160920 MAD (Wetland Buffer Averaging Enhancement Plan).pdfWetland Buffer Averaging and Enhancement Plan
New Madrona K-8 Project
Edmonds, Washington
September 20, 2016
Submitted To:
Ms. Taine Wilton
Edmonds School District #15
20420 68th Avenue West
Lynnwood, Washington 98036
By:
Shannon & Wilson, Inc.
400 N 34th Street, Suite 100
Seattle, Washington 98103
21-1-22082-006
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TABLE OF CONTENTS
Page
1.0 PURPOSE ..............................................................................................................................1
2.0 INTRODUCTION ..................................................................................................................1
3.0 WETLAND BUFFER AVERAGING ...................................................................................2
3.1 Edmonds Community Development Code (ECDC) Requirements ...........................2
3.2 Existing Wetland B Buffer Condition and Functions ................................................2
3.3 Wetland B Buffer Averaging Strategy .......................................................................3
4.0 WETLAND BUFFER ENHANCEMENT .............................................................................4
4.1 Wetland Buffer Enhancement Plan ............................................................................4
4.2 Wetland Buffer Enhancement Sequence ....................................................................5
4.3 Maintenance ...............................................................................................................6
4.4 Monitoring Plan ..........................................................................................................6
4.5 Performance Standards ...............................................................................................8
5.0 CLOSURE ..............................................................................................................................8
6.0 REFERENCES .....................................................................................................................10
TABLE
1 Vegetation Performance Standards ..........................................................................8
FIGURES
1 Vicinity Map
2 Wetland Buffer Averaging Plan
3 Wetland Buffer Enhancement Plan
APPENDICES
A Wetland Buffer Enhancement Area Photos
B Important Information About Your Wetland Delineation/Mitigation and/or Stream
Classification Report
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WETLAND BUFFER AVERAGING AND ENHANCEMENT PLAN
NEW MADRONA K-8 PROJECT
EDMONDS, WASHINGTON
1.0 PURPOSE
Shannon & Wilson, Inc. (Shannon & Wilson) was contracted by the City of Edmonds School
District (District) No. 15 to assist with the wetland buffer averaging and enhancement strategy
associated with a site wetland, Wetland B, identified by Shannon & Wilson on the New Madrona
K-8 project site in Edmonds, Washington (Figure 1). This plan was prepared for the exclusive
use of the Edmonds School District and their representatives for the purpose of complying with
the Edmonds Community Development Code (ECDC), which regulates activities within wetland
buffers.
2.0 INTRODUCTION
The District plans to construct a new Madrona K-8 school on the south side of the approximately
40-acre property, located at 9300 236th Street SW (Snohomish County tax parcel
27033600404600). The project is located within Section 36 of Township 27 N, Range 4 E,
Willamette Meridian.
The property is dissected by two steeply sloped wooded areas running in north-south alignments;
one is a ravine located along the eastern property boundary and the other is a forested incline
located near the middle of the property. The existing Madrona Elementary School is located
in the northeast corner of the property and the former Woodway Elementary School is located in
the opposite southwest corner of the property. Recreational areas including a track and baseball
field, and soccer fields are located in the southeast and northwest corners of the property. The
areas surrounding the property consist primarily of residential development.
A wetland and stream delineation completed in July 2015 identified three wetlands (Wetlands A,
B, and C) on the project site. Wetland delineation findings are described in the Revised Wetland
and Stream Delineation Report for the New Madrona K-8 Project (Shannon & Wilson, 2016).
The current design for the new school is constrained by the property’s steep slopes and would
unavoidably extend into a portion of the standard buffer for Wetland B. This plan describes the
Wetland B buffer averaging strategy and also describes proposed Wetland B buffer
enhancements that would complement the wetland buffer averaging strategy.
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3.0 WETLAND BUFFER AVERAGING
3.1 Edmonds Community Development Code (ECDC) Requirements
The City regulates wetland buffers under Chapter 23.50 of the ECDC (City, 2016).
