff that would be responsible for
the Hoodsport SWMP, as well as the administration and implementation of SWM planning
throughout the County.
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Section 9—Costs, Funding and Implementation
9.1 Introduction and Overview
The intent of this section is to address the annual revenue needs identified in the
recommended SWM Plan for the Hoodsport RAC.
• The first part of this analysis combines the capital and programmatic SWM needs, as
identified previously in Sections 7 and 8 respectively, so that total annualized costs
can be identified in Section 9.2.
• Section 9.3 summarizes the short and long term SWM program and capital needs,
and presents annualized costs to revenue needs for the next six years.
• Funding alternatives are reviewed and preferred revenue options and
recommendations are selected and presented in Section 9.4.
• Section 9.5 assesses the adequacy of potential revenue sources and identifies revenue
gaps that may be anticipated in the future. The funding analysis concludes with an
evaluation of the adequacy of the proposed revenue sources to address the future
stormwater management needs within the RAC.
9.2 Recommended Hoodsport SWM Plan: Funding and Implementation
Hoodsport SWM Plan: Program Elements, Priorities, Schedule and Costs
Annual Revenue Needs
The Comprehensive SWM Program for the Hoodsport RAC has been created by integrating
the capital needs/costs identified in Section 7 with the programmatic and regulatory
compliance needs/costs presented in Section 8. The recommended plan includes a
combination of programmatic activities and capital improvement projects over the next six
years, 2009 to 2012.
• Total SWMP costs for the next six years, including both capital and programmatic
needs, amounts to $840,000 or about $140,000 annually.
• Capital projects consist of four projects that total $423,000 (rounded to $420,000), or
about $70K annually. (Note that these costs do not include water quality tetrofitprojects; the
retrofit projects will be included in the County -wide Stormwater Management Program.)
• Programmatic and regulatory compliance needs include various activities ranging
from public education/involvement to SWM Program monitoring, and include the
adoption of new ordinances, development of new funding mechanisms, completion
of inventory and GIS mapping of existing drainage facilities, along with a number of
other SWMP activities Programmatic costs have been estimated to be $420,000 over
the six years or about $70,000 annually.
The funding/revenue needed to implement the recommended SWMP for the Hoodsport
RAC is presented below in Table 9-1.
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Section 9—Costs, Funding and Implementation
Continued
Plan
Stormwater
Management
Plan
for
Hoodsport
Table
9-I—Financial
the
Annualized
Revenue
Needs
Over the
Six Year
Planning
Period
Priority
for
Schedule
& Costs by Years
($1000s)
Relative
Implementation
I
2
3
4
5
6
Total
SWM
Programmatic
$65
$420
Needs
$65
$75
$75
$75
$65
$420
SWM
Capital
Needs
$70
$70
$70
$70
$70
$70
Total*
$135
$145
$145
$145
$135
$135
$840
*Average Annual SWM cost for years #1 6 is $420K/6 years =
per year.
Funding Analysis
Presented in Table 9-1 is an estimate of the cost of the recommended SWM Plan for the
Hoodsport RAC. New revenue is needed over the next six years to support programmatic
initiatives, as well as over the next 20 or more years to support both future programmatic
and capital projects that will be needed to support ultimate buildout.
SWM Policies Guide Selection of Financial Options
The SWM management pohcies and approaches preferred by the County, as presented in
this plan, play a large role in determining the funding strategies to implement the proposed
SWM Plan for the Hoodsport RAC. In general the proposed funding strategy has been
guided by the following policies and technical decisions that have been created to manage
stormwater within the Hoodsport RAC
• Low impact development will be required for all new development and
redevelopment.
• No regional detention facilities will be created to accommodate either existing or
future development; if needed, detention will be provided onsite by each new
developer on an as needed basis.
• New development/redevelopment will pay for the cost of onsite water quality
treatment (per the adoption of the 2005 Manual by the County).
• New development/redevelopment may help pay for future regional conveyance
facilities, as/if needed to support future growth through the establishment of SF PA
mitigation and system developer charges.
• There are currently no major flooding or maintenance problems associated with the
current drainage system within the Hoodsport RAC.
• Retrofitting existing homes and businesses for detention or water quality treatment
has not been included at this time, but is currently being considered as part of the
County's new stormwater grant from F cology.
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Section 9—Costs, Funding and Implementation
Continued
As the County builds new roads within the RAC the County will design and pay for
some new water qualities retrofit systems that will be located within the County road
right-of-ways to collect and treat road runoff.
