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09-104380 B
SUPPLEMENT TO EXHIBIT B - SITE PLAN (CONT.) THENCE NORTH 88036'24" WEST 176.02 FEET TO THE TERMINUS OF SAID EASEMENT CENTERLINE: THE ILINES OF THIS EAs&mFjn MEET AT ANGLE POINTS AND SHALL BE I INATE SHORTENED SAID SOWN NEN ED SO ASTOOF _. ..---------THE�iORTH-33-00-FF,ET—---------------------------------------- �__ ..-- SITUATE IN THE CITY OF FEDERAL WAY, KING COUNTY, WASHINGTON. 199989g9001504 PPGE Bai OF 041 YtIc ;��i8WA r*,Rsr w9RICAN KQ. 4e ea a Recording requested by and when recorded return to Jll 43111111141111 1I11111! I���� 111 111 E IIII Lane Powell Spears Lubersky 1 0207170��445 1420 Filth Avenue, Suite 4100 LOVE 00, of ai$cPc 28,00 Seattle, WA 98101-2338 KZ/17,/20NG fNTY14y'g8 Attn Jane Rakay Nelson FIRST AMENDMENT TO -DECLARATION OF COVENANTS, CONDITIONS AND RESTRICTIONS GR.A:NTORS Video Only, Inc HD Development of Maryland, Inc GRANTEES The General Public AFFECTED DOCUMENT Auditor's File No 919990909001504 LEGAL DESCRIPTION (Abbrev) Ptn NW '/4 NW '/4 S 28 T 2l N R 4 E ASSESSOR'S TAX PARCEL NO 282104-9079-06 and 282104-9008-02 This First Amendment to Deckration of Covenants, Conditions and Restrictions with Rights of Access (the "First Amendment") is dated as of the t b day of a 2002 and is between HD Development of Maryland, Ina ClUl and Video 0n1y, Ina ("Video Only"). RECITALS A. On September 9, 1999, Home Depot U S A, Inc., a Delaware corporation ("Home Depot"), recorded a Declaration of Covenants, Conditions and Restrictions at King County Recording No 19990909001504 (the "CC&Its") affecting the properties legally described on Exhibits A and B attached hereto B On September 9, 1999, Home Depot conveyed its interest in the "Outparcel," as that term is defined in the CC&Rs, to Video Only, Inc 106666 0121/9153713 1 C Home Depot thereafter conveyed its interest in the "Major Parcel," as that term is defined in the CC&Rs, to HD D Video Only has applied for and was granted a sign permit by the City of Federal Way and completed a Site Plan as part of its sign Permit Application detailing the location of the sign A copy of the Sign Permit and the Site Plan are attached hereto as Exhibits C and D E. HD and Video Only desire to amend paragraph 2 3 of the CC&Rs entitled "Signs" as provided herein AGREEMENT 1. Signs. At the end of paragraph 2 3, the following shall be added (a) Cons# ction Erection and Maintenance of the Si . 1-5 Signs, Inc construct the sign to be used for advertising in the location and manner described in the Site Plan and Permit Application Such sign shall remain in its designated location and be used in the manner described in the Permit Application \ (b) Cost of Construction Erection Utilities and Maintenance of Si n. Video Only and Home Depot hereby agree that they will share equally all costs related to the sign c to include, but not limited to, the initial construction and erection of the sign, all utilities associated with the sign, and any maintenance to the sign which Home Depot requires All such costs shall be in accordance with a budget approved by Home Depot Home Depot shall be responsible for receiving and paying electric bills and the annual maintenance fee, o and shall invoice Video Only for its equal share on a periodic basis, such invoice to include C-A copies of maintenance and electric bills that have been paid, the frequency of such periodic C= invoicing to be determined by Home Depot in its sole discretion Video Only shall `" reimburse Home Depot for Video Only's share of cost of electricity and the annual maintenance fee within 30 days after receipt of the invoice from Home Depot (c) Decision Making Authority. Both parties must consent, in writing, to any change in the appearance (except due to a change of store logo of one of the parties, which will not require consent), location, or use of the sign No such decisions may be made without prior written approval absent an emergency (d) Inspection/Registration. Erection and installation of the sign is subject to final inspection by the City of Federal Way 106666 0121/915371 3 2 2. Other_ Provisions Unchanged Except as expressly provided herein, the CC&Rs remain unchanged. 3. CounteMarts. This First Amendment may be executed in one or more counterparts and all of the counterparts shall constitute one and the same agreement. Executed as of the day and year first written above HD DE NT OF MARYLAND, VIDEO Y INC, a Washington INC Mary' corporation corpora a $Y el R Ilatch Its Pros~ s Fta ewr Corporate Counsel +T�r • Sq �z-5 STATE OF CALIFORNIA ) ss 41 COUNTY OF ORANGE ) On�fbrsaid 2002, before me, - 1� - � I —�. a Notary Fu is in e, personally appeared DANIEL R HATCH, personally known to me (or proved to me on the basis of satisfactory evidence) to be the person whose o name is subscribed to the within instrument, and acknowledged to me that he executed the e-- same in .his authorized capacity, and that by his signature on the instrument the person, or �. the entity upon behalf of which the person acted, executed the instrument CD WITNESS Wy hand and official seal LISA M SMITH Comm. # 1250415 SIGN TUItE OF NOTARY PUBLIC "'b^ NOTAAYO'OB'r nlyFOANIA Vt My Comm :xp :es Jan 12, 2005 -+ (SEAL) 106666 0121/915371 3 3 _b, Washbugton State �f Department of Transportation Performance Evaluation Consultant Services Consultant Name IBI Group Consultant Address IBI Group 801 Second Avenue —Suite 1400 Seattle WA 98104-1573 United States Type of Work ® Study ❑ Design ❑ R/W ❑ PS&E ❑ Other (Specify Below): Evaluation Type ❑ Interim ❑ Subconsultant ® Final Project Title Express Toll Lanes Signing and Pricing Project Agreement Number Y-10464 Type of Agreement ❑ Lump Sum ® Hourly Rate Complexity of Work Date Agreement Approved ❑ Cost Plus Fixed Fee ® Difficult ❑ Routine Jther Amount of Original Agreement Total Amount Modifications Total Amount Agreement $ 116,000.00 $ 0.00 $ _ 116,000.00 Completion Date Including Extensions Actual Completion Date 7 Actual Total Paid July 31, 2009 July 7 2009 $ _ 88,556.04 Type and Extent of Subcontracting The only subcontractor used was a communications firm, PRR. PRR's role was minimal; they conducted the focus groups and produced a results report. Performance Rating Scale (From Average Score Below) 1 10 9 8 7 6 5 4 3 2 Superior Above Reqmnts Meets Reqmnts Below Reqmnts Poor Criteria Comment Score 1. Negotiations The negotiations went smoothly. 