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MA (425) 337-3174
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CRITICAL AREA STUDY
AND
BUFFER MITIGATION PLAN
FOR
ANGUM - 625 61H AVENUE S
EDMONDS� WA .�....�.�.�.�.........�
Wetland Resources, Inc. Project # 16028
Prepared By
Wetland Resources, Inc.
9505 19th Avenue SE, Suite 106
Everett, WA 98208
(425) 337-3174
Prepared For
Zach and Terra Mangum
625 61h Avenue S
Edmonds, WA 98020
March 7, 2016
TABLE OF CONTENTS
1.0 PROJECT LOCATION AND SITE DESCRIPTION...........................................................................1
2.0 REVIEW OF EXISTING INFORMATION........................................................................................2
3.0 METHODOLOGY.....„,„....,................„...............................„,..................... ..<,,..,....,...,, .........2
4.0 BOUNDARY DETERMINATION FINDINGS/RESULTS...,.,,.....„.....................„..............................3
4.1 STREAM ................................ .................. .......,. ...... .....,.. .......... ........ .........:.5
4.2 UPLAND AREAS .................... .......... ............ ..,,„.. ....................4
4.3 ARTIFICIAL POND ................ ......... ......... ..................„.. .„....„.,........... ...,..... ..... .... - ................
4
5.0 STREAM CLASSIFICATION...„ .„.„.,,..„......... ......... ...„........... „.............................. ............,...........4
6.0 FUNCTIONAL ASSESSMENT ............... ...„.... ............ ................................... ..., ......,,..... ,..,..,,,....,.4
7.0 PROPOSED DEVELOPMENT ACTIVITIES......................................................................................5
8.0 APPLICABLE CITY OF EDMONDS COMMUNITY DEVELOPMENT CODE ... ......................... .........6
9.0 MITIGATION SEQUENCING...........................................................................»....„..„...............»....6
10.0 BUFFER MITIGATION PLAN......................................................................................................7
11.0 GOALS, MONITORING, MAINTENANCE, AND CONTINGENCY,....„.....,......„.,,.„.........................8
1 1.1 GOALS, OBJECTIVES, AND PERFORMANCE STANDARDS ............. ........ .... --- ................................
8
11.2 PLANTING NOTES....................................................................................„....,....................................
9
11.3 MONITORING.................................................................................................................................
11
11.4 CONTINGENCY...............................................................................................................................
11
11.5 MAINTENANCE................................................................................................................................
11
11.6 COST ESTIMATE AND FINANCIAL GUARANTEE ....................... ....... ,............. ._...........
12
12.0 USE OF THIS REPORT............................................................................................................12
13.0 REFERENCES ......... ........... -- ............,.......,..............,.........................,....„........„..............,13
LIST OF ATTACHMENTS
CRITICAL AREA STUDY AND MITIGATION PLAN MAP SHEET 1 / 1
KING COUNTY BOND QUANTITY WORKSHEET
USIT OF ]FIGURES
FIGURE 1. AERIAL VIEW OF SUBJECT PROPERTY,........ ....., ........ ...........„,.....1
11
1.0 PROJECT LOCATION AND SITE DESCRIPTION
Wetland Resources, Inc. (WRI) performed a site investigation on February 9, 2016 to delineate
jurisdictional wetlands and streams on and in proximity to Snohomish County parcel number
27032500205200. The subject property is located at 625 6th Avenue S in Edmonds,
Washington. The Public Land Survey System (PLSS) locator for the subject property is Section
25, Township 27N, Range 03E, W.M. The study site is situated within the Cedar/Sammamish
Watershed, Water Resources Inventory Area (WRIA) 8.
The 0.32 -acre subject property is situated in an urban/ residential setting approximately one-half
mile southeast of downtown Edmonds. The property contains a single-family residence and
associated improvements. The surrounding land use is single-family residential. The topography
of the site slopes generally to the west. The vegetation on the subject property consists entirely of
maintained lawn and landscape plants. One stream - a tributary to Shellabarger Creek - flows
onto the property from the east and continues along the southern property boundary. It is a
Type Np (perennial, non -fish habitat) stream. Type Np streams in the City of Edmonds receive
50 -foot standard buffers (Edmonds Community Development Code — ECDC 23.90.040(D)(1)(e)).
No wetlands were found on the property. An existing artificial pond (landscape feature) exists at
the southeast corner of the property.
Figure 1. Aerial view of subject property.
Wetland Resources, Inc. 1 Mangum — 625 6th Avenue S
March 7, 2016 WRI # 16028
2.0 REVIEW OF EXISTING INFORMATION
Prior to conducting the site investigation, public resource information was reviewed to gather
information on the subject property and the surrounding area in regards to wetlands, streams,
and other critical areas. The following information was examined:
LJriite ifServiceU, FWS Nationalm Wetlands Inve�'ato The
' cl States is an Wildlife e S e
National Wetland Inventory (NWI) does not illustrate any wetland areas on or near the
subject property. The Edmonds Marsh approximately 0.5 miles to the east is the nearest
feature.
•
USDA/Natural Resources Conservation Service (NRCS) Web „Soil „Survev: The Web
ULL_
Soil Survey indicates that the subject property is underlain by Everett very gravelly sandy
loam, 0-8 percent slopes. Included in this soil unit are small areas of Alderwood,
Indianola, and Ragnar soils. None of these soils is listed as hydric.
