HomeMy WebLinkAboutHabitat Management Plan 021-184-004WESTECH COMPANY
Environmental Consulting Site Permitting
MITIGATION AND HABITAT MANAGEMENT PLAN
81 REEF ROAD
ASSESSOR'S PARCEL # 021-18-4004
JEFFERSON COUNTY, WASHINGTON
July 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) 565-9333
email: brad@westechcompany.com
MITIGATION AND HABITAT MANAGEMENT PLAN
81 REEF ROAD
ASSESSOR'S PARCEL # 021-18-4004
JEFFERSON COUNTY, WASHINGTON
July 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
CHAPTER/SECTION
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
Figure 2.
2.1 Approach
7
Figure 3.
2.2 Methods
7
3.0
MITIGATION PLAN
9
Figure 5.
3.1 Regulatory Setting
9
Figure 6.
3.2 Existing Conditions
11
3.3 Project Impacts
13
3.4 Plan Components
15
3.5 Detailed Mitigation Measures
16
3.6 Implementation and Timing
17
3.7 Mitigation Monitoring
17
3.8 Contingency Plan
19
4.0
PLANTING PLAN
20
5.0
CONCLUSIONS AND RECOMMENDATIONS
24
5.1 Conclusions
24
5.2 Recommendations
24
6.0
REFERENCES
26
TABLES
Table 1. List of Native Plants for Buffer Mitigation and Enhancement
22
FIGURES
Figure 1.
Location Map
2
Figure 2.
Vicinity Map
3
Figure 3.
Parcel Map
4
Figure 4.
2013 Aerial Parcel Map
5
Figure 5.
Site Plan
6
Figure 6.
Site Map Showing Planting Areas
21
APPENDICES
Appendix A — Site Photographs A-1
Appendix B — Arborist Report B-1
Appendix C — Geology Hazard Assessment C-1
WVV 1516-ReefRd H M P. TOC/070617/m as
1.0 INTRODUCTION
1.1 BACKGROUND
The Property (Site) is located at 81 Reef Road, on Marrowstone Island in Jefferson
County Washington. The Property is owned by Mr. Rickey Whitworth currently
located at 113 East Northgate Drive, Irving Texas 75062-3883. It is recorded as
Assessor's Parcel # 021-18-4004. The Site lies within Jefferson County,
Washington in the Southeast Quarter of Section 18, Township 30 North, Range 1
East, W.M. (Figures 1, 2, 3, and 4). The Site is located on the northwest corner of
Marrowstone Island approximately two miles north of Nordland, Washington on the
eastern shore of Kilisut Harbor in unincorporated Jefferson County, Washington.
The property is listed by Jefferson County as 4.68 acres in size. The Parcel has a
high bank (80-90 feet in height) above Kilisut Harbor, 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).
A Wetland Delineation was prepared during 2016 (Westech 2016a) which was
approved by Jefferson County. The Wetland Delineation indicated the presence of
several wetlands on the Site and along the southern property boundary. Due to the
necessary proximity of the access driveway within the wetland buffer zones,
Westech then prepared a Critical Area Stewardship Plan (CASP) (Westech 2016b)
in order to offset impacts to the wetlands from the driveway. Native plants were
specified and planted during the fall of 2016 in accordance with that CASP. The
County approved the CASP and the As -Built Conditions Report (Westech 2017a)
following the plantings (Frostholm 2017, personal communication). The driveway
was placed as specified by the County and now provides vehicular access to the
property from Reef Road.
1.2 PROPOSED PROJECT
There are currently no structures on the property. The owner is proposing a
Glendon type Septic System, a garage and a residence to be placed on the parcel
(see Figure 5).
Planned construction activities will occur on the northwest area of the parcel. The
home -site and septic system are governed by Jefferson County Code which
requires a standard buffer of 150 feet from the OHWM.
The owner has requested to reduce the shoreline buffer by a distance of 20-30 feet
as per house plans submitted for the building permit (see Appendix A for site
photographs). The buffer reduction would require preparation of a Habitat
Management Plan (HMP) as provided in this document.
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1.3 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 Salmon (50 C.F.R. Section 226). The shoreline is
classified as a "Fish and Wildlife Habitat Conservation Area" (FWHCA) by
Jefferson County, requiring a 150 -foot standard buffer from the OHWM plus a 10
foot additional setback for structures.
