HomeMy WebLinkAboutHabitat Management Plan 975901202 and 975900102WESTECH COMPANY
Environmental Consulting - Site Permitting
MITIGATION AND HABITAT MANAGEMENT PLAN
8533 FLAGLER ROAD, MARROWSTONE ISLAND
ASSESSOR'S PARCEL # 975-900-102 & 975-901-202
JEFFERSON COUNTY, WASHINGTON
August 2013
G. Bradford Shea, Ph.D.
Submitted to:
JEFFERSON COUNTY
DEPARTMENT OF COMMUNITY DEVELOPMENT
621 Sheridan Street
Port Townsend, Washington 98368
Submitted by:
WESTECH COMPANY
P.O. Box 2876
Port Angeles, Washington 98362
P.O. Box 2876 - Port Angeles, Washington 98362 - Telephone: (360) 565-1333
email: brad@westechcompany.com
MITIGATION AND HABITAT MANAGEMENT PLAN
8533 FLAGLER ROAD, MARROWSTONE ISLAND, WASHINGTON
ASSESSOR'S PARCEL # 976-900-102 & 975-901-202
JEFFERSON COUNTY, WASHINGTON
August 2013
G. Bradford Shea, Ph.D.
Copyright 2013 by G. Bradford Shea, Westech Company -- All Rights Reserved
Submitted to:
JEFFERSON COUNTY
DEPARTMENT OF COMMUNITY DEVELOPMENT
621 Sheridan Street
Port Townsend, Washington 98368
Submitted by:
WESTECH COMPANY
P.O. Box 2876
Port Angeles, Washington 98362
CONTENTS
CHAPTER/SECTION
PAGE NO.
1.0 INTRODUCTION
1
2.0 APPROACH AND METHODS
7
2.1 Approach
7
2.2 Methods
7
3.0 MITIGATION PLAN
8
3.1 Regulatory Setting
8
3.2 Existing Conditions
10
3.3 Project Impacts
13
3.4 Plan Components
14
3.5 Detailed Mitigation Measures
14
3.6 Implementation and Timing
15
3.7 Mitigation Monitoring
16
3.8 Contingency Plan
17
4.0 HABITAT MANAGEMENT AND PLANTING PLAN
18
5.0 CONCLUSIONS AND RECOMMENDATIONS
22
5.1 Conclusions
22
6.2 Recommendations
22
6.0 REFERENCES
23
TABLES
Table 1. List of Native Plants for Buffer Mitigation and Enhancement
20
FIGURES
Figure 1. Location Map
2
Figure 2. Vicinity Map
3
Figure 3. Parcel Map
4
Figure 4. Aerial Photograph (August 25, 2011)
5
Figure 5. Site Map with Topography
6
Figure 6. Site Development Plan
12
Figure 7 Site Map with Planting Areas A & B
19
APPENDICES
Appendix A — Site Photographs A-1
Appendix B -- Detailed Site Plan B-1
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1.0 INTRODUCTION
The Property (Site) is located at 8533 Flagler Road, Marrowstone Island,
Washington. The Property is owned by Brian R. and Mary E. Mooers of 2312 Glen
Kerry Court, SE, Olympia, Washington 98513-3411. It is recorded as Assessor's
Parcels #'s 975-900-102 and 975-901-202. The Site lies within Jefferson County,
Washington in the Northeast Quarter of Section 29 of Township 30 North, Range 1
East, W.M. (Figures 1, 2, 3, and 4). The Site is located approximately 1.0 miles
north of Nordland on the western shore of Marrowstone Island in unincorporated
Jefferson County, Washington.
The property is approximately 339 feet long by 50 feet wide. The parcel abuts a
sand beach to the west and rises to about 35 feet above msl on the eastern
boundary. The parcels together are approximately 0.39 acres in size. An existing
driveway provides vehicular access to the property. The property currently contains
a 750 square foot house and deck as well as a one car garage. The owners have
requested to increase the residence size to approximately 1,800 square feet or
more by expanding to the south and east (away from the shoreline) (Figure 5) (see
Appendix A for site photographs).
