HomeMy WebLinkAboutZON2016-00042 Habitat Management PlanWESTECH COMPANY
r Environmental Consulting Site Permitting
Ms. Emma Bolin, Planner
Jefferson County DCD
621 Sheridan Street
Port Townsend, WA 98368
Dear Ms. Bolin:
July 25, 2017
JUL 19 1011 3
JEFFERSON CDUN7y DC
D
As you requested, this letter constitutes an Addendum to our Habitat Management Plan for the
property at 41 Pine Way, APN Nos. 984-00-0410, 0412 and 0414 in Port Ludlow, Washington.
As you are aware, the property owner has applied for Permits to replace the current on-site
Septic System with a new Septic System consisting of two Glendon Biofilter Units.
The current Habitat Management Plan (HMP) provides mitigation for that system installation. In
addition, the Jefferson County Environmental Health Department has required extension of a
stream culvert on the adjacent property, extending approximately 50 feet upstream from its
present upstream end, terminating at the property line and existing fence. In addition, a small
gap at the downstream end of the culvert will be sealed. Work will be completed in accordance
with plans shown in Sheets 2, 3 and 4 of 8 prepared by Creative Design Solutions (2016) for the
property.
Additionally, the culvert installation will comply with requirements of the Hydraulic Project
Approval from Washington Department of Fish and Wildlife issued October 28, 2016, Permit
Number 2016-6-558+01. Those conditions include:
1) Completion of Project (Culvert installation) by September 1, 2016
2) Work to Approved Plans (CDS 2016)
3) Invasive Species Control
4) Pre- and Post -Construction Notification
5) Fish Kill/Water Quality Problem Notification
6) Limit Vegetation Removal
P.O. Box 2876, Port Angeles, Washington 98362 - Telephone: (360) 565-9333
email: brad@westeclicoinpany.com
Emma Bolin
July 25, 2017
Page Two
7) Protect Disturbed Areas from Erosion
8) Straw used for erosion and sediment control free of noxious weeds
9) preveott contaminants from reaching Waters of the State
10) Route construction water — In -Water Work Area Isolation
11) Use least -impacting re-routing of water
12) Return diverted water to the channel below work area, dissipate energy
13) Install culvert in dry or in isolation by pumping water around work area
These measures are incorporated into the HMP by reference in this Addendum.
Additionally, a small amount of low -importance habitat (currently lawn area) will be converted
through culvert installation. Westech Company recommends adding a small number of
additional plants into Planting Areas A and B as shown in Figure 6 and Table 1 attached to
compensate for this minor decrease in habitat. Disturbed areas should be replanted with native
grass seed mix (this has been increased to include the culvert extension construction area).
With these modifications, the HMP will achieve No Net Ecological Loss, with the culvert
replacement and the septic system replacement. It should be noted that septic replacement can
occur following culvert replacement, however, the culvert replacement should be completed by
September 1, 2017 in order to comply with the terms of the Hydraulic Project Approval (WDFW
2016).
With these modifications to the HMP, Westech believes that the project will cause no significant
impacts under the State Environmental Policy Act (SEPA).
Please call or email me if you have any questions regarding this Addendum to the HMP for the
Project. Thank you.
Sincerely, ,�
G. Bradford S ea, Ph.D.
Senior Environmental Scientist
GBS/ms
P.O. Box 2876, Port Angeles, Washington 98362 - Telephone: (360) 565-9333
email: brad@westechcompany.com
U)
0
c
�u
a
G) 0
o =r
� o
CD 3
M
v v
N N
O O
v v
TABLE 1, LIST OF NATIVE PLANTS FOR
BUFFER MITIGATION AND ENHANCEMENT
Location
Species
Scientific Name
Number
Size
A
Salal
Gaultheria shallop
12
1 gallon
A
Ore on Grape
Mahonia nervosa
10
4" pot
A
Bracken fern
Pteridium a uilinum
10
1
gallon
A
Snowber
Svmphorocarpus albus
_ 10
1gallon
A
Red Elderberry
Sambucus racemosa L.
5
1
gallon
B
Salal
Gaultheria shallon
12
1
gallon
B
Deer fern
Blechnum s icant
10
1
gallon
B
Vine Maple
Acer circinatum
5
1
gallon
B
Oceanspray
Holodiscus discolor
5
1
" allon
C
Native grass seed mixture
Gramme spp.
