21-104125-Revised Mitigation Plan-09.25.23T
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LOT 1
LOT 2
LOT 3
LOT 4
LOT 5 LOT 6 LOT 7
LOT 8 LOT 9
LOT 10
LOT 11
S 298TH STREET
35'
50'
36.9'
35'
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37.5'
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PLAN LEGEND:
CATEGORY IV WETLAND WETLAND BUFFER ALTERATION - STORM OUTFAL (1,037 SF)WETLAND BUFFER RESTORATION (1,037 SF)
TYPE Ns STREAM WETLAND BUFFER REDUCTION - STORM POND (886 SF)WETLAND BUFFER ENHANCEMENT (5,753 SF)
WETLAND/STREAM BUFFER CRITICAL AREA FENCE/SIGNAGE (310 LF; 3 SIGNS)
Wetland Delineation
Mitigation Design
Mitigation Monitoring
PO BOX 1721
ISSAQUAH, WASHINGTON 98027
TEL - (425) 677-7166
WWW.EVERGREENARC.COM
Resource Consultants, LLC
Evergreen Aquatic
PROJECT NO: 20030
DATE: 09/21/2022
DESCRIPTIONDATENO
SHEET NUMBER:
1/1
PERMIT NO:
APPROVED BY:
DATE:
THE UNDERGROUND ROUTING AND CONDITION OF
BURIED UTILITIES HAS NOT BEEN VERIFIED OR
CONFIRMED. FIELD LOCATE, VERIFY DEPTH OF, AND
ADEQUATELY PROTECT ALL UTILITIES PRIOR TO THE
START OF WORK.
Know what's below.
before you dig.Call
R
SHEET TITLE:
SITE PLAN,
NOTES, AND
DETAILS
PROJECT:
WETLAND &
STREAM
BUFFER
MITIGATION
PLAN
VSM PLAT
CITY OF FEDERAL WAY
PERMIT NO:
21-104125-00-SU
VSM PLAT
NW 1
4 OF SE 1
4 OF SECTION 4, TOWNSHIP 21 NORTH, RANGE 4 EAST, W.M.
CITY OF FEDERAL WAY, KING COUNTY, STATE OF WASHINGTON
30150
CONTOUR INTERVAL = 2 FEET
VERTICAL DATUM = NAVD88
NOXIOUS WEED CONTROL SPECIFICATIONS:
PRIOR TO PLANT INSTALLATION, CONTROL NOXIOUS WEEDS WITHIN THE PLANTING
AREA. TARGET NOXIOUS WEED SPECIES SHALL INCLUDE THE FOLLOWING: ALL CLASS
"A", "B", AND "C" NOXIOUS WEEDS (INCLUDING NON-REGULATED "B" AND "C" NOXIOUS
WEEDS AND "WEEDS OF CONCERN") IDENTIFIED ON THE LATEST KING COUNTY
NOXIOUS WEED LIST.
HYDROSEED SPECIFICATION:
APPLY HYDROSEED TO BUFFER RESTORATION AREA USING APPROPRIATE CELLULOSE
FIBER, FERTILIZER, AND TACKIFIER. SEED MIX SHALL BE:
·SUNMARK NATIVE EC MIX (SUNMARK SEEDS INTERNATIONAL, INC. 503-241-7333;
WWW.SUNMARKSEEDS.CO/NATIVE-EC-MIX) OR APPROVED EQUAL:
SEED APPLICATION RATE: 43.63 LBS PER ACRE. SEED, FIBER, AND FERTILIZER SHALL BE
APPLIED IN A UNIFORM MANNER UTILIZING A HYDROSEEDER THAT USES WATER AS THE
CARRYING AGENT AND MAINTAINS CONTINUOUS AGITATION THROUGH PADDLE
BLADES. THE SEEDER SHALL HAVE AN OPERATING CAPACITY SUFFICIENT TO AGITATE,
SUSPEND, AND MIX INTO A HOMOGENEOUS SLURRY THE SPECIFIED AMOUNT OF SEED,
MULCH, FERTILIZER AND WATER. DISTRIBUTION AND DISCHARGE LINES SHALL BE LARGE
ENOUGH TO PREVENT STOPPAGE AND SHALL BE EQUIPPED WITH A SET OF HYDRAULIC
DISCHARGE SPRAY NOZZLES WHICH WILL PROVIDE A UNIFORM DISTRIBUTION OF THE
SLURRY. THE FERTILIZER SHALL BE PLACED IN THE HYDROSEEDER TANK NO MORE THAN
30 MINUTES PRIOR TO APPLICATION.
TREE AND SHRUB PLANT MATERIAL SPECIFICATIONS:
1. PLANTS SHALL BE PROPAGATED FROM STOCK NATIVE TO THE PUGET SOUND REGION
OF WASHINGTON STATE. SALVAGED PLANTS ARE ACCEPTABLE.