The marine shoreline along this Property is considered a Shoreline of Statewide
Significance and has been designated as critical habitat for Hood Canal Summer
Chum and Puget Sound Chinook (50 C.F.R. 226). The shoreline is classified as a
"Fish and Wildlife Habitat Conservation Area" (FWHCA) by Jefferson County,
requiring a 150 foot buffer from the Ordinary High Water Mark (OHWM) and a
five foot building setback from the buffer.
It is the intention of the owner to replace the current residence on -site with a new
structure with an expanded footprint to the south and east. The owner also intends
to place a new septic system with a drainfield landward of the house (Figure 5 also
Appendix B).
Because the proposed plan is inside a potentially reduced buffer (about 105 feet in
the home expansion area), it will disturb soils and some existing vegetation and
slightly increase impervious surfaces on -Site. The Property owners have contracted
with Westech Company (Westech) to satisfy the County's requirements in regards
to Critical Areas. This Report constitutes a Habitat Management Plan which will
describe existing conditions on the Site, define the impacts of development, and
outline a management proposal to maintain and enhance the existing functions and
values of the buffer and its associate watershed and will ensure "No Net Ecological
Loss of Shoreline Functions" (RCW36.70A.480). This document is intended to
satisfy the requirements of pertinent Jefferson County and State ordinances.
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2.0 METHODS
2.1 APPROACH
The approach for this investigation into the impacts of development of this Site
included a detailed review of County Assessor's parcel maps, Critical Area Maps,
aerial photographs of the Site, mapped locations of Species of Concern by the
Washington State Department of Fish and Wildlife, mapped locations of ESA
(Endangered Species Act) listed species' critical habitat by NOAA-NMFS (National
Marine Fisheries Service) and topographic maps of the area. A Site Plan prepared
by Creative Design Solutions was also reviewed and utilized to define proposed
planting areas (see Section 3.3 and Appendix B).
Westech Company's (Westech) field investigations for the Habitat Management
Plan (HMP) were carried out in July and August 2013 by Dr. G. Bradford Shea,
Principal Ecologist, with assistance from Mr. Charles Tanner, staff Environmental
Scientist. During Site visits, the Property was inspected and Site characteristics
were noted. Relevant measurements were taken for mapping purposes,
photographic documentation of the Site was acquired, and potential mitigation was
identified.
2.2 METHODS
Westech's field reconnaissance involved examining the existing conditions found at
the Site. This included reviewing the area proposed for development in relation to
the natural features found on -site. Botanical studies were conducted involving
identification of plant species that could be found growing at the Site. Site
measurements were taken (including dimensions of proposed planting areas) using
a fiberglass tape measure.
A qualitative assessment of the landscape was conducted to determine the
presence of invasive species, the composition and characteristics of plants in the
critical area, evidence of historical land uses, the slope of lands adjacent to critical
areas, soil textures and stability and an assessment of the role of existing
vegetation in supporting soil stability. Westech also assessed the extent of existing
human disturbance in the critical areas. This information was used to assess the
potential impacts of the proposed project.
This HMP has been formulated to assure "no net ecological loss" and to "maintain
or enhance the existing functions and values of the associated watershed" (JCC
18.22.480; RCW36.70A.480). Chapters 3.0 and 4.0 describe the goals and
objectives of this HMP as well as the performance standards that will be utilized to
assess the effectiveness of this plan. This Plan is intended to restore and enhance
the integrity of the Site by improving the quality of habitat and erosion control
though planting of additional native vegetation at the Site.
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3.0 MITIGATION PLAN
3.1 REGULATORY SETTING
There are several jurisdictional issues related to the development of this parcel of
land. The Site is a low bank site with gradual uphill topography to an elevation of
35 feet above mean sea level (msl). As such, there is no distinct "top of bank"
above the beach. The gradual slope decreases at a fence line located about 30
feet inland from the Mean Higher High Water (MHHW) mark. The existing
residence is located approximately 70 feet from MHHW.
The Site is zoned Rural Residential 1:5 (RR1:5), which has a maximum density
of one dwelling per five acres with a minimum lot size of one acre. The purpose
of rural residential zoning is to allow for "continued residential development" in
areas of the County of "relatively high density pre-existing patterns of
development," including "along the County's coastal areas" (JCC 18.15.015).
