HomeMy WebLinkAboutMLA16-00027 Mitigation and Habitat Management PlanWESTECH COMPANY
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MITIGATION AND HABITAT MANAGEMENT PLAN
651 BACHELOR ROAD
ASSESSOR'S PARCEL # 002352019
JEFFERSON COUNTY, WASHINGTON
February 2016
G. Bradford Shea, Ph.D.
Submitted to:
JEFFERSON COUNTY
DEPARTMENT OF COMMUNITY DEVELOPMENT 11PP
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
651 BACHELOR ROAD
ASSESSOR'S PARCEL # 002352019
JEFFERSON COUNTY, WASHINGTON
February 2016
G. Bradford Shea, Ph.D.
Copyright 2016 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
CHAPTERISECTION PAGE NO,
1.0 INTRODUCTION
1
2.0 APPROACH AND METHODS
7
2.1 Approach
7
2.2 Methods
7
3.0 MITIGATION PLAN
9
3.1 Regulatory Setting
9
3.2 Existing Conditions
11
3.3 Project Impacts
12
3.4 Plan Components
14
3.5 Detailed Mitigation Measures
14
3.6 Implementation and Timing
15
3.7 Mitigation Monitoring
15
3.8 Contingency Plan
17
4.0 PLANTING PLAN
18
5.0 CONCLUSIONS AND RECOMMENDATIONS
22
5.1 Conclusions
22
52 Recommendations
22
6.0 REFERENCES
24
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. 2013 Aerial Photograph
5
Figure 5. Site Map
8
Figure 6. Planting Areas A, B and C
19
APPENDICES
Appendix A — Site Photographs
A-1
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1.0 INTRODUCTION
1.1 BACKGROUND
The Property (Site) is located at 651 Bachelor Road, in Jefferson County
Washington. The Property is owned by Terrence Parks and Christine Clark of that
address. It is recorded as Assessor's Parcel # 002352019. The Site lies within
Jefferson County, Washington in the Northwest Quarter of Section 35 of Township
30 North, Range 2 West, W.M. (Figures 1, 2, 3, and 4). The Site is located
approximately 13.0 miles southwest of Port Townsend on the southwestern shore
of Discovery Bay in unincorporated Jefferson County, Washington.
The property is about 425 feet long (land area is 305 feet) by 100 feet wide or 0.97
acres (land area is roughly 0.70 acres). The Parcel has a seventy (70) foot high
bank above Discovery Bay, with a cobble -sand beach at the foot of the bank. The
bank slopes back at a relatively steep angle (35 — 45 degrees) from the Ordinary
High Water Mark (OHWM). An existing driveway provides vehicular access to the
property from Bachelor Road.
1.2 PROPOSED PROJECT
The property currently contains a one story house with a 24 x 40 foot footprint (960
square feet) plus a 14 x 14 master bedroom (200 square feet) with a 10 x 10
wooden front deck. A 24 x 36 foot three car garage is located on the southern end
of the property outside of the shoreline buffer. A small shed (8 x 12 foot) previously
on the property has been removed.
Planned construction activities (removal and replacement of 200 square foot
bedroom, addition of 126 square foot footprint as part of a two story addition and
septic upgrades as required) will occur on the northwest area of the parcel. Any
reserve drainfield area required by the County will occur outside of the 150 foot
shoreline buffer area. Stormwater drainage pipes will also be replaced as
necessary as per the engineered Drainage Plan for the Site (NTI 2015a).
The owners have requested to remove and rebuild the existing master bedroom
(200 square feet) due to concerns about recent slumping of soils in that area, and
to add approximately 126 square feet (12 foot x 14 foot area) to the southwest
comer of the house, away from the shoreline (see Appendix A for site
photographs). This expansion will lie over an area which is presently lawn, and
adjacent to a parking area.
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1.2 Regulatory Framework
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 OHWM.
It is the intention of the owner to add a small increase to the current residence on-
site with a new two story remodelladdition within the 150 foot shoreline buffer. The
house will then have an expanded footprint on the southwest corner of the
residence (foot print expansion of 126 square feet), which lies at a distance of
about 125 feet from the OHWM. There will be no expansion toward the water
(northward), nor any extension beyond the present westernmost wall of the house.
