6.1 PUBLIC INFRASTRUCTURE IMPACTED BY ILLAHEE CREEK
The primary
public infrastructure systems in Illahee are sewer, water, and storm water and
each of these systems is impacted in a significant way by Illahee Creek. As stated in the transportation
chapter, Illahee Creek essentially forces the roadway system to detour one and
a half miles around the creek. This
impacts the water distribution system and especially impacts the sewer systems
in the area as Illahee Creek also provides the general separation boundary
between the city of BremertonÕs sewer basin area and the Kitsap County sewer
basin area. The storm water impact
is one of trying to minimize or mitigate the effects of storm water on Illahee
Creek as a salmon bearing stream.
Because the area
is at near build out conditions no major capital improvement systems are currently
planned for this area for sewers, water, or stormwater. There are nevertheless, some major
issues with sewers, water, and stormwater that need to be resolved by the
community and other governmental bodies.
6.2
SEWER
Kitsap
County provides the sewer infrastructure currently existing in Illahee. Sewer service is provided along the
Wheaton Way corridor and east along McWilliams Road where it serves
developments primarily to the north.
See Figure 6.1. Kitsap
County notes the sewer system has been sized to accommodate growth in the basin
area.
The City of
Bremerton would be the logical provider of future sewer service to the area
south of Illahee State Park and south of Sylvan Way due to formidable barrier
of the canyons of Illahee Creek and the distance and cost to run the sewer
connector lines. This area is
covered by the City of Bremerton in the Trenton Avenue Basin as noted in its
2005 Comprehensive Plan Update.
Because of
the delicate ground water balance situation in this area and the necessity of
groundwater to support baseflows in Illahee Creek, the advisability of sewers
for the area around Illahee Creek is being questioned by the community. Sewers diminish the water recharge of
the basin area and can thereby diminish stream flow. Recent studies note that one proposed development in the
area will decrease the baseflow in Illahee Creek by a minimum of 15
percent. Additionally, when sewer
systems are provided the zoning density increases as does the commensurate impermeable
surfaces, which also diminish groundwater recharge. Other hydrological studies of this area point to the fact
that this area is a recharge sensitive area, and sewers and stormwater runoff
are not supportive of salmon in Illahee Creek.
Goal S-1 Provide the availability
of sewer service to residents within the Illahee Community boundary where sewer
systems already exist and where they are outside critical aquifer recharge
areas.
Policy S-1 Require all new
construction and remodel projects involving an increase in sewage beyond the
existing capacity of the septic system to connect to sewer if within 200 feet
of an existing line.
Goal S-2 Conduct additional
hydrological studies of the critical aquifer recharge areas around Illahee
Creek to determine the appropriate boundaries around the creek and the
recommended policies and procedures necessary to ensure baseflow levels are
maintained.
Policy
S-3 Prohibit,
under this Plan, the introduction of sewers into the critical aquifer recharge
regions of Illahee Creek, until the necessary hydrological studies are
completed.
Policy
S-4 Require
all newly installed septic systems within the critical aquifer recharge area be
capable of returning essentially nitrate free effluent to drain fields.
6.3 WATER
General
The Illahee Community is served by only one water purveyor,
North Perry Avenue Water District.
The Water System Plan (WSP) for the North Perry Avenue Water District
has been prepared in accordance with Washington State Administrative Code
246-290-100 and the Department of Health ÒWater System Planning Handbook, April
1997Ó. The WSP is on file at the
District office located at 2921 Perry Ave NE, Bremerton WA 98310.