The Site is located along a section of shoreline that is considered a "Shoreline of
Statewide Significance" and is regulated under Jefferson County's Shoreline
Master Program. This shoreline has been designated under the Shoreline
Master Program as a "Conservancy" shoreline. These are defined as areas with
"valuable natural, cultural, or historical resources or environmental conditions that
should be protected, conserved, and managed to the extent that a continual
supply of those resources such as soil, water, timber, fish, shellfish, or wildlife are
not degraded or depleted but are maintained." They also include "areas
containing sensitive environmental conditions that may limit the potential for
development or use, including, but not limited to, steep slopes, flood prone areas,
eroding bluffs, marshes, bogs, swamps, and accretion shore forms."
The permitted activities in these areas include "low density residential and
recreational uses...provided these activities do not significantly degrade or
deplete resources and respect limiting environmental conditions." The purpose of
the Conservancy designation is to "protect, conserve, and manage existing
resources and valuable historical and cultural areas in order to ensure sustained
resource stabilization and that sensitive natural conditions are not subject to
inappropriate uses" (JCC 18.25.130),
Under the Shoreline Master Program the standard set -back for residential
structures is "30 feet or one foot for each foot of bank height, whichever is
greater." This set -back is to be measured from the bank's edge when the bank
height is greater than 10 feet and shall not exceed 100 feet. The elevation of the
bank at this property is approximately 8-10 feet and is a gradual slope, not a
steep bluff (JCC 18.25.410). The property grades upward to a maximum height
of about 35 feet at the eastern property line. The underlying soils are considered
stable in terms of shoreline stability.
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This shoreline has been designated "critical habitat" for threatened salmonid
species, specifically the Puget Sound Chinook and Hood Canal Summer Chum.
This listing comes from the National Marine Fisheries Service (NMFS) pursuant to
the Endangered Species Act (ESA). The Growth Management Act
(RCW36.70A.480) mandates that the County protect such critical areas.
Jefferson County carries out this mandate by classifying this shoreline as a "Fish
and Wildlife Habitat Conservation Area" (FWHCA). These areas are considered
to be of "critical importance to the maintenance of endangered, threatened or
sensitive species of fish, wildlife, and/or plants" (18.22.200).
Jefferson County requires a buffer of 150 feet from the Ordinary High Water Mark
(OHWM) for areas in which "federally listed species have a primary association."
In addition, a five foot building setback from the buffer is required. Local and site
specific factors may be taken into account and the buffer width is to be "based on
the best available information concerning the species/habitat in questions" (JCC
18.22.270(2)). Any project located within this buffer must follow Jefferson County
drainage and erosion control, grading and vegetation retention standards (JCC
18.22.270).
Landowners may obtain a reduction in the size of the buffer required for
FWHCAs. The administrator has the "authority to reduce buffer widths on a case -
by -case basis" provided that standards are met for avoiding and minimizing
impacts and that the buffer reduction does not "adversely affect the habitat
functions and values of the adjacent FWHCA or other critical area" (JCC
18.22.270). However, the administrator may not reduce the buffer to less than
75 percent of the standard buffer (JCC 18.22.270). Any projects that "alter,
decrease or average the standard buffer" require an accompanying Habitat
Management Plan (HMP) (JCC 18.22.265).
Because this project involves elements to be built in the buffer area, but behind
previously constructed features, an HMP is required to mitigate and offset any
adverse ecological effects. This document is also the best way to meet the intent
of RCW36.70A.480 which provides for Jefferson County to make a determination
of "No net loss of ecological functions" with or without mitigation, for renovation of
existing shoreline structures. This document includes a "No Net Loss" ecological
evaluation, proposed Mitigation Measures to offset impacts and a Habitat
Management Plan to assure long-term health and ecological productivity.
These documents (HMPs) must include maps showing the proposed
development Site and its relationship to surrounding topographic features; the
nature and density of the proposed development; and the boundaries of forested
areas. The report shall also describe the density and nature of the proposed
development in enough detail to allow analysis of impacts on identified fish and
wildlife habitat. The report must describe how any adverse impacts resulting from
the project will be mitigated. Possible Mitigation Measures may include, but are
not limited to, establishing buffer zones, preserving plant and tree species,
WVV1281 F1agerRd(8533)H MP10816131mas
limiting access to habitat areas, seasonally restricting construction activities and
establishing a timetable for the periodic review of the Plan (18.22.440).