Review and Evaluate Potential Funding/Revenue Options
Discussions with the County suggest that there are several financial options that should be
considered to fund stormwater management within the Hoodsport RAC. A preliminary
review of these potential funding sources suggests that multiple sources of funding will likely
be needed; no single source of funding will likely be adequate by itself. Funding sources that
are currently being considered include:
• Formation of a Local Drainage/Stormwater Improvement District, which
would have an annual assessment usually based on assessed property value, or some
other equitable means of establishing value and/or benefit to the various rate payers.
• Real Estate Excise Tax (REET) Funding, which currently amounts to about
$750K per year for the County and is currently being used to pay for a number of
capital projects throughout the County. Securing periodic appropriations from
REET funding for either capital or program needs may be available on an annual
basis depending on other County project priorities.
• Annual County Portion of State Sales Tax, which has recently been raised from
.08% to .09% this will amount to about $450K per year for the County with the
recent increase to 0.09 per cent.
• Public Sector Funding. such as grants and low interest loans from the State
(Ecology or the Puget Sound Partnership) or federal government, including federal
319 Water Quality Grants, and the State Public Works Trust Fund and State
Revolving Fund. While available, they potential funding sources are generally limited
in duration and amount. They are also very competitive and have limitations
regarding timing, applicability reporting, and administrative costs.
• Formation of a Local Stormwater Utility throughout the Hoodsport RAC where
a monthly service fee is assessed to rate payers, often based on the amount of
impervious area per parcel.
• Continued collection and use of developer fees to review and approve plans for
new development and re -development, as well as conducting inspection and
enforcement in the field
• System Development Charges (SDCs), where any person moving into an
upstream drainage area by the purchase of a home would be required to pay for a
portion of the downstream collection, conveyance, detention, treatment, and outfall
facilities that may be needed to support continued development within the drainage
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•
es
•
Section 9—Costs, Funding and Implementation
Continued
basin. These would be assessed to the developer prior to the construction of the
home during the County's permitting process.
SEPA Mitigation Funds, which would be established on a per development basis
as a project enters and is ultimately approved through the State SEPA review
process. This has historically been used very successfully by the County for
additional infrastructure that has directly resulted from new proposed development/
redevelopment.
Partnering with prospective developers, land owners and other State agencies can
be especially effective in establishing funding for larger regional drainage facilities.
These are usually project -specific types of funding agreements based on use or
contribution of stormwater runoff.
Other potential, but less likely sources of direct internal county funding`
include the General Fund, Road Fund, Park Fund and the Utility (Sewer) Fund;
however, these funds are perhaps best used as potential sources for the joint funding of
projects with common community purposes.
From this list of ten potential sources of funding, the most likely sources of new future
funding for SWM within the Hoodsport RAC in relative order of priority, are the following:
1. Forming a Stormwater Utility to support programmatic SWM activities.
2. Ensuring developer and permit fees are adequate to support development review,
inspection, and enforcement services.
3. Using project related SEPA mitigation funding to support capital projects,
especially those required by an increase in capacity within a regional conveyance
system.
4 Establishing System Development Charges for new growth -related capital
drainage projects; this is also another good source of funding for regional
conveyance and/or treatment systems.
5. Annually appropriating a portion of Annual State Sales Tax Returns.
6. Securing periodic appropriations from REET funding for either capital or program
needs.
7. Obtaining capital project funding, from Future Road, Park, and/or Utility
Projects, with common objectives that include stormwater management
opportunities.
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Section 9—Costs, Funding and Implementation
Continued
Estimate of Potential Annual Revenues
Funding Source #I. Stormwater Utility
Type/Source of Funding: A monthly service fee to residences and businesses based on the
amount of impervious area on each parcel. Rates are usually in the $6-$12 per month per
equivalent rate unit (ERU).
Allowed Uses: These funds can be used for both capital and programmatic needs
H stimated Annual Amount: $27, 000
Assumes: 300 ERUs* in the Hoodsport RAC at $7.50/mo X 12 months = $27,000 per year;
utility funding is good for both programmatic and capital costs.
*Note that ERU estimates are conservative; the actual HRU count may be as high as 350 or more,
depending on future impervious area measurements. This would allow projected rates to be reduced or capital
project funding to be accelerated.
Funding Source #2. Developer and Permit Fees
Type/Source of Funding: These are the fees that developers pay for plan and permit review and
approval by the County. These generally entirely paid for by developers with little to no
subsidies from the County. These funds reimburse the County for development review staff
time, as well as field time in the field during construction for inspection and enforcement.