The Jefferson County Code allows in certain circumstances, the reduction of the
standard shoreline buffer by 25 percent (to 112.5 feet, plus the 10 -foot building
setback), Justification of this setback requires a demonstration of "No Net
Ecological Loss" to the shoreline environment. The buffer reduction also requires
preparation of a Habitat Management Plan to offset impacts from buffer reduction
and to demonstrate "No Net Ecological Loss".
It is the intention of the owner to build a new home within the 150 -foot shoreline
buffer. The house will lie at a distance of at least 130 feet from the OHWM. The
owner also will situate the home and septic areas to maximize protection and
retention of mature trees, both inside and outside of the standard shoreline buffer
zone.
The Glendon bio -filter septic system will be placed to the east of the house as
shown in Figure 5. The system consists of four Glendon Units located east of the
home -site and north of the existing driveway.
The Project will disturb surface soils and some existing vegetation. Stormwater
drains will be installed as necessary. The parking area will slightly decrease
impervious surfaces on the Site. 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.
W W 1516-ReefRdH MP. RPT/070617/mas
2.0 METHODS
2.1 APPROACH
The approach for this investigation into the impacts of development of the 81 Reef
Road Project 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 Shipley Architects (2017) 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 buffer
reduction were reviewed. Also reviewed were updated reports by the Project
Arborist (Sitkum Tree Service 2017) and the Geotechnical Engineers (Stratum
Group 2017).
Westech's field investigations for the Habitat Management Plan (HMP) were carried
out during the period March — June 2017 by Dr. G. Bradford Shea, Principal
Ecologist. Mr. Paul Ruben, Ecologist, assisted with identification of tree species
and GPS measurements of tree location in and near the shoreline buffer zone.
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 June
2017 for preparation of this HMP.
2.2 METHODS
Westech's field studies 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 near the proposed Home -Site. Site
measurements were taken (including dimensions of proposed planting areas, tree
species and existing shrub species) using fiberglass and steel tape measures and a
tree circumference tape measure.
A qualitative assessment of the landscape was conducted to determine the
presence of invasive species, the composition and characteristics of plants in and
near the standard buffer zone. Other data had been previously collected for the
Wetland Delineation and the CASP Reports. This information was used, as
appropriate, 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 the Geological Report (Stratum Group
2017).
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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 (80-90 feet at top of bank), with relatively flat
topography to an elevation of about 90-100 feet above mean sea level (msl).
The steep bank hillslope above the beach slopes back sufficiently (about 35-45
degrees) to be somewhat covered by vegetation. The area in front of the home
is relatively flat for a distance of about 60 feet. The proposed residence would be
located approximately 75 feet from the top of bank and about 130-140 feet from
OHWM.
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 foot per foot of bank height, whichever is greater
unless modified by recommendations of a Geological Report" This set -back is to
be measured from the bank's edge when the bank height is greater than 10 feet
WVV 1516-ReefRd H M P. RPT/070617/mas 10
and shall not exceed 100 feet. The elevation of the bank at this Property is
approximately 80 feet of steep bluff (JCC 18.25.410). The Property grades
upward to a maximum height of about 90-100 feet at the northeastern corner.
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 2017).
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 OHWM for areas in which
"federally listed species have a primary association." In addition, a ten 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 within the standard 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
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.
W W 1516-ReefRd H M P. RPT/070617/mas 11
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 HMP 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 and
enhancing trees and other plant species, limiting access to habitat areas,
seasonally restricting construction activities, control of potential erosion and
sedimentation, and establishing a timetable for the periodic review of the Plan
(18.22.440).
3.2 EXISTING CONDITIONS
The Site is located on a westward facing bluff along the western shoreline of
northern Marrowstone Island. The land area of the parcel is approximately 4.7
acres. The Site is located north of Fort Gate Road at the northern end of Reef
Road, which provides vehicular access to the Property. The lot is roughly 260 feet
wide by 780 feet in length (east to west).
Figure 5 shows topographic features on the Site and the proposed home -site. The
parcel abuts a sand beach to the west and rises to 80-90 feet above msl at the Top
of Bank. The Property has been developed with an access driveway and parking
area adjacent to the proposed home -site and septic system.