History
The North Perry Avenue Water District was formed on November
24, 1942. The original project
consisted of construction of approximately 6.6 miles of water mains along North
Perry Avenue from Riddell Road to Stoneway and adjacent streets. Water supply was purchased from the
City of Bremerton, and a 50,000 gallon tank on a 70 foot tower was constructed
for storage near the corner of Olympus Drive and Sylvan Way. Significant additions to the water
system were made in the 1950s, including additional mains, new wells, booster
station, and storage tank. The
District was expanded to two pressure zones. The Illahee Water District, which operated a small system in
the Illahee area, merged with North Perry in the 1960s, as well as the merger
of a small, private system in the Gilberton area. Negotiations between the District and the City of Bremerton
in the 1970s resulted in an agreement on a joint service area boundary. The agreement was signed in 1976, which
resulted in transferring some customers to establish the current boundary
between the two systems. The
present service area boundary was further defined in 1989 by agreement between
the District and Silverdale Water District No. 16 and with Kitsap County PUD
NO. 1. The District service area
currently covers approximately 12 square miles and has 12 wells in service,
seven storage reservoirs, and more than 82 miles of water main. Figure 6.2 denotes the boundaries of
the service area.
Geography
Most of the
service area is rolling with a ridge running north and south through the
approximate center of the District.
A creek valley cuts through the District in an east-west direction near
Brownsville. The ground elevation
varies from near sea-level at the eastern side of the District to approximately
460 feet at the highest point.
Steep slopes exist in some areas, and several small streams with steep
side slopes intercept the service area.
The occasional occurrence of wetlands restricts building in some
areas. These topographic features
affect the locations of water facilities and the method of serving the
District.
Description
of Facilities/Components
The District service area contains five pressure zones, ten
source wells, two backup wells, and one well that is drilled but not yet in
service. The total sustainable
capacity of the District is 3680 gpm.
Because the raw water quality is so high, the District does not perform
water treatment, but does add chlorine to the water for the purpose of taste
and odor control. There are seven
storage reservoirs, with a current total capacity of 4.75 MG, with 1.898 MG of
standby/fire suppression storage.
There are more than 82 miles of water mains. Much of the older pipe in the District is constructed of
asbestos cement, and recent installations have used ductile iron pipe, with a
typical diameters of 6 or 8 inches.
There are three pump stations.
One inter-tie exists between the District system and adjacent
(Bremerton) systems, used only for emergencies. A significant distance between the District system and other
adjacent systems and the topography of the service area typically makes
inter-ties infeasible.
Related
Plans
Land use planning and coordination of capital facility
planning on a regional basis is the responsibility of Kitsap County. Water facilities are planned to
accommodate and provide for the level of zoning and density included in the
following related plans:
Zoning
and Land Use
The Land use planning for the service area is controlled by
Kitsap County. The northwest part
of the District is zoned for rural medium density, which provides for
relatively large lots for residential use. Regulations generally prohibit utility service for
development in rural areas. Most
of the remaining portion of the District is zoned for low-to Ðmedium density
residential use, with some commercial areas along H303 and other selected
locations. Past water system
planning has been based on serving the use as it has developed. Land use is generally consistent with
zoning.
Future
Service Area
As part of its Capital Improvement Program, the District
plans to construct new distribution piping in portions of its service area not
currently served by water mains.
These service areas are undeveloped property within the current District
boundaries. Water service to these
areas will generally be provided through developer extension agreements.
Design
and Performance Standards
Any property owner developing a new plat of commercial property
not served by existing water mains is required to design and construct a water
main extension in accordance with the DistrictÕs current developerÕs standards
and transfer title of the facilities to the District upon completion of the
construction as a condition of acceptance. Costs associated with the design and construction of these
water main extensions are the responsibility of the developer.
Population
Projections and Demand Forecasting
The Kitsap County Comprehensive Plan projects an average
annual growth rate of 1.0% from 1997 to 2012 in unincorporated areas, however
the historical average annual growth rate within the District has been
higher. A more conservative growth
rate of 2.5% is being used for demand forecasting. A second factor affecting demand is the overall weather
condition and the weather pattern during the summer. A third condition is the success of a conservation
program.