Washine-tton of Fish and Wildlife (WDFW) SalmonScape Interactive
all_rg �wtern: The SalmonScape interactive map illustrates Shellabarger Creek
approximately 500 feet west-southwest of the property. SalmonScape indicates that Coho
salmon utilize Shellabarger Creek.
• WDNR „Forest„Practices ADnlication Mapping' Tool (FPAMT) ,Interactive Map: The
FPAMT map also shows Shellabarger Creek to the west-southwest of the subject
property. It is mapped as a fish -bearing (Type F) stream to the west and changing to a
Type N upstream at the point where it passes the Pine Street Playfield (southwest of the
subject property).
• —WDFW Priorit Habitat and _.Speck., P .) Intcractiyc Mapr The PHS Interactive Map
illustrates Shellabarger Creek to the west of the subject property. The PHS data indicates
that both Coho salmon and resident coastal cutthroat utilize Shellabarger Creek.
•Snohomish C'01g ty ��ra Sc �I�� 1lrtmmt_t��c �lv� Maq) W The SnoScape Interactive Map shows
Shellabarger Creek to the west of the subject property and indicates that it is a Type F
stream with a water type break changing to a Type Ns (intermittent, non -fish bearing)
stream southwest of the property.
3.0 METHODOLOGY
Wetland boundaries were determined using the routine determination approach described in the
Co�,;rs lw nal rwr Wetlands Delineation Manual (Environmental Laboratory 1987) and the
lit iorla SLIP (nign,,t to t:he., C womrps ..of Mla tac,�,ts__ t�c�t.�a�xel Delineation Manual:.. Western
and Coastm R!,gjpp (Version a0 (U.S. Army Corps of Engineers 2010).
Under the routine methodology, the process for making a wetland determination is based on
three steps:
1.) Examination of the site for hydrophytic vegetation (species present and percent cover);
2.) Examination of the site for hydric soils;
Wetland Resources, Inc. 2 Mangum — 625 6th Avenue S
March 7, 2016 WRI # 16028
3.) Determining the presence of wetland hydrology
The following criteria must be met in order to make a positive wetland determination:
Vegetation Criteria
The Corps Manual and 2010 Regional Supplement define hydrophytic vegetation as "the
assemblage of macrophytes that occurs in areas where inundation or soil saturation is either permanent or of
sufcient frequency and duration to influence plant occurrence." Field indicators are used to determine
whether the hydrophytic vegetation criteria have been met. Examples of these indicators include,
but are not limited to, the rapid test for hydrophytic vegetation, a dominance test result of greater
than 50%, and/or a prevalence index score less than or equal to 3.0.
Soils Criteria
The 2010 Regional Supplement (per the National Technical Committee for Hydric Soils) defines
hydric soils as soils "that formed under conditions of saturation, flooding or ponding long enough during the
growing season to develop anaerobic conditions in the upper part." Field indicators are used to determine
whether a given soil meets the definition for hydric soils. Indicators are numerous and include,
but are not limited to, presence of a histosol or histic epipedon, a sandy gleyed matrix, depleted
matrix, and redoximorphic depressions.
Hydrology Criteria
Wetland hydrology encompasses all hydrologic characteristics of areas that are periodically
inundated or have soils saturated to the surface for a sufficient duration during the growing
season. Areas with evident characteristics of wetland hydrology are those where the presence of
water has an overriding influence on the characteristics of vegetation and soils due to anaerobic
and chemically reducing conditions, respectively. The strongest indicators include the presence of
surface water, a high water table, and/or soil saturation within at least 12 inches of the soil
surface.
4.0 BOUNDARY DETERMINATION FINDINGS/RESULTS
One stream — a tributary of Shellabarger Creek — was identified flowing along the southern
boundary of the subject property. No wetlands were observed. The ordinary high water mark
(OHWM) of the stream was identified using the methodology described in the Washington State
Department of Ecology document Determining e rc��°+ gh Water Mark on Str(,arns in
Washin-ton State Sec(,-)nd review Qry t) (Olson and Stockdale 2010). No wetlands were
identified on the subject property.
4.1 STREAM
The onsite portion of the stream flows through a man-made channel lined with concrete. It flows
onto the site from the east, curves around a man-made rock/concrete artificial pond feature, and
flows along the southern property boundary to the west where it joins with Shellabarger Creek; a
fish -bearing stream supporting Coho salmon. Shellabarger Creek flows west to Edmonds Marsh
where it joins Willow Creek and then outfalls to Puget Sound. The fish -bearing portion of
Shellabarger Creek is more than 200 feet from the subject property.
Wetland Resources, Inc. 3 Mangum — 625 6th Avenue S
March 7, 2016 WRI # 16028
The onsite stream channel is approximately 8 to 24 inches wide and ranges from approximately
2 to 12 inches deep. The depth of water during the February 9 site investigation ranged from 1
inch to approximately 4 inches. The homeowner indicated that the stream flows year-round.
Another Type N tributary flows along the northern property boundary of the adjacent property
to the south. It flows through a gravel -lined channel/ditch and merges with the on-site stream to
the west of the subject property.
