NATURAL SYSTEMS
4.1 INTRODUCTION
The natural
systems contained within the Illahee Community borders are unique and a major
part of the character of the area. Two large tracts of land have already
been recognized for their unique natural systems and have been set aside as
parks; Illahee State Park and Kitsap County Illahee Preserve Heritage
Park. Some of the natural features
in these two parks are wetlands, streams, bluffs, mature forests, shorelines,
gullies, meadows and wildlife corridors. Additionally, Rolling Hills Golf
Course provides a third large tract of land that was recognized for its natural
features.
The park
areas and golf course contain only a portion of these natural features, with
the rest being in private ownership.
There has been limited development in much of this area primarily
because of these natural systems, such as steep and unstable slopes, and
secondarily because until recently the area was zoned semi-rural. A major portion of the area has
remained semi-rural in spite of being rezoned urban, because most owners of the
land want to maintain these natural systems in a near natural state and because
few land parcels have been put up for sale.
The natural systems located within the Illahee Community are: saltwater shorelines;
streams, wetlands and frequently flooded areas; aquifer recharge areas;
geologically hazardous areas; wildlife corridors/fish and wildlife conservation
areas; and open space or greenways.
Each of these areas is regulated or controlled in some way by State and
Kitsap County regulations and ordinances.
The aggregate of these natural systems, each of which in its own way
deters or by law limits development, most often results in available open
space. Because of the phenomenal
amount of natural resources Illahee is approximately one third official open
space via parks & golf course, and another third unofficial open space via
the semi-rural character of the area.
4.2 SALTWATER SHORELINES
The Illahee
Community contains over 3 miles of saltwater shorelines, see Figure 4.1. The shoreline runs nearly due north and
south and faces easterly out to what marine maps refer to as Port Orchard Bay,
a major waterway approximately one mile wide, of Puget Sound waters separating
Bainbridge Island and the Kitsap mainland. Through this stretch of water are all types of fish,
waterfowl, and marine mammals; some using the water for transit and for others
this is their home.
The
shoreline varies significantly from sandy to rocky beaches, high bluffs to low
bank waterfront, a large accretion delta and estuary plateau where Illahee
Creek empties into the bay to undistinguishable water discharge areas where
storm water outfalls dump directly into the bay. The shoreline area is still predominately relatively densely
treed along the banks, which greatly benefits resident birds such as
Kingfishers, Bald Eagles and Osprey.
In the more densely populated area around the community dock there are
few perch trees for the birds and they use the dockÕs light poles, boat houses,
or residentÕs floats for perch areas.
While
residential structures occupy nearly all the available waterfront lots in the
Illahee community, the natural resources along the waterfront have benefited
from the previous semi-rural zoning and also waterfront setback
regulations. Also, along the
shoreline areas where steep and high banks predominate, trees help keep the
banks from mass wasting, which provide slide protection for the landowner and
habitat for wildlife. The density
of the waterfront homes varies from about 4 per acre in the older sections of
Illahee, to one or less per acre in other areas. This has resulted in a primarily pristine marine shoreline
which in turn supports the fish and wildlife in the area.
The
saltwater shorelines are important habitat for many species of fish and
wildlife. Shellfish abound in the area. Salmon, smelt, and other fish are near shore dwellers. Waterfowl are always present with many
species wintering in the area, primarily in the delta area at the mouth of
Illahee Creek. Osprey, blue
herons, and bald eagles are permanent residents. Marine mammals such as otters and seals are also residents
that frequent the shoreline and nearshore areas. An occasional sea lion will sometimes winter in the
area. Other mammals such as the
fox and raccoon and others depend on the shoreline and nearshore areas for food
and shelter.
Additional shoreline regulations are being considered. Several species of
salmon (chum, Coho, sockeye, and Chinook) were listed as ÒthreatenedÓ or
ÒendangeredÓ by the National Maine Fisheries Service (NMFS). One of these
species, the Puget Sound Chinook, uses the entire Illahee Community shoreline
as critical habitat. Marine inter-tidal, nearshore, and sub-tidal areas provide
critical habitat for salmon, particularly for juvenile smolts as they migrate
from freshwater systems in Puget Sound watersheds to the ocean. Shallow
nearshore areas are known to provide rearing habitat and shallow-water
migration corridors that offer protection from predators.
Saltwater Shorelines
Environmental Designations
The Kitsap County Shoreline Management Master Program developed in 1999 set
shoreline designations and development requirements for Kitsap County
shorelines. In this program the Illahee community shoreline has been
assigned three designations:
rural, semi-rural, and conservancy. See Figure 4.2.