Wetland B is a Category III depressional wetland (Shannon & Wilson, 2016). The City requires
a 60-foot standard buffer width around Category III wetlands (ECDC 23.50.040(F)(1). Under
ECDC 23.50(G)(3), the City allows for wetland buffer averaging with wetland buffer
enhancement if the following requirements are met:
The buffer averaging and enhancement plan provides evidence that wetland functions
and values will be:
― Increased or retained through plan implementation for those wetlands where
existing buffer vegetation is generally intact; or
― Increased through plan implementation for those wetlands where existing
buffer vegetation is inadequate to protect the functions and values of the
wetland.
The wetland contains variations in sensitivity due to existing physical characteristics
or the character of the buffer varies in slope, soils, or vegetation, and the wetland
would benefit from a wider buffer in places and would not be adversely impacted by
a narrower buffer in other places;
The total area contained in the buffer area, or the total buffer area existing on a
subject parcel for wetlands extending off-site, after averaging is no less than that
which would be contained within a standard buffer; and
The buffer width at any single location is not reduced by more than 25 percent to less
than 50 percent of the standard buffer width.1
The following sections of the plan demonstrate how the Wetland B buffer averaging and
enhancement strategy meets these criteria.
3.2 Existing Wetland B Buffer Condition and Functions
The standard buffer associated with Wetland B is primarily located in the forested ravine located
along the eastern property boundary, and a portion of the wetland buffer extends beyond the
steep slopes of the ravine and into playfield south of the existing school. A chain link fence is
located at the top of the slope at the edge of the play field. Most of the Wetland B buffer is
densely vegetated, with the exception of several areas in the ravine adjacent to the wetland’s
1 As shown on the City’s ECDC website. Communication with the City has clarified the sentence to mean, “The
buffer width at any single location is not reduced by more than 25 percent of the standard buffer width.”
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eastern boundary and the playfield area. The wetland buffer’s vegetation within the ravine is
generally dominated by a forested strata of western red cedar (Thuja plicata), big leaf maple
(Acer macrophyllum), and Douglas fir (Pseudotsuga menziesii), a shrub strata of salal
(Gaultheria shallon), Oregon grape (Mahonia nervosa), English laurel (Prunus laurocerasus),
and Indian plum (Oemleria cerasiformis); and a ground cover of sword fern (Polystichum
munitum). The vegetation, in combination with the topographic variation in the ravine, visually
screen and reduce noise in the wetland from the surrounding residential developments and
school. The vegetation also has the potential to provide wildlife habitat to passerine birds and
small mammals and slow surface water flow through the area.
The portion of Wetland B buffer that extends beyond the steep slopes and into the playfield is
comprised of lawn and due to its vegetation and proximity to school activities, provides minimal
wildlife habitat, water quality function, or screening.
Several unimproved footpaths are located in and around the Wetland B buffer. The paths are
part of a large trail system located throughout the project area. The paths provide educational
opportunities to students and the community and are part of an orienteering course. Chapter
23.50.040.G.5.c.i of the ECDC allows walkways and trails within wetland buffer and the project
does not plan on removing the paths.
Based on the site survey, there are two existing stormwater outfalls located in the Wetland B
buffer. One outfall, an 8-inch metal pipe, is located in the field and will continue to be used to
discharge stormwater following project construction. However, as part of the project, the site’s
stormwater treatment prior to reaching the outfall will be updated to meet current standards.
Additionally, the area around the 8-inch outfall has been scoured by the discharge. To prevent
further erosion and sedimentation, the project will install quarry spalls underlain by geotextile
fabric, which will not require vegetation removal. The second outfall, a 10-inch polyvinyl
chloride pipe, has not been identified in the field and may be buried or dysfunctional.
3.3 Wetland B Buffer Averaging Strategy
The project proposes to average the Wetland B buffer width where improvements associated
with the new school design would unavoidably impact the wetland buffer, mainly at the top of
the steep slope and in the play field area. This strategy would involve reducing the standard
wetland buffer width to no less than 45 feet (25 percent of the standard 60-foot buffer width) in
the locations closest to the new school design, which would be a reduction of 3,835 square feet,
and extending the wetland buffer by 3,835 square feet at its northern boundary (Figure 2).