3.2 EXISTING CONDITIONS
The Site is located roughly one mile north of Nordland (also Marrowstone) on the
western shore of Marrowstone Island in Kilisut Bay. It is approximately 339 feet
long by 50 feet wide. The parcel is approximately 0.39 acres in size. An existing
driveway provides vehicular access to the property.
Figure 5 shows topographic features on the Site. The parcel abuts a sand beach to
the west and rises to about 35 feet at above msl at its eastern edge (at Flagler
Road). The property is separated from adjacent areas to the east by Flagler Road,
after which the terrain continues to grade upward. The property can be divided
between a beach area and a partially disturbed upland area characterized by an
open lawn area and three structures and graveled parking areas.
The beach was observed on July 28 at about 1:00 PM. The tide at this time was
nearly high. The beach consists of sand in the upper intertidal zone and a mix of
sand and cobble in the middle intertidal zone. A variety of shellfish including butter
clam (Saxidomus giganteus), cockles, crabs, sand dollars and pacific littleneck
clams (Protothaca staminea) were observed, indicating that the adjacent shoreline
provides habitat for these species. No kelp beds or algae beds were observed,
though the lower intertidal zone was not visible due the high tide. Logs have
moved naturally to a point at the upper edge of the upper intertidal zone. A
vegetated strip including dunegrass and several other beach species is present
immediately behind the logs across from the beach and adjacent low hillside.
Other plants that dominate the area just upland of the upper intertidal zone include
dunegrass (Elymus mollis), Nootka rose (Rosa nutkana), pearly everlasting
(Anaphalis margarrtacea), Canada thistle (Circium arvense), hairy cat's ear
(Hypochaerrs radicata) and snowberry (Symphoricarpos albus). The southern end
of the property appears to be covered by a groundcover from the mint family, Yerba
buena (Satureja douglasii) located east of the log barrier. Various algae and some
pieces of kelp were also found on the beach waterward of the log barrier. This
beach area is also used for storing a small row boat and a short set of steps
provides access to the nearshore beach.
The shoreline adjacent to the property has been designated as critical habitat for
two species listed as threatened under the Endangered Species Act: Puget Sound
Chinook and Hood Canal Summer Chum (50 C.F.R. 226).
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From the beach habitat, the land slopes gradually upward to a height of about 10
feet, 30 feet back from MHHW. The face of the hill is dominated by a variety of
grasses, low forts and some shrubs (Nootka rose).
The upland area is characterized by low grasses (lawn area), however a few native
trees, mainly Pacific madrone (Arbutus menziesh) are present. Other, non-native
tree species on the Site include a large apple tree and a cherry tree. The upper
portion of the site includes native trees including Douglas fir (Pseudotsuga
menziesii) and western red cedar (Thuja plicata). The groundcover in the upland
area is dominated by salal, honeysuckle and sword fern.
The Natural Resource Conservation Service (MRCS) has mapped three dominant
soils on and in the immediate vicinity of the Site (NRCS 2013). Because NRCS
maps can be inaccurate at this scale it is not possible to determine the actual
boundary between these soils or the specific soils among these that are found on -
site. These soils include:
Coastal Beaches This soil is usually very well drained (sand, gravel
and cobble) and has a depth to water table of about 0 - 72 inches. It
has a high frequency of flooding. It consists of sands and gravels to a
depth of 72 inches.
• Ho us gravelly loamy sand 0 —15 percent slopes. This soil formed
on terraces and originated from glacial outwash. It is somewhat
excessively well drained and has a depth to a restrictive layer of 80
inches or more as is the depth to water table. It has no frequency of
ponding of flooding. It consists of gravelly loamy sand to 60 inches
depth.
• Whidbpy gravellysaDdy loam 0 to 15 percent slopes: This soil is well
drained and has a depth to water table of about 18 to 30 inches. It
has no frequency of ponding or flooding. It consists of gravelly sandy
loam and very gravelly sandy loam to 60 inches depth.
The Site has coastal beach soils at the western edge, with most of the Site
underlain by Hoypus soils. The Whidbey soils are generally not found on the Site
itself, but lie to the east of Flagler Road.