The owner may need to upgrade the existing septic system with a drainfield west of
the house if required by the County, by modifying the existing gravity system if
possible, or using Glendon bio -lifters if required. The reserve drainfield will be
outside of the 150 foot buffer zone.
Because of the proposed home addition and storm -drainage reconstruction and
potential drainfield modification, the Project will disturb surface soils and some
existing vegetation. Stormwater drains will be replaced as necessary. The new
addition and recommended modification of the present parking area will slightly
decrease impervious surfaces on the Site (NTI 2015a). The Property owners have
contracted with Westech Company (Westech) to satisfy the County's requirements
in regards to Critical Areas and Shoreline Buffer Requirements through preparation
of this Habitat Management Plan.
This Report constitutes a Habitat Management Plan (HMP) 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 associated watershed and to 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 regulations and 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 help define
proposed planting areas (see Section 3.3 and Figure 5).
During January 2016, an updated home design with the current planned
remodeVaddition were reviewed (PDD 2015). Also reviewed were updated reports
by NTI Surveying and Engineering on Stormwater Erosion and Sediment Control
(NTI 2015a) and on Geotechnical considerations (NTI 2015b).
Westech's field investigations for the Habitat Management Plan (HMP) were carried
out in December 2014 by Dr. G. Bradford Shea, Principal Ecologist. 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. Updated plans and
studies cited above were reviewed by Dr. Shea during January 2016.
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
fiberglass and steel tape measures.
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.
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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
through planting of additional native vegetation at the Site. These
recommendations have been formulated to be implemented in accordance with
recommendations for erosion control by NTI (NTI 2015a,b).
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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 high bank site (70 feet at top of bank), with gradual uphill
topography to an elevation of about 100 feet above mean sea level (msl). The
steep bank hillslope above the beach slopes back sufficiently (about 35-45
degrees) to be well covered with vegetation, mostly shrubs and trees. The area
in front of the home is relatively flat for a distance of 35 feet on the east side and
60 feet on the west side. The proposed residence addition is located
approximately 75 feet from the top of bank and about 125 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.
Conservancy Shorelines 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 f. oQ t per 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
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this property is approximately 70 feet of steep bluff (JCC 18.25.410). The
property grades upward to a maximum height of about 100 feet at the southern
property line. The underlying soils are considered stable in terms of shoreline
stability. There are no landslide hazard or erosion hazard areas on the property
(Jefferson County 2016).
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 in line
with or 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 of the buffer zone.
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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,
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 five miles north of the commercial area of Discovery
Bay, about 13 miles southwest of Port Townsend. The land area of the parcel is
approximately 305 feet long by 100 feet wide, however, another 120 feet of the
length extends into Discovery Bay. The entire parcel is approximately 0.97 acres in
size with 0.70 acres of land area. An existing driveway off of Bachelor Road
provides vehicular access to the property.
Figure 5 shows topographic features on the Site and the proposed development.
The parcel abuts a sand beach to the north and rises to 70 feet above msl at the
Top of Bank. The property is separated from adjacent areas to the south by
Bachelor Road and then U.S. Highway 101, after which the terrain continues to
grade upward. The property can be divided between a residential area surrounded
by lawn (at 70 feet elevation), the garage area (at 90 feet elevation) and an upland
area consisting of lawn and bordered by lowland forest (extending to 100-110 feet
in elevation).
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).
The house area is characterized by low grasses (lawn area), however a few native
trees, mainly Douglas fir (Pseudotsuga menziesir) and western red cedar (Thuja
plicata) are present. Other, non-native species include ivy and Himalayan
blackberry which are present along the western forest edge. The western portion of
the site includes native trees including Douglas fir, western red cedar, madrone
(Arbutus menziesh) and red alder (Alnus rubra). The groundcover in the
undeveloped upland area is dominated by salal (Gaultheria shallon), rhododendron
(Rhododendron spp.), bracken fern (Pteridium aquilinum) and sword fern
(Polys(ichum munitum). Other plants present include ocean spray (Holodiscus
discolor), Oregon Grape (Mahonia nervosa), willow (Salix spp.) and silver fir (Abies
lesiocarpa). Wetland plants found in a ditch included creeping buttercup
(Ranunculus repens), piggyback plant (Tolmiee menziesil) and facultative grasses.