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Given the variation in wetland buffer condition between the ravine and play field area, the
wetland would benefit from a greater wetland buffer width where dense vegetation is present to
the north and would not be adversely affected by a reduction in buffer width to the west, at the
top of the steep slope, and in the existing play field area.
Section 23.50.40.H.3 of the ECDC includes a requirement for the installation of permanent
fencing at the wetland buffer boundary when buffer averaging is implemented as part of a
development proposal, and also states that the director may waive this requirement (City, 2016).
The majority of the Wetland B buffer boundary is located on densely vegetated steep slopes,
largely negating the need for a fence. Additionally, the few available access points to the
wetland buffer are used to support the education opportunities described above in Section 3.2.
For these reasons, fencing is not part of the wetland buffer averaging plan and we recommend
that this requirement be waived.
4.0 WETLAND BUFFER ENHANCEMENT
4.1 Wetland Buffer Enhancement Plan
A wetland buffer enhancement plan has been developed to meet the City’s criteria for wetland
buffer averaging, as described above in Section 3.1. The proposed enhancements are meant to
compliment the averaging strategy as well as offset the removal of two 10-inch red alder (Alnus
rubra) trees at the top of the slope within the western wetland buffer boundary. The project
arborist identified the two hazard trees as diseased and has recommended them for removal. The
trees will be cut off at or near the ground surface, leaving the root ball intact and avoiding earth
disturbance.
The proposed enhancement plan consists of dense plantings of native shrub and fern species in
the currently bare areas adjacent to the eastern wetland boundary. These areas were selected
because although they are shaded by a forest of Western red cedar they have limited shrub and
ground cover and are in a part of the buffer that would most benefit from the enhancements
(Photos 1 and 2). Our wetland buffer enhancement will provide greater vegetation structure and
wildlife habitat and will improve screening for the wetland. To provide continuity and to
increase the planting success, the plant species selected for the enhancement area include native
species already thriving in the wetland buffer and surrounding area (Figure 3). These species
have also been used successfully in similar wetland buffer planting projects. The wetland buffer
enhancement plan includes removal of existing patches of English holly (Ilex aquifolium) from
the planting areas (See Section 4.2 below and planting note 2 on Figure 3).
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The wetland buffer enhancement plan also includes placing large woody debris (LWD) around
the outer borders of the planting areas to discourage disturbance and to provide insect, passerine
bird, and small mammal habitat (Figure 3). In total, the wetland buffer enhancement area is
approximately 1,380 square feet.
The proposed wetland buffer enhancement plan will increase wetland and wetland buffer
function and value in an area where existing buffer vegetation is inadequate by providing the
following ecological benefits:
Increased woody species at the wetland boundary will help contribute woody debris
and other organic material to the wetland;
Invasive species will be replaced by native species in the planting areas;
Native woody vegetation will provide wildlife habitat, forage, and cover for birds and
small mammals; and
Increased vegetation in the planting areas will filter pollutants in surface water runoff
through capturing of mobilized sediment, phytoextraction, transpiration, and soil
microbial interactions.
4.2 Wetland Buffer Enhancement Sequence
The sequence below summarizes the steps that should be taken to implement the wetland buffer
enhancement plan. Additional detail can be found in the Planting Notes section of Figure 3.
A. A wetland biologist will re-flag or stake the eastern wetland B boundary in the
vicinity of the enhancement areas prior to the start of enhancement work.
B. Install erosion control Best Management Practices (BMPs) and protect existing native
woody vegetation in and adjacent to the planting areas. Earth disturbance should be
minimized to the extent possible to avoid damaging existing tree roots in the area.
C. Remove existing non-native invasive species such as English holly (Ilex aquifolium)
from the planting areas using a combination of hand pulling, cutting, and application
of triclopyr or similar, depending on size of individuals. Relocate existing downed
woody debris within the site to locations outside of the enhancement areas, to be
replaced and reoriented following plant installation.
D. Place LWD along the boundaries of the enhancement areas. LWD must be at least
12 inches in diameter. Existing downed woody debris that was removed from the site
prior to planting may be used in this delineation, if size criteria is met.