Figure 6 shows the present level of development on the Site. A driveway (partially
concrete and partially gravel) provides access to the Site from Flagler Road, Three
separate structures are presently located on the Site. A house with an 8-10 foot
wide deck approximately 28 by 36 feet in size (about 750 square feet) is located
about 70 feet from the MHHW mark. Stairs extend from the edge of the small
grassy yard down to the beach. Uphill from the house is a detached single car
garage and a small storage shed.
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3.3 PROJECT IMPACTS
The landowner's plan for this Property entails the expansion of the house to the
side and rear, as well as the placement of a new septic system. The primary
impacts associated with these projects are those generally associated with
construction. Figure 6 is a map of existing and proposed structures on the Site.
Currently existing structures on the Site, described from those closest to the
shoreline to those furthest away, include the following:
Steps provide access to the nearshore area and extend from
approximately 20 feet from OHWM to 30 feet from OHWM.
■ A 10 foot wide deck on the front (east) and south side of the
residence
• The existing house. The proposed expansion will be built on the
footprint of the existing structure, extending sideways past the
existing deck and back to the existing garage as shown in Figure 6.
The garage structure will remain unchanged
A 10 foot by 8 foot shed located about 20 feet to the southeast of the
garage. This shed appears to be used for storing firewood. This
structure will be removed to accommodate the new septic system.
The new septic system will include a 1,000 gallon septic tank and a 1,000 gallon
pump chamber which will be placed on the west side of the house, and a new open
bottom sand filter drainfield will be placed above the existing shed in a currently
grassed -in area. The previous septic system will be removed from the area near
the house.
The potential impacts of this project will result primarily from the processes of
grading and clearing on the Site as well as removal of some earth and the
movement of construction vehicles on the Site. These potential impacts include the
following:
The area surrounding these structures and drainfield area will be
cleared. This may create the conditions for potential short-term
erosion and soil instability caused by the construction process and
the removal of some vegetation in the buffer (mostly lawn area).
Additional earth moving and grading during the construction process
may contribute to increased erosion.
The removal of some native vegetation in the buffer zone. Native
vegetation has already been removed near the structures. More may
be removed in order to expand the house and drainfield, including the
movement of construction vehicles on the Site.
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Because the residence is being built partially on the same footprint as
the previous structure, this part of the project will not increase the
impervious surface on the Site. The footprint and impervious surface
are expected to increase by about 1,000 square feet.
• The removal of vegetation from the Site has already resulted in the
direct loss of some habitat. Many species of bird, small mammal and
insect use native plants for food sources and refuge. The loss of this
vegetation in the buffer zone could reduce habitat for these
organisms.
The Management Plan below is intended to offset these adverse impacts. The
Mitigation Measures developed in this Plan are intended to compensate for the
impacts to the shoreline habitat and buffer zone.
3.4 PLAN COMPONENTS
The components of the Mitigation Plan include the following:
Erosion control methods will be used to prevent on -Site rill or sheet
erosion from moving sediments toward the adjacent shoreline. This
will be accomplished through project timing and emplacement of
control measures during construction. A silt fence will be placed on
the western edge of the construction area, adjacent to the
construction envelope.
Native vegetation will be planted to mitigate disturbance to existing
plants in the buffer zone.
• No nutrients, pesticides or other contaminants will be used within 100
feet of the shoreline.
3.5 DETAILED MITIGATION MEASURES
The detailed Mitigation Measures corresponding to the Plan Components listed
above area as follows:
Timing of construction should be limited to the "dry season" between
April 1 and October 15. By limiting construction to this time period,
less effort will be required to inhibit erosion and silt runoff. All graded
areas should be covered or re -vegetated prior to November 1. If it is
necessary to continue construction into the "wet season," then extra
measures will be required for erosion and silt runoff control.
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All erosion control measures should be installed prior to beginning
grading or other ground -disturbing construction activities. A silt fence
has already been placed between the residence structure and the
beach, This should be kept in place, Straw bales, jute netting or other
appropriate material should be kept on -Site and used to stabilize any
open areas following grading.
Two areas within the buffer zone will be re -vegetated with native plant
species as per the Planting Plan described in Chapter 4.0 in order to
reduce future erosion and enhance buffer function. Planting success
will be monitored and will conform to performance standards as
described in Sections 3.6 and 3.7. If performance standards are not
met, additional plantings or other remedial actions will be taken to
meet standards as per requirements in Section 3.7.