10 Cooperative and responsive. 2. Cost / Budget Yes, the project was completed under budget. 10 Complete within agreement budget including supplements. 3. Schedule The schedule contained very little flexibility, but IBI was 10 Complete within agreement schedule including supplements. able to remain on schedule. 4. Technical Quality Yes. 10 Met Standards. 5. Communications IBI's communication was clear, concise and tailored to the 10 Clear, Concise Communication (Oral, written, drawings). audience 6. Management They did an excellent job, although the communication 8 Team player. Managed subs. Accurate, timely invoices. with PRR could have been improved. 58 Total Score Average Score (Total Score / Number of criteria rated) 9.7 Rated By (Project Manager Name and Title) Project Manager Signature Date Tyler Patterson, Tolling Engineer November 25, 2009 Rated By (Area Consultant Liaison Name and Title) Area Consultant Liaison Signature Date Stacy Scott, Consultant Liaison Executive Review (Name and Title) Executive Signature Date Jennifer Charlebois, Tolling and Systems DOT Form 272-019 EF Distribution: Original: Consultant Revised 3/2002 Copies: Project Manager - Area Consultant Liaison - Consultant Services Office T.21N. RAE. W.M. S 324TH ST ND PROJECT 1-5 MP 142.95 LE 641+63.30 16 541+57.26 S 17 LIAM 15 BEGIN CONSTRUCTION SR 18 3 LLXrH ST WE-01 20+34.69 ... .................. ....... EW-01 20+34.69 CITY OF FEDERAL WAY NW-02 LINE S 3"44TH T 21 END CONSTRUCTION SR 161 20 le NS-03 31+86.60 ND ONSTRUCTION SR 18 ES-01 LINE EW-01 88+11.64 LE LINE ..... ....... .. ---------_--- I-- ....... ..... ..... ......... WE-01 88+38.02 LOW LW LINE -NS-06 LINE BEGIN CONSTRUCTION NS-03 LINE 29 siq lei NS-03 12+73.12 s 360TH ST 28 Mud . . ...... .......... .. . . ............ ........... .................. .... BEGIN PROJECT a 1-5 MP 140.65 LW 430+62.11 a ISO 300 AUBURN LE 430+20.39 SCALE IN FEET rEDERAL WAY RECEIVED i PUllOSl: IMPROVE SAFETY AND DEC 0 1 2009 INCREAS� INTERCHANGE CAPACIrf ITY MAP CITY OF FEDERAOLWATu,'Ll N'Dv c lis LONGITUDE: APPLICANT: WASHINGTON STATE DEPT. OF TRANSPORTATION 1-5 SR 1611SR 18 /0000) INTERCHANGE IMPROVEMENTS BERGERIAHAM USAGE REFERENCE NUMBER: NEAR: FEDERAL WAY, KING CO., WA LOCATION ADDRESS: FEDERAL WAY, I(ING CO., WA DATE: &234)9 SHEET I OF 32 T. 21 N. R. 4E. W.M. { 0 Goo 1200 SCALE IN FEET t - 1 r + 'r r r, 13 rr r i; rr i 12 „ r 'i ry r, 16 r r rr � ' r r r ' 75 SHEET INDEX REF. SHEET SHEET TYPE 14 1 COVER SHEET 2 INDEX SHEET � 3 PLAN VIEW 4 PLAN VIEW 5 PLAN VIEW 6 PLAN VIEW 7 PLAN VIEW 7 8 PLAN VIEW 9 PLAN VIEW r Ir 10 PLAN VIEW e 11 PLAN VIEW 12 PLAN VIEW y +r 13 PLAN VIEW 14 PLAN VIEW !' 5, 24, 26 15 PLAN VIEW , 16 CROSS SECTION r..j 17 CROSS SECTION " 4 18 CROSS SECTION 19 CROSS SECTION 20 CROSS SECTION 3 21 CROSS SECTION WETLAND INDEX 22 CROSS SECTION 23 CROSS SECTION 24 PLAN VIEW 25 PROFILE 26 LANDSCAPE 27 PLAN VIEW 28 PROFILE 29 LANDSCAPE 30 DETAIL 31 DETAIL 32 DETAIL REFERENCE NUMBER: 1 SRR 16T5R 18 INTERCHANGE IMPROVEMENTS BEnlA8 APPLICANT BY: WASHINGTON STATE E Y\ I m E E A f r h c. DEPT. OF TRANSPORTATION LOCATION ADDRESS: FEDERAL WAY, TONG CO., WA USAGE REFERENCE NUMBER: DATE: 623,09 SHEET 2 OF 32 DETAIL DRAWINGS REF. SHEET WETLAND AB 3, 4, 5 WETLAND K 16 WETLAND M 14, 15 WETLAND N 15 WETLAND P 12, 13 WETLAND U-1 11 l a 2� (NAVD) 88 =yA� a 1, S. 28. T. 21 N. R. 4E. W. M. MATCH TO SHEET 4 rr 1 N N Ir 1 I 11 1 H � n EXISTING EDGErr' If r OF PAVEMENT 1+� RETAINING 1 PROPOSED EDGE N 3 OF PAVEMENT n II �. EXISTING EDGE 1 p' OF PAVEMENT PROPOSED EDGE I: OF PAVEMENT '�, ,ram fir ly V I! rry . y \ / I 11 / r ,rr •��. �� rr / 1 )Y 2 f / A- 1 Y o ice. j; I t -0-61 ACRES OF PERMANENT STREAM BUFFER DISTURBANCE -- 0.02 ACRES OF TEMPORARY STREANI BUFFER DISTURBANCE PROPOSED STORMWATER POND EXPANSION LIMITS OF GRADING, POND EXPANSION li I '/ : I / r, 1- a t f I t \w BARRIER r'r /+� ++ ++ \ \ C1�`i\ 1 �I Ice 0 50 100 SCALE IN FEET PLAN -- TRIBUTARY 0015A AB DIRECTION OF .. FLOW �-aO6 ACRES OF PERMANENT WETLAND BUFFER DISTURBANCE (WHICH IS ALSO 0.06 ACRES OF PERMANENT STREAM BUFFER) . ti0.44 ACRES OF PERMANENT .STREAM BUFFER DISTURBANCE LEGEND & SUMMARY OF IMPACTS - - - - - - - - • EXISTING EDGE OF PAVEMENT PERMANENT WETLAND BUFFER IMPACT TEMPORARY WETLAND BUFFER IMPACT WETLAND IMPACT 465 DITCH PERMANENT WETLAND TEMPORARY STREAM PERMANENT STREAM ALIGNMENT & STATION IMPACT BUFFER IWACT mumME ,L1[� . . . . • SAND STREAM BUFFER ® ••••••.• • PERMANENT STREAM BUFFER IMPACT WETLAND BUFFER LIMIT OF CUT OR FILL PROPOSED EDGE OF PAVEMENT - - - - - RIGHT OF WAY WETLAND BOUNDARY WETLAND NUMBER WETLAND CATEGORY (ECOLOGY) WETLAND SUE PERMANENT WETLAND IMPACT TEMPORARY WETLAND IMPACT TOTAL WETLAND BUFFER IMPACT TEMPORARY 61JFFER IMPACT WETLAND AB III 0.42 ACRE 0 ACRE 0 ACRE 023 ACRE 0.14 ACRE WETLAND K 10 0.13 ACRE 0 ACRE 0 ACRE 0 ACRE 0.01 ACRE WETLAND M II 1.16 ACRE 003 ACRE 0.02 ACRE 0.56 ACRE D.17 ACRE WETLAND N 111 0.20 ACRE 020 ACRE 0 ACRE 0 ACRE 0 ACRE WETLAND P 11 1.91 ACRE 0 ACRE 0 ACRE 0.12 ACRE 0.24 ACRE WETLAND U 01 0.13 ACRE 0 ACRE 0 ACRE 0.14 ACRE 0.04 ACRE STREAM TOTAL TOTAL STREAM TOTAL TEMPORARY STREAM IMPACT BUFFER IMPACT )STREAM BUFFER IMPACT 0016A 0.12 ACRE 4.44 ACRE 128 ACRE 0016 0.00 ACRE 0.20 ACRE 0.00 ACRE USAGE REFERENCE NUMBER: S. 28. T. 21 N. R. 4E. W.M. MATCH TO SHEET 5 r RETAINING WALL p . ❑A TUM l �. r, EXISTING EDGE � r' l► �OF PAVEMENT r '' (NAVD) 88 r PROPOSED EDGE OF PAVEMENT RETAINING •,1 - WALL 1 FUTURE EDGE ' OF PAVEMENT r E)OSTING EDGE Z •' OF PAVEMENT Np ' U PROPOSED EDGE OF PAVEMENT ;r T ♦• 2 (� TRIBUTARY ;• r r 0016A • TEMPORARY CONSTRUCTION /� � EASEMENT � DIRECTION OF FLOW f . 