E. Procure plants and store properly. Biologist shall review plant material and plant
layout prior to planting. Install plants by hand in the planting areas in natural,
random clusters. Planting should occur between September 15 and January 15 to take
advantage of cool temperatures and precipitation.
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F. Mix 3 inches of compost into soil at plant pits and hand-dig circular plant pits. Take
care to avoid cutting through existing native tree roots. Backfill with native
soil/compost mix.
G. Water plants thoroughly after planting to avoid capillary stress.
H. Mulch the wetland buffer enhancement areas with 4 to 6 inches of wood chips to
discourage weed establishment.
I. Remove construction debris. Remove BMPs after site is stabilized.
4.3 Maintenance
The contractor will be responsible for maintenance of the enhancement areas for the first year
following installation. The District will be responsible for maintenance of the enhancement area
for the remaining four years of the monitoring period (see Section 4.4). Maintenance will
include watering during the first dry season following planting, weeding around base of installed
plants, pruning, replacing plants to meet survival requirements (see Section 4.5), removing all
classes of noxious weeds (see Washington State Noxious Weeds List, Washington
Administrative Code 16-750-005), and implementing any other measures needed to ensure plant
survival. All proposed maintenance shall be reviewed by the biologist.
Water shall be provided to installed plants during the dry season (June 1 through October 15) for
the first year after plant installation to enhance plant survival and establishment. Water should
be applied at a rate of one inch of water, once per week.
4.4 Monitoring Plan
Monitoring shall be conducted in years 1, 3, and 5 following installation of the enhancement
areas (ECDC 23.40). Below we have outlined proposed monitoring methods, success criteria,
and reporting schedule. Monitoring will be conducted by a qualified biologist and will consist of
documenting plant mortality in the first year after installation and estimating plant cover
thereafter. Monitoring will also include identifying maintenance needs as they relate to plant
survival and weed control. Monitoring will be conducted soon after installation to document
baseline conditions and in years 1, 3, and 5 to assess whether the site is meeting the success
criteria in Section 4.5.
A. Baseline Documentation. Within 30 days of completion of the vegetation
enhancement installation, the site will be visited to document the as-built condition.
The final plant count by species will be verified, and any approved departures from
the plan will be mapped and recorded. Recommendations for correcting any
unauthorized plan deviations will be included in a Baseline Monitoring Report.
Permanent photo points will be established during the as-built site visit to provide a
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record of the entire monitoring area. These points will be noted on the map and
baseline photos included in the report.
B. Vegetation Monitoring.
― Year 1: Each installed plant will be assessed and counted, and its condition
recorded. Invasive species cover will be visually estimated.
― Years 3 and 5: Total percent cover of native shrub and fern/ground cover
species and percent cover of invasive species will be visually estimated.
Native volunteer species may be counted in the cover assessment.
― All vegetation monitoring shall occur between May 15 and September 30
(prior to leaf drop), unless otherwise specified.
― Photos of the vegetation enhancement shall be taken from consistent locations
established during baseline monitoring.
The monitoring reports will include:
A. Reports. Monitoring reports shall be submitted to the City December 31 of each
reporting year (baseline and years 1, 3, and 5). Monitoring reports will include the
following description/data:
1. Site plan and location map.
2. History of project, including date of plant installation, current year of monitoring,
and restatement of performance standards.
3. Plant survival and/or cover and vigor of the installed vegetation, in the context of
assessing achievement of performance standards.
4. Observed wildlife, including amphibians and birds.
5. Assessment of nuisance/exotic biota and recommendations for management.
6. Color photographs taken from permanent photo points established during the as-
built visit.
7. Summary of maintenance and contingency measures proposed for the next season
and completed for the past season.
B. Deficiencies. Any deficiency discovered during any monitoring or inspection visit
must be corrected within 60 days.
C. Contingency Plan. If any monitoring report reveals that the enhancement plan has
failed in whole or in part, and if that failure is beyond the scope of routine
maintenance, a Contingency Plan shall be prepared and submitted. The Contingency
Plan may range in complexity from a list of plants substituted to cross-sections of
proposed engineered structures. Once approved, contingency measures may be
installed and will replace the approved wetland buffer enhancement plan.