Implementation of these Mitigation Measures is anticipated to
mitigate impacts associated with the further development of the Site
and disturbance to the buffer zone. However, the narrow size of
buffers at this site and the limited filtering capacity of sandy soils will
limit the extent to which the Site will filter long-term pollution and
sediments entering the adjacent waters. To minimize the potential for
contaminants to enter these waters, no additional nutrients,
pesticides or additional contaminants should be used on the Site
within 100 feet of the OHWM.
3.6 IMPLEMENTATION AND TIMING
The continuation of construction on the Site should be conducted between April 1
and October 15 in order to minimize ground -disturbing activities during the rainy
season. Any work carried out during the rainy season should have all erosion
control measures in place prior to beginning.
New plantings in the buffer zone should be carried out during early fall if possible
(September -October) to avoid the necessity of supplemental watering. Plantings
can be placed during the winter or early spring (March -May) if necessary. If
plantings occur during summer months, supplemental watering with a drip irrigation
system or equivalent method may be necessary. Westech recommends that
monitoring of these plantings be conducted by an independent landscaping firm,
certified arborist, registered nursery or qualified botanists and that success of the
plantings be maintained above a performance standard of 90 percent as described
in Section 3.7.
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3.7 MITIGATION MONITORING
Buffer areas serve a variety of functions. They are important in that they reduce the
adverse impacts of adjacent land uses by stabilizing soil and preventing erosion;
filter suspended solids, nutrients and toxic substances; moderate impacts of
stormwater runoff; and reduce noise disturbance and light intrusion. They can also
provide important habitat for wildlife.
The narrow size of buffers at this Site (about 70 feet from OHWM to the house) and
the limited filtering capacity of sandy, gravelly soils limit the extent to which the
Mitigation Measures will filter pollution and sediments from ongoing activity. This
can include pollutants from hydrocarbons, heavy metals, pesticides and fertilizer.
Literature on buffer size indicate that buffers of 100 feet may be necessary to
consistently filter sediments and pollution that occur in stormwater runoff (Wenger
1999, Mayer et al. 2005).
Precluding the use of pesticides, nutrients and other potential contaminants within
100 feet of the OHMW will limit the impact of these pollutants on nearshore critical
habitat. The literature also indicates that plantings can increase the effectiveness of
the buffer zone, or decrease the size needed to filter contaminants.
Because buffer zones serve several functions, it is important that the Mitigation
Measures that are implemented to offset significant impacts are successful.
Monitoring over an extended period of time provides the best assurance of
success. Monitoring success of erosion control measures during construction will
be carried out daily during construction. Any evidence of erosion or sedimentation
leaving the construction area will result in immediate action to block erosion and
sediments. Such siltation can best be blocked through the use of additional silt
fences, straw bales, wattles, or temporary berms.
Monitoring the success of new native plants (as per the Habitat Plan described in
Section 4.0) should be carried out and enforced by the county according to the
following schedule and performance standards:
• Following construction, the areas shown in the Habitat Plan (Section
4.0) should be replanted.
The coverage of replanted native vegetation should remain at 90
percent of the original area planted. If monitoring indicates that this
vegetation drops below this level, contingency measures must be
implemented.
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The homeowners should have a monitoring report prepared by a
qualified professional at the end of the first growing season. Follow-
up monitoring reports should be completed at the end of the second
and third full years after construction and restoration. These reports
should address the success of the plantings. Any plant mortality
should be noted and corrected if plant survival falls below 90 percent
during the first three years. Documentation should include any
necessary corrective measures that include supplemental planting to
compensate for plant mortality and notation of the apparent reasons
for such mortality.
All reports should be submitted to Jefferson County for review and concurrence.
For this plan to be successful, the County must monitor compliance with its
conditions. The failure of the County to monitor the implementation of the Plan may
lead to its ineffectiveness.
3.8 CONTINGENCY PLAN
A Contingency Plan should be followed if Mitigation Measures appear to be failing.