0.14 ACRES OF TEMPORARY ^O WETLANO BUFFER DISTURBANCE (WHICK IS ALSO 0.14 ES TEMPORARY STREAM B FFER F C DISTURBANCE) 0.10 ACRES OF PERMANENT WETLAND BUFFER DISTURBANCE RETAINING �/, TWNICT4 TS ALSO 0.10 ACRES OF WALL r• PERMANENT STREAM STIFFER DISTURBANCE) ri i< VVEIlANO AS e 0.05 ACRES OF TEMPORARY STREAM BUFFER i DISTURBANCE 002 ACRES OFF PERMANENT r i' STREAM BUFFER DISTLRiBANGE u � u " n 0 60 100 � SCALE IN FEET MATCH TO SHEET 3 PLAN LEGEND & SUMMARY OF IMPACTS BUSTING EDGE OF PAVEMENT PERMANENT WETLAND BUFFER IMPACT TEMPORARY VyEnAND MMPORARY WETLAND DITCH 6UPFER IMPACT 465 PERMANENT WETLAND TEMPORARYSTTREAM STREAM ALIGNMENT & STATION IMPACT BUFFER IMPACT 4 -11ETLAND W ® PERMANENT STREAM BUFFER IMPACT -wr�--.u— UMOF CUT OR FILL R 7TJ777777 RIGHT OF WAY • • . . . STREAM BUFFER ........ WETLAND BUFFER PROPOSED EDGE OF PAVEMENT WETLAND BOUNDARY WETLAND NUMBER WETLAND CATEGORY (ECOLOGY) WETLAND SIZE PERMANENT WETLAND IMPACT TEMPORARY WETLAND IMPACT TOTAL WETLAND BUFFER IMPACT TEMPORARY BUFFER IMPACT WETLAND AB III 0.42 ACRE 0 ACRE 0 ACRE 023 ACRE 014 ACRE WETLAND K III 0.13 ACRE 0 ACRE 0 ACRE 0 ACRE 001 ACRE WETLAND M II 1.16 ACRE 003 ACRE 0-02 ACRE 058 ACRE 017 ACRE WETLAND N III 0.20 ACRE 020 ACRE 0 ACRE 0 ACRE 0 ACRE WETLAND P II 1.01 ACRE 0 ACRE 0 ACRE 012 ACRE 024 ACRE WETLAND U III 0-13 ACRE 0 ACRE 0 ACRE 014 ACRE 004 ACRE STREAM TOTAL STREAM IMPACT TOTAL STREAM BUFFER IMPACT TOTAL TEMPORARY STREAM BUFFER IMPACT 0016A 012 ACRE 4.44 ACRE 1.28 ACRE D016 0.00 ACRE 0.20 ACRE 0.00 ACRE USAGE REFERENCE NUMBER: t TEMPORARY STREAM BUFFER IMPACT FOR STREAM CONSTRUCT 0.18 ACRES OF TEMPORARY • STREAM BUFFER DISTURBANCE • • hlab . STREAM CHANNEL TO BE ABANDONED F RELOCATED STREAM PROPOSED CULVERT RELOCATED STREAM RELOCATED STREAM •• BUFFER E`7 W vN� PROPOSED CULVERT � EXTENSION PROPOSED EDGE OF PAVEMENT RETAINING WAIL R DA UM TEMPORARY — CONSTRUCTION EASEMENT (NAVD) 88 S. 28. T. 21 N. R. 4E. W.M. MATCH TO SHEET 6 / ///'RETAINING ' WALL i EXISTING EDGE // OF PAVEMENT 1 l / 0.07 ACRES OF PERMANENT VM"ND BUFFER DISTURBANCE {/WyµH� y�' ICH IS ALSO Q07 ACRES OF $ERMRNEN7 BUFFER / BT1tinAM DISTURBANCE) / b MATCH TO SHEET 4 PI AN PROPOSED EDGE OF PAVEMENT — DIRECTION OF FLOW �r TRIBUTARY 0016A . Y&ILAND AB LEGEND & SUMMARY OF IMPACTS - - - - - - - EXISTING EDGE OF PAVEMENT omPERMANENT WETLAND TEMPORARY WETLAND TEMPORARY WETLAND 7 DITCH BUFFER IMPACT BUFFER IMPACT IMPACT 465 00 PERMANENT WETLAND TEMPORARY STREAM PERMANENT STREAM ALIGNMENT & STATION IMPACT BUFFER IMPACT ® IMPACT il11� WETLAND ® PPERMARNENNTPASCTTREAM _eur--nu— LIMIT OF CUT OR FILL 777777T1i RIGHT OF WAY . . . . . STREAM BUFFER . • • • • .... WETLAND BUFFER PROPOSED EDGE OF PAVEMENT _ _ _ WETLAND BOUNDARY WETLAND WETLAND CATEGORY WETLAND PERMANENT TEMPORARY WETLAND TOTAL WETLAND TEMPORARY BUFFER IMPACT NUMBER (ECOLOGY) SIZE WETLAND IMPACT IMPACT BUFFER IMPACT WETLAND AS it; 0.42 ACRE 0 ACRE 0 ACRE 023 ACRE 0.14 ACRE WETLAND K III 0.13 ACRE 0 ACRE 0 ACRE 0 ACRE 0-01 ACRE WETLAND M II 1.16 ACRE 0.03 ACRE 002 ACRE 058 ACRE 0.17 ACRE WETLAND N III D20 ACRE 020 ACRE 0 ACRE 0 ACRE 0 ACRE WETLAND P 11 1.91 ACRE 0 ACRE 0 ACRE 012 ACRE 024 ACRE WETLAND U III 013 ACRE 0 ACRE 0 ACRE 014 ACRE 0.04 ACRE STREAM TOTAL STREAM IMPACT TOTAL STREAM BUFFER IMPACT TOTAL TEMPORARY TREAM BUFFER IMPACT D016A 012 ACRE 4.44 ACRE 1.28 ACRE 0010 0.00 ACRE 020 ACRE 0.00 ACRE USAGE REFERENCE TEMPORARY CONSTRUCTION EASEMENT TRIBUTARY 0016A DIRECTION OF FLOW WETLAND D TEMPORARY STREAM BUFFER IMPACT FOR STREAM CONSTRUCTION S. 28. T. 21 N. R. 4E. W.M. MATCH TO SHEET 7 F31 � PROPOSED OF PAVEMI i' a� 1° l 0 t0 PROPOSED EOpE •� OF PAVEMW .' RETAMVWG WALL— .• I � . 1 _ 1 021 ACRES OF TEMPORARY STREAM BUFFER OISTURIW • � r + r i r r + i + lt/ + ' EXISTING EDGE J 1 ± G + OF PAVEMENT r + r + x r 0 + v ' + + I r ' , i I r ! i + i 's' x + i Q ' + y , W �2 -0.03 ACRES, OF PERMANENT STREAM BUFFER 01MRSANCE I I 1 r i I 9KISTING EDGE r OF PAVEMENT a 0.02 ACRES OF PERMANE STREAM DISTURBANCE _ MATCH TO SHEET 5 PI AN ATUM (NAVD) 88 PROPOSED EDGE OF PAVEMENT 0 SO 1D0 SCALE IN FEET LEGEND & SUMMARY OF IMPACTS - -- - - -- - - EXISTING EDGE OF PAVEMENT ETLA PERMANENT WND BUFFER IMPACT TEMPORARY WETLAND BUFFER IMPACT TEMPORARY WETLAND r—i 1 IMPACT U_JJTLJJ > 465 DRCH PERMANENT WETLAND IMPACT TEMPORARY STREAM BUFFER IMPACT PERMANENT STREAM IMPACT ALIGNMENT & STATION ' • • • • • WETLAND STREAM BUFFER ® ......••• PERMANENT STREAM BUFFER IMPACT WETLAND BUFFER -eur--+u- LIMIT OF CUT OR FILL PROPOSED EDGE OF PAVEMENT TiJTii _ _ _ _ _ RIGHT OF WAY WETLAND BOUNDARY WETLAND NUMBER WETLANO CATEGORY (ECOLOGY) WETLAND 912E PERM1NEti1 WETLANO IMPACT TEMPORARY WETLAND IMPACT TOTAL WETLAND BUFFER IMPACT TEMPORARY BUFFER IMPACT WETLAND AS III 0.42 ACRE 0 ACRE 0 ACRE 0.23 ACRE 014 ACRE WETLAND K II] 0.13 ACRE 0 ACRE 0 ACRE 0 ACRE 001 ACRE WETLAND M II 1.16 ACRE 003 ACRE 0.02 ACRE 0.58 ACRE 017 ACRE WETLAND N 111 020 ACRE 020 ACRE 0 ACRE 0 ACRE 0 ACRE WETLAND P II 1.91 ACRE 0 ACRE 0 ACRE 0.12 ACRE 024 ACRE WETLAND U III 0.13 ACRE 0 ACRE 0 ACRE 014 ACRE 004 ACRE STREAM TOTAL STREAM IMPACT TOTAL STREAM BUFFER IMPACT TOTAL TEMPORARY STREAM BUFFER IMPACT 0016A 0.12 ACRE 444 ACRE 1.20 ACRE 016 0.00 ACRE 0.20 ACRE 0.00 ACRE USAGE REFERENCE NUMBER: A S. 28. T. 21 N. R. 4E. W.M. MATCH TO SHEET 8 r A Li)A PROPOSER EDGE OF PAVEMENT PROPOSED EDGE OF PAVEMENT (NAND) 88 RETAINING WALI 0.18 ACRES OF TEMPORARY STREAM BUFFER DISTURBANCE flUMOTION . • • OF FLOW c= O •• •TRIBUTARY 0016A = • o f a EDGE EXISTING OF PAVEMENT f i f ' � I + ! e -a p I ! EXISTING RAMP TO,, BE REMOVED r 10 I EXISTING EDGE 11, rr , OF PAVEMENT J+ fl + r , r I � r r r + J !r I r i r r � EXISTING RAMP TO BE REMOVED r y] r r � I ! . ' r r � ! 