3.PLANTS SHALL BE NORMAL IN PATTERN OF GROWTH, HEALTHY, WELL-BRANCHED
AND HAVE ALL LEADERS AND BUDS INTACT. TREES SHALL NOT HAVE SUNSCALDS,
DISFIGURING KNOTS, FRESH CUTS OF LIMBS, DAMAGED LEADERS, AND/OR
DEFORMED TRUNKS.
4.CONTAINERIZED PLANT STOCK SHALL BE GROWN IN A CONTAINER LONG ENOUGH
TO DEVELOP A ROOT SYSTEM THAT REACHES THE EDGES OF THE CONTAINER IN
WHICH IT HAS GROWN. TREES AND SHRUBS SHALL BE WELL ROOTED AND SHALL
HAVE SUFFICIENT ROOT MASS TO HOLD TOGETHER THE SOIL, IN WHICH PLANT IS
GROWING, WHEN REMOVED FROM THE POT.
TREE AND SHRUB INSTALLATION SPECIFICATIONS:
1. PLANT MATERIAL QUALITY AND LOCATIONS SHALL BE INSPECTED BY THE PLAN
DESIGNER OR OWNER PRIOR TO INSTALLATION.
2. PLANT LOCATIONS SHOWN ARE APPROXIMATE. ADJUST PLANT LOCATIONS TO
ACCOMMODATE SITE CONDITIONS, TO PRESERVE AND PROTECT EXISTING NATIVE
VEGETATION, AND/OR PER PLAN DESIGNER AT TIME OF INSTALLATION.
3. FOLLOWING PLANT INSTALLATION, PLACE MULCH AT THE BASE OF EACH INSTALLED
PLANT.
4. CAUTION SITE CONDITIONS MAY VARY BASED ON SEASON AND/OR TIME OF YEAR.
UNLESS IMMEDIATELY IRRIGATED, PLANT INSTALLATION SHALL BE LIMITED TO
NOVEMBER 15 TO FEBRUARY 15.
TREE AND SHRUB PLANT SCHEDULE: 5,753 SF
COMMON NAME SCIENTIFIC NAME SIZE/FORM SPACING QTY
SITKA SPRUCE PICEA SITCHENSIS 2 GALLON 9' O.C.20
BLACK COTTONWOOD POPULUS BALSMIFERA 2 GALLON 9' O.C. 25
DOUGLAS-FIR PSEUDOTSUGA MENZIESII 2 GALLON 9' O.C.25
VINE MAPLE ACER CIRCINATUM 2 GALLON 6' O.C.20
INDIAN PLUM OEMLERIA CERASIFORMIS 2 GALLON 6' O.C.35
REDFLOWER CURRANT RIBES SNAGUINEUM 2 GALLON 6' O.C.24
SALMONBERRY RUBUS SPECTABILIS 2 GALLON 6' O.C.35
SNOWBERRY SYMPHORICARPOS ALBUS 2 GALLON 6' O.C.48
MULCH SPECIFICATION:
MULCH SHALL BE COMMERCIALLY AVAILABLE "MEDIUM MULCH"
(WWW.CEDAR-GROVE.COM; 1-877-SOILS4U), ARBORIST CHIPS, OR APPROVED EQUAL.
TEMPORARY IRRIGATION SPECIFICATIONS:
TEMPORARY IRRIGATION SHALL BE PROVIDED FOR TWO (2) GROWING SEASONS
FOLLOWING PLANT INSTALLATION. IRRIGATION SHALL PROVIDE A MINIMUM RAINFALL
EQUIVALENT OF 1 INCH PER WEEK FROM JUNE 15 THROUGH SEPTEMBER 15.
IRRIGATION SHALL BE APPLIED IN A MANNER THAT MAINTAINS PLANT HEALTH,
PREVENTS WILTING, AND PROMOTES DEEP PLANT ROOT SYSTEMS. IRRIGATION SHALL
INCLUDE AN ABOVE OR BELOW GROUND TIMER BASED AUTOMATIC SYSTEM, BY HAND,
OR OTHER SIMILAR AND ACCEPTABLE METHOD.
PLANT INSTALLATION DETAIL:
CRITICAL AREA SIGN DETAIL:
MONITORING PLAN:
THE FIVE YEAR MONITORING PLAN OUTLINED BELOW WILL ENSURE AND DOCUMENT
THAT THE PERFORMANCE STANDARDS ESTABLISHED FOR THIS PLAN HAVE BEEN MET.