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The Natural Resource Conservation Service (NRCS) has mapped three dominant
soils on and in the immediate vicinity of the Site (NRCS 2016). 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. These soils are subject to influence of tides and
storm waves (although the seawall precludes this most of the time).
Hoypu s gravelly loamy sand 15 - 30 percent slopes (HuD). This soil
formed on terraces and originated from glacial outwash near steep
ravines and drainageways. 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. Runoff is medium and the hazard of water
erosion is slight. This soil has no frequency of ponding of flooding. It
consists of gravelly loamy sand to 60 inches depth.
Clallam gravelly sandy loam — 0-15 percent slopes (CmC). This well -
drained soil formed on hills above glacial till at depths of 23-60
inches. This soil is well drained above the till and drainage is very
slow within it. Depth to water table is 19-39 inches.
The Site has coastal beach soils at the eastern edge, with most of the Site
underlain by Hoypus sails. These soils tend to be dominant along this area of
Discovery Bay. The Clallam soils are on the southern edge, near Bachelor Road.
Other soil types including Tukey gravelly loam are located to the northwest of the
parcel and Cassolary sandy loam is located several hundred feet to the southeast.
3.3 PROJECTIMPACTS
The landowner's plan for this Property entails the expansion of the southwest
corner of the house by approximately 126 square feet, demolition and removal of a
200 square foot room at the rear of the house, and rebuilding a two story
remodel/addition on the new footprint (Figure 5). The project also involves
replacement of existing stormwater drainage as necessary and modification of the
existing septic system within the area west of the house If required by the County.
A reserve dminfield would be located outside of the buffer zone.
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The primary impacts associated with this project are those generally associated
with construction. Figure 5 is a map of the existing and proposed structural footprint
on the Site. Currently existing structures on the Site, described from those closest
to the shoreline to those furthest away, include the following:
A 10 foot wide deck on the front (north) side of the residence.
The existing house including front deck. The proposed expansion will
be built on the footprint of an area in the southwest comer of the
home (126 square feet), and will not extend further waterward than
the front of the house.
• A 200 square foot room is located on the south side of the main
residence. This will be removed and then rebuilt as part of the two
story remodeVaddi ion.
A small shed previously in the buffer zone has already been
removed.
• The current septic tank will likely remain in place and continue to be
used if approved by the County. The existing drainfield will be
modified as required by the Jefferson County Health Department.
Any reserve drainfield required by the County will be located outside of the buffer
zone.
The potential impacts of this project will result primarily from the processes of
grading and clearing the areas for construction of the two story addition. Grading
and clearing of areas near existing drainage lines to be replaced and septic
modifications (if needed) and the movement of construction vehicles on the Site.
These potential impacts include the following:
The area surrounding the new addition and the area near the storm -
drainage pipes to be replaced will be cleared. Also, if required by the
County, the drainfield area to be modified will need 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 and some parking
area (NTI 2015a)). Additional earth moving and grading during the
construction process may contribute to increased erosion.
M1467-eachelorRdHMPRevision.RPT/020416/mas 14
The removal of some native vegetation in the buffer zone. Native
vegetation has already been removed near the structures and
replaced by native grasses and lawn. More may be removed in order
to expand the house, replace drainage pipes, and possibly (if
required by the County) replace the drainfield. There may be soil
impacts from the movement of construction vehicles on the Site.
Because the residence is being expanded onto an existing lawn area,
and some existing parking area will be removed, this part of the
project will actually decrease the impervious surface on the Site. The
overall footprint of the house is expected to increase by 126 square
feet. Roughly 100 square feet has already been decreased from the
recent removal of the storage shed.
The historical removal of native 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.
Any further loss of 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 onsite 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 sift fence will be placed on
the edges of the construction area, adjacent to the construction
envelope and between the construction and the shoreline.
Native vegetation will be planted in two nearshore areas and one
area near the residence 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.