Note that these designations are not to be confused with inland zoning
designations. The shoreline
designations are in general agreement with the Illahee shoreline geology and
reflect the proposed land use zoning called for in the Community Plan.
The rural
designation is designed to restrict intensive development along undeveloped
shorelines and to function as a buffer between more urban like densities. The majority of Illahee shorelines
(approximately two linear miles) are designated rural and reflect areas of high
bluffs at both ends of Illahee and the bay area between the state park and the
mouth of Illahee Creek. This rural
designation corresponds well with the previous semi-rural inland zoning prior
to 1998, and with the zoning densities called out in the Community Plan.
The
semi-rural designation is designed to Òpromote a multiple-use shoreline area in
which the scale of uses fall between that of the rural and urban
environments. Certain aspects of
the natural environment will be retained in conjunction with permitted
uses.Ó This designation was
assigned the area from the bottom or Roosevelt Street north to where Wise
Street intersects with Illahee Road (approximately one half mile in
distance). It essentially takes in
the 1916 platted area of old historic Illahee and provides less restrictive
shoreline uses than a rural designation.
The
conservancy designation is designed to protect fish and wildlife habitat and
environmentally sensitive areas and includes a sub element for parks,
recreational sites or open space.
In Illahee the shoreline area of Illahee State Park has a conservancy
designation. Additionally, the
southern most shoreline area of Illahee has been given the higher conservancy
designation, which follows the environmentally sensitive
shoreline
of the Cheney estate.
Saltwater Shorelines
Protection Guidelines
To protect
our sensitive shorelines, the least invasive protection or bulk heading methods
should be utilized. Traditional rock and concrete bulkheads are
recommended in high erosion areas and areas above mean high tide where existing
homes are endangered. A reduction in or prohibition of the use of harmful
chemical fertilizers and pesticides by shoreline property owners is another
opportunity to diminish environmental impacts. This should be done via an educational program.
4.3 STEAMS, WETLANDS, AND
FREQUENTLY FLOODED AREAS
Streams
The primary stream located within the Illahee community boundary is Illahee Creek which branches into a south and north fork and also has a north tributary. Illahee Creek and these forks and tributary also account for the major wetlands and frequently flooded areas within Illahee, see Figure 4.2. The only other significant stream
is a seasonal stream the runs through Illahee State Park. The other streams noted on the map are
essentially seasonal streams that handle primarily excess storm water.
Illahee
Creek is one of only a few Class 3 salmon streams in Kitsap County with the
entire watershed in an Urban Growth Area.
In spite of this fact, the watershed is essentially rural with less than
15 percent of the surface area impervious, and over 60 percent forested. A recent study notes ÒAlthough salmonid
abundance and diversity are lower than historic levels, multiple species of
salmon and trout continue to utilize Illahee Creek, making it a potentially
significant salmon refuge in the eastern part of the Kitsap Peninsula.Ó
Illahee Creek supports a rich
variety of plant and animal life. The stream and its tributaries are deeply
incised into steep slopes, which overall remain in their pristine forested
condition with extensive under story of native vegetation. Illahee Creek is the
habitat for salmon, deer, and possibly black bear. At least one bald eagle nest
exists along the stream.
Illahee Creek is largely fed by seeps, springs and shallow perched ground water
in the main channel and three secondary channels (or forks and tributaries).
The north fork begins in an area north of McWilliams Road. It travels south to meet the South
Fork, which flows north from an area east of Perry Avenue, midway between
Sylvan Way and Riddell Road. The joined streams flow east from the
confluence and are joined by the north tributary. Illahee Creek discharges into
Port Orchard Bay at SchuttÕs Point.
While Illahee Creek has many natural and pristine amenities, it also has some
major problems. The first of these
is the problem of excess storm water resulting from early developments in the
area. The second is the presence
of pollution found in the creek.
Illahee
Creek must now handle the excess storm flow in the watershed that is not
absorbed back into the groundwater system primarily because of impermeable
surfaces. Unmitigated storm water
flows, arising from property development at the upper reaches of the north
fork, have resulted in excessive sediment deposits downstream. These deposits
are visible as brown turbid water far into the Port Orchard Bay as they move
north or south depending on the direction of the tidal currents. This uncontrolled runoff, results in
bank erosion and slope failure, has diminished and threatened Illahee Creek as
a salmon-bearing stream. The
Washington State Department of Ecology is also aware of these problem and
recently awarded a grant of $181,000 to determine how best to correct the
problems.