THE PLAT DEVELOPER IS RESPONSIBLE FOR SUCCESSFUL COMPLETION OF THE WORK
DESCRIBED ON THIS PLAN. IF THE PROPERTY IS SOLD OR PROPERTY OWNERSHIP IS
OTHERWISE TRANSFERRED, RESPONSIBILITY FOR ANY REMAINING WORK SHALL BE
TRANSFERRED TO THE NEW OWNER AND RECORDED WITH FEDERAL WAY.
GOALS/OBJECTIVES/PERFORMANCE STANDARDS:
THE GOALS AND OBJECTIVES OF THIS PLAN ARE CONSIDERED ACHIEVED WHEN THE
PERFORMANCE STANDARDS ARE SATISFIED.
GOAL - ENHANCE ECOLOGICAL FUNCTIONING OF ON-SITE WETLAND/STREAM BUFFERS.
OBJECTIVES - INSTALL AND SUCCESSFULLY ESTABLISH NATIVE PLANTINGS WITHIN THE
AREAS SHOWN ON THIS PLAN
PERFORMANCE STANDARDS:
1. PERCENT SURVIVAL - INSTALLED PLANTS
YEAR 1: 100%; YEAR 2: 80%. THIS STANDARD CAN BE ACHIEVED THROUGH
PLANT ESTABLISHMENT OR THROUGH PLANT REPLACEMENT.
2. PERCENT COVERAGE - NATIVE TREES/SHRUBS
YEAR 1: 10% ; YEAR 3: 30%; YEAR 5: 60%. UP TO 20% NATIVE TREE/SHRUB
COVERAGE CAN BE NATIVE COLONIZING SPECIES.
3. PERCENT COVERAGE - NOXIOUS WEEDS
ALL YEARS LESS THAN 10% COVERAGE BY CLASS "A", "B", AND "C" NOXIOUS
WEEDS INCLUDING NON-REGULATED "B" AND "C" NOXIOUS WEEDS AND
"WEEDS OF CONCERN".
AS-BUILT
FOLLOWING COMPLETION OF THE WORK SHOWN ON THIS PLAN, A QUALIFIED
PROFESSIONAL SHALL PREPARE AN AS-BUILT OF THE COMPLETED WORK. THE AS-BUILT
SHALL SUMMARIZE THE COMPLETED WORK AS WELL AS ANY DEVIATIONS FROM THE
APPROVED VERSION OF THIS PLAN. THE AS-BUILT SHALL BE SUBMITTED TO FEDERAL
WAY NO LATER THAN 30 DAYS FROM THE DATE THAT THE WORK SHOWN ON THIS PLAN
HAS BEEN COMPLETED.
ANNUAL MONITORING (5 YEARS)
ANNUAL MONITORING SHALL BE COMPLETED FOR A PERIOD OF FIVE (5) YEARS BY A
QUALIFIED PROFESSIONAL. MONITORING SHALL COMPRISE A SITE INVESTIGATION IN
AUGUST OR SEPTEMBER AND REPORTING TO THE CITY OF FEDERAL WAY NO LATER
THAN 30 DAYS FOLLOWING EACH MONITORING. THE PURPOSE OF THE SITE
INVESTIGATION IS TO EVALUATE CONDITIONS WITHIN THE BUFFER ENHANCEMENT
AREA PER THE CURRENT YEAR'S PERFORMANCE STANDARDS. THE FOLLOWING
INFORMATION SHALL BE COLLECTED AND ASSESSED RELATIVE TO THE PERFORMANCE
STANDARDS ESTABLISHED FOR THE PROJECT:
·A DIRECT COUNT INVENTORY AND ASSESSMENT OF ALL INSTALLED PLANTS SHALL
BE USED TO EVALUATE PERCENT SURVIVAL. THE RATIONALE FOR POOR
CONDITIONS, IF PRESENT, WILL BE DETERMINED TO THE EXTENT FEASIBLE.
·THE PERCENT COVERAGE OF NATIVE TREES/SHRUBS AND NOXIOUS WEEDS SHALL
BE ASSESSED USING APPROPRIATELY SIZED SAMPLE PLOTS OR LINE INTERCEPT
TRANSECTS.
IN ADDITION TO THE ABOVE INFORMATION, PHOTOGRAPHS SHALL BE TAKEN FROM THE
PERMANENT PHOTO POINTS ESTABLISHED DURING THE AS-BUILT.