Recent
Hydrologic Studies
Kitsap
County has noted Category 1 and Category 2 Critical Aquifer Recharge areas next
to Illahee Creek. Additionally,
recent hydrologic studies in the area have noted low baseflows in Illahee Creek
and the discovery of a relatively porous separation layer between the shallow
aquifer supplying the creek and the deeper aquifers that supply local
wells. This means that the use of
wells within the hydraulic drawdown vicinity of Illahee Creek can result a
decrease in the baseflow of the creek.
Goals
and Policies
Goal W-1 Conduct hydrological
studies of the well systems around Illahee Creek to determine the appropriate
boundaries around the creek to ensure baseflow levels in the creek are
maintained.
Policy
W-1 Prohibit,
under this Plan, the introduction of new wells in the regions of Illahee Creek,
until the necessary hydrological studies are completed.
Policy
W-2 Begin
a water balance monitoring system comparing baseflows in Illahee Creek with
drawdown rates of local wells.
6.4 STORM WATER
Historic
Conditions
The Illahee Community is comprised of plateau areas and
steep slopes and is primarily located on the east facing slope of a ridge that
reaches approximately 500 feet above Port Orchard Channel. The plateaus and hillsides were
originally covered with forests and a variety of vegetation typically found in
the Puget Sound. The limited
amount of surface water runoff generated in the forested environment was
carried to small streams by many shallow swales and larger ravines.
Existing
Conditions
The existing stormwater conditions vary considerably from
historic conditions according to long time residents. Probably the greatest impact has been on Illahee Creek where
local fishermen note the devastating effects of increased stormwater discharges
on local trout and salmon fishing.
The storm water problems in Illahee are significant. They mostly result from natural
topography of steep and unstable slopes that cannot handle either a major
single event storm, or a series of smaller storms in rapid succession. These have been documented since the
late 1960s and early 1970Õs when there were no stormwater mitigation
requirements. As storm water
flushes through ravines during these storm events they create problems for the
streams and ravines as well as the downstream property owners. There are no easy fixes for these
problems so they have existed for nearly 40 years. The most recent acknowledgement of the problem with Illahee
Creek occurred in the mid 1990Õs when a new culvert was being planned. It was noted in the report for the
culvert that a complete basin study was required to best understand how to deal
with controlling the storm water in Illahee Creek. To our recollection, no other studies have been undertaken
since then.
More recently two significant stormwater related items have
surfaced. The first was a report
entitled ÒIllahee Creek, A Stream Destined for DisasterÓ which highlighted
problems with various issues, including stormwater surge problems. The second was a statement of area
stormwater problems via a Department of Ecology grant application submitted by
the Port of Illahee. The PortÕs
grant scored high in the State of WashingtonÕs rating system and is likely to
be funded. This will allow the
necessary studies to be conducted to determine how to resolve the areas storm
water problems.
Goals
and Policies
Goal SW-1
Support development of a comprehensive approach to storm water
management.
Policy SW-1 Review all new developments to ensure
coordination with regional storm
water system planning.
Policy
SW-2 Use environmentally proven methods to enhance runoff quality
and control runoff rates.
Policy
SW-3 Involve the Illahee Community in the assessment and
prioritization of
storm water capital facility projects.
Policy
SW-4 Identify areas needing improved storm water
infrastructure within the
Illahee Community.
Goal SW-2
Encourage storm water management systems that preserve natural drainage
systems such as streams and construct facilities that complement these systems
by taking advantage of opportunities for filtration , infiltration, and flow
control where feasible and reasonable.
Policy
SW-5 Preserve stream and natural drainage systems.
Policy
SW-6 Identify the remaining areas of the natural drainage
system in the CountyÕs
Geographical Information System as critical drainage areas.
Goal SW-3 Limit
the amount of impervious surface that can be created on individual residential
lots to reduce future increases in storm water runoff.
Policy
SW-7 Limit impervious surface for each residentially zoned
lot to a maximum
of 50% on lots less than .50 acre and 40% on lots more than
.50 Acre.
Policy
SW-8 Encourage the use
of permeable surfaces and other new technologies
in building construction and property development.
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