15
pounds
WW1508-PinewayHMP/0725171mas 20
WES TECH COMPANY
Environmental Consulting - Site Permitting
MITIGATION AND HABITAT MANAGEMENT PLAN
41 PINE WAY
PORT LUDLOW, WASHINGTON 98365
ASSESSOR'S PARCEL # 984-00-0410, 0412, 0414
JEFFERSON COUNTY, WASHINGTON
Cquly. jOCo
June 2017
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
41 PINE WAY
PORT LUDLOW, WASHINGTON 98365
ASSESSOR'S PARCEL # 984-00-0410,0412,0414
JEFFERSON COUNTY, WASHINGTON
June 2017
G. Bradford Shea, Ph.D.
Copyright 2017 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
1.1 Background
1
1.2 Proposed Project
1
1.3 Regulatory Framework
6
2.0 APPROACH AND METHODS
7
2.1 Approach
7
2.2 Methods
7
3.0 MITIGATION PLAN
10
3.1 Regulatory Setting
10
3.2 Existing Conditions
11
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
15
3.8 Contingency Plan
17
4.0 HABITAT MANAGEMENT AND PLANTING PLAN
18
5.0 CONCLUSIONS AND RECOMMENDATIONS
22
5.1 Conclusions
22
5.2 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. Parcel Map Showing DNR Stream on the Project Site
5
Figure 5. Glendon Septic System Design Plan
8
Figure 6. Proposed Planting Areas for Habitat Management Plan
19
APPENDICES
Appendix A — Site Photographs
A-1
W W 1508-PinewayH M P. TOC/061317/ma f
1.0 INTRODUCTION
1.1 BACKGROUND
The Property (Site) is located at 41 Pine Way in Port Ludlow, Jefferson County
Washington. The Property is owned by the Ardoin Living Trust, Conrad M. Ardoin
and Christine M. Ardoin Trustees, listed at the 41 Pine Way address. It is recorded
as Assessor's Parcels # 984-00-0410, 0412, 0414. The Site lies within Jefferson
County, Washington in the Southeast Quarter of Section 22 of Township 28 North,
Range 1 East, W.M. (Figures 1, 2, 3, and 4). The Site is located approximately 4.0
miles south of Port Ludlow near the shoreline of Paradise Bay in unincorporated
Jefferson County, Washington.
The Property consists of three parcels. Parcel 0410 is the Site of the existing
residence and is 0.11 acres in size. Parcel 0412 is 0.21 acres and Parcel 0414 is
0.16 acres in size for a total of 0.48 acres. Parcels 0412 and 0414 are traversed by
a small perennial stream. The stream lies south of Parcel 0410 on an adjacent
parcel. There are no wetlands, other than a small fringe along the stream channel.
1,2 PROPOSED PROJECT
The Property currently contains a one story house with irregular footprint (roughly
1500 square feet) with a front deck. There are existing small sheds located on both
Parcels 0412 and 0414.
The proposed project is a new septic system using two Glendon units. The new
septic system will be located on the northeast side of the existing residence on Parcel
0410 as shown in Figure 5 (CDS 2016).
The existing residence is located on both Parcels 0410 and 0412 (see Appendix A
for site photographs). The new septic system will be placed on the lawn area south
and east of Pine Way. Septic tanks will be located northeast of the House. This new
Glendon system will lie over an area which is presently lawn, and adjacent to a gravel
parking area. The new septic system will lie within 20-25 feet of the perennial stream
channel on the adjacent property.
The Washington Department of Fish and Wildlife (WDFW) has issued a Hydraulic
Project Approval for the new septic system. Its provisions include a timeframe
beginning on July 15 and ending on September 1, 2017. It requires compliance with
existing plans (CDS 2016) and approval by Jefferson County.
WWI 60 8- P i n eway H M P .RPT/061317/m as
Jol 4--J
Lij
/f kL7
U)
0
w IA:co
Uri
�WL
n
m
m
a
M
W
rn
ii
CD 0
N N
C C
O' O
o U
U c
O
r L4
O
Cl)
I
Q1
CD
U
O
.o
N
L
C
O
E
m
.r
CO
w
Z
rn
c
O
L
CO
CL
ca
m
a
rn
ii
r ti
0 0
N N
C C
0
E °
O U
U c
O
L 12
N N
O
1.2 Regulatory Framework
The stream channel is listed as Non -Fish Habitat by Washington Department of
Natural Resources (DNR) and Jefferson County. East of the Site, the stream flows
into a culvert and crosses under Paradise Bay Road before discharging into Paradise
Bay, several hundred feet to the east. Site investigations and conversations with the
owner and others indicate that the stream appears to be perennial, likely originating
from a small spring located on the hillside to the west of the Site.
Non -fish bearing streams which are perennial (Np streams) require a 75 foot buffer
zone under the Jefferson County Critical Areas Code (JCC 18.22). Non -fish bearing
seasonal streams (Ns streams) of less than 20 percent slope require a 50 foot buffer.