0.36 ACRES OF PERMANENT r �+ STREAM BUFFER DISTURBANCE ' Y — PROPOSED EDGE ! + r OF PAVEMENT r i r � a � r r ; r r w 3 � Ir 0 SO 700 r SCALE IN FEET MATCH TO SHEET 6 PLAN LEGEND & SUMMARY OF IMPACTS - EXISTING EDGE OF PAVEMENT PERMANENT WETLAND BUFFER IMPACT TEMPORARY WETLAND BUFFER IMPACT ^I — TEMPORARY WETLAND IMPACT 7 465 DITCH PERMANENT WETLAND TEMPORARY STREAM PERMANENT STREAM ALIGNMENT & STATION IMPACT BUFFER ® IMPACT • WETUWD STREAM BUFFER ® •••••••'• PERMANENT STREAM BUFFER IMPACT WETLAND BUFFER LIMIT OF CUT OR FILL PROPOSED EDGE OF PAVEMENT 777Ti77Ti — _ _ _ _ RIGHT OF WAY WETLAND BOUNDARY WETAND NUMBER WETLAND AB WETLAND CATEOORY (ECOWGY! III WETLAND SIZE 0.42 ACRE PERMANENT WETLAND IMPACT 0 ACRE TEMPORARY WETLAND IMPACT 0 ACRE TOTAL WETLAND BUFFER IMPACT 0.23 ACRE TEMPORARY BUFFER IMPACT 0.14 ACRE WETLAND K lil 0.13 ACRE 0 ACRE 0 ACRE 0 ACRE 0.01 ACRE WETLAND M 0 1.16 ACRE 003 ACRE 0.02 ACRE 0.56 ACRE 0.17 ACRE WETLAND N VII 0.20 ACRE 0.20 ACRE 0 ACRE 0 ACRE 0 ACRE WETLAND P II 1.91 ACRE 0 ACRE 0 ACRE 0.12 ACRE 0.24 ACRE WETLAND U III 0.13 ACRE 0 ACRE 0 ACRE 0.14 ACRE 0.04 ACRE STREAM TOTAL TOTAL STREAM TOTAL TEMPORARY STREAM IMPACT BUFFER IMPACT 'STREAM BUFFER IMPACT 0016A 0.12 ACRE 4.44 ACRE 126 ACRE 0016 0.00 ACRE 020 ACRE 0.00 ACRE USAGE REFERENCE NUMBER: S. 28. T. 21 N. R. 4E. W.M. MATCH TO SHEET 10 TRIBUTARY 0016A STREAM BUFFER Z + 1 H �5 I p DISTURBANCE J O PROPOSE. CULVERT DIRECTION h tr 1 EXTENSION g OF FLOW 'S `' S•` -co EXISTING RAMP `f• *• TO BE REMOVED iA C) r I� a `' 0.02 ACRES OF •� 'PERMANENT STREAM Z '• ■ ISTVRBANCE 'r PROPOSED EDGE OF PAVEMENT e = AT M + 3 •, 022 ACRES OF PERMANENT -,- - STREAM BUFFER (NAVD) 88 DISTURBANCE --- ✓_1 --- -- ' ' - - - ---- ' r 1 1 ... •....... ' ! 1 ' 1 FJUSTNG RAMPW- E01 CENTER LINE ; TO BE REPLACED EXISTING EDGE rr , OF PAVEMENT i WE-01 CENTER LIN 25 ; 0.36 ACRES OF PERMANENT + STREANI BUFFER DISTURBANCE ' + r ' r -�� r r -• DIRECTION • OF FLOW r 1 r yy i •• rl rr I 1 TRIBUTARY 0010A •. i'' E7USTING EDGE J / i- Ir' WETLAND U • OF PAVEMENT + r • �EXISTING EDGE � OF PAVEMEM 003 ACRES OF TEMPORARY O 1 ' WETLAND BUFFER DISTURBANCE +� O 1 (WHICH IS ALSO 0.03 ACRES OF h �1 TEMPORARY STREAM BUFFER O 1 DISTURBANCE) O e H 1 0) 0.10 ACRES OF PERMANENT jl WETLAND BUFFER DISTURBANCE D 6D 700 III MMICH IS AM 0.10 ACRES OF PERMANENT STREAM BUFFER SCALE IN FEET D;MRBANCE) i o MATCH TO SHEET 8 PI AN LEGEND & SUMMARY OF IMPACTS -- - - - - • EXISTING EDGE OF PAVEMENT ffmPERMANENT WETLAND BUFFER IMPACT PERMANENT WETLAND om ® TEMPORARY WETLAND BUFFER 1MPACT TEMPORARY STREAM TEMPORARY WETLAND IMPACT r;-' PERNIANENI 5[RE.n1A 465 DITCH ALIGNMENT & STATION IMPACT BUFFER IMPACT IMPACT illy ,11! • • • • • WETLAND STREAM BUFFER ® • • • • • • • • PERMANENT STREAM BUFFER IMPACT WETLAND BUFFER -eur--ruL— LIMIT OF CUT OR FILL PROPOSED EDGE OF PAVEMENT •' _ _ _ _ RIGHT OF WAY WETLAND BOUNDARY WETLAND NUMBER WETLAND CATEGORY (ECOLOGY) WETLAND SIZE PERMANENT WETLAND IMPACT TEMPORARY WETLAND IMPACT TOTAL WETLAND BUFFER IMPACT TEMPORARY BUFFER IMPACT WETLAND AS tlI 0.42 ACRE 0 ACRE 0 ACRE 023 ACRE 014 ACRE WETLAND K III D.13 ACRE 0 ACRE 0 ACRE 0 ACRE 001 ACRE WETLAND M II 1.18 ACRE 0.03 ACRE 002 ACRE 058 ACRE 0.17 ACRE WETLAND N III 0.20 ACRE 020 ACRE 0 ACRE 0 ACRE 0 ACRE WETLAND P II 191 ACRE 0 ACRE 0 ACRE 012 ACRE 024 ACRE WETLAND U III 0-13 ACRE 0 ACRE 0 ACRE 014 ACRE 004 ACRE STREAM TOTAL STREAM IMPACT TOTAL STREAM BUFFER IMPACT I TOTAL TEMPORARY STREAM BUFFER IMPACT 0016A 012 ACRE 4.44 ACRE 1.28 ACRE 0016 0.00 ACRE 0.20 ACRE 0.00 ACRE REFERENCE NUMBER: S. 28. T. 21 N. R. 4E. W.M. TRIBUTARY 0016A DIRECTION \ , • OF FLOW 3 i • WETLAND D x CI / PROPOSED EC OF PAVEMENT I I +� TAR LINE STR Z • EXISTING RAMP pi ME RESTORATION -� TO BE REMOVED •--------- - •ir �_ '• RESTORED STR �l\' • BUFFER EXISTING CULVERTS` " • •t TO BE REMOVED \ •• V1 I .•' o • , WETLAND T �' k 81� V R'DCS MATCH TO SHEET 9 PI AN r, DATUM i' (NAVD) 88 0 50 100 SCALE IN FEET LEGEND & SUMMARY OF IMPACTS --------- EXISTING EDGE OF PAVEMENT PERMANENT WETLAND TEMPORARY WETLAND MAMPCORARY WETLAND 7 DITCH BUFFER IMPACT BUFFER IMPACT 465 PERMANENT WETLAND RM TEMPORARY STREAM STREAMALIGNMENT & STATION IMPACT BUFFER IMPACT •yFy '�' WETLAND ® PERMANENT STREAM BUFFER IMPACT -cur--ru- LIMIT OF CUT OR FILL 77777,-7J7 RIGHT OF WAY • • STREAM BUFFER • • • • • • • • WETLAND BUFFER PROPOSED PAVEMENT EDGE OF _ _ _ _ WETLAND BOUNDARY WETLAND WETLAND CATEGORY WETLAND PERMANENT TEMPORARY WETLAND TOTAL WETLAND TEMPORARY BUFFER IMPACT NUMBER ECOLOGY) SIZE WETLAND IMPACT IMPACT BUFFER IMPACT WETLAND AB III 0.42 ACRE 0 ACRE 0 ACRE 0.23 ACRE 0.14 ACRE WETLAND K III 0.13 ACRE 0 ACRE 0 ACRE 0 ACRE 0.01 ACRE WETLAND M 11 1.16 ACRE 0.03 ACRE D.02 ACRE 0.56 ACRE 0.17 ACRE WETLAND N RI 0-20 ACRE 020 ACRE 0 ACRE 0 ACRE 0 ACRE WETLAND P II 191 ACRE 0 ACRE 0 ACRE 0.12 ACRE 0.24 ACRE WETLAND U III 0.13 ACRE 0 ACRE 0 ACRE 0.14 ACRE 004 ACRE STREAM TOTAL TOTAL STREAM TOTAL TEMPORARY STREAM IMPACT BUFFER IMPACT STREAM BUFFER IMPACT 0016A 0.12 ACRE 4.44 ACRE 1.28 ACRE 0016 0.00 ACRE 020 ACRE 0.00 ACRE USAGE REFERENCE NUMBER: S. 28. T. 21 N. R. 4E. W.M. MATCH TO SHEET 12 PROPOSED EDP OF PAVEMENT ATUM ' (NAVD) 88 0.24 ACRES OF TEMPORARY STREAM BUFFER DISTURBANCE WETLAND 11 . DIRECTION OF FLOW TRIBUTARY 001BA--\ i J 1 WETLAND U-1 ' rr ; i rr r r I I i r r 0-30 ACRES OF PERMANENT STREAM BUFFER DISTURBANCE 1 r/ + + , WIf zzzzmm , �` - _i� z r I r I r I J 3 r : J r C17 r i Ly r F: r r EDGE- 2 � r rrEXJST1NG OF PAVEMENT r � EXISTING EDGE r r I / ` OF PAVEMENT I ; , r , -- ' PI AN I OF PAVEMENT 0 So 100 SCALE IN FEET LEGEND & SUMMARY OF IMPACTS --------- EXISTING EDGE OF PAVEMENT PERMANENT WETLAND BUFFER IMPACT TEMPORARY WETLAND BUFFER IMPACT ® TEMPORARY WETLAND IMPACT > 46$ DITCH PERMANENT WETLANO TEMPORARY STREAM PERMANENT STREAM ALIGNMENT & STATION IMPACT BUFFER IMPACT ® IMPACT • WETLAND STREAM BUFFER ® ......... PERMANENT STREAM BUFFER IMPACT WETLAND BUFFER -cur--ru- LIMIT OF CUT OR FILL PROPOSED EDGE OF PAVEMENT 777,J77T7 - - - - - RIGHT OF WAY WETLAND BOUNDARY WETLAND NUMBER WETLAND CATEGORY (ECOLOGY) WETLAND SIZE PERMANENT WETLAND IMPACT TEMPORARY WETLAND IMPACT TOTAL WETLAND BUFFER IMPACT TEMPORARY BUFFER IMPACT WETLAND AB III 0.42 ACRE 0 ACRE 0 ACRE 023 ACRE 014 ACRE WETLAND K III 0.13 ACRE 0 ACRE 0 ACRE 0 ACRE 0.01 ACRE WETLAND M II 1.16 ACRE 0.03 ACRE 0.02 ACRE 056 ACRE 0.17 ACRE WETLAND N III D.20 ACRE 020 ACRE 0 ACRE 0 ACRE 0 ACRE WETLAND P II 191 ACRE 0 ACRE 0 ACRE 0.12 ACRE 024 ACRE WETLAND U 01 0.13 ACRE 0 ACRE 0 ACRE 014 ACRE 0.04 ACRE STREAM TOTAL TOTAL STREAM TOTAL TEMPORARY STREAM IMPACT BUFFER IMPACT iTREAM BUFFER IMPACT 0016A 0.12 ACRE 4.44 ACRE 1.28 ACRE 0015 000 ACRE 0.20 ACRE 0.00 ACRE REFERENCE NUMBER: S. 28. T. 21 N. R. 4E. W.M. MATCH TO SHEET 13 TRIBUTARY W1 DIRECTION OF FLOW li I OF OF P ED EDGE rr' jj � PAVEMEM I r 9-12 ACRES OF I PORARY r' WETLAND BUFFER OiSTUR84NCE ' y jV4MCH RARY IS ALSO 0.08 ACRES OF • TEMPOSTREAM BUFFER r • �v 7 I DISTURBANCE) r r j1 y 7 r I 9.09 ACRES OF PERMANENT 1p •f11! y J VYETLAND BUFFER OI,STURBMCE r rr (NMICH is ALSO 11.08 ACRES OF I PERWWENT STREAM BUFFER WETLAND P �v i! 