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 property is characterized by forest dominated by native trees, mainly Douglas
fir (Pseudotsuga menziesh), hemlock (Tsuga heterophylla) and western red cedar
(Thuja plicata). Non-native species include Himalayan blackberry (Rubus discolor)
which is present mainly within a small cleared area near the southern property
boundary. The western portion of the site also includes native trees including
Douglas fir, western red cedar, madrone (Arbutus menziesi/) and red alder (Alnus
rubra). The groundcover includes salal (Gaultheria shallon), rhododendron
(Rhododendron spp.), bracken fern (Pteridium aquilinum) and sword fern
(Polystichum munitum). Other plants present include oceanspray (Holodiscus
discolor), Oregon Grape (Mahonia nervosa), willow (Salix spp.) and silver fir (Abies
lasiocarpa).
Shrub species are present near the shoreline west of the proposed house site.
These include small willows (Salix spp.), twinberry (Lonicera involucrata) and rose
(Rosa gymnocarpa) as well as herbaceous plants and low shrubs characteristic of
the Site (salal, Oregon grape, etc.).
VVVV1516-ReefRd HM P. RPT/070617/mas 12
The Natural Resource Conservation Service (NRCS) has mapped four 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.
Hoypus gravelly loamy sand 0 - 15 percent slopes (HuC). 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. I
consists of gravelly loamy sand to 60 inches depth.
Townsend fine sandy loam — 0-15 percent slopes (TIC). This
moderately well drained soil has a depth of 24-36 inches above its
restrictive layer. This soil is well drained above the till and drainage is
very slow within it. Depth to water table is 23-35 inches. This soil is
recorded as having low water storage capacity in its profile (about 3.1
inches) and no frequency of flooding or ponding.
Whidbey gravelly sandy loam — 0-15 percent slopes (WhC). This is a
well drained soil with a depth of 20-40 inches to its restrictive layer. 11
has a low to moderately low capacity to transmit water in its most
limiting layer (0.00 — 0.06 inches/hour). Depth to water table is 18-30
inches. This soil is recorded as having low water storage capacity in
its profile (about 1.9 inches) and no frequency of flooding or ponding.
The Site has coastal beach soils at the western edge, with most of the Site
underlain by Hoypus, Townsend and Whidbey soils. None of these soils is listed on
the NRCS Hydric Soils list, however, hydric soils were found in depressional areas
on the southern and eastern areas of the property as documented in the Wetland
Delineation and CASP Reports (Westech Company 2016 a,b).
3.3 PROJECT IMPACTS
The landowner's plans for this Property are to construct a residence, garage and
septic system as shown in Figure 5. A reserve drainfield would be located outside
of the buffer zone.
VVW 1516-ReefRd H M P. RPT/070617/mas 13
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. No structures currently exist on the Site. Proposed home -site features
include
• A single family residence including two living pods (main and guest
areas) and front deck. The proposed deck will extend 8-10 feet
further waterward than the front of the house, which will be located
landward a distance of 130 feet from the OHWM.
• A two car detached garage located on the east side of the main
residence outside of the standard buffer zone.
• A four Glendon Unit septic system located on the east side of the
main residence outside of the standard buffer zone.
• A proposed reserve drainfield will be located outside of the 150 foot
buffer zone.
• The home will utilize the existing driveway and graveled parking area,
which will not extend within the 150 foot standard buffer zone.
These features are shown in Figure 5. The proposed Buffer Zone reduction will
allow siting of these features to preserve a significant number of mature native
trees adjacent to the buffer zone. This has been documented by an Arborist Report
(Sitkum Tree Service 2017, see Appendix B). The ecological significance of this
will be discussed further below.
The potential impacts of this project will result primarily from the processes of
grading and clearing the areas for construction of the home and septic system.
Grading and clearing will also result in the movement of construction vehicles on
the Site. These potential impacts include the following:
Grading and clearing 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 standard buffer zone.
The removal of some native vegetation within the buffer zone. Native
vegetation has already been removed outside of the buffer zone for
the entrance driveway and parking area. Those impacts have been
offset and approved by the County during the CASP process.
The removal of native trees within the buffer zone will be reduced by
using the reduced buffer and by siting the home at 130 feet from
OHWM. The arborist report shows that seven mature trees including
five Douglas fir, one Pacific Madrona and one Western Red Cedar
WVV 1516-ReefRd H MP. RPT/070617/mas 14
would be preserved by moving the home roughly 20-30 feet closer to
the shoreline and within the standard buffer zone (see Appendix B,
Figure B-1). This will constitute a POSITIVE impact and contribute to
ecological benefits, some occurring within the shoreline zone (within
200 feet of OHWM) and the others, adjacent to this. Sitkum Tree
Service has stated that the trees which will be saved by this
relocation of the home are healthy and viable long-term trees.