Determination of the perennial or seasonal nature of the stream would require
additional confirmation during late summer, however, the septic system location
would be within the buffer in both cases. This Habitat Management Plan is not
dependent on the determination of seasonality in the stream but has been formulated
to mitigate and compensate for impacts from the new septic system for either
determination.
The marine shoreline to the east of 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 salmon (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. The proposed septic system
will be located roughly 275 feet from that shoreline, well outside of the shoreline
buffer zone.
Because of the proposed new septic system location, the Project will disturb surface
soils and some existing vegetation within the stream buffer. 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 (HMP).
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 associated watershed and to ensure "No Net Ecological Loss of functions within
the stream and its buffer zone, or the nearby shoreline (RCW36.70A.480). This
document is intended to satisfy the requirements of pertinent Jefferson County and
State regulations and ordinances.
WW1 508-PinewayHMP. RPT/061317/mas
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 DNR
streams and 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 (CDS 2016) was reviewed and
utilized to help define proposed planting areas (see Section 3.3 and Figure 5). The
Hydraulic Project Approval issued by Washington Department of Fish and Wildlife for
this project was also reviewed.
Westech's field investigations for the HMP were carried out during the period March
— May 2017 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 May 2017.
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 residential uses and 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.
WW1508-PinewayHMP.RPT/061317/mas 7
z
z A
Cl)
Z5
Lu
11
LJI
7. A8
0
Cl-
Ljj
fz�
�
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 standard recommendations
for erosion control.
WW1508-PinewayHMP.RPT/061317/mas 9
3.0 MITIGATION PLAN
3.1 REGULATORY SETTING
There are several jurisdictional issues related to the new septic system proposed
for these parcels of land. The Site is at an elevation of 70 feet above mean sea
level near the proposed septic system location.
The new septic system will be located at a distance of approximately 275 feet from
the marine shoreline, which is outside of the Shoreline Management zone. The
shoreline in this area is designated as "Suburban" in the Shoreline Master Program
of Jefferson County.
There is a non -fish bearing stream (Type Np or Ns) located on Parcels 0412 and
0414, and adjacent to Parcel 0410. This Stream is less than 50 feet from the new
septic system location. The new septic system will be located in a lawn area
northeast of the existing residence. Vegetation near the stream channel is mostly
shrubs and trees.
The Property 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 nearby marine 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 ten foot building setback from the buffer is required. Any project
located within this buffer must follow Jefferson County drainage and erosion
control, grading and vegetation retention standards (JCC 18.22.270). Since the
proposed project is more than 275 feet from the marine shoreline, these
requirements do not apply, however, erosion control features will be an important
part of the project requirements, due to the presence of a non -fish bearing stream
near the proposed Project.
WW1508-PinewayHMP RPT/061317/mas 10
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) to offset
potential ecological effects (JCC 18.22.265).
Because this project involves elements to be built in the stream buffer area, 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 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 stream buffer zone.
In accordance with Jefferson County requirements, 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 three miles southeast of Port Ludlow. The Parcels are
approximately 0.48 acres in size. The Property has an existing residence and
adjacent graveled parking areas. Pine Way provides vehicular access to the
Property.
Figure 5 shows topographic features on the Site and the proposed new septic
system. The Property lies on a hillslope which continues to grade upward to the
west. The southern area of the Property is undeveloped except for the presence of
three small sheds. There are two wooden pedestrian bridges across the stream
channel on Parcels 0412 and 0414.
WWI 608-PinewayHMP.RPT/061317/mas 11
VLqetatian
The area near the house is characterized by low grasses (lawn area), however a few
native trees, mainly Douglas fir (Pseudotsuga menziesh) and western red cedar
(Thuja plicata) are present. Other species include a mixture of native and non-native
planted shrubs and small trees. Skunk cabbage (Lysichiton americanum), creeping
buttercup (Ranunculus repens) and a variety of ferns (sword fern, deer fern, lady
fern) are found along the stream -side zone.
On -Site Soils
The Natural Resource Conservation Service (MRCS) has mapped three dominant
soils on and in the immediate vicinity of the Site (NRCS 2017). 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).
Alderwood graven sandy loam 15 - 30 percent slopes (AIC). This soil
formed on terraces and originated from glacial till with a component of
volcanic ash in the upper part. It is moderately well drained and has a
depth to a restrictive layer of 20-40 inches or more as is the depth to
water table (18-36 inches). Runoff is medium and the hazard of water
erosion is low. Available water storage is low (2.5 inches). This soil
has no frequency of ponding of flooding. It consists of gravelly sandy
loam and very gravelly sandy loam to 60 inches depth.