'r DISTURBANCE) �r I uj 1p rr 41 r • 11� �� � �1 �C7 3 W .�� � � r r' y • .y y T • \ PROPOSED EDGE a OF PAVEMENT \\4, _ ' eho r � DA ll J M (NAVD) 88 EXISTING EDGE • .................. EXISTING EDGE J I r •�OF PAVEMENT r �I OF PAVEMENT r 0.01 ACRES OF TEMPORARY 1 11 STREAM BUFFER DISTURBANCE 0.01 ACRES OF PERMANENT 0 60 100 STREAM BUFFER DISTURBANCE SCALE IN FEET MATCH TO SHEET 11 PLAN LEGEND & SUMMARY OF IMPACTS - - EXISTING EDGE OF PAVEMENT MMPERMANENT WETLAND 55mTEMPORARY WETLAND M ACTRARY WETLAND — > DITCH BUFFER IMPACT BUFFER IMPACT 465 PERMANENT WETLAND TEMPEORARY AM ENT STREAM ALIGNMENT &STATION IMPACT R IMPACT IMPACT il11� WETLAND ® PERMANENT STREAM BUFFER IMPACT -eur--nu— LIMIT OF CUT OR FILL 77TlJ7TJ7 RIGHT OF WAY • • . . . STREAM BUFFER ........ WETLAND BUFFER PROPOSED EDGE OF PAVEMENT _ _ _ WETLAND BOUNDARY WETLAND WETLAND CATEGORY WETLAND PERMANENT TEMPORARY WETLAND TOTAL WETLAND TEMPORARY BUFFER IMPACT' NUMBER (ECOLOGY) SIZE WETLAND IMPACT IMPACT BUFFER IMPACT WETLAND AB III 0.42 ACRE 0 ACRE 0 ACRE 023 ACRE 0.14 ACRE VVETLAND K III 0.13 ACRE 0 ACRE 0 ACRE 0 ACRE 0.01 ACRE WETLAND M it 116 ACRE 0-03 ACRE 0.02 ACRE ass ACRE 0-17 ACRE WETLAND N III 0.20 ACRE 020 ACRE 0 ACRE 0 ACRE 0 ACRE WETLAND P ii 1.91 ACRE 0 ACRE 0 ACRE 012 ACRE 0.24 ACRE �j WETLAND U [0 0.13 ACRE 0 ACRE 0 ACRE 014 ACRE 0.04 ACRE STREAM TOTAL STREAM IMPACT TOTAL STREAM BUFFER IMPACT TOTAL TEMPORARY STREAM BUFFER IMPACT 0016A 0.12 ACRE 4.44 ACRE 128 ACRE 0010 000 ACRE 020 ACRE 0.00 ACRE USAGE REFERENCE NUMBER*. S. 28. T. 21 N. R. 4E. W.M. TRIBUTARY 1316A DIRECTION OF FLOW y , \\ 1 Y !I r + ' O y • Y 1' ^_ 7 I I 1 Y ' f 1p aaa ,acaEs OF rERfeANErir WETLAND BUFFER DISTURBANCE rl / `I • �` �` �y ++ + 1 PROPOSED EDGE OF PAVEMENT 0.11 ACRES '! Ir �w OF TEMPORARY WETIMD BUFFER/ / ! + + �y plSTL1RBANCE � .•• _ r 1 '' /•• � EXISTING EDGE F r r/ OF PAVEMENT f +r Ie I J T i JJJ iilr EXISTING EDGE PAVEMENT ' • �OF / yIV % fl r .•• 4 DATUM /. r � 1 , OF PAVEMENT GE i1 � J' 0.01ACRES 1 �OF TEMPOR1RY 41 (NAVD) 88 v WETLAND BUFFER I' DISTURBANCE 1• it + co 1 r r 0 60 100 51 cc I �' SCALE IN FEET WATCH TO SHEET 12 Pi AN LEGEND & SUMMARY OF IMPACTS - - - - - - - EXISTING EDGE OF PAVEMENT [•:< .c',c. PERMANENTWETLAND TEMPORARY WETLAND TEMPORARY WETLAND 7 DITCH CT BUFFER IMPACT PACT 465 �+r WETLAND STREAMUFFER �" �L ENT STREAM ALIGNMENT B. STATION IMPACT BTEMPORARY BUFFER IMPACT - Y'• IMPACT illf! WETLAND ® PERMANENT STREAM BUFFER IMPACT _�'^—_�_ LIMIT OF CUT OR FILL lJ7JJ'llT7 RIGHT OF WAY • STREAM BUFFER ••••••••• WETLAND BUFFER PROPOSED EDGE OF PAVEMENT _ _ _ _ _ WETLAND BOUNDARY WETLAND WETLAND CATEGORY WETLAND PEFUAMIENT TEMPORARY WETLAND TOTAL WETLAND TEMPORARY BUFFER IMPACT NUMBER ECOLOGY] STYE W5TLtND IMPACT IMPACT BUFFER IMPACT WETLAND AB 01 0.42 ACRE 0 ACRE 0 ACRE 023 ACRE 0.14 ACRE WETLAND K III 0-13 ACRE 0 ACRE 0 ACRE 0 ACRE 0.01 ACRE WETLAND M II 1-16 ACRE 003 ACRE 002 ACRE 056 ACRE 0-17 ACRE WETLAND N tll 020 ACRE 020 ACRE 0 ACRE 0 ACRE 0 ACRE WETLAND P II 1.91 ACRE 0 ACRE 0 ACRE 012 ACRE 024 ACRE WETLAND U III 0.13 ACRE 0 ACRE 0 ACRE 014 ACRE 0.04 ACRE STREAM TOTAL STREAM IMPACT TOTAL STREAM BUFFER IMPACT TOTAL TEMPORARY STREAM BUFFER IMPACT 0016A 0.12 ACRE 4.44 ACRE 128 ACRE 0016 000 ACRE 020 ACRE 0.00 ACRE USAGE REFERENCE 0.01 ACRES OF TEMPORARY — S. 28. T. 21 N. R. 4E. W.M. MATCH TO SyHEEETT115 WETLAND SUFFER DISTURBANCE r / eggS+ — FY.* 111i •GE WETLAND M r/ F^� JAS/ OF PAVEMENT 0.06 ACRES OF TEMPORARY RETAINING DISTURBANCE DBUFFER. WALL // /3Y / 64-50.b PROPOSED EOGE L0.03 ACRES 0 _ WETLAND DIS OF PAVEMENT ' 0.02 ACRES OF TEMPO% WETLAND 0IS1VR8ANCE 1i1 u 10.19 ACRES OF PERMANENT 's WETLAND BUFFER DISTURBANCI .. FUTURE EDGE OF PAVEMENT ik i n u n n � u u u u �'�� - - PROPOSED STORMWATER 11 ' ` POND LIMITS OF GRADING FOR PROPOSED STORMWATER POND ti [1 dN ��• 5v L EZ EXISTING EDGE OF PAVEMENT ti — TRIBUTARY 0016 DIRECTION OF FLOW (NAVD) 88 0 60 100 SCALE IN FEET 020 ACRES OF PERMANENT STREAM BUFFER OISTLIRBANCE PI AN LEGEND & SUMMARY OF IMPACTS - - -- -- - - EXISTING EDGE OF PAVEMENT PERMANENT WETLAND TEMPORARY WETLAND TEMPORARY WETLAND 7 DITCH BUFFER IMPACT BUFFER IMPACT 465 PRO PMERMANENT WETLAND ® STREAM® TEMPORARYBUFFER STREAM ALIGNMENT 6 STATION IMPACT ill! WETLAND ® PERMANENT STREAM BUFFER IMPACT -eur--Au— LIMIT OF CUT OR FILL 77777777i RIGHT OF WAY • • • • • STREAM BUFFER ......••• WETLAND BUFFER PROPOSED EDGE OF PAVEMENT _ WETLAND BOUNDARY WETLAND WETLAND CATEGORY I WETLAND PERMANENT TEMPORARY WETLAND TOTAL WETLAND TEMPORARY BUFFER IMPACT NUMBER (ECOLOGY) SIZE WETLAND IMPACT IMPACT BUFFER IMPACT WETLAND AB 111 042 ACRE 0 ACRE 0 ACRE 023 ACRE 014 ACRE WETLAND K III 0.13 ACRE 0 ACRE 0 ACRE 0 ACRE 001 ACRE WETLAND M 11 1.1B ACRE 003 ACRE 0.02 ACRE 056 ACRE 017 ACRE WETLAND N III 020 ACRE 020 ACRE 0 ACRE 0 ACRE 0 ACRE WETLAND P It 191 ACRE 0 ACRE 0 ACRE 0.12 ACRE 024 ACRE WETLAND U j III 013 ACRE 0 ACRE 0 ACRE 014 ACRE 004 ACRE STREAM TOTAL STREAM IMPACT TOTAL STREAM BUFFER IMPACT TOTAL TEMPORARY :STREAM BUFFER IMPACT 0016A 012 ACRE 4.44 ACRE 1.28 ACRE 0016 0.00 ACRE 020 ACRE 0.00 ACRE USAGE REFERENCE NUMBER: S. 28. T. 21 N. R. 4E. W.M. pATUM u (NAVD) 88 INDIRECT WETLAND IMPACTS OF 1,30E 80 FT. MPACTS MITIGATED AS DIRECT DUE TO ANTICIPATED LOSS OF WETLAND FUNCTIONS NO BUFFER ON WETLAND N AS ENTIRE WETLAND WILL BE IMPACTED AND MITIGATED 020 ACRES OF TOTAL -----.