The adjacent streamside/buffer vegetation onsite is comprised of maintained lawn and landscape
plants. The channel is lined with Western red cedar (Thuja plicata, FAC) and cherry laurel (Prunus
laurocerasus, N/I) that is planted on the neighboring property to the south along a portion of the
southern property boundary.
4.2 UPLAND AREAS
The remainder of the property consists of upland containing ' maintained lawn and landscape
plants typical of a single-family residence. No wetland vegetation or hydrologic indicators were
observed that would suggest the presence of wetland on the site or in the near vicinity.
Topography of the site is a moderate slope to the west with little undulation and no depressional
areas.
4.3 ARTIFICIAL POND
The artificial pond located in the southeast corner of the property is constructed from rock and
concrete. It is a man-made landscape feature with no natural hydrology and is therefore not
considered a critical area per ECDC (20.090.010(A)(7)).
5.0 STREAM CLASSIFICATION
The stream was classified according to the water typing criteria contained in the Washington
Administrative Code (WAC), section 222-16-030. This is consistent with ECDC section
23.90.010. The stream was further classified using the U.S. Fish and Wildlife Service (USFWS)
document Class licatioiis of WetlaWndswwand D �w Ovate alAta�ls of the (united States (Cowardin et
al., 1979), also known as the Cowardin Classification System.
A a watl ,L typing t:las dna titan: Type Np
Q,owardin cl assil calm, is Riverine, Upper perennial, Unconsolidated bottom, Mud/Concrete.
6.0 FFTNCTIONAL ASSESSMENT
The methodology for this functions and values assessment is based on professional opinion
developed through past field analyses and interpretations. This assessment pertains specifically to
the on-site stream system, but is typical for assessments of similar systems throughout western
Washington.
Streams and their associated buffers in western Washington perform a variety of ecosystem
functions including the movement of water and sediment, flood flow alteration, recharge of
Wetland Resources, Inc. 4 Mangum — 625 6th Avenue S
March 7, 2016 WRI # 16028
groundwater, treatment of pollutants, dynamic stability, and habitat diversity. The functional
assessment for the on-site stream and its buffer is provided below.
The on-site stream serves to collect stormwater from the surrounding areas and convey it to
downstream systems, which support anadromous fish populations. The on-site portion of the
stream is contained within a man-made channel and the condition of the vegetation around the
stream shows no indication that overbank flooding occurs for a significant enough period of time
to alter soil and vegetation conditions. There is little or no slowing of water by vegetation on the
site and the stream provides little habitat value except as a water source for wildlife. The western
red cedar and cherry laurel on the neighbor's property are dense and overhang the stream along
a portion of the southern property boundary and do provide some cover for wildlife, but the on-
site side of the stream consists of maintained lawn.
7.O PROPOSED DEVELOPMENT ACTIVITIES
The property owner/project applicant is proposing to construct a second story addition, replace
and expand a deck on the west and south side of the existing house, move an existing deck on the
east side of the house, and install a permanent fence. The second story addition will remain
within the existing building footprint.
The existing deck on the east side of the house will be moved a short distance to the north (away
from the stream). No changes to this deck will occur except that it will move approximately 5.5
feet north.
The existing deck on the west and south sides of the house will be removed, which will result in a
small decrease in impervious surface (30 square feet) near the stream. The new deck to be
constructed on the west and south sides of the house will result in a net increase in the size of the
deck of 72 square feet, including a net increase of 37 square feet of impervious surface. A portion
of the surface below the deck addition is paved and a portion is lawn, so the 35 square feet that is
located over pavement is not counted as additional impervious surface. The proposed addition is
located further away from the stream than the current deck.
A fence will be constructed around an area of the southeast corner of the property.
Temporary erosion and sediment control measures (TESL) and standard BMPs will be
employed as needed to ensure that no materials enter the stream during construction and all
staging will take place on existing impervious surfaces so that no impact to the stream or buffer
will result from this activity.
Because a large portion of the house and associated decks occur within the standard 50 -foot
stream buffer, it is not possible to accommodate these improvements outside of the buffer area. A
small area of buffer reduction is necessary to accommodate the deck expansion on the west and
south sides of the house. The ECDC allows for additions to existing structures within stream
buffers, subject to specifications outlined in the section below.
Wetland Resources, Inc. 5 Mangum — 625 6th Avenue S
March 7, 2016 WRI # 16028
8.0 APPLICABLE CITY OF EDMONDS COMMUNITY DEVELOPMENT CODE
Section 23.90.040(D)(4) of the ECDC "Additions to Structures Existing within Stream Buffers"
states the sequencing required for this type of project. The following cites the applicable code
section in italics with responses regarding the present project proposal following each point in
regular font:
"Additions to legally constructed structures existing within stream buffers that increase the footprint of development
or impervious surfacing shall be permitted consistent with the development standards of this chapter (ECDC
23.90.030 and this section). Provisions for standard stream buffers, buffer reductions through enhancement, and
stream buffer averaging require applicants to locate such additions in accordance with the following sequencing. -
a. Outside of the standard stream buffer;
The entire existing deck and area of proposed deck expansion are within the standard 50 -
foot stream buffer. More than half of the home's building footprint lies within the stream
buffer and it is not feasible to move the deck to another portion of the house outside the
buffer.
b. Outside of a stream buffer reduced through enhancement per subsection (D)(2) of this section;
Subsection (D)(2) allows for buffer reduction through enhancement provided that the
buffer is reduced by no more than 50% at any point. The addition to the deck footprint
requires a buffer reduction of 36% (from 50 feet to 32 feet) in a small area. The resulting
reduction in total buffer area is 131 square feet, and the impact is as far from the stream
as possible. The deck footprint nearest the stream will be reduced with the removal of the
old deck. The applicant proposes enhancement of an area of 262 square feet adjacent to
the stream by planting native plants in two areas that are currently not vegetated or
consist of maintained lawn. This results in a mitigation ratio of 2:1. As the current on-site
buffer contains virtually no native vegetation, the resulting buffer condition after
mitigation will provide a higher level of function than the current condition. Native plants
along the stream will provide food sources and cover for wildlife.