Vegetation will be removed in order to construct the home and
drainfield. There may be soil impacts from the movement of
construction vehicles on the Site.
Construction of the residence will increase the impervious surface on
the Site. The overall footprint of the house is expected to be about
2,200 square feet for the main pod and about 1,800 for the second
(guest pod) plus decking. An engineered storm -drainage plan will be
required for the residence. Stormwater should be directed away from
the shoreline.
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 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 edges of the construction area, adjacent to the construction
envelope and between the construction and the shoreline.
Native vegetation will be planted in the nearshore area west of the
residence and in two areas north and south of 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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The home should be sited to save mature trees within and adjacent
to the shoreline zone as per the arborist report.
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 by the Geologist report
(Stratum Group 2017, see Appendix C).
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. Mature
trees will be saved through careful siting of the home as per the
Arborist report (Sitkum Tree Service 2017). 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 150 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 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.
The size of buffers at this Site (about 130 feet from OHWM to the house) and the
limited filtering capacity of sandy and 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.
Scientific literature on buffer size indicate that buffers of at least 100 feet may be
necessary to consistently filter sediments and pollution that occur in stormwater
runoff (Wenger 1999, Mayer et al. 2005). Westech recommends that pesticides,
hydrocarbons and other contaminants not be used or disposed within 150 feet of
the OHWM or within 60 feet of the top of the bluff, whichever is greater.
Precluding the use of pesticides, nutrients and other potential contaminants within
150 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.
W W 1516-ReefRd H MP. RPT/070617/mas 17
Since 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 (100 percent during the first year).
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 100 percent during the first year and below 90 percent
during the next four 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
could potentially lead to its ineffectiveness.
W W 1516-ReefRdH M P. RPT/070617/mas 18
3.8 CONTINGENCY PLAN
A Contingency Plan should be followed if Mitigation Measures appear to be failing.
This plan should address any mortality of revegetated areas below the 100 percent
level during the first year or below the 90 percent survival level during the
subsequent four years. Should plant survival fall below these levels, 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.
WVV1 516-ReefRdHMP. RPT/070617/mas 19
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. Plantings have been proposed
to offset construction of the home in the buffer zone, plus revegetation of the
construction area with native grasses (including the septic system and adjacent to
the garage) is recommended for erosion control within and adjacent to the buffer
zone.
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 is
presently low shrubs and weedy species. New native shrubs and trees are
recommended within three planting areas (A, B1, B2 and C) as shown in Figure 6
and Table 1). New native grass -seed mixture should be used to replant the
construction area near the residence, garage and septic system upon completion of
those activities (Planting Area C. The three areas designated for additional shrub
and tree plantings (to offset the house Project) include:
Planting Area A is a 15 foot by 120 foot area adjacent to and
landward of the existing Top of Bank on the west side of the home
(roughly 112.5-127.5 feet from OHWM). The area is presently
covered by low shrubs and weedy herbaceous species. This area
should be planted with the mix of native shrubs and ground cover
found in Table 1. Plants may be clustered so as to leave a pathway
to the bluff overlooking the beach.
Planting Area B1 is an approximately a 12 foot by 40 foot area that
will be planted north of the house. This area is presently vegetated
by mixed shrubs and forbs. This area should be planted with an
additional mixture of selected low shrubs and groundcover (Table 1).
These plants should be planted in similar patterns as Area A,
however, existing native plants which are not removed during home
construction should not be disturbed. Non-native invasive plants
should be removed during this process.