MAINTENANCE PLAN:
INSTALLED PLANTS SHALL BE MAINTAINED AT REGULAR INTERVALS DURING THE
MONITORING PERIOD TO PROMOTE THE SUCCESSFUL ESTABLISHMENT AND VIGOROUS
GROWTH OF THE INSTALLED PLANT STOCK. GENERAL MAINTENANCE SHALL INCLUDE: 1)
RE-APPLYING BARK MULCH TO MAINTAIN A 6" MINIMUM APPLIED THICKNESS - YEAR 1
ONLY; 2) THE PRUNING OF INSTALLED PLANTS TO REMOVE DEAD WOOD AND PROMOTE
VIGOROUS PLANT GROWTH AND PROPER FORM; 3) THE REPLACEMENT OF PLANTS
THAT APPEAR TO BE IN DISTRESS AND/OR DISEASED; 4) THE REMOVAL OF TRASH,
LITTER, AND/OR OTHER NON-DECOMPOSING DEBRIS. GENERAL MAINTENANCE WORK
SHALL OCCUR MONTHLY DURING THE GROWING SEASON AND/OR AT A FREQUENCY
OTHERWISE NECESSARY TO ENSURE THE SUCCESSFUL ESTABLISHMENT AND VIGOROUS
GROWTH OF THE INSTALLED PLANTS.
CONTINGENCY PLAN:
SHOULD ANY MONITORING ASSESSMENT REVEAL THAT THE PERFORMANCE STANDARDS
FOR THE RESPECTIVE YEAR ARE NOT SATISFIED, THE PERMITTEE SHALL WORK WITH THE
CITY OF FEDERAL WAY TO DEVELOP A CONTINGENCY PLAN TO ADDRESS THE
DEFICIENCY(IES). CONTINGENCY PLANS CAN INCLUDE, BUT ARE NOT LIMITED TO, THE
FOLLOWING ACTIONS: 1) ADDITIONAL PLANT INSTALLATION; 2)EROSION CONTROL; 3)
HERBIVORY PROTECTION; 4) MODIFICATION TO THE IRRIGATION REGIME; AND/OR 5)
PLANT SUBSTITUTIONS OF TYPE, SIZE, QUANTITY, AND LOCATION. SUCH CONTINGENCY
PLAN SHALL BE SUBMITTED TO THE CITY OF FEDERAL WAY WITHIN 30 DAYS OF WHEN
DEFICIENCIES ARE DISCOVERED. UNLESS OTHERWISE APPROVED BY THE CITY OF
FEDERAL WAY, ACTIONS SPECIFIED ON AN APPROVED CONTINGENCY PLAN MUST BE
COMPLETED WITHIN 60 DAYS. IF THE FAILURE IS SUBSTANTIAL, THE CITY OF FEDERAL
WAY MAY EXTEND THE COMPLIANCE MONITORING PERIOD FOR THE ENHANCEMENT
WORK.
CRITICAL AREA FENCE INSTALLATION DETAIL:
REMOVE CONTAINER.
IF ROOTBOUND,
LOOSEN
ROOTS PRIOR TO
PLANTING.
MULCH 6" MIN.
THICKNESS
AROUND BASE
OF PLANT.
COMPACT
SOIL
UNDER
ROOTBALL
6"
MIN.
LEAVE NATIVE
SOIL INTACT.
DO NOT
DISTURB.
2X
ROOT BALL
NATIVE
BACKFILL
SET MAIN
STEM(S)
VERTICAL
Critical Area
Help protect and care for these special natural areas.
Please contact King County at 206-296-6660 with questions or concerns.
1.SIGN CONTENT SHOWN IS REPRESENTATIVE IN NATURE.
SIGN CONTENT, COLOR, AND MATERIAL SHALL CONFORM
TO CITY OF FEDERAL WAY STANDARDS.
2.SIGNS SHALL BE POSTED AT THE OUTER LIMITS OF THE
CRITICAL AREA (WETLAND OR STREAM) BUFFER FACING
AWAY FROM THE CRITICAL AREA.
3.SIGNS SHALL BE POSTED EVERY 150 LF ALONG THE
BUFFER LIMITS OR ONE PER LOT, WHICHEVER IS GREATER.
4.ATTACH SIGN TO FENCE USING 5/16" DIA. GALVANIZED
LAG BOLT.
PLAN REFERENCES:
1.THE SURVEY AND SITE PLAN USED TO PREPARE THIS PLAN WAS PREPARED BY
ENCOMPASS ENGINEERING & SURVEYING (165 NE JUNIPER STREET, SUITE 201 -
ISSAQUAH, WA 98027). THE SURVEY AND SITE PLAN WERE MODIFIED FOR VISUAL
ENHANCEMENT. SHOULD A CONFLICT EXIST BETWEEN THE INFORMATION SHOWN
ON THIS DRAWING AND THE ORIGINAL SURVEY AND SITE PLANS, THE INFORMATION
SHOWN ON THE ORIGINAL PLANS SHALL PREVAIL.