9.0 MITIGATION SEQUENCING
Section 23.040.120 of the ECDC lists mitigation sequencing requirements for projects that will
result in alterations to critical areas. Per the ECDC, alterations to critical areas shall be avoided,
minimized, or compensated for in the following sequential order of preference (project specific
responses follow each item):
1) Avoiding the impact altogether by not taking a certain action or parts of an action.
Because the stream buffer encumbers more than half of the subject property and a significant
portion of the footprint of the home necessarily lies within the buffer, it is not possible to
completely avoid actions within the standard 50 -foot stream buffer.
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2) Minimizing impacts by limiting the degree or magnitude of the action and its implementation by using
appropriate technology or by taking affirmative steps, such as project redesign, relocation, or timing to avoid or
reduce impacts.
The proposed deck improvements will occur mostly above existing paved surface and the deck
footprint will be reduced on the side of the house closest to the stream. TESC and BMPs will be
employed as needed to ensure that no impact to the stream occurs during construction. All
staging will take place on existing paved areas to avoid/minimize impact to the stream buffer.
3) Rectifying the impact to wetlands, frequently flooded areas, and fish and wildlife habitat conservation areas by
repairing rehabilitating or restoring the affected environment to the historical conditions or the conditions existing at
the time of the initiation of the project.
The area where the work will take place is already developed. No vegetation will be removed and
no grading will be involved in association with this project so no restoration will be necessary.
Mitigation provided as compensation for the additional deck area that will be located within the
stream buffer will result in overall improvement to the stream buffer functions through planting
of native species, which are currently lacking on the site.
4) Minimizing or eliminating the hazard by restoring or stabilizing the hazard area through engineering or other
methods.
There are no hazard areas of concern on the property. TESC and BMPs will be employed as
needed to ensure that there are no impacts to the stream during construction.
5) Reducing or eliminating the impact or hazard over time by preservation and maintenance operations during the
life of the action.
The new deck addition has been designed to minimize impact to the stream. The new deck will
have a reduced footprint on the side of the house closest to the stream and the addition occurs
mostly over existing paved surfaces. Buffer enhancement will result in improved stream buffer
function on the site.
6) Compensating for the impact to wetlands, frequently flooded areas, and fish and wildlife habitat conservation
areas by replacing enhancing or providing substitute resources or environments.
A buffer mitigation plan has been developed to compensate for the work performed within the
standard stream buffer. The mitieation plan is discussed below.
7) Monitoring the hazard or other required mitigation and taking remedial action when necessary.
Monitoring, maintenance, and contingency plans have been developed concurrently with the
mitigation plan.
10.0 BUFFER MITIGATION PLAN
The expansion of the deck on the west side of the house will take place within the standard 50 -
foot stream buffer. To compensate for a buffer reduction of 131 square feet, buffer enhancement
of 262 square feet (2:1 ratio) is proposed.
Per ECDC section 23.40.110(B), mitigation shall be in-kind and on-site, when possible. On-site
Wetland Resources, Inc. 7 Mangum — 625 6th Avenue S
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mitigation in the form of buffer enhancement is proposed to compensate for the proposed buffer
impacts. To enhance the stream buffer, the applicant is proposing to plant native trees and
shrubs along the stream in two areas that are currently not vegetated or consist of maintained
lawn. The following planting plan consists of native species that will provide cover and food
sources for wildlife and shade for the stream.
Buffer Enhancement Planting Plan (Area A — 200 SF)
Conxxaraon Name,
Latin Name
Size
mm�..PAg___
anti .
Indian plum
Oemleria cerasiformis
1 gallon
8'
1
Snowberry
Symphoricarpos albus
1 gallon
5'
3
Red -flowering currant
Ribes sanguineum
1 gallon
5'
3
Sword fern
Polystichum munitum
1 gallon
3'
5
Buffer Enhancement Planting Plan (Area B — 62 SF)
Common Name Latin Name Size Snacine Quantity
Vine maple Acer circinatum l gallon 8' 1
Lady fern Athyrium filix /emina 1 gallon 3' 3
11.0 GOALS, MONITORING, MAINTENANCE, AND CONTINGENCY
11.1 GOALS, OBJECTIVES, AND PERFORMANCE STANDARDS
Project goals are established to identify what the mitigation plan is attempting to accomplish.
Objectives identify specific actions that are taken or components that are initiated in order to
meet the project goals. Finally, performance standards provide measurable criteria for
determining if the goals and objectives are being achieved (Washington State Department of
Ecology et. al., 2006).