Planting Area B2 is an approximately a 12 foot by 60 foot area that
will be planted south of the house. This area is presently vegetated
by some mature trees which will be retained in addition to some
shrubs and forbs. This area should also be planted with an additional
mixture of selected low shrubs and groundcover (Table 1). These
plants should be planted in similar patterns as Area A, however,
WW1 516-ReefRdHMP. RPT/070617/mas 20
T-
A-
A 1 114'--V
r
i
Figure 6. Site Map Showing Planting Areas
Westech Company 2017
Source: Shipley Architects 2017
TABLE 1. LIST OF NATIVE PLANTS FOR
BUFFER MITIGATION AND ENHANCEMENT
Planting
Area
Species
Scientific Name
Number
Size
A
rn
WesteHemlock
Tsu a hetero h lla
5
5- allon
A
Dou las fir
Pseudotsu a menziesii
5
5- allon
A
Western red cedar
Thujaplicata_
5
5- al Ion
A
Salal
Gaultheria shallon
15
3 allon
A
Common snowberry
Symphoricarpos albus
15
3- allon
A
Tall Oregon Grape
Mahonia aquifolium-
10
1 - gallon_
_ A
Bald -hip rose
Rosa avmnoca
5
1 -gallon
A
Nootka Rose
Rosa nutkana
10
A
Salmonbee _
Rubus s ectabilis
20
1- allon
A
Sword fern
Pol stichum munitum
10
1 gallon
A
Indian plum
Oemleria cerasiformis
10
3 -gallon
A
Oceas�ra
ny_
Holodiscus discolor
10
3 -gallon
B-1
Indian plum
Oemleria cerasiformis
5
3alq Ion
B-1
Common snowber —_
Symphoricarpos albus
5
3- allon
B-1
Salal
Gaultheria shallon
10
3 -gallon
B-1
Dull Orapee
Mahonia nervosa
10
1 -gallon
B-2
Oceanspray
Holodiscus discolor_
10
3 -gallon
B-2
Western red cedar
Thu a licata
5
5 -gallon
B-2
Salm_onber
Rub_us spectabilis
_ 10
1 -gallon
B-2
Douglas fir
Pseudotsuga menziesii
5
5- alg Ion
C*
Native grass seed mixJ
Graminae spp.
20.._
pounds
*Area C includes the septic system and graded areas adjacent (within 10 feet) of
the house and garage.
VVW 1470-ReefRdCASP. Tab 1 /071316/mas 22
existing native plants which are not removed during home
construction should not be disturbed. Non-native invasive plants
should be removed during this process.
Planting area C will include areas disturbed by construction around
the residence, as well as the garage and septic system east of the
residence. This area will include planting of a native grass seed
mixture to prevent erosion in and adjacent to 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.
Soils on the Site are mostly sandy gravelly foams and loamy sands 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.
VVW 1516-ReefRd H MP. RPT/070617/mas 23
5.0 CONCLUSIONS AND RECOMMENDATIONS
5.1 CONCLUSIONS
The Property presently contains an existing driveway and parking area adjacent to
a proposed residence, garage and septic system. The home, in accordance with
requirements of Jefferson County and this Habitat Management Plan will be placed
within the standard 150 foot buffer zone (plus 10 foot setback) at a distance of
approximately 130 feet from OHWM. A two car garage, a drainfield and planned
drainfield reserve area are located outside of the buffer zone. The residence will be
fronted by a deck approximately 10 feet in width. Placing the residence within the
buffer zone will save seven mature trees (Douglas fir, Western Red Cedar and
Pacific Madrona as per the arborist report (Sitkum Tree Service 2017).
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 (see also Stratum
Group 2017). A Planting Plan (See Figure 6 and Table 1) will be implemented to
provide additional vegetation adjacent to the shoreline, and west, north and south
of the house. Also, Himalayan blackberry, 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 if it is implemented by the property owners and enforced by the County. The
Plan includes the Siting of the home -site to save seven mature trees presently on
the Site as per the Arborist recommendation (Sitkum Tree Service 2017).
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.
WVV 1516-ReefRd H MP. RPT/070617/mas 24
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. It should be implemented if plant survival in the revegetated
areas falls below 100 percent during the first year and below 90 percent after the
first year.
Property owners should refrain from the use of pesticides or additional nutrients on
the Site and should introduce no contaminants within 150 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 reduced size of the buffers and limited filtering capacity of
the soils in this area.
VVVV1516-ReefRd H MP. RPT/070617/mas 25
6.0 REFERENCES
Frostholm, D. 2017. Letter via email dated April 7, 2017 from Donna Frostholm,
Jefferson County Department of Community Development to Mr. Rickey
Whitworth, Landowner. Port Townsend, Washington.
Google Earth. 2017. Online mapping software. www._googleearth.com.
Imagery date July 26, 2016. Europa Technologies.