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4.5 Performance Standards
Plant survival and cover standards are established to measure enhancement plan success. The
proposed performance standards are summarized in Table 1.
TABLE 1
VEGETATION PERFORMANCE STANDARDS
Monitoring
Year Survival (%) Native Cover (%)*
Invasive/Non-native
Cover (%)**
Year 1 100 -- ≤10
Year 3 -- ≥20 ≤10
Year 5 -- ≥50 ≤10
Notes:
* Includes native plants in that category that are naturally recruiting.
** Applies to all exotic invasive species. If weed cover exceeds 10 % during vegetation monitoring, this
performance standard can be met by removing weeds within 60 days of vegetation monitoring.
100 percent (%) survival criteria shall be met by replacing all mortalities the first year after planting.
≥ = greater than or equal to
5.0 CLOSURE
This report has been prepared for specific application to the New Madrona K-8 project. This
report has been developed in a manner consistent with the level of care and skill normally
exercised by members of the environmental science profession currently practicing under similar
conditions in the area. The wetland buffer averaging and enhancement approach presented in
this report incorporates professional opinions based on interpretation of information currently
available to us, and was completed within the operational scope, budget, and schedule constraints
of this project. No warranty, express or implied, is made.
This report was prepared for the exclusive use of the District and its representatives. We have
prepared Appendix B, “Important Information About Your Wetland Delineation/Mitigation
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6.0 REFERENCES
Edmonds, Wash., 2016, Wetlands: Edmonds, Wash., City Code and Development Code Title
23.50, available: http://www.codepublishing.com/WA/Edmonds/.
Shannon & Wilson, Inc., (Shannon & Wilson), 2016, Revised wetland and stream delineation
report for new Madrona K-8 project, City of Edmonds, Washington: Report prepared by
Shannon & Wilson, Inc., Seattle, Wash., 21-1-22082-002, for City of Edmonds School
District, Edmonds, Wash., August, 94 p.
104
NE 205th St
238th St SW
236th St SW
240th St SW
Lake
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PROJECT
LOCATION
99
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VICINITY MAP
FIG. 1
New Madrona K-8 Project
Edmonds, Washington
Map adapted from aerial imagery provided by
Google Earth Pro, reproduced by permission
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WETLAND BUFFERAVERAGING PLAN
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WETLAND B
89-FT
WETLAND B
18-FT
13-FT
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AREA 1Approximate Buffer
Enhancement Location
AREA 2Approximate Buffer
Enhancement Location
New Madrona K-8 ProjectEdmonds, Washin gton
WETLAND BUFFERENHANCEMENT PLAN
FIG. 3
Se pte mb er 20 16 21-2208 2-006
Filename: I:\WIP\21-1\22082 Madrona K-8\GIS\MXD\BufferEnhancementPlan.mxd Date: 9/16/2016 beo
A WETLAN D BIOLOGIST WILL REFLAG OR STAK ETHE EASTERN WETLAND B BOUND ARY IN THEVICINITY OF THE ENHA NCEMENT AREAS PRIOR TOTHE START OF ENHANCEMENT WORK.
INSTALL EROSION CONTROL BEST MANAGEMENTPRACTICES AND PR OTECT EXISTING NATIVEWOODY VEGETATION IN AND AD JACENT TO THEPLANTING AREAS. EAR TH DISTUR BANCE SHOULDBE MINIMIZED TO THE EXTENT POSSIBLE TO AVOIDDAMAGING EXISTING TREE ROOTS IN THE AR EA.
REMOVE EXISTING NON-NATIVE INVASIVE SPECIESFROM PLANTING AREAS, INCLUDING BUT NOTLIMITED TO ENGLISH HOLLY (ILEX AQU IFOLIUM).SMALL IN DIVIDUALS OF ENGLISH HOLLY SHOU LDBE HAN D PULLED AND LARGE INDIVIDUALSSHOULD BE C UT OFF AT OR NEAR GROUND LEVELAND TRICLOPYR OR SIMILAR SHALL BEIMMEDIATELY A PPLIED TO CUT STEM BY APESTICIDE APPLICATOR WITH A VA LID WA STATEDEPARTMENT OF AGRICULTURE PESTICID EINSPECTOR LICENSE. RELOC ATE EXISTINGDOWNED WOOD Y D EBRIS IN THE PLA NTING A REASOUTSIDE OF THE ENHA NCEMENT AREAS, TO BEREPLACED AN D REORIENTED FOLLOWING PLANTINSTALLATION.