The goals of this mitigation plan include the following:
• Compensate for the loss of stream buffer (131 SF) resulting from the development (deck
expansion).
• Improve the function of the stream buffer.
These goals will be met by performing the following actions (i.e. objectives):
Enhance 262 SF of existing stream buffer by installing 1 native tree, 7 native shrubs and 8
ferns in the enhancement area.
The performance standards for the buffer enhancement areas include the following:
• Survival of planted shrubs and ferns will be 100% following the first year of monitoring;
90% following the second year; and 80% by the third year. All dead plants shall be
replaced following the first year of monitoring.
• Areal coverage of native species in the enhancement area will be at least 80% at the end
of the third year of monitoring.
• Invasive and non-native species shall not provide more than 10% areal coverage
throughout the enhancement area at any time.
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11.2 PLANTING NOTES
Inspections
The lead ecologist shall be present on site to inspect the plants prior to planting and may
periodically inspect the mitigation installation process. Minor adjustments to the original design
may be necessary prior to and during construction due to unusual or unknown site conditions. A
City of Edmonds representative and/or the lead ecologist will make these decisions during
construction.
Planting
If possible, plant installation will take place in late fall or early spring (prior to the start of the
growing season). Plants shall be obtained from a reputable nursery familiar with native vegetation
and that is capable of providing local genetic stock. Limited species substitution may be allowed,
but must be approved by City of Edmonds personnel and/or the lead ecologist.
Erosion and Sediment Control Measures
Standard erosion and sediment control measure BMP's shall be employed during construction as
needed.
Handling
Plants shall be handled to avoid damage, including breaking, bruising, root damage, sunburn,
drying, freezing, or other injury. Plants must be covered during transport. Plants shall not be
bound with wire or rope in a manner that could damage branches. Protect plant roots with shade
and wet soil in the period between delivery and installation. Do not lift container stock by trunks,
stems, or tops. Do not remove from containers until ready to plant. Water all plants as necessary
to keep moisture levels appropriate to the species requirements. Plants shall not be allowed to dry
out. All plants shall be watered thoroughly immediately upon installation. Soak all containerized
plants thoroughly prior to installation.
Storage
Plants stored for longer than one month prior to planting shall be planted in nursery rows and
treated in a manner suitable to specific species requirements. Plants must be re -inspected by the
lead biologist prior to installation.
Damaged plants
Damaged, dried out, or otherwise mishandled plants will be rejected at installation inspection.
All rejected plants shall be immediately removed from the site.
Plant Names
Plant names shall comply with those generally accepted in the native plant nursery trade. Any
question regarding plant species or variety shall be referred to the lead ecologist. All plant
materials shall be true to species and variety and legibly tagged.
Quality and condition
Plants shall be normal in pattern of growth, healthy, well branched, and vigorous, with well-
developed root systems, and free of pests and diseases. Damaged, diseased, pest -infested, scraped,
bruised, dried out, burned, broken, or defective plants will be rejected.
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Roots
All plants shall be containerized. Root bound plants will be rejected. Immediately before
installation, plants with minor root damage (e.g. broken and/or twisted roots) must be root -
pruned. Matted or circling roots of containerized plantings must be pruned or straightened and
the sides of the root ball must be roughened.
Sizes
Plant sizes shall be the size indicated above. Larger stock may be acceptable provided that it has
not been cut back to the size specified, and that the root ball is proportionate to the size of the
plant. Smaller stock may be acceptable, and preferable under some circumstances, based on site-
specific conditions. Any changes to the original mitigation design must be approved by the lead
ecologist and/or the City of Edmonds. Measurements, caliper, branching, and balling and
burlapping shall conform to industry standards.
Form
Shrubs shall have multiple stems and be well branched.
Weeding
Non-native and invasive vegetation in the mitigation areas will be hand weeded from around all
newly installed plants at the time of installation and on a routine basis throughout the monitoring
period. No chemical control of vegetation on any portion of the site is allowed without the
approval of the City of Edmonds.
Site conditions
The contractor shall immediately notify the lead ecologist of drainage or soil conditions likely to
be detrimental to the growth or survival of plants. Planting operations should not be conducted
under the following conditions: freezing weather, when the ground is frozen, excessively wet
weather, excessively windy weather, or in excessive heat.
Planting Pits
Planting pits should be circular with vertical sides, and should be at least twice the size of the root
ball. In compacted soils, the sides of the planting pits should be scarified/broken up. Set plants
upright in pits. Backfill shall be worked back into holes such that air pockets are removed without
compacting the soils.
Water
Plants should be watered midway through backfilling, and again upon completion of backfilling.
For late spring/early summer plantings (if approved), a rim of earth should be mounded around
the base of the tree or shrub no closer than the drip line, or no less than 30" in diameter, except
on steep slopes or in hollows. Plants should be watered a second time within 24-48 hours after
installation. The earthen rim/dam should be leveled prior to the second growing season.
Staking
Due to the small size of the proposed plantings, staking should not be necessary. If the plant does
need support, then strapping or webbing should be used as low as possible on the trunk to loosely
brace the tree with two stakes. Do not brace the tree tightly or too high on the trunk. Do not use
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wire in a rubber hose for strapping as it exerts too much pressure on the bark. As soon as
supporting the plant becomes unnecessary, stakes should be removed. All stakes must be
removed within two (2) years of installation.