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3.5 DETAILED MITIGATION MEASURES
The detailed Mitigation Measures corresponding to the Plan Components listed
above are as follows:
Timing of construction, as feasible, should be limited to the "dry
season" between May 1 and September 30. 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 'vet
season," then extra measures will be required for erosion and sift
runoff control as per recommendations by NTI (NTI 2015a).
All erosion control measures should be installed prior to beginning
grading or other ground -disturbing construction activities. A silt fence
will be placed between the residence structure and the beach. This
should be kept in place until plantings and new grasses have become
established. Straw bales, jute netting or other material should be
kept on -Site and used to stabilize open areas following grading.
Three 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.
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3.6 IMPLEMENTATION AND TIMING
The continuation of construction on the Site should be conducted between May 1
and September 30 as feasible, 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 carded 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 plantings be conducted by a landscaping firm, certified arborist,
registered nursery or qualified botanists and that success of plantings be
maintained above a performance standard of 90 percent (see Section 3.7).
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 110 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 earned out daily during construction. Any evidence of erosion or sedimentation
leaving the construction area (particularly during or after storm events) will result in
yWV1467-BachelorRdHMPRevision.RPT/020416/mas 17
immediate action to block erosion and sediments. Such siltation can 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 Planting 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 Planting 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 viable
vegetation drops below this level in the planting areas, contingency
measures must be implemented.
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 include 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 PLANTING PLAN
A Planting Plan as diagrammed in Figure 6 will be implemented to mitigate for the
disturbance of native vegetation in the buffer areas. Since the exact extent of
drainfield modification is not known at this time, plantings have been proposed to
offset potential modification of the drainfield area in case this is required. A list of
native plants that will be used for mitigation and restoration can be found in Table 1.
Revegetation 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, stormwater pipe replacement, and septic system modification is grassy
lawn. New native grass -seed mixture should be used to replant the construction
area near where the 126 square foot addition to the house will occur, where
stormwater drainage work will occur and where the modified septic-drainfield area
will be placed (if required by the County), upon completion of those activities. The
three areas designated for additional plantings (to offset the house expansion
project) include:
Planting Area A is a 10 foot by 35 foot area adjacent to and landward
of the existing Top of Bank on the west side of the parcel. The area is
presently covered by low-cut mixed grasses and forbs (lawn). This
area should be planted with the mix of shrubs and ground cover
found in Table 1. Plants may be clustered so as to leave pathways to
the bank and beach.
Planting Area B is an approximately a 10 foot by 25 foot area that will
be planted north of the house on the east side of the parcel. This
area is presently vegetated by mixed grasses and forts. This area
should be planted with a mix of selected low shrubs and groundcover
(Table 1). These plants should be planted in similar patterns as Area
A.
Planting area C will be a 20 foot by 20 foot area behind (south of) the
house, immediately behind the room which will be removed. This
area will include planting of small trees, shrubs and groundcover to
enhance the buffer zone.
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.
MI 467-BachelorRd H MPRevision. RPT/020416/mas 19
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TABLE 1. LIST OF NATIVE PLANTS FOR
BUFFER MITIGATION AND ENHANCEMENT
— --
r Location
--
Species
Scientific Name
Number
Size
31
^
A
Salal -
Gaultheria shallon
10
gallon
A
_
Oregon Grape
Mahonia nervosa
10
4" pot
A
Bracken fern
Pteridium a uilinum
15
1
gallon
A
Snowberry
S mphorocarpus a/bus
12
1
gallon
8
Red Elderbe
Sambucus racemosa L
5
1
gallon
i$
B
y".'r•�2"vi*v,.
Salal
Gaultheria shallop 10 1 gallon
B
Kinnikinnick
Amtosta h los uva-ursi
10
1
gallon
B
Vine Ma le _,_
Acercircinatum_
5
_5_1
1
gallon
B
_
Oceans ray ,.