- PERMANENT WETLAND DISTURBANCE ------ WETLAND N PROPOSED EDGE OF PAVEMENT /,• I RETAINING 1 WALL WETLAND M0.10 OF WETLANDACRES BUF ER DISTURBANCE 4 �¢ i� 0 SO 100 SCALE IN FEET ►� G ROPOSED EDGE OF P�AVEIAEN17 i77 � EXISTING EDGE OF PAVEMENT 1 _ 0.37 ACRES DF PPJi00000, WETLAND BU ER DISTU1 E 1 . MATCH TO SHEET 14 PI AN LEGEND & SUMMARY OF IMPACTS - - - - - - - - EXISTING EDGE OF PAVEMENT PERMANENT WETLAND BUFFER IMPACT TEMPORARY WETLAND BUFFER IMPACTIMPACT T TEMPORARY WETLAND 465 DITCH PERMANENT WETLAND TEMPORARY STREAM PERMANENT STREAM ALIGNMENT &STATION IMPACT BUFFER IMPACT ® IMPACT ,11[� • • • • • WETLAND STREAM BUFFER ® •.. • • • PERMANENT STREAM BUFFER IMPACT WETLAND BUFFER LIMIT OF CUT OR FILL PROPOSED EDGE OF PAVEMENT 777777J77 - _ _ _ - RIGHT OF WAY WETLAND BOUNDARY WETLAND NUMBER WETLAND CATEGORY (ECOLOGY) WETLAND SIZE PERMANENT WETLAND IMPACT TEMPORARY WETLAND IMPACT TOTAL WETLAND BUFFER IMPACT TEMPORARY BUFFER IMPACT WETLAND AB III 042 ACRE 0 ACRE 0 ACRE 0.23 ACRE 014 ACRE WETLAND K I!I 0-13 ACRE 0 ACRE 0 ACRE 0 ACRE 001 ACRE WETLAND M It 1.16 ACRE 003 ACRE 0.02 ACRE 0.56 ACRE 017 ACRE WETLAND N tll 0.20 ACRE 020 ACRE 0 ACRE 0 ACRE 0 ACRE WETLAND P tt 1.91 ACRE 0 ACRE 0 ACRE 0.12 ACRE 024 ACRE WETLAND U 111 0.13 ACRE 0 ACRE 0 ACRE 0.14 ACRE 004 ACRE STREAM TOTAL STREAM IMPACT TOTAL STREAM BUFFER IMPACT TOTAL TEMPORARY 'STREAM BUFFER IMPACT 00164 0.12 ACRE 4.44 ACRE 1.28 ACRE 0016 0.00 ACRE 0.20 ACRE 0.00 ACRE REFERENCE NUMBER: e S. 28. T. 21 N. R. 4E. W.M. AT L (NAVD) BB WETLAND K RETAINING WALL - 0.01 ACRES OF TEMPORARY WETLAND BUFFER DESTURBA PROPOSED EDGE OF PAVEMENr� RETAINING WALL G� PLAN /f / PROPOSED EDGE OF PAVEMENT EXISTING EDGE OF PAVp1ENT �dy PROPOSED EDGE OF PAVEMENT 0 60 100 SCALE IN FEET LEGEND & SUMMARY OF IMPACTS EXISTING EDGE OF PAVEMENT PERMANENT WETLAND BUFFER IMPACT OORARYAM1T�RAND TEMMP WETLAND ® > DITCH ER AC MCMAPORARY 465 PERMANENT WETLAND TEMPORARY STREAM PERMANENT STREAM ALIGNMENT & STATION IMPACT BUFFER IMPACT ® IMPACT ' WETLAND ® PERMANENT STREAM BUFFER IMPACT -eur--au- LIMIT OF CUT OR FILL 777,.77TTi RIGHT OF WAY • • • STREAM BUFFER ••••....• WETLAND BUFFER PROPOSED EDGE OF PAVEMENT _ _ WETLAND BOUNDARY WERAND WETLAND CATEGORY WETLAND PERMANENT TEMPORARY WETLAND TOTAL WETLAND TEMPORARY NUMBER ECOLOGY) SIZE WETLAND IMPACT IMPACT BUFFER IMPACT BUFFER IMPACT WETLAND AB 01 0--42 ACRE 0 ACRE 0 ACRE 023 ACRE 0-14 ACRE WETLAND K 111 0.13 ACRE 0 ACRE 0 ACRE 0 ACRE 0-01 ACRE WETLAND M 11 1.16 ACRE 0.03 ACRE 002 ACRE 0.56 ACRE 017 ACRE WETLAND N 111 020 ACRE 020 ACRE 0 ACRE 0 ACRE 0 ACRE WETLAND P II 1.91 ACRE 0 ACRE 0 ACRE 012 ACRE 0.24 ACRE WETLAND U 111 013 ACRE 0 ACRE 0 ACRE 0.14 ACRE 0.04 ACRE STREAM TOTAL TOTAL STREAM TOTAL TEMPORARY STREAM IMPACT BUFFER IMPACT TREAM BUFFER IMPACT 0015A 012 ACRE 444 ACRE 1.28 ACRE 001E 000 ACRE 0.20 ACRE 0.00 ACRE USAGE REFERENCE NUMBER: � | � \ � / � �y \ / Z / ; / r � i i | i i i i i i | i \ \ , \ � \ i i i i i § § o ■ § J 00 § &Uk ru 2 77 § § .LU §§ � 2 7 CC)k2 )k 3 R mm ��° � �®% § § i■22� _ 89 ;7 z z § § s � § � g a e k § . §2�§g k § �B §\§�- |§)� 2� i i\ ci ( ( TE JE & a e F k Lc) w s LLI � |,. I.7 � §2 § �§§ % o �° b 2 LOU 2 z g § V 2 ■ , � § )§ 7 �.. s :{� G 2 \ o_ e ) e Ln 2 7 7� \ ® m ) \ / \ \ m m a a ■ 2 . � ! ` � i � � o § a � | �- j �| , 4[1 � � I � Iz12� {§■ r5 � �( � —;�,-}- } \ � / $ � � r {V H! Q W O ch 03 f� C9 o C I.- u � I� d i W zz > o °z ° 3 \ m� ZO 0 zCE \ W N W Xm \\ ly? 3Q W W \ \ W W K \ ' 0 z m Q \ W F IIl"CJJJ z ICo S' W u F \ IN J � W \ ad < C 1 LO 1 P In m m m In m In m In m In m_ In m Lo f W CD W In In 1- 7 M M N M M M M M M M M M M M M M M N m I W" N IJ.I e = ~ m 0 3 2 C O 0 i (�D C�D � CD �S) (�D m 00 c cC� m m CD c� c� cn �Q w 1 z Z I \ � s \ I \ s \ w 4 1 ° I z °Qa I 1 I i p \ J I o \ I� a \ � I 1 LD i Lo I \ r \ � II � 1 I \ z \ W W w H N LL \ W WLU S �5 2 � VQj O 0 3 z 0 = Z - z G a ° H I W LLLLf 4q W z a I CDI n I r Icn I a I I W ; I zz I I LL LL ' Lo I Lo I -IiL i � I i I I � I � 1 O I - - o�- I I Z tI a I m 6, 00 C9 LSD -4- 2 U W IS ad 14 « In ) 00 1- � § J (Y) o .k u ru K 4§ z X rAK L4 B LU § § �a §§ § ° § §§ k� z � @ 2 0 ) � �LUk § k LD 2\ \} I\ k w ® k E 1 LINE WFWOZE DE 3007— — — — — — — — — — ------------- —, I I l I.svo+ 2901 ---------- --------- --- - :L o� l � CwwHE1 FJRENSION p11.yE8T1 — J 280 L----------- — -------L---------- CULVERT EXTENSION AT 476+45 LW NVV-03 CONSTRUCTION �.-. — — — -- r— -- ^ -- — .._. — — — .-. — — — — — �" — -- �. -- — — --- 1 I i pRElr_AST REINF_02 D fi CYJf7E I 15.0' 5-5' 3051 I I3001� 1----------- ------- ------------------- --------- — I f8N1f L TA L 1ar .D - -0' FNY-09 16Mf.7 +f0.3' I EL A N 6r51.0 — — — — — — .— - — — — — — — — — ELEV. 70.3r I — — — I PRaPOSFp 51REAMREo -0.v3% I I — — 2901 �.-J .— — - — i9i PROPOSED MEAMSED 1 � I- : � ��:' �;%' it �' -�-•r PRECAST FOOTING I z.a ---------------------- ------ --_.-----.—_-----------I 3.0 I I I L— — — _.----------------J------------------------------------� I PROPOSED CULVERT AT 18+07 NW-03 PRECAST REINF. CONC. THREE -SIDED STRUCTURE ., 10.0' 37WA 0• TYP' TA LINE HEADWALL 5 -- 4 I I 2.0' e FLOW LINE BFI;ry � 0l1:1V } - HEADWALL -- -- - - - - - � • -- � FOOTING t PRECAST FOOTING TO BE A MINIMUM OF _. THREE FEET BELOW FLOW UNE OF STREAM. PRECAST FOOTING REFERENCE NUMBER: 340------------------ — — — — — — - --- — — — — -- I I — _ I 320r---------- — — — — I _ —— —_---------� I � I I � I 310r----------- ——I------------------1 300E—— — — —-—�------I�-------------� I O I wca� 290--------------I--------------------- LI , I I , I 280 L — — — — — — — — — — — ----I--- — — — — — — — — — — — — J CULVERT EXTENSION AT 22+00 WS-01 350 r — — — — — — — — — — — — — — — i — — — — — — — — — — — — — — — — 1 Iµvor urn —Il I f 330�_= 320L-----"""°N-- '"—`'—I-----------------J CULVERT EXTENSION AT 14+86 NW-01 USAGE REFERENCE NUMBM S. 28. T. 21 N. R. 4E. W.M. • r 1'1 7 i TA LWE 70+52.68 7.7. C ' r r e I SW 22'45W • r r A LINE 11.08.70 