Hitchcock, C.L. and A. Cronquist. 1973. Flora of the Pacific Northwest. University
of Washington Press. Seattle, Washington.
Jefferson County. 2017a. Online Map Database. http://www.co.jefferson.wa.us/.
Jefferson County, Washington.
Jefferson County. 2017b. Jefferson Counly Critical Areas Code. Title 18.22 JCC.
Department of Community Development. Port Townsend, 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.
hftp-.//websoilsurvey.nres-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. 2016. RCW36.70A.480. Shoreline of the State.
http://apps/leg.wa.gov/rcw/defauIt.aspix?cite=3670A.480.
Shipley Architects. 2017. Unpublished Site Plans for 81 Reef Road (Parcel 021-18-
4004. Dallas, Texas.
Sitkum Tree Service. 2017. Site Inspection and Consultation Repo . Submitted to
Peter Bates, Good Homes Construction by Sitkum Tree Service. Seattle,
Washington.
Stratum Group. 2017. Geology Hazard Assessment Parcel 021184004 Reef
Road, Nordland, Washington. Submitted to Good Homes Construction by
Dan McShane, L.E.G. Bellingham, Washington.
WW1 516-ReefRdH M P. RPT/o7o617/mas 26
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.
Westech Company. 2016a. Final Wetland Delineation Report 81 Reef Road
Nordland Washington 98358 Assessor's Parcel # 021-184-004 Jefferson
County, Washington. Port Angeles, Washington.
Westech Company. 2016b. Critical Areas Stewardship Plan 81 Reef Road
County, Washington. Port Angeles, Washington.
VVW 1516-ReefRd HM R RPT/070617/mas 27
APPENDICES
WW1 516-ReefRdH MP. RPT/070617/mas 28
APPENDIX A
SITE PHOTOGRAPHS
WW1 516 -Reef Roadh m p.APPA/070617/mas A-1
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APPENDIX B
ARBORIST REPORT
WW1 516-ReefRoadH M P.APPB/070617/mas B-1
June 13, 2017
Site inspection and consultation report
For: Peter Bates
Good Homes Construction
Site: 81 Reef Road
To Whom It May Concern:
After evaluation of the future building site at 81 Reef Road I have the following
conclusions. The proximity to mature conifer trees as the permit currently defines
in the initial site layout for building placement is not optimal for retention of
significant trees. Approving a shift to the east of approximately 20' would provide
significant benefit to the arboreal landscape.
Placement of the house as the current permit defines will require removal of seven
significant trees. All trees slated for removal are relatively healthy and significant in
size. Shifting the placement of the building to the east as the contractor is proposing
will require grubbing of brush and removal of insignificant willow and scrub trees.
Light grubbing work has been done to roughly define the clearing -limits required
for the garage structure. After careful examination of the site, referencing the
blueprint and site plan for the home it is very clear that the shift would preserve the
multiple viable trees listed below.
#19 - 24" conifer - Douglas -fir
#20 - 22" conifer - Douglas -fir
#21 - 16" conifer- Douglas -fir
#22 - 16" deciduous - Pacific Madrona
#24 - 24" conifer - Douglas -fir
#25 - 12" conifer - Douglas -fir
#26 - 10" conifer - Western Red Cedar
The trees that are currently slated for removal are healthy and viable long term. To
effectively retain these trees as an asset to the site installation of tree protection
fencing and placement of 6" - 9"of arborist chips is required to prevent construction
equipment and materials fi•om damaging the root systems of these trees. Protection
fencing will be installed prior to commencement of additional site
development/construction and will remain on site for the duration of the project.
This protection will play an important role in limiting the compaction of the critical
root zone from equipment or material staging.
In summary 1 strongly advise the approval of the relocation of the building. The
significant trees that are in question are currently healthy and have not sustained
critical damage. They will require basic tree protection for the duration of the
project but after the project is complete they will remain as an asset to the property
in perpetuity.
Terms and Conditions
Thank you for the opportunity to evaluate your project. I appreciate your business
and look forward to working with you in the future.