Holodiscus discolor
gallon
C
Deer fern
Blechnum s icant
61
gallon
_
C
Indian plum
Oemleda cerasiformis
2
1
gallon
C
Oceanspray
Holodiscus discolor
3
1
gallon
C
Oregon grape
Mahonia nervosa
10
1
allon
C
Sword fern
Pol stichum munitum
10
1
gallon
C'
W
a
VWV1467-BachelorRoadHMPRevision/02D416/mas 21
Soils on the Site are mostly gravelly loams and sandy gravelly foams which are
generally 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 6. Large trees, where recommended, should be placed on 10 -
foot centers. Small trees will be placed on eight -foot centers (oceanspray and
Indian plum) and shrubs will be planted on six-foot centers or less. Staggering of
plants, 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.
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.
W W 1467-BachelorRdHMPRevision.RPT/020416/mas 22
5.0 CONCLUSIONS AND RECOMMENDATIONS
5.1 CONCLUSIONS
The property presently contains an existing home and deck, septic-drainfield
system, and an existing shed within the buffer zone. A three car garage is located
outside of the buffer zone. The residence will be expanded by constructing a 126
square foot footprint addition on the southwest comer (but not closer to the water
than the present front of the house), and remove and replace an existing 200
square foot room (southern part of the current residence) with a two story
remodel/addition. A 100 square foot shed has already been removed from the
buffer zone.
The property owner also intends to replace existing water drainage lines adjacent to
the house as recommended by NTI Engineering and Surveying (NTI 2015a).
Modifications to the existing septic system will be made as required by Jefferson
County. 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 (roughly 110 feet from OHWM).
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 sift fence and other standard measures and
will be used during construction to minimize sheet and rill erosion (see also NTI
2015a). A Planting Plan (See Figure 6 and Table 1) will be implemented to provide
additional vegetation adjacent to the shoreline, and south of the house. Also, ivy
and any other invasive, non-native plants should be removed from the buffer zone.
This report and associated Habitat Management Plan 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 N it is implemented by the property owners and enforced by the County.
The silt fence should be emplaced prior to construction and should be left in place
throughout construction. Additional erosion control materials should be kept on
Site to address any erosion observed during construction.
vvvv1467-Ba0he1orRdH1VlPRevision.RPT/020416/mas 23
The Planting Plan outlined in this report should be implemented. The Plan should
be monitored according to the instructions outlined in this report 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 fiRering capacity of
the soils in this area.
W W 1467-BachelorRdHMPRevision.RPT/020416/mas 24
6.0 REFERENCES
Creative Design Solutions. 2016. Unpublished Site Plan for 651 Bachelor Road,
Jefferson County, Washington. Port Angeles, Washington.
Jefferson County. 2016. Online Map Database. http://www.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. 2016. Online mapping software. www.googleearth.com.
Imagery date July 5, 2013. 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
Natural Resource Conservation Service (NRCS). 2016. Web Soil Survey.
http://webSolisurvey.nrcs.usda.gov/app/HomePage.htm
NTI Surveying and Engineering (NTI). 2015a.
NTI Surveying and Engineering (NTI). 2015b. Geotechnical Site Review for 651
Bachelor Road (#002352019). Port Angeles, Washington.
Pojar, J. and A. MacKinnon. 1994 (reprinted 2004). Plants of the Pacific Northwest
Coast. Lone Pine Publishing Company. Redmond, Washington.
Precision Drafting and Design (PDD). 2015. Unpublished Building Plans for
Remodel/Addifion for 651 Bachelor Road. Sequim, Washington.
Revised Code of Washington. 2016. RCW36.70A.480. Shoreline of the State.
hftp://apps/leg.wa.gov/rcwfdefault.aspix?cfte=3670A.480.
VNN1467-BachelorRdHMPRevision.RPTl0204161mas 25
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
WW1 467-13achelorRdHMPRevision. RPT/020416/mas 26
APPENDICES
VVVd1467-BachelorRdHMPRevision.RPTl0204161mas 27
APPENDIX A
SITE PHOTOGRAPHS
W W 1467-BachelorRoadHMPRevision.APPA1020416/mas A-1
1) Front or house.
Idition.
WW1467-BachelorRoadHMPRevision.APPA/020416/mas A-2
3) West side of house.
4) Planting Areas A and B.
M1467-BachelorRoadHMPRevision.APPA/020416/mas A-3