T e • • N BEGIN N AUG NT i • C TA L1NE 7 r a1 ES-01 LINE 20+3053 (125D7'LT) + • • C i N: 435251.639 r E: 1602067.774 r TA. LINE 10.84A7 P-C, I' T LINE ]1 + r TA NE 12+" P.T. • I \ I i p I r . S39' i p e r • � A- -• I 1 Q I r r TA LINE 12.44 P. TA 1 r r . S76"ri'5m rr RETAINING i WALL TA LINE •I 77 P.C. ' • TA LINE 13.06.S3 P.T. 1 STREAM CHANNEL TO ; 7.G L44➢ w1THour BE ABANDONEO r , •' ROOT SOLE [7yP.) TA UNE 13.7&74 P. - i +' rE7GISTING EDGE , �• LINO WI ROOT ' ■ OF PAVEMENT Ir •BOLE {(gp � Ir! r TA WNE 14+17.48 P-T. r � ' a p 539•0T47E i •TA UNE 74• 2 P.C. TA LINE e14+4226 P.T. T L 4 ] e NEW CULVERT SEE SHEET 25� TR L E 1•4+77.044 ' FOR REALIGNMENT. PROFILE ! �• I r r Ay • •• S36'G1'48'E l� iI J • 15.50,99 P 0 — r FE%I STING EDGE •TA •(SHE gi OF PAVZMI=NT , ' ^ EXISTING S CULVERT f I, �[iF^ N 16.04 ' �--i• RETAlNBdG WALL Z + �r CULVERT _ EXTENSION, RETAINING n r + WALL t� Z.7 • ENO NEW STREAM AUGNMEHT ' TA LIN' 154 881 = r r DIRECTON i PROPOSED EDGE r ES-01 LINE 16-45.80 (87.74'LT) 7l . OF FLOW N: 434773386 E: 1801E184.:56 OF PAVEMENT .n = W PROPOSED STREAM REALIGNMENT NEAR 356TH STREET RAMP (ES-01 15+45 TO ES-01 20+30) STREAM ALIGNMENT CURVE DATA P.L STATION DELTA RADIUM TANGENT LENGTH I SR 1fiKR 18 INTERCHANGE IMPROVEMENTS 6eRGER�RBAM APPLICANT BY: WASHINGTON STATE r c i K: E k 1 1 r DEPT. OF TRANSPORTATION LOCATION ADDRESS: FEDERAL WAYr IONG CO., WA USAGE REFERENCE NUMBER: DATE: 623�09 SHEET 24 OF 32 TA LINE 10.43.26 74.17'23" RT 78.00' 8.34 18.A7P TA LINE 7G•9R9G 32°02'22" LT 40-fla' 77.iB' 22.3T TA LINE 71+87.Z8 40°4T88" RT 5G.00' 78.38' CD pNj o C7 c CM rn N om N V- N 00 O O O O co 0 W $ _J fD �0�/ I.f li O Oct W o O co O W M / c 0 a. 0 C.O N R O R S. 28. T. 21 N. R. 4E. W.M. aUSTiNG STREAM BUFFER L . • . LLLI L TEMPORARY CONSTRUCTION EASEMENT Q RELOCATED BUFFER NEW L C LL L� LL L L.: LL L 4 ' h LL c LLL /\ L LLL 4 L , LLL a LL VL /� LLLLL a4 L! LL LLLL 4 LLL J L�— LL LLL L f LL LL LL 4 a� LLL LLL LL a 4 L4 LLLL LLL L C LLL LL �L L 4 L LL -LLL L L L L L L L L L LLLL 4 � L.L LL L L 4 L r, i f l + I r , r r i 1 + I , I I , , 1 r + r a it r I , r � I r RETArNING i f WALL r 1 STREAM CHANNEL TO do BE ABANDONED + I + rE]dBTIHG EDGE i / OF PAVEMENT r� r !r[ r + r 1 r � h , ' 1 � ' W f � J LL I14 1 mSTING EDGE J J L f OF PAVEMENT , r � L a. + L L a + L LL L4 LL F.a • F N `y, PLANTING MIX" - SPIRAEA MIX VMROI, BOTANICAL NAME COh1MOR NAME SIZE CONDITION 5RAGINB $pavdaug<er,l HARDHACK 01 CONTAOER 90.C. G MULCH (CY) ❑ O 9 TOPSOIL WATER OVAUTY SEED MEL SEE SPECS USAGE PLANTING MIX C - RIPARIAN FORESTISCRUS SHRUB r ' st6camfin RED AIAER 01 CONTAINER 10e O.C. Cv a nuRd# PACIFIC DOGWOOD #1 CONTAINER 1P O.C. CAmle udaAMem RED TWIG DOGWOOD #I CONTAINER 5.O.C. F-limush#hlls OREGON ASH #1 CONTAINER IV D.C. Osm+uls cway(farmh INDIAN PLUM #I CONTAINER 5' O.C. ph"a—po caplalus PACIFIC NINEBARK #1 CONTAINER 5' O.C. pppyhra hlaTA pa BLACKCOTTONWOOD #1 CONTAINER IV D.C. Ryyersspechhw's SALMONBERRY #1 CONTAINER 5.O.C. tdm uwtwitw SCOULER'S WILLOW UVESTAKE Ir O.C. Sdht sRcheasls SITKAWILLOW UVESTAXE IrD.C. SwnpucysnrxAosa RED ELDERBERRY 51 CONTAINER 51O.C. Thup plfcah WESTERN RED CEDAR #1 CONTAINER IV D.C. MULCH (CY) TOPSOR (LYI WATER AVALIIY SEED MIX ISFI, SEE SPECS P LANTiNG MIX D-UPLANO RIPARIAN FOREST _ BOTPNi['.AI- CD ON SIZE COHflTTlON I L- Cyunahm NNE MAPI•E #1 CO1fTAlNER S•O.C. LAer LL Acvmawphyllum BIG LEAF MAPLE M CONTAINER 10, D.C. LArhufusmendss# MADRONE TUBE 10, D.C. LL L Carylus comufa BEAKED HAZELNUT #1 CONTAINER 51O.C. L NolooSscus dscolar OCEANSPRAY #1 CONTAINER 51O.C. LL L Oemlada censfhrmis INDIAN PLUM #1 CONTAINER SO.C. L Pswdofsuga meows# DOUGLAS RR #1 CONTAINER 10, O.C. LL L Symphod SNOWBERRY I"carposa05us CONTAINER VO.C. L Tauga helwophy#a WESTERN HEMLOCK #1 CONTAINER IV O.C. L MULCH (CY) L L LL TOPSOIL(CY) RATIVE SEED MIX {SF), SEE SPECS REFERENCE NUMBER: 1-5 SR 16VSR 16 INTERCHANGE IMPROVEMENTS APPLICANT BY: WASHINGTON STATE DEPT.OF TRANSPORTATION LOCATION ADDRESS: FEDERAL WAY, RUNG CO., WA DATE: 623'09 SHEET 26 OF 32 S. 21. T. 21 N. R. 4E. W.M. 0 ;' WETLAND BUFFER S7 . •y h? TAR LINE 2.41.W P.C. 1 TAR ONE 2+ •OB PT. S12.44'13'W AR r N 7 _ --_T R • N ' P.T. - !JEVSTING RAMPS TO.BE REMOVED _ • . I / TRR L1NE 4.55.70 = LW UNE 506+99.03 W&04' ll y' 1 1/1� E: 7602382.63 11 f H ■ to 1+ r 1 I el 1 1 i • rl ii r r 1r E%ISTIN3 e 1 STREAMS BUFFER �yl' i 1 r + • '3L' r � I � r ' I 4 f f i I o u '1 TAR LINE Z+DODO = —LW LINE 506M647 (329.25LT) ' E: 16D269286 y Gf EXISTING CULVERTS TO BE REMOVED r—LWD rrvo NEWJ 1 �. STREAM �`�• BUFFER I . /// 3 DIRECTION _ ' ,�',`` \ , •�Ip O OF FLOW 0 60 100 SCALE IN FEET PROPOSED Ea OF PAVEMENT STREAM AUGNMENT CURVE DATA P.L. STATION DELTA RADIUS ITAH6ENT I.ENGTIi TAR LIRE 2.90.62 16.442r RT 111.80' 1 1&4w 30.72' TAR UNE S.44.0 14"3T67" LT 517.3i SS.OT 2&107' / O � H / / / i i / i i O / N / i r !NUMBER: m p 0 n J O f S. 21. T. 21 N. R. 4E. W.M. WETLAND BUFFER �` 0 . • � r • � r L ..� L L ❑ LL ��. ALL •■�L L�L�4.L� pL-1.�` LL�jr4 �L o LLL L LL LL LL��L L� LL LL LL L L.L'r LL L �' Y E L'� LL�� LL LC 4�L v' k LL LLLL LL LLL + LL LL L LL L-t4 L o ! LL" LL L� -L L LL o L L LL L ��_: - LL LL L- L '�' LL LL LL LL . � Lt L-L eLL' �� LL L1_ - LL LLL LL L L _ S L L L- L-L L L4,L-L I=LL L-� LLL• ty ,�r LLB I v v LL c +y Nm 2 �` I / , �UFM \ I I I � /' / .• n � 1 I r r r / • ' r e r r u •• I` I � EXISTING �' y •' 1 F2~ If sTRF_3ii�i ja 4 u ;' ,' I I I I BUFFERIER _LT�� ll I Y a 7 w 1 I 1 � ' I ' •• '! I Q ti 2 I � I I • ' � Qr r Z I 1 I � _ PLANTING MIX D - UPLAND RIPARIAN FOREST 4 i COMMON NMI FIONING LL L A[.rcirf-a VOLE MAPLE $1 CONTRlfIfR 5'0,C. L Ac.rm.aophyflum BIG LEAF MAPLE f1 CONTAINER 10' O.C. 