Consultation report respectfully submitted by,
Conor Haggerty
360. 808. 3216
Sitkun Tree Service LLC
Licensed, Bonded and hisured
# SITKUTS901JB
ISA Certified Arborist PN -6968A
ISA Certified Tree Risk Assessor - CTRA - 1824
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APPENDIX C
GEOLOGY HAZARD ASSESSMENT
WVV1516-Reef Road HMP.APPC/070617/mas C-1
STRATUM GROUP
P.O. Roa 2546, Bellingham, WA 98227
Phone (3 60) 714-9409
Mauch 15, 2017
Good Homes Construction
1401 Cleveland St.
Port Townsend WA, 98368
Re: Geology Hazard Assessment
Parcel 021184004
Reef Road
Norland, Washington
Stratum Group is pleased to present the results of our geology evaluation of the above referenced
property on a shoreline bluff. The purpose of this geology hazard assessment was to 1) determine
the suitability of the property for the building a home, 2) qualitatively evaluate the risk of slope
failures and shoreline bluff retreat, and 3) provide general site development and maintenance
recommendations for development of the property adjacent to a potentially unstable bluff. This
evaluation included a visual inspection of the property and vicinity, a visual inspection of the
bluff face, review of available geologic mapping in the area, and inspection of the shoreline at the
base of the bluff.
GENERAL GEOLOGY
The Geologic Map ofNortheastern Jefferson County, Washington (Gayer, 1976) and the
,Yu ficial Geologic Map of the Por! Townsend 30 by 60 Quadrangle, Paget Sound Region,
Washington (Pessl, Dethier, Booth and Minard, 1989) indicate the upland area of the property is
underlain by glacial till and the steep shoreline bluff exposed on the subject property is underlain
glacial till and advance glacial deposits.
Observations on the subject property and on the bluff face in the vicinity of the property are
consistent with the mapping described above. The upper approximately 25 feet of the bluff face
and the entire upland area on the property are underlain by very compact glacial till. The till
consists of very poorly sorted sediments ranging from clay to boulders deposited directly by
glacial ice between approximately 18,000 to 14,000 years ago when glacial ice covered the Puget
lowlands. The lower 65 feet of the bluff consists of compact advance glacial outwash sand and
silt units. These units were deposited by melt water streams associated with the advancing glacial
ice approximately 20,000 to 18,000 years ago. The outwash units are highly compacted and in
places have been deformed from ice loading and rapid deposition. The advance outwash
sediments are partially covered with loose sediment from material that has failed off of the bluff
face.
Match 15, 2017
Pat eel Number 021194044, RcefRoad, Norland, WA
Ceologq Hazard Assessment
SPECIFIC SITE OBSERVATIONS
The upland area of the property between Reef Road on the east and the steep shoreline bluff is
nearly level and is mostly forested. The upland has a very gentle slope towards the east away
from the shoreline bluff. Soils on the upland consist of compact sandy silt with cobbles and
occasional boulders and is consistent with glacial till. Areas of wet ground are located in some
areas of the upland and surface water flow towards the east was observed in the vicinity of Reef
Road
A steep southwest facing shoreline bluff is located along the west side of the property. 'The bluff
is approximately 100 feet high. The uppermost pall of the bluff is vertical throughout its length
on the subject property and is underlain by very compact glacial till. The till is approximately 25
feet thick at the subject site.
Advance outwash sediments consisting of sand and silt units with a few layers of gravel underlay
the rest of the bluff. The units are layered, but are somewhat obscured by the loose soil that has
raveled onto the slope from areas above. The loose soil and advance glacial outwash slope is
mostly covered with grasses and low growing forbs and brush. A few Douglas fir trees are
present on the slope as well.
Small shallow sloughing of soil is evident on the lower slope of the shoreline bluff. No recent
upper bluff failures were observed. Some recent erosion is evident along the toe of the slope.
The bluff is eroded primarily by wave action that undermines the base of the bluff with some
wind related erosion of steep areas of exposed sand acid silt soils. The shoreline at the site is not
exposed to large waves so toe erosion is not frequent but the fine grained sediment from bluff
failures is readily transported so that when there are larger waves or waves associated with a high
tide and tidal storm surge erosion will take place.
Because of the very compact nature of the bluff soils, the slope failures appear to consist of
relatively shallow slab type failures or upper bluff topples. Some wind erosion and surface
ravelling on this bluff is also a factor if bluff retreat rates. Wave action along the toe of the slope
will readily erode any fine grained sediment coming off the bluff face. The material eroded from
the bluff face is removed from the base of the bluff and transported along the shore towards the
north by prevailing wave action.