Allowed Uses: Reimburses County for staff time, has limited direct cash value to SWM
Program.
Hstimated Annual Amount: $0 directly to SWM Fund (usually goes into the General Fund).
These revenues support the SWM effort and pay for some of the regulatory comphance
costs but generally do not provide additional cash that can be used for other programmatic
or capital needs.
Funding Source #3. SEPA Mitigation
Type/Source of Funding: These are payments made by developers to the County to mitigate the
impacts associated with new development. These payments are usually project specific and
are often used to provide additional supporting infrastructure such as access roads, or
lighting, or downstream flow attenuation, or wetland impact mitigation
Allowed Uses. Usually these payments go toward new capital facilities; normally not useful for
addressing programmatic costs.
HstzmatedAnnual Amount: About $20,000 per year. (The annual amount is difficult is predict
since the County does not have a long history to track these types of payments.)
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Section 9—Costs, Funding and Implementation
Continued
Funding Source #4. System Development Charges
Type/Source of Funding: These are specific payments that developers make to support drainage
utilities and infrastructure within the region. They are common to support the extension of
roads and water and sewer services to new developments. Lately, they have been growing in
popularity and are used in the development of new revenue to help pay for new capacity in
detention, treatment, conveyance capacity, and outfall drainage systems. Similar in some
ways to a SW -VI utility in establishing a unit price for each residential unit, usually about
$400-$600 per home, with new commercial developments paying more based on a measured
number of equivalent residential units
Allowed Use: These funds areprimarily used of future capital improvements associated with future growth.
H stzmated Annual Amount.: $3, 000 peryear (over the next six years)
Assumes:
® 20 homes X $600/home = $12,000/6 years = 2,000 per year
® 10 business units X $600/unit = $60,000/6 years = $ 10,000 per year
Funding Source #5 Sales Tax Returns
Type/Source of Funding: These funds are provided to the County from the State based on a
formula that distributes a portion of the State sales tax returns back to local governments.
Recently, the per cent return has increased from 0.08 to 0.09% annually this amounts to
about $450K.
Allowed Uses: Could be used to address either capital or programmatic costs.
list:mated Annual Amount.: $20,000
Funding Source #6: REET Funding
Type/Source of Funding: A portion of annual real estate sales throughout the County, as
determined by the local real estate tax, are annually returned to the County. This currently
amounts to about $750K per year.
Allowed Uses: These funds could go right into the SWM Fund for either capital projects or
programmatic needs.
F stimated Annual Amounts About $20,000
Funding Source #7. Road, Park, Utility Common Capital Projects
Type/Source of Funding: When other departments of the County build capital projects, a
portion of their project often is needed to address local drainage related impacts and needs.
Some times these types of projects provide direct funding to SWM to build projects or the
SWM fund could contribute to create larger drainage related projects that have regional
benefits. A good example is when the Road Fund builds future roads in Hoodsport; the
Road Fund will likely be used to pay for portions of the regional conveyance collection
and/or treatment facilities proposed in the Hoodsport SWM Plan.
Mason C o unty — H o o d s p o r t RAC S t o r m zv a t e r Management Plan 100
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Section 9—Costs, Funding and Implementation
Continued
Allowed Uses: Primarily for capital project assistance.
Estimated Annual Amount° Estimated to be about t10K-$30K per year.
Summary of New Potential Annual Revenue Sources
(Creation of Multiple Funding Sources to Realite Needed Revenue)
By optimizing the revenue potential of the proposed SWM funding mechanisms,
approximately $110,000 - $130,000 may be realized on an annual basis to support the
development and implementation of the Hoodsport RAC SWM Plan, as shown in Table 9-
2. Approximately $67,000 in annual programmatic funding and $100,000 to $120,000 in
annual capital funding could be realized from these sources.