This plan should address, in particular, any mortality of revegetated areas below
the 90 percent survival level at the end of three years. Should this level be
exceeded, the Contingency Plan should included an assessment of the reasons for
failure by a qualified botanical professional and the development of a plan for
introducing plants likely to be successful in the location where performance
standards were not met.
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4.0 HABITAT MANAGEMENT AND PLANTING PLAN
A Planting Plan as diagrammed in Figure 7 will be implemented to mitigate for the
disturbance of native vegetation in the buffer areas. A list of native plants that will
be used for mitigation and restoration can be found in Table 1. Re -vegetation and
planting of additional vegetation will occur as an integral part of the Project to
compensate for environmental impacts caused by the ground -disturbing activity.
Most of the area immediately adjacent to the location of the proposed residence
expansion, shed, deck and stairs is grassy lawn. The two areas designated for
additional plantings include:
Planting Area A is a 50 foot by 25 foot area adjacent to and landward
of the upper intertidal zone. This planting area lies immediately
behind the line of MHHW consisting of a line of logs in the upper
intertidal zone. The area is presently covered by low-cut mixed
grasses and forbs. This area should be planted with the mix of shrubs
and ground cover found in Table 1.
Planting Area B is an approximately a 20 foot by 40 foot area that will
be planted on and around and behind the present location of the
shed. When this shed is removed it will allow covering this area with a
mix of selected low shrubs and groundcover over the new drainfield
(Table 1).
Success of the planting plan depends on choosing species that are suitable to both
the on -Site soil conditions, but that are hardy and capable of handling nutrient poor
soils, shading and some salt spray. The native vegetation selected for this
Mitigation and Habitat Management Plan were chosen for these reasons. Plants in
Area B were also chosen to be non -water seeking since they will be planted above
the drainfield area.
Soils on the Site are mostly gravelly loams and well drained. Normal rainfall will
quickly drain through these soils. Plants may require additional watering during the
first year in order to meet performance criteria. A simple drip irrigation system
would be the most effective method of accomplishing this.
The species size and number of plants that will be used to revegetate these areas
is shown in Table 1. Plants will be placed in a semi -random fashion within the areas
indicated in Figure 7. Small trees will be placed on ten -foot centers (oceanspray
and Indian plum) and shrubs will be planted on six-foot centers or less. Staggering
of plants in this fashion, rather than planting in straight rows, will create a more
natural appearing configuration. Plants may be clustered by species in order to
promote natural reseeding.
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TABLE 1. LIST OF NATIVE PLANTS FOR
BUFFER MITIGATION AND ENHANCEMENT
Location
Species _
American dunegrass
Scientific Name
Number
Size
A
El mus mollis
30
3.5" of
A
Beach sand-spursand-spurry
S e ularia macrotheca
10
1 gallon
A
A
Coastal strawberry
Yellow sand -verbena
Fra aria chiloensis
Abronia latifolia
25
10
4" pot
1 gallon
A
Yerba buena
Sature a douglasii
20
1 gallon
B
Deer fern _
Blechnum s icant
20
1 gallon
B
Indian plum
Oemleria cerasiformis
2
1 gallon
B
Oceanspray
Holodiscus discolor
3
1 gallon
B
Oregon grape
Mahonia nervosa
10
1 gallon
B
Speedwell
Veronica serpyllifolia
20
1 gallon
B
Sword fern
Pol stichum munitum
10
1 gallon
VWV1281 FlagerRd(8533)HMP/081613/mas 20
Plants installed in the fall usually out -perform those installed in the late winter or
spring. Planting projects scheduled for early October to mid -December are
generally the most successful. The earlier plants go into the ground in the fall, the
more time they have to recover from transplant shock, adapt to the site, and
expand their roots systems before the growing season. They will require less water
and grow more vigorously than if they are planted in the spring. To increase the
potential for the planted species to survive, four inches of mulch should be placed
around the installed plants with the mulch two inches away from the stem of the
plants.
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5.0 CONCLUSIONS AND RECOMMENDATIONS
5.1 CONCLUSIONS
The property presently contains an existing home and deck, stairs leading from the
yard to the nearshore area, a garage, and an existing shed. A new residence is
being constructed on the footprint of the existing residence, but expanded to the
side and back (southward and eastward). The property owner also intends to place
a new septic system on the property and remove the current septic system. The
proposed project is being constructed inside the buffer zone, though it will move the
present structures no closer to the shoreline than has previously been the case.