• Everett gravelly sandy loam — 0-15 percent slopes EvC . This
somewhat excessively drained soil formed on terraces in glacial
outwash at depths of 0-60 inches. This soil is well drained above the
restrictive layer (80 inches). Depth to water table is more than 80
inches. It transmits water within the restrictive layer (1.98 -- 5.95
inches/hr). It has no frequency of flooding or ponding. It consists of
gravelly and very gravelly sandy loam to depths of at least 60 inches.
The Site has coastal beach soils roughly 250 feet east of the Site. The Site itself is
mostly underlain by Alderwood soils. These soils tend to be dominant along this area
of Paradise Bay, The Everett soils are on the eastern edge, near Paradise Bay Road.
WUv1508-PinewayHMP.RPT/061317/mas 12
3.3 PROJECT IMPACTS
The landowner's plan for this Property entails the replacement of the current failing
septic system with a new septic system (CDS 2016) (Figure 5). The new septic
system is within 50 feet of the non -fish -bearing stream, thus requiring preparation of
this HMP.
The primary impacts associated with this project are those generally associated with
construction. Figure 5 is a map of the proposed septic system footprint on the Site.
Currently existing structures on the Site include:
• A 10 foot wide deck on the front (east) side of the residence.
The existing house including front deck.
• Three small sheds located south of the house.
• The current septic tank will likely be abandoned in place if approved by
the County. The new Glendon septic system will be installed as
required by the Jefferson County Health Department.
The potential impacts of this Project will result primarily from the processes of grading
and clearing the areas for placement of the new septic system. These potential
impacts include the following:
The new Glendon drain -field area 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 (CDS
2016)). Earth moving and grading during the construction process may
contribute to increased erosion.
The removal of some native vegetation in the stream 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 replace the drainfield. There may be soil impacts from the
movement of construction vehicles on the Site.
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.
vWU1508-PinewayHMP.RPT/061317/mas 13
The Management Plan below is intended to
Mitigation Measures developed in this Plan a
impacts to the shoreline habitat and buffer zone
3.4 PLAN COMPONENTS
offset these adverse impacts. The
re intended to compensate for the
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 nearby stream. This will be
accomplished through project timing and emplacement of control
measures during construction. A silt fence will be placed on the edges
of the construction area, adjacent to the construction envelope and
between the construction and the stream.
Native vegetation will be planted in three areas to mitigate disturbance
to existing areas and plants in the buffer zone.
No nutrients, pesticides or other contaminants will be used within 100
feet of the stream.
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 "wet season," then
extra measures will be required for erosion and silt runoff control as
per recommendations in this Plan.
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 stream channel.
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.
W W 1508 -Pi newayH M P. RPT/061317/mas 14
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 stream and nearby marine 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 50 feet of the OHWM of the stream channel.
3.6 IMPLEMENTATION AND TIMING
The continuation of construction on the Site should be conducted between May 1
and September 30 as feasible (the current HPA limits construction to July 15 —
September 1, 2017), 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 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.
WW1508-PinewayHMP.RPT/061317/mas 15
The narrow size of buffers at this Site (20-30 feet from OHWM to the new septic
system) 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 (particularly during or after storm events) will result in 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. Fallow -Lip
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.
WW1508-PinewayHMP.RPT/061317/mas 16
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.
WW1 508-PinewayHMP.RPT/061317/mas 17
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. 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 septic system
is grassy lawn. New native grass -seed mixture should be used to replant the
construction area over the new septic -drain -field area upon completion of
construction. The three areas designated for additional plantings (to offset the
project) include:
Planting Area A is a 10 foot wide area adjacent to the northern edge of
the stream channel, across Parcels 0412 and 0414. The area is
presently covered by low-cut mixed grasses and forbs (lawn) and a
narrow band of streamside vegetation. This area should be planted
with the mix of shrubs and ground cover designated for Planting Area
A as found in Table 1. Plants may be clustered so as to leave the
existing pathways and bridges across the stream.
Planting Area B is an approximately a 50 foot by 15 foot area that will
be planted south of the house on the south side of the stream on
Parcels 0412 and 0414. This area is presently vegetated by mixed
grasses and forbs, although a portion of it has been cleared. This area
should be planted with a mix of selected low shrubs and groundcover
(Table 1, Planting Area B). These plants should be planted in similar
patterns as Area A.
Planting Area C will be a 30 foot by 60 foot area over the new Glendon
units and the septic tanks. This area will include planting of native
grasses 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, and shading. The native vegetation selected for this Mitigation and Habitat
Management Plan were chosen for these reasons.