PLACE LAR GE WOODY DEBRIS (LWD ) ALONG THEBOUNDARIES OF THE BUFFER ENHAN CEMENTAREAS. LWD MUST BE AT LEAST 12 INCHES INDIAMETER. EXISTING WOOD Y D EBRIS THAT WA SREMOVED FROM THE ENHANCEMENT AREASPRIOR TO PLAN TING MAY B E USED IN THISDELINEATION, IF SIZE C RITERIA IS MET.
PROCURE PLA NTS A ND STORE PROPERLY.PLANTS SHALL CON FORM TO THE COD E OFSTANDARDS OF THE A MERICAN A SSOCIATION OFNURSERYMEN. PLANT MATERIA L WILL BE NATIVETO THE PA CIFIC NORTHWEST AN D FROM PLANTSTOCK GENOMES FR OM WESTER N WASHIN GTON.BIOLOGIST SHALL R EVIEW PLANT MATERIALPRIOR TO PLAN TING. BIOLOGIST RESERVES THERIGHT TO REQUIR E REPLACEMENT ORSUBSTITUTION OF PLANTS DEEMED UNSUITABLE.
INSTALL PLAN TS BY HAND IN TH E PLANTINGAREAS IN N ATURAL, RANDOM C LUSTERS. PLANTLAYOUT SHA LL BE REVIEWED BY BIOLOGISTPRIOR TO INSTALLATION OF PLANTS. IF POSSIBLE,PLANTING SHOULD OCCUR B ETWEEN SEPTEMBER15 AND JANUARY 15 TO TAKE ADVANTA GE OFCOOL TEMPERATURES AND PRECIPITATION.PLANTS SHOULD BE INSTALLED THE SAME D AY
THEY ARE DELIVER ED TO THE SITE. PLANTS THATARE NOT INSTALLED ON THE DAY OF D ELIVERY TOTHE SITE SHA LL BE HEELED INTO THE SOIL IN ASHADED LOCATION FOR PROTECTION AGAINSTDRYING.
MIX 3 INC HES OF COMPOST (CEDAR GR OVECOMPOST OR EQUIVA LENT) IN TO THE SOIL ATPLANT PITS. HAN D-DIG C IRCULAR PLANT PITSWITH VERTIC AL SIDES AND INSTALL PLANTS,TA KING CA RE TO AVOID CUTTING THROUGHEXISTING NATIVE TREE ROOTS. BACKFILL WITHNATIVE SOIL/COMPOST MIX.
WATER PLANTS THOROUGH LY TO AVOIDCAPILLARY STRESS. PLANTED AREAS SH ALL BEWATERED WITH APPROXIMATELY 1 INCH OF WATERIMMEDIATELY A FTER PLANTING.
MULCH THE B UFFER EN HANCEMEN T AREA WITH 4TO 6 INCHES OF WOOD C HIPS TO DISC OURAGEWEED ESTA BLISHMENT.
REMOVE ALL CONSTRUCTION DEBRIS. REMOVEEROSION CONTR OL BMPS AFTER SITE ISSTABILIZED.
LANDSCAPER SHALL SUBMIT A COPIES OF TH EPLANTING INVOIC ES SHOWING PLANTED SPECIESAND QUANTITIES.
THE PLANTED AR EAS SHALL BE WATERED WITH 1-INCH OF WATER ON CE PER WEEK DURING THE DRYSEASON (JUNE 1 THROUGH OCTOBER 15) FOR THEFIRST YEAR A FTER PLANT INSTALLATION .
LANDSCAPER SHALL REPLACE ALL PLANTMORTALITIES A ND PERFORM MAINTENA NCE FORONE YEAR A FTER INSTALLATION.