Measures outlined in this report will be enacted to mitigate additional construction
on the Site and incrementally improve habitat and vegetation in the nearshore area.
Erosion control measures will include a silt fence and other standard measures and
will be used during construction to minimize sheet and rill erosion. A Planting Plan
(See Figure 7 and Table 1) will be implemented to provide additional vegetation
adjacent to the beach and south of the existing garage (over the new septic
system). The site of the shed will also be replanted once this structure is removed.
This report meets the intent of RCW36.70A.480 ensuring "No Net Loss of Shoreline
Ecological Function" due to the Mitigation proposed, and applicable Jefferson
County Codes.
5.2 RECOMMENDATIONS
This report constitutes a Mitigation and Habitat Management Plan. A Planting Plan
has been included in this report and we recommend that it be implemented on the
Site upon approval by the County. Benefits deriving from this Plan will only take
place if it is implemented and enforced by the County.
The silt fence should be emplaced prior to construction and should be left in place
and additional erosion control materials should be kept on Site to address any
erosion observed during construction. The Planting Plan outlined in this report
should be implemented; the Plan should be monitored according to the instructions
outlined in this plan and the Contingency Plan implemented in the event that plant
survival in the revegetated areas falls below 90 percent.
Property owners should refrain from the use of pesticides or additional nutrients on
the Site and should introduce no contaminants within 100 feet of the OHWM. While
these measures will provide mitigation for additional construction and use of the
Site, the shoreline and marine critical areas may experience continued cumulative
impacts as a result of the narrow size of the buffers and limited filtering capacity of
the soils in this area.
WW1281 F1agerRd(8533)HMP/081613/mas 22
6.0 REFERENCES
Creative Design Solutions. 2013. Unpublished Site Plan for 8533 Flagler Road,
Marrowstone Island, Washington. Port Angeles, Washington.
Jefferson County. 2013. Online Map Database. http:/AAww.co.jefferson.wa.us/.
Jefferson County, Washington.
Jefferson County. 2009. Jefferson County Critical Areas Code. Title 18.22 JCC.
Department of Community Development. Port Townsend, Washington.
Google Earth. 2013. Online mapping software. www.goo.gleearth.com.
Imagery date August 25, 2011. Europa Technologies.
Hitchcock, C.L. and A. Cronquist. 1973. Flora of the Pacific Northwest. University
of Washington Press. Seattle, Washington.
Lyons, C.P. 1997. Wildflowers of Washington. Lone Pine Publishing. Renton,
Washington.
Mayer, P.M., S.K. Reynolds, and T.J. Canfield. 2005. Riparian Buffer Width,
Vegetative Cover, and Nitrogen Removal Effectiveness: A Review of Current
Science and Regulations. Cincinnati, Ohio. U.S. Environmental Protection
Agency.
Natural Resource Conservation Service (NRCS). 2013. Web Soil Survey.
hftp:/twebsoilsurvey.nrcs.usda.gov/app/HomePage.htm
Pojar, J. and A. MacKinnon. 1994 (reprinted 2004). Plants of the Pacific Northwest
Coast. Lone Pine Publishing Company. Redmond, Washington.
Revised Code of Washington. 2013. RCW36.70A.480. Shoreline of the State.
http://apps/leg.wa.gov/rcw/default.aspix?cite=3670A.480.
Taylor, R. 1995. Northwest Weeds. Mountain Press Publishing Company.
Missoula Montana.
Wegner, S. 1999. A Review of the Scientific Literature on Riparian Buffer Width,
Extent and Vegetation. Athens, Georgia: Institute of Ecology, University of
Georgia.
WW1281FIagerRd(8533)HMP/081613/mas 23
APPENDICES
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APPENDIX A
SITE PHOTOGRAPHS
WW1281 FlaglerRd(8533)HMP.APPA/081613/mas A-1
AI IV If t
Ow
.pt
aWK
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ol
5) Driveway and garage area.
6) Upper portion of property.
WW1281Flag lerRd(8533)HMP.APPA/081613/mas A-4
APPENDIX B
DETAILED SITE PLAN
WW1281 FlagerRd(8533)HMP/081613/mas B-1