WW1508-PinewayHMP.RPT/061317/mas 18
T
m
rn
U-
ti ti
C) 0
N N
A L
C �
Q coJ
E w
O
U OM
0
s o
U ('
N
O
j
O
U)
TABLE 1. LIST OF NATIVE PLANTS FOR
BUFFER MITIGATION AND ENHANCEMENT
Location
Species
Scientific Name
Nurrrlaer
Size
Gaultheria shallon
A
Sala[
10 1
allon
A
A
Oregon Grape
Bracken fern
Mahonia nervosa
Pterrdium a uillnum
8
10
10
5
10
8
5
1
1
1
1
1
4" of
gallon
gallon
gallon
allon
_gallon
allon
A
Snowberry
S m horoca us albus
A
B
B
B
Red Elderber
Salal
Deer fern _ _
Vine Maple _ _
Sambucus racemosa L
Gaultheria shallop
Blechnum s icant
Acer circinatum
B
Oceans ray
Holodiscus discolor
5
1
gallon
C
Native rass seed mixture
Graminae SPA
10ounds
WW1508-PinewayHMP/061317/mas 20
Soils on the Site are mostly gravelly sandy loams 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 grew 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.
VWV1508-PinewayHMP. RPT/061317/mas 21
5.0 CONCLUSIONS AND RECOMMENDATIONS
5.1 CONCLUSIONS
The Property presently contains an existing home and deck, septic-drainfield system,
and three existing sheds within the stream buffer zone.
The new septic system will be installed as required by Jefferson County. The
proposed project is being constructed inside the stream buffer zone. No new
structures are part of the Project. The new septic system will be located roughly 20-
30 feet from the Stream's off-site Ordinary High Water Mark (OHWM).
Measures outlined in this report will be enacted to mitigate additional construction on
the Site and incrementally improve habitat and vegetation in the stream's buffer 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 (see CDS 2016).
A Planting Plan (See Figure 6 and Table 1) will be implemented to provide additional
vegetation adjacent to the stream and south of the existing house. Also, ivy,
Himalayan blackberries and other invasive, non-native plants should be removed
from the buffer zone where feasible.
This report (Habitat Management Plan) meets the intent of the Jefferson County
Critical Areas Code ensuring "No Net Loss of Ecological Function" due to the
Mitigation proposed, and applicable sections of the 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 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.
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.
WW1508-PinewayHM P. RPT/061317/mas 22
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 stream's
OHWM. These measures will provide mitigation for the new Glendon system on the
Site, and should improve conditions in the stream and any indirect impacts to the
nearby shoreline of Paradise Bay.
WW1508-PinewayHMP.RPT10613171mas 23
6.0 REFERENCES
Creative Design Solutions. 2016. Unpublished Site Plan for 41 Pine Way, Jefferson
County, Washington. Port Angeles, Washington.
Jefferson County. 2017. Online Map Database. http://www.co.jefferson.wa.us/.
Jefferson County, Washington.
Jefferson County. 2017. Jefferson County Critical Areas Code. Title 18.22 JCC.
Department of Community Development. Port Townsend, Washington.
Google Earth. 2017. Online mapping software. www.googleearth.com. Imagery
date August 18, 2016. Europa Technologies.
Hitchcock, C.L. and A. Cronquist. 1973. Elora 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). 2017. Web Soil Survey.
httpal/websoilsurvey.rires.usda.gov/aoo/HomePage.lato7
Pojar, J. and A. MacKinnon. 1994 (reprinted 2004). Plants of the Pacific Northwest
Coast. Lone Pine Publishing Company. Redmond, Washington.
Revised Code of Washington. 2016. RCW36.70A.480. Shoreline of the State-
http://apps/leg.wa.gov/rcw/defauIt.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.
WW1508-PinewayHMP.RPT/061317/mas 24
APPENDICES
WW1508-PinewayHMP.RPi1061317/mas 25
APPENDIX A
SITE PHOTOGRAPHS
W W 1508 -Pi newayM P.APPA/060317/mas A-1
1) Location of proposed Glendon Septic System on lawn area east of the
residence.
i v tti1 w P V,
2) Stream crossing Parcel 0412 and flowing onto neighboring property.
WW1508-PinewayMP.APPA/060317/mas A-2
3) Stream and streamside vegetation crossing Parcels 0412 and 0414.
4) Stream and Planting Area A.
WW1508-PinewayMP.APPA/060317/mas A-3
5) Upper (western) portion of Planting Area B.
6) Pedestrian bridge across stream channel and lower part of Planting Area B.
WW1508-PinewayMP.APPA/060317/mas A-4