Arrangement and Spacing
The plants shall be arranged with the appropriate numbers, sizes, species, and distribution to
achieve the required vegetation coverage. The actual placement of individual plants shall mimic
natural, asymmetric vegetation patterns found on similar undisturbed sites in the area.
Mulch
A wood chip mulch will be placed around the base of each plant in a 3 -foot radius and at a depth
of 2 to 4 inches. Mulch shall not be allowed to contact plant stems in order to avoid plant decay
and rot.
11.3 MONITORING
A monitoring plan will begin with the preparation of an as -built report following installation of
the mitigation plan. This report will address the completed mitigation plan and identify if any
changes or revisions have been made. Following submittal of the as -built plan, monitoring visits
will occur. Monitoring will begin the first year following mitigation installation. Monitoring visits
will occur annually (in the late spring/early summer) for a period of three years.
Due to the small size of the enhancement area, monitoring techniques will include visual
observations to assess shrub and fern survivability and coverage. Plant counts will also be
performed within the enhancement area. Photos will be taken of the enhancement area. At least
one photo will be included in each monitoring report.
Monitoring reports will be submitted to the City of Edmonds in the fall of each monitoring year.
The reports will summarize the overall conditions of the mitigation areas and discuss whether the
performance standards are being met. On year 3, the final monitoring report will be prepared
and will discuss whether or not the mitigation plan has been successful per the established goals,
objectives, and performance standards. If the mitigation plan is deemed unsuccessful,
contingency actions will be utilized and/or the monitoring period may be extended.
11.4 CONTINGENCY
If, during any of the monitoring visits, 20% of the plants within the enhancement area are
severely stressed, or it appears that 20% may not survive, additional plants will be installed. If
invasive and non-native species exceed 20% aerial coverage within any of the enhancement areas
at any time, control measures will be initiated. Additional contingency actions may include, but
will not be limited to, more aggressive weed control, additional mulching, species substitution,
soil amendments, and/or additional irrigation. If necessary, a meeting between the lead ecologist
and City of Edmonds personnel will be held to develop additional contingency actions.
11.5 MAINTENANCE
Maintenance will be performed within the enhancement areas annually. Maintenance actions
may include, but are not limited to, replacement of dead vegetation, removal of invasive and
non-native vegetation and replacement of mulch. Maintenance needs will be discussed in the
annual monitoring reports. Completed maintenance tasks and maintenance that needs to be
Wetland Resources, Inc„ 11 Mangum 625 6th Avenue S
March 7, 2016 WRI # 16028
done will be addressed in each monitoring report.
11.6 COST ESTIMATE AND FINANQIAL GUARANTEE
Per ECDC section 23.40.1300, a financial guarantee is required to ensure that the mitigation
plan is fully implemented. The financial guarantee shall be posted in accordance with ECDC
section 23.40.290 ("Bonds to Ensure Mitigation, Maintenance, and Monitoring"). The financial
guarantee must be in the amount of 120 percent of the estimated cost of the uncompleted actions
or the estimated cost of restoring the functions and values of the critical area that are at risk,
whichever is greater. The King County Bond Quantity Worksheet was used to calculate the
appropriate bond amount for this project.
Mulch - $3.25/SY:
$94.25
Labor — (plant installation) $40.00/HR:
$80.00
Plants — $11.50/plant:
$184.00
Mobilization/ Contingency:
$143.30
Estimated cost of monitoring:
$2,028.60
Estimated cost of maintenance:
$559.44
Total:
$3,089.59
Therefore, the financial guarantee for this project will be $3,089.59.
12.0 USE OF THIS REPORT
This Critical Area Study and Mitigation Plan is supplied to Zach and Terra Mangum as a means
of determining and protecting on-site critical areas, as required by the City of Edmonds. This
report is based largely on readily observable conditions and, to a lesser extent, on readily
ascertainable conditions. No attempt has been made to determine hidden or concealed
conditions.
The laws applicable to critical areas are subject to varying interpretations and may be changed at
any time by the courts or legislative bodies. This report is intended to provide information
deemed relevant in the applicant's attempt to comply with the laws now in effect.
This delineation and report conforms to the standard of care employed by wetland ecologists.
No other representation or warranty is made concerning the work or this report and any implied
representation or warranty is disclaimed.
Joie Goodman
Associate Ecologist
Wetland Resources, Inc.
Wetland Resources, Inc. 12 Mangum — 625 6th Avenue S
March 7, 2016 WRI # 16028
13.0 REFERENCES
Brinson, M.M. 1993. A li dreasaaa�ta�a��ae lxa��al��,�xtica�for WW daridsIT Technical Report
WRPDE-4. US Army Engineers Waterways Experiment Station, Vicksburg, MS.
Code Publishing Company. Edmonds Cior Code and Conin'iaramD va
http://www.codepublishing.com/wa/edmonds/. Seattle, WA
Cowardin L.M. V. Carter F.C. Golet and E.T. Laroe. 1979. Classification of Wetlands and.,_..�_.m..._..�...m.,m..�.�...�
Deep Water Habitats of the United States. U.S. Fish and Wildlife Service. FWS/OBS 79/31.
Environmental Laboratory. 1987. Cor S ofE,�i uc �Ks_We(land Delineation Manual. Technical
Report Y-87-1. Environmental Laboratory, Department of the Army, Corps Waterways
Experiment Station, Vicksburg, MS.