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DEPTH = T O STREAM SUBSTRATE Og SATREAM SECTION TYP RIGHT MEANDER M MTS COIR WRAP 8-16 IN THICK AT FACE COIR MATTING ANCHOR TRENCH (TYP.) ss �I1 am it SUBGRADE WOOD STAKE AT SO.C. DEPTH = T STREAM SUBSTRATE C STREAM SECTION TYP LEFT MEANDER SCAi,)~ NITS REFERENCE NUMBER: I-5 SR 16LSR 18 INTERCHANGE IMPROVEMENTS BERGERAB" APPLICANT BY: WASHINGTON STATE a I N E e P 1 I x C. DEPT. OF TRANSPORTATION LOCATION ADDRESS: FEDERAL WAY, KING CO., WA USAGE REFERENCE NUMBER: DATE: 623,09 SHEET 30 OF 32 SAND MOB MIN' V FREEBOARD MEAN WATER ELEV. WORK AREA • S MIL POLYETHFlENE PLASTIC COVERED WITH (1) LAYER OF SAND BAGS SCALE: HITS \\\ - TOP OF BANK \I'\\ - - - - - - - - - - - - - - - - - 1-4 OHW NOTES: 1. GENERAL POSITION AS SHOWN. LOGS SHALL BE PLACED PER PLAN ON DWG SD1. 2. DEBRIS SHALL HAVE A MIN DIAMETER OF 11' AND A MIN LENGTH OF 20'. SPECIES SHALL BE CONIFEROUS IN 4 I� ACCORDANCE WITH SPECIFICATIONS. EXTEND ROOT BALL BELOW STREAM SUBSTRATE NOT TO EXCEED 50% OF INSTALLED DEPTH SCALE: NTS SCALE: NTS LOG BURY AT LEAST 12 DIAMETER INTO TOP OF BANK ll � NOTES: 1. GENERAL POSITION AS SHOWN. POSITION OF LWD RELATIVE TO THE CREEK AS PER SHEET SD1. 2 DEBRIS SHALL HAVE A MIN DIAMETER OF 11' AND A MIN LENGTH OF 20'. SPECIES SHALL BE CONIFEROUS IN ACCORDANCE WITH SPECIFICATIONS - - TOP OF BANK USAGE REFERENCE NUMBER: STREAWI BED BOULDERS PER POND OUTLET PIPE WSDOT STANOARO SPECIFICA=N 9A3.17(3)-ONE MAN ROCK SIZE DEPTH = Z SUBGRADE POND OUTFALL DETAIL SCALE: NTS DAYLIGHT PONO OUTLET PIPE TOP OF BANK j FLOW LINE OF OUTLET CHANNEL -4 I I- BOERGY 01SIER WS BERM USINGNCLAR STREAM BED _ f BOULDERS PER WSOOT STANORRO SPECIFICATION j I 9-03 11(3) 1 I II I I 1 uI I EXISTING STREAM TOP OF BANK FLO'.v LINE OF STREAM -:I I El I II I I SUBGRADE - -i 1=1 I ICI POND OUTFALL DETAIL SCALE: NTS REFERENCE NUMBER: I--S SR 16LSR 18 INTERCHANGE IMPROVEMENTS APPLICANT BY: WASHINGTON STATE air. s x a DEPT. OF TRANSPORTATION LOCATION ADDRESS: FEDERAL WAY, IQNG CO., WA USAGE REFERENCE NUMBER: DATE: 62309 SHEET 32 OF 32 CHAPTER 1— INTRODUCTION The Washington State Department of Transportation (WSDOT) proposes to improve safety, relieve congestion and improve mobility in southern King County by reconstructing a major freeway interchange in Federal Way, Washington. The Interstate 5 (I-5)/State Route (SR)161/SR 18 Triangle Improvements Project (Triangle project) will replace two existing cloverleaf loop ramps with direct access flyovers and add new roadway lanes in high traffic areas. Building new SR18 to I-5 access ramps will result in the unavoidable loss of 0.23 acre of Washington State Department of Ecology (Ecology) -rated Category II and Category III wetlands. In addition to these direct wetland impacts, the project will result in 1.05 acres of permanent wetland buffer impacts. This mitigation plan describes wetland and wetland buffer mitigation that will offset wetland and buffer impacts and ensure that the project does not result in a net loss of wetland and buffer functions. This mitigation report will be used to obtain the following permits. ■ US Army Corps of Engineers (Corps) Section 404 permit ■ Ecology Section 401 Water Quality Certification ■ Washington Department of Fish and Wildlife (WDFW) Hydraulic Project Approval (HPA) ■ City of Federal Way Critical Areas Permit The plan's preparation used the following documents and guidelines. • I-S-SR 1611SR 18 Triangle Improvements Wetland/Biology Report (BERGER/ABAM Engineers, 2006) ■ 1-5-SR 1611SR 18 Triangle Improvements Fish Vegetation, Wildlife Habitat Report (BERGER/ABAM Engineers, 2007) • Fisheries and Stream Survey Report, 1-5-SR 161 I/C & /SR 18 I/C Triangle Project (WSDOT, 2006) ■ WSDOT Wetland Mitigation Guidelines — (WSDOT, 2008) e Wetlands in Washington State, Volume 1 (Sheldon et al., 2005) ■ Wetlands in Washington State, Volume 2 (Granger et al., 2005) ■ Wetland Mitigation in Washington State, Part 1 (Ecology et al., 2006a) ■ Wetland Mitigation in Washington State, Part 2 (Ecology et al., 2006b) Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 I-5 — SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page 1 CHAPTER 2 — PROPOSED PROJECT 2.1 Location The Triangle project area is located within the City of Federal Way and is roughly bound to the north by South 336th Street, to the east by Weyerhaeuser Way, to the south by SR 161, and to the west by Enchanted Parkway South (Figure 1). The entire project area is located in the City of Federal Way in King County, Washington. The area east of I-5 and South of SR 18 is in unincorporated King County. Zoning adjacent to the project within the city limits is Commercial Enterprise and Office Park. In the unincorporated areas southeast of the project area, residential developments and urban open space are the dominant land uses. 2.2 Purpose and Description The purpose of the proposed project is to reduce traffic congestion, increase vehicle and freight mobility, and address safety concerns. Increased traffic volumes, combined with explosive land use that in part resulted from statewide land use regulations and zoning requirements, has caused increasing congestion and safety problems within the project area. Current traffic counts exceed capacity on SR 161 and are expected to continue to rise as south King County and north Pierce County continue to grow. These facts, combined with the safety problems stemming from loop ramps that do not meet current design guidelines, have resulted in congestion and higher accident numbers. This project will be necessary to alleviate the existing congestion and safety problems and allow future efficient and safe travel in the face of growing population and business growth. The Triangle project will construct road modifications that will increase driver safety and reduce existing and projected traffic congestion. During the design process, a number of different build alternatives were developed and analyzed in a two-phase WSDOT screening process. The project team selected the current build alternative for its top scores in minimizing environmental impacts, as well as in four of the six categories reviewed. Figure 2 shows the proposed project improvements. The principal features of the project will include ■ Constructing a collector -distributor road between southbound I-5/westbound SR 18 to SR161 via the construction of new ramps at South 356