In addition to the storm water problems, high levels of fecal coliform bacteria
have been found in Illahee Creek in 7 of the last 9 years of monitoring.
Community members are currently working in partnership with Kitsap County Heath
Department to try and identify the source of the bacteria.
Wetlands
The Illahee Community contains several wetlands, most of which are in the
Illahee Creek watershed and along the shoreline. Many of these have been
mapped by the county, though not all, and those identified remain largely
untyped. These wetlands, including hydric soils along Illahee Creek and two
underground seasonal streams in the watershed (recently identified), merit
further evaluation in order to appropriately develop around these fragile
and vital parts of our ecosystem.
Frequently Flooded Areas
Illahee Creek has potential flooding issues, currently monitored by Illahee
Community members. A culvert allows passage of Illahee Creek under Illahee
Road, just upstream from the creekÕs discharge into Port Orchard Bay. The
culvert creates the possibility of blockage and/or damming from sediment and
woody debris. A blockage could create upstream flooding; more deforestation
and development mean more debris. Therefore, careful consideration must be
given prior to any development approval in order to minimize harm to people
and property.
The accretion delta at the mouth of Illahee Creek formed by excessive
sediment deposits has caused channel migration in the recent past. This
lateral shifting of the Illahee Creek stream bed has resulted in flooding of
adjacent properties.
4.4 AQUIFER RECHARGE AREAS
The Illahee
Community contains a large percentage of land area designated as
critical aquifer recharge areas of both type one and type two. Type one
critical aquifer recharge areas includes an extensive area around the Illahee
Creek drainage area. Type two critical aquifer recharge areas extend along most
of the Illahee Community shoreline.
Impervious surfaces (paving and concrete, roofs, etc.) and some pervious
surfaces (such as lawns) arising from development cause an increase in storm
water runoff, which reduces aquifer recharge. Also, chemicals and pollutants
associated with developed areas, including fertilizers, herbicides and
pesticides, and petroleum products, increase the risk of groundwater
contamination. Possible adverse effects to the availability and quality of safe
drinking water must be considered prior to any further development approval.
4.5 GEOLOGICALLY HAZARDOUS AREAS
Significant
portions of the areaÕs soil are rated as moderately or highly unstable.
development in these areas is problematic. Due to steep slopes and unstable
soils, some areas recently proposed for development were found barely adequate,
even using optimistic figures and now outdated criteria.
Much of the area in the Illahee community that is not currently at near
build-out status has been rated by the county as a Moderate Hazard Area. This
includes nearly all of the shorelines. Moderate Hazard Areas are defined
as slopes of fifteen to thirty percent, and soils classified as highly or
potentially highly erodible.
High Hazard Areas also exist within the community, mainly along the banks of
Illahee Creek and its tributaries, along the shoreline north of Third Street,
and in a large portion of Illahee State Park. High Hazard Areas are slopes
greater than thirty percent.
In addition, the Illahee community falls on or near the Blakely Harbor Fault, a
splay of the Seattle Fault, identified following the Seattle earthquake of
2001.
4.6 WILDLIFE CORRIDORS
In addition to wildlife
habitats, preservation of wildlife corridors is essential. Corridors provide
safe paths, free of vehicles and other human disturbance, for wildlife to
travel between areas used for sleeping, accessing drinking water, foraging or
hunting, and breeding. Naturally existing corridors can be retained by
conserving areas of native forest and marine shoreline. In those areas where
development does impede wildlife movement, new corridors options need to be
investigated.
4.7 OPEN SPACE
IllaheeÕs
natural resources contribute to its abundance of open space. The three largest
open areas within Illahee are Illahee State Park, the Illahee Preserve, and
Rolling Hills Golf Course. These
three areas alone comprise nearly 700 acres of open space by themselves and
represent over one-third of the Illahee Community. This plus the private open space areas being left in their
natural or near natural state leaves the Illahee area approximately half open
space. Addition grant monies are
being requested to complete purchases of targeted private properties that
within the Illahee Creek corridor and meet the criteria established by the
Illahee Preserve Stewardship Plan.
Preserving
these open areas in their pristine forested state does much to help reduce
pollution in Puget Sound waters by eliminating detrimental storm water runoff.
They also provide recreation areas for residents and visitors, as well as
habitat for wildlife.
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