I have not observed any evidence indicating an incipient global -type or deep-seated failures on
the subject property or in the vicinity of the subject property. No seeps or areas of seasonal wet
areas are present along this bluff face area. LiDAR imagery does not indicate any large scale
Stratum Gaup Fk: 11.2.1 G
March 15, 2017
Parcel Number 021 184044, Reef Road, Norland, WA
Geolo* Hazard Assessment
landslide features on the site or in the vicinity of the site. The underlying geology is not
susceptible to large deep-seated landslides.
The shoreline below the subject property consists of a primarily sand beach with some gravel and
cobbles. The beach along this reach of shoreline is in good condition and there are very few
armored sections along this shoreline reach.
Historic oblique aerial photographs of the shoreline at the site indicate very little bluff retreat
since the 1970s and bluff retreat is not discernible in reviewing historic aerial photographs
dating back to the 1950s and U.S. Coastal Surveys dating back to 1856. The 1977 oblique aerial
did show that the steep shoreline bluff slope was much less vegetated at that time and it appeared
that there had been a number of shallow surface slides along the bluff face including areas where
the upper bluff had failed.
CONCLUSIONS AND RECOMMENDATIONS
Based on my visual inspection of the subject property and vicinity, I conclude that a home can be
located on the upland portion of the property such that landslide or shoreline bluff retreat will not
threaten the home within the expected life of the structure (100 years) as long as the
recommendations presented below are followed.
Building Setbacks
Any home development should be located at least 40 feet back from the top edge of the shoreline
bluff slope. This distance will be adequate to provide protection for a residence for at least 100
years even if an bluff retreat rate of 3 inches per year is used. It is my opinion that this rate of
bluff retreat is very conservative and will likely much less rapid even in the event of sea -level
rise. An erosion rate of 3 inches per year would require a setback of 25 feet for a 100 year period,
however, topple failures of the hard glacial till on the upper bluff may up to 10 feet wide. Hence
the setback distance should be greater than the simple bluff retreat rate from wave action to
account for large glacial till, top of bluff topples.
Development of the subject property with a home will not cause any negative impacts on the
stability of the shoreline bluff as long as our recommendations are followed.
Because the bluff is an eroding bluff, slope failures should be expected to occur on a periodic
basis. The only way to prevent continued erosion of the base of the bluff is to construct hard
armoring at the shoreline at the base of the bluff. However, the eroding bluff acts as a feeder
bluff (erosion of the bluff provides sediment) for the beaches north of the subject property, and
any shoreline armoring will have a negative impact on properties down drift from the bluff. The
slmhuu Gruup Pile: 11.2.16
March 15, 2017
Parcel Number 021184044, Rcef Road, Norland, WA
Geology Hazard Assessment
construction of shoreline armoring on other properties may cause an increase of erosion of the
subject property. The owner of the subject property should contact Jefferson County officials
regarding any proposed shoreline protection projects along the bluff or any shoreline protection
construction. There are currently no shoreline -armored areas along this shoreline reach in the
vicinity of the property.
,%rinu,ater
The upper soils on the upland portion of the property appear to be moderately well drained, but
very hard compact till at depth does allow water to become perched in some areas of the site. The
overall slope of the upland area is towards the east such that water drainage will be away from
the shoreline bluff. Storm water drainage should be directed away from the top of the bluff and
should be dispersed and infiltrated into the ground as much as practical through splash blocks or
level dispersion spreaders or dispersion trenches.
Other Recommendations
Site grading soils or debris, landscape debris, or any other material should not be disposed of
over the bluff face or placed at the top of steep bluff.
The septic drain fields should be located at least 40 feet back from the top of the steep slope. 'The
minor volume of water from a household drain field will not cause slope stability problems at
this site. The septic drain field should not cause problems for slope stability, as the general slope
direction of the upland portion of the property will not direct drainage towards the top of the
bluff.
Please note that there are inherent risks associated with building on lots near or adjacent to steep
slopes. These are risks that the building owner should recognize and be willing to accept. If
conditions appear different than those described in this report, or other concerns arise, we request
that we be notified so we can review those areas and modify our recommendations as required.
Stratmn Group appreciates the opportunity to be of service to you. Should you have any
questions please contact our office at (360) 714-9409.
Sincerely yours,
Stratum Group
Dan McShane, M.Sc., L.E.G.
Licensed Engineering Geologist
SI, Mum Group Pile: 11.2.16
4