PLAN TING NOTES
0 20 4010
Feet
PLAN T SPECIES, QUANTITY, SIZE, AND SPACING
1. Quantity is based on an estimated planting area of 1,380 square feet.2 O.C. = cumulative on center
S ymbol Common Name Scientific Name Quantity1 Spacing2 Size Condition
salal Gaultheria shallon 30 >12 inches 1-gallo n co ntainer
Oregon grape Mahonia nervosa 30 >12 inches 1-gallo n co ntainer
Indian plum Oemleria cerasiformis 26 >24 inches 1-gallo n co ntainer
sword fern Polystichum munitum 190 2.5 feet O.C.>12 inches 1-gallo n co ntainer
4 feet O.C.
@
@
@
888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888
888 888 888 888 888 888 888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888
APPLY 4-6 INCHESOF MULCH. KEEPMULCH AWAY FROMPLANT STEMS TOPREVENT ROT.
HAND DIGCIRCULAR PITSWITH VERTICALSIDES.
2X ROOTBALLWIDTH
CON TAINER DETAIL (n .t.s.)
Wetland B
PROPOSEDBUILDINGS
Parcel Boundary
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
®!
P!
®!
Î
240TH STREET SW
238TH ST SW
91 PL W
µ
12.
13.
AREA 1
AREA 2
= Larg e Wood y De bris
21-1-22082-006
APPENDIX A
WETLAND BUFFER ENHANCEMENT AREA PHOTOS
21-1-22082-006-R1f-AA/wp/lkn 21-1-22082-006
Photo 1: A portion of buffer enhancement area 1, viewing northeast, taken on
September 12, 2016.
Photo 2: A portion of buffer enhancement area 2, with Wetland B shown on the left, viewing north,
taken on September 12, 2016.
21-1-22082-006
APPENDIX B
IMPORTANT INFORMATION ABOUT YOUR WETLAND
DELINEATION/MITIGATION AND/OR STREAM CLASSIFICATION REPORT
Page 1 of 2 1/2016
SHANNON & WILSON, INC.
Geotechnical and Environmental Consultants
Attachment to and part of Report 21-1-22082-006
Date: September 20, 2016
To: Ms. Taine Wilton
Edmonds School District #15
IMPORTANT INFORMATION ABOUT YOUR WETLAND DELINEATION/MITIGATION
AND/OR STREAM CLASSIFICATION REPORT
A WETLAND/STREAM REPORT IS BASED ON PROJECT-SPECIFIC FACTORS.
Wetland delineation/mitigation and stream classification reports are based on a unique set of project-specific factors. These typically
include the general nature of the project and property involved, its size, and its configuration; historical use and practice; the location
of the project on the site and its orientation; and the level of additional risk the client assumed by virtue of limitations imposed upon
the exploratory program. The jurisdiction of any particular wetland/stream is determined by the regulatory authority(s) issuing the
permit(s). As a result, one or more agencies will have jurisdiction over a particular wetland or stream with sometimes confusing
regulations. It is necessary to involve a consultant who understands which agency(s) has jurisdiction over a particular wetland/stream
and what the agency(s) permitting requirements are for that wetland/stream. To help reduce or avoid potential costly problems, have
the consultant determine how any factors or regulations (which can change subsequent to the report) may affect the recommendations.
Unless your consultant indicates otherwise, your report should not be used:
If the size or configuration of the proposed project is altered.
If the location or orientation of the proposed project is modified.
If there is a change of ownership.
For application to an adjacent site.
For construction at an adjacent site or on site.
Following floods, earthquakes, or other acts of nature.
Wetland/stream consultants cannot accept responsibility for problems that may develop if they are not consulted after factors
considered in their reports have changed. Therefore, it is incumbent upon you to notify your consultant of any factors that may have
changed prior to submission of our final report.
Wetland boundaries identified and stream classifications made by Shannon & Wilson are considered preliminary until validated by the
U.S. Army Corps of Engineers (Corps) and/or the local jurisdictional agency. Validation by the regulating agency(s) provides a
certification, usually written, that the wetland boundaries verified are the boundaries that will be regulated by the agency(s) until a
specified date, or until the regulations are modified, and that the stream has been properly classified. Only the regulating agency(s)
can provide this certification.
MOST WETLAND/STREAM "FINDINGS" ARE PROFESSIONAL ESTIMATES.