Lichvar, R.W. 2014. The National Wetland Plant List: 2013 wetCand aatingl . Phytoneuron
2014-41: 1---42. Published April 2, 2014.
Munsell Color. 2012. Munsell Soil Color Book. Munsell Color, Grand Rapids, MI.
Snohomish County Planning and Development Services (PDS). "oaaall
1 ndsc llrcw Inl"A'caig Iltl. gis,sric,ac o oa
U.S. Army Corps of Engineers (Corps). 2010. lea g1 �a���al *ati le,nat.aat to t.11a Corl; S of l�? :n
l cees
Wetland Delineation Manual: Western 9Mo untKaaais Valleys and Coast Region (Version 2.0).
U.S. Army Engineer Research and Development Center Environmental Laboratory. Vicksburg,
MS. Publication # ERDC/EL TR -10-3.
U.S. Fish and Wildlife Service. National Wetland Inventory (f ll�" S mmm m "w ctl a�lcls L !ial l cl.
http://www le s,.µggy/wclIaiids/.
USDA-NRCS. WebSoil Survey_, (lam ",rvtrallra^c yw aaac �-asdoylapl/lflarIe l�gc lltf).
Washington State Department of Natural Resources (DNR). Forest Practices Application
Mapping Tool.(1otl)sr://fjaalura',�,wr"�.`off'/ la laaa;��tae�� al.a:a r 1ldu �: i►�aia .11aaal i •
Washington State Department of Fish and Wildlife (WDFW). Priority Habitats and Species:
PHS on the Web (htt �://wdfw wa.gLw plrt,gilal�s;,/).
Washington State Department of Fish and Wildlife (WDFW). 2011. SalmonScape
l l g ).
(l�att�://wdfw.wa � as mm/znwl � �rmra �/w�al.tllc��asc
Wetland Resources, Inc, 13 Mangum — 625 60, Avenue S
March 7, 2016 WRI # 16028
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Critical Areas Mitigation
Bond
Quantity Worksheet
Kir tg Cou ty,
Altig SFR
Date: 2/17/16 Prepared by:
JG
Project Number:
Project Description:
Buffer Enhancement/Restoration
Location: 625 6th Ave S
Applicant: Zach and Terra Mangum
Phone:
PLANT MATERIALS*
Type
Unit Price
Unit
Quantitv
Description
Cost
PLANTS: Potted, 4" diameter, medium
$5.00
Each
$
PLANTS: Container, 1 gallon, medium soil
$11.50
Each
16.00'
$
184.00
PLANTS: Container, 2 gallon, medium soil
$20.00
Each
$
W
PLANTS: Container. 5 gallon, medium soil
$36.00
Each
$
PLANTS: Seeding, by hand
$0150
Sy
$
PLANTS: Slips (willow, red -osier)
$2.00
Each
$
PLANTS: Stakes (willow)
$2.00
Each
$
-
PLANTS: Stakes (willow)
$2.00
Each,
PLANTS Flats/plugs
$2.00
Each
1,
$
Y
" All costs include installation
ITOTAL
$
184.00' '..
INSTALLATION COSTS ( LABOR, EQUIPMENT, & OVERHEAD)
Tvpe
Unit Price
Unit
Cost
Compost, vegetable, delivered and spread
$37.88
CY
$
Decompactinq 1111/hardpan, medium, to 6" depth
$1.57
CY
$
Decompacting till/hardpan, medium, to 12" depth
11-S7
C .$
Hydroseeding
$0.51SY
$
Labor, general (landscaping)
$4EW
HR 2.00
$
80.00
Labor. aeneral (construction)
$40"00
HR
$
Labor: Consultant, supervising
$55.00
HR
$
Labor: Consultant. on-site re-desion
$85,00
HR'
$
Rental of decompactirm machinery & operator
$70.00
HR
T.
Sand, coarse builder's, delivered and spread
$42.00
CY
$
Staking material(setpertree)
$7.00
Each
$
Surveying, line & grade
$250.00
HR
$
Surveying, topographical
$250.00
HR
Watering, 1" of water, 50' soaker hose
$3.62
MSF
$
Irrigation - temporary
$3.000.00
Aare
$
Irrigation - buried
$4.500.00
Acre,
$
Tilling topsoil, disk harrow, 20hp tractor, 4'-6° deep
s
$
-
$25.00
HR
$
TOTAL
$
80.00
HABITAT STRUCTURES*
ITEMS
Unit Cost
Unit
Cost.
Fascines(willow)
$ 2°00
Each
$
Logs, (cedar), w/ root wads, 16'-24' diam., 30' long
$..1,000.00,
Each
$
Logs (cedar) w/o root wads, 16'-24° diem„ 30'
$400.00
Each.
$
Logs, w/o cool wads, 16°-24° diam., 30' long
$2_ 45.:.0(7',
Each
$
"
Logs w/root wads, 16°-24°diam.,30'long
$46000'.