Table
9-2
Potential
SWM
Funding
Sources and
Estimated
Annual
Revenues
Funding
Source
Potential
Estimated
Annual
Revenue
Amount
Programmatic
Capital
$27,000
X
Ok
for either
#1:
Stormwater
Utility
$0
---
#2°
Developer
and
Permit
Fees
$20,000
---
X
#3°
SEPA
Mitigation
$12,000
---
X
//4:
System
Development
Charges
$20,000
X
Ok
for either
#5:
Sales
Tax
Returns
$20,000
X
Ok
for either
#6:
REET
Funding
$10K
-
$30K
---
X
#7:
Project
-Specific
Funding
Annual
Total*
r4110K-$130K
�$67K
�$100K-$120K
Adequacy of Potential Future Funding Mechanisms
'Matching Available Funding with the Revenue Needs of the Implementation Plan)
Assessment of Proposed Stormwater Management Funding Strategy
The proposed Hoodsport SWM Plan totaling averaging $140,000 over each of the next six
years is a reasonable level of funding that matches the local drainage needs, as well as the
County's and community's ability to pay.
As shown in Table 9-2, estimated annual revenues from the above listed funding sources
totals about $110K to $130K pet year. With the annual capital appropriation of $70,000, the
total average annual level of funding needed over the next six years is $140,000, and closely
matches available resources, projected in above in Table 9-2.
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Section 9—Costs, Funding and Implementation
Continued
While the overall funding is about $10K-$20K short per year, it is suggested that there is
adequate funding for the $70K needed per year for the programmatic SWM activities, and
about $50K-$60K per year for capital projects. If the four capital projects are completed
over an eight year period rather than a six year period, the proposed level of funding would
be adequate to meet the needs of the proposed Hoodsport SWM Program and this
Hoodsport SWM Plan. Alternatively, in order to build the proposed capital projects within
the next six years, the County may choose to prioritize the $70K to the capital projects and
appropriate the $50K to programmatic SWM activities.
(Note that this initial funding analysis has not estimated any annual increases in the amount of annual
funding available from each of the seven proposed funding mechanisms. It is likely that future funding f om
these sources will increase along with the increased annual funding needs of the Hoodsport SIVM Program.
Also, new funding mechanisms may present themselves as the SWM Program is implemented. For example,
future grants would be an excellent way to augment these local funding mechanisms and should be actively and
aggressively pursued. Additional funding analyses may be needed to substantiate and further refine this
conceptual fundingplan, as the various proposed funding mechanisms are developed, approved, and
implemented.)
9.6 Findings and Conclusion
The Hoodsport RAC area is a unique geographic environmental, and cultural area of Mason
County. This SWMP has been prepared to fix deficiencies within the drainage infrastructure,
assess proposed land uses and develop guidelines for new development, and assist the
County in addressing existing and future regulatory requirements. In the course of doing this
a financial plan has been developed to facilitate implementation with the primary intent of
protecting and maintaining the unique water quality and habitat functions of the region.
Consistent with the State's Growth Management Planning process, this Stormwater
Management Plan for the Hoodsport Rural Activity Center demonstrates that here is
adequate local funding to develop and maintain the needed drainage infrastructure and
associated SWM Program, as required to support continued economic development within
the Hoodsport RAC.
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Section 10—Public Review and Approval
10.1 Public Involvement Process
Meet and Greet with the County and the Port of Hoodsport
Mason County is planning an open house style of public meeting to review and receive
comment on this proposed SWM Plan, with its proposed capital projects and funding
sources. The public meeting and will be held in the Mason County conference room, located
in the same building as the Board of Commissioner's meetings. This public meeting will be
followed by a formal public meeting, to be held approximately two months after the public
meeting.
Hoodsport Stormwater Questionnaire
In addition to the public meeting and public hearing, Mason County conducted a drainage
survey for the Hoodsport Rural Activity Center and surrounding areas. The results of this
survey were reviewed and used in the development of this Stormwater Management Plan.
Participation in this survey was voluntary A copy of the questionnaire and more detailed
results are included as Appendix B. The surveys were sent out to all Hoodsport addresses
and therefore covered areas that are outside of the RAC. The County received 103 filled out
questionnaires.
10.2 Public Meeting
A public meeting was held on June 19, 2008, at the Hoodsport Timberland Library to
present the draft Hoodsport RAC SWM Plan and receive public comment. Written
comments were received from three agencies, F cology, the Puget Sound Partnership and the
Lower Hood Canal Watershed Coalition (LHCWC). A master comment response matrix
listing all comments and associated responses is included in Appendix F.
10.3 Formal Review and Approval Process
The remaining elements of the formal review and approval process include the following•
Issuance of the draft SWM Plan to the public for additional comment.
Presentation of the draft SWM Plan to the County Planning Commission for
additional discussion, and potential edits and/or revisions.
Presentation to the Board of County Commissioners.
Another public meeting and public hearing to receive additional public comment
prior to final review/approval by the Board of County Commissioners.
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