Site exploration identifies wetland/stream conditions at only those points where samples are taken and when they are taken, but the
physical means of obtaining data preclude the determination of precise conditions. Consequently, the information obtained is intended
to be sufficiently accurate for design, but is subject to interpretation. Additionally, data derived through sampling and subsequent
laboratory testing are extrapolated by the consultant who then renders an opinion about overall conditions, the likely reaction to
proposed construction activity, and/or appropriate design. Even under optimal circumstances, actual conditions may differ from those
thought to exist because no consultant, no matter how qualified, and no exploration program, no matter how comprehensive, can
reveal what is hidden by earth, rock, and time. Nothing can be done to prevent the unanticipated, but steps can be taken to help reduce
their impacts. For this reason, most experienced owners retain their consultants through the construction or wetland mitigation/stream
classification stage to identify variances, to conduct additional evaluations that may be needed, and to recommend solutions to
problems encountered on site.
Page 2 of 2 1/2016
WETLAND/STREAM CONDITIONS CAN CHANGE.
Since natural systems are dynamic systems affected by both natural processes and human activities, changes in wetland boundaries
and stream conditions may be expected. Therefore, delineated wetland boundaries and stream classifications cannot remain valid for
an indefinite period of time. The Corps typically recognizes the validity of wetland delineations for a period of five years after
completion. Some city and county agencies recognize the validity of wetland delineations for a period of two years. If a period of
years have passed since the wetland/stream report was completed, the owner is advised to have the consultant reexamine the
wetland/stream to determine if the classification is still accurate.
Construction operations at or adjacent to the site and natural events such as floods, earthquakes, or water fluctuations may also affect
conditions and, thus, the continuing adequacy of the wetland/stream report. The consultant should be kept apprised of any such events
and should be consulted to determine if additional evaluation is necessary.
THE WETLAND/STREAM REPORT IS SUBJECT TO MISINTERPRETATION.
Costly problems can occur when plans are developed based on misinterpretation of a wetland/stream report. To help avoid these
problems, the consultant should be retained to work with other appropriate professionals to explain relevant wetland, stream,
geological, and other findings, and to review the adequacy of plans and specifications relative to these issues.
DATA FORMS SHOULD NOT BE SEPARATED FROM THE REPORT.
Final data forms are developed by the consultant based on interpretation of field sheets (assembled by site personnel) and laboratory
evaluation of field samples. Only final data forms customarily are included in a report. These data forms should not, under any
circumstances, be drawn for inclusion in other drawings because drafters may commit errors or omissions in the transfer process.
Although photographic reproduction eliminates this problem, it does nothing to reduce the possibility of misinterpreting the forms.
When this occurs, delays, disputes, and unanticipated costs are frequently the result.
To reduce the likelihood of data form misinterpretation, contractors, engineers, and planners should be given ready access to the
complete report. Those who do not provide such access may proceed under the mistaken impression that simply disclaiming
responsibility for the accuracy of information always insulates them from attendant liability. Providing the best available information
to contractors, engineers, and planners helps prevent costly problems and the adversarial attitudes that aggravate them to a
disproportionate scale.
READ RESPONSIBILITY CLAUSES CLOSELY.
Because a wetland delineation/stream classification is based extensively on judgment and opinion, it is far less exact than other design
disciplines. This situation has resulted in wholly unwarranted claims being lodged against consultants. To help prevent this problem,
consultants have developed a number of clauses for use in written transmittals. These are not exculpatory clauses designed to foist the
consultant's liabilities onto someone else; rather, they are definitive clauses that identify where the consultant's responsibilities begin
and end. Their use helps all parties involved recognize their individual responsibilities and take appropriate action. Some of these
definitive clauses are likely to appear in your report, and you are encouraged to read them closely. Your consultant will be pleased to
give full and frank answers to your questions.
THERE MAY BE OTHER STEPS YOU CAN TAKE TO REDUCE RISK.
Your co nsultant will be pleased to discuss other techniques or designs that can be employed to mitigate the risk of delays and to
provide a variety of alternatives that may be beneficial to your project.
Contact your consultant for further information.