_Each
$
Rocks, one-man
$60.00
Each
$
Rocks, two-man
$1.20:00
Each
$
$i
Root wads
$163.00
Each
SpaWnmq gravel, lVpe A
$22.00
CY
$
-
Weir - log
$1.500.00
Each
Weir-adiustable
$2°000.00
Each
$
Woody debris, large
$163.00
Each
Snags - anchored
$400.00
Each
$
Snags - onsite
$50.00
Each,
$
Snags -imported
$800.00
Each
$
_
$
" All costs include delivery and installation
TOTAL
$
..
EROSION CONTROL
ITEMS
Unit
Cost
Backfill and Compaction -embankment
CY
$Crushed
surfacing, 11/4" minus
nCost
CY
$
Ditching
CY
$
Excavation, bulk
CY
$
Fence, silt
$1.60 LF
$
Jute Mesh
$1.26 SY
!9
Mulch, by hand. straw. 2" deep
$1.27' SY
Mulch, by hand, wood chips. 2" deep
!0:25 SY 29.00
94.25
Mulchby machine. straw, I" deep
—'FP—ina,
qY
temporary, CPP, 6--
$930 LF
$
Piping, temporary, CPP, 8'
114.00. LF
$
Piping, temporary, CPP, 12"
$18.0 LF
$
Plastic covering, 6mm thick, sandbagged
$2.00 SY
Rip Rap, machine placed, slopes
$33.98 CY
Rock Constr. Entrance 100'x15'x1'
Each
q;
Rock Constr. Entrance 50'xl5'xl'
Q1 snn no F;irh
$
Sediment pond riser assembly
�V 69511 Each
Sediment trap, Thiah berm
$15"S7 LF
$
Sedimpn( trap, 5' high berm w1spillway Ind. riprap
$59.601 Lr
$
Sodding, 1' deep, level ground
SY
$5.24 SY
$
Sodding, V deep, sloped ground
$6.48 SY
$
Straw bales, place and remove
$600.00 TON
I
Haulina and disposal
$20.00 CY
CY
$
Topsoil, delivered and Spread
'M5;73 Cy
$17.00 CY
$
$
TOTAL
$ 94.251
GENERALITEMS
ITEMS
Unit Cost
Unit
Cost
Fencing, chain link, 6' high
$18.89
LF
$
..
Fencing, chain link, corner posts
$111.17
Each
$
_
Fencing, chain link, gate
1277S1
Each.
$
-
Fencina, solit rail. T hioh (2 -rail)
$10=54
LF
$
Fencing, temporary (NGPE)
$1.20
LF
$
-
Sions. sensitive area boundary (inc. backing, post, install)
$28.50
Each
$
$
$
TOTAL
$
?Construction Cost
OTHER
Subtotal) $
358.25
Percentage of
ITEMS
Construction
Cost
Unit,
Cost
Mobilization
10or6
1
$
35.83
Contingency
30%
1
$
107.48
TOTAL
$
143.30
NOTE: Projects with multiple permit requirements may be required to have longer
MAINTENANCE AND MONITORING
monitoring and maintenance
terms.
This will be evaluated on a case -by -ease basis for
development applications. Monitoring
and malntance ranges may be assessed anywhere
from 5 to 10 years.
Maintenance, annual
kW
Less than 1,000 sq ft, and buffer mitigation only
$ 1.08
SF
S 18,00
0 W W. .1
events; Includes monitoring)
$
559;44
Less than 1,000 sq,ft. with wetland or aquatic area mitigation
$ 1.35
SF
(3 A SF total t 3 annual
events; Includes monitoring)
$
Larger than 1,000 sq. ft but less than 5,000 scift of buffer
mfinallop
$ 180.00
EACH
(4hr@$45/hr)
$
-
Larger than 1,000 sq. It but less than 5,000 sq ft of wetland
v sq uehc anm M ` Mon
$ 270.00
EACH
(6hr @$45/hr)
$
Larger than 5,000 sq.ft, but < 1 acre -buffer mitigation only
$ -460-00
EACH
(B hrs @ 45/hr)
$
Larger than 5,000 sq,ft, but < 1 acre with wetland or aquatic
areamilicaton
$ 450.00
EACH
(10 hrs @ $45/hr)
$
Larger than 1 acre but < 5 acres - buffer and / or wetland or
aeualic area mitigation
$ 1.600.00
DAY
(WEC crew)
$
Larger than 5 acres - buffer and / or wetland or aquatic area
mihoatipn
$ 2.000.00
DAY',
(1.25 X WEC crew)
$
Monitoring, annual
Larger than 1,000 sq.tL but less than 5,000 wetland or buffer
milieaton
$ 720.00
EACH
(8 hrs @ 90/hr)
$
-
Larger than 5,000 sq ft but <1 acre with wetland or aquatic
area impvs
$ 900.00
EACH
(10 hrs @ $90/hr)
$
Larger than 1 acre but < 5 acres - buffer and / or wetland or
aquatic area impacts
$ 144000
DAY
(16 hrs @ $90/hr)
$
Larger than5 acres - buffer and / or wetland or aquatic area
impacts
$ 2.400.00
_DAY
(24 hrs @ $90/hr)
$
Maintenance and Monitoring Inspection (DDES), annual
$362.25
F.A. CH
4.001 V2.5 hrs @ $144.90/hr)
$17449,00
Maintenance and Monitoring Inspection (DDES), final
$579.60
EACH
1.00 (4 hrs @ $144.90/hr)
$
579.60
TOTAL
$
2,588,04
Total)
$3,089.59'