2."WETLAND AND STREAM DELINEATION AND RATING REPORT" PREPARED BY
EVERGREEN AQUATIC RESOURCE CONSULTANTS, LLC DATED MARCH 15, 2021.
GENERAL CONSTRUCTION NOTES:
1.CONSTRUCTION SHALL BE IN ACCORDANCE WITH ALL CITY OF FEDERAL WAY CODES,
ORDINANCES, AND REGULATIONS.
2.BEFORE THE START OF ANY CONSTRUCTION, A PRE-CONSTRUCTION MEETING MUST
BE HELD BETWEEN CITY OF FEDERAL WAY, THE OWNER, AND THE PLAN DESIGNER.
3.A COPY OF THESE APPROVED DRAWINGS MUST BE ON THE JOB SITE WHENEVER
CONSTRUCTION IS IN PROGRESS.
4.SITE CONDITIONS MAY VARY BASED ON SEASON AND/OR TIME OF YEAR. THE
CONSTRUCTION CONTRACTOR SHALL ACCOMMODATE REALIZED AND ANTICIPATED
SITE CONDITIONS WHEN COMPLETING THE WORK SHOWN ON THESE DRAWINGS.
5.THE CONSTRUCTION CONTRACTOR SHALL BE RESPONSIBLE FOR PROVIDING
ADEQUATE SAFEGUARDS, SAFETY DEVICES, PROTECTIVE EQUIPMENT, FLAGGERS,
AND ANY OTHER NEEDED ACTIONS TO PROTECT THE LIFE, HEALTH, AND SAFETY OF
THE PUBLIC, AND TO PROTECT PROPERTY IN CONNECTION WITH THE PERFORMANCE
OF THE WORK SHOWN ON THESE DRAWINGS. ANY WORK WITHIN TRAVELED
RIGHT-OF-WAY SHALL REQUIRE TRAFFIC CONTROL IN ACCORDANCE WITH ANY AND
ALL FEDERAL WAY STANDARDS.
RECOMMENDED CONSTRUCTION SCHEDULE:
1.FLAG WORK AREA LIMITS AND REQUEST REVIEW FROM OWNER.
2.CONTROL NOXIOUS WEEDS.
3.INSTALL HYDROSEED AND NATIVE PLANTS.
4.INSTALL CRITICAL AREA FENCE AND SINAGE.
5.INSTALL TEMPORARY IRRIGATION SYSTEM.
6.CLEAN-UP AND DEMOBILIZE FROM SITE.
7.REQUEST AND OBTAIN FINAL INSPECTION FROM OWNER.
8.OWNER TO COMPLETE AS-BUILT AND SUBMIT TO THE CITY OF FEDERAL WAY.
9.OWNER TO IRRIGATE PLANTS FOR TWO GROWING SEASONS.
10.OWNER TO COMPLETE POST-CONSTRUCTION MONITORING FOR FIVE GROWING
SEASONS WITH ANNUAL REPORTING TO THE CITY OF FEDERAL WAY.
NATIVE SOIL
5 8" MINUS CRUSHED ROCK
BACKFILL. COMPACT TO 95%
MIN. DENSITY
MOUND TO
DRAIN AWAY
FROM POST
6" MIN. DIA. SQUARE
OR ROUND ROUGH
CUT WOOD POST -
UNTREATED (TYP)
5" MIN. DIA. ROUGH CUT
WOOD RAIL -UNTREATED (TYP)
3' MIN.
12" - 18"
2' MIN.
NOTES:
1. FENCE SHALL BE COMMERCIALLY
AVAILABLE POST AND RAIL SYSTEM PER
THE ABOVE MIN. SPECIFICATIONS.
2.WODD SHALL BE WESTERN REDCEDAR
OR EQUAL.
CRITICAL
AREA SIGN.
REVISED PER NEW SITE PLAN03/21/231
INSTALL HYDROSEED
IN BUFFER
ALTERATION AREA
INSTALL NATIVE
TREES AND SHRUBS
IN REDUCED
WETLAND BUFFER
INSTALL CRITICAL
AREA FENCE AND
SIGNAGE AT
REDUCED BUFFER
LIMITS
INSTALL CRITICAL
AREA FENCE AND
SIGNAGE AT
REDUCED
BUFFER LIMITS
INSTALL CRITICAL AREA
FENCE AND SIGNAGE AT
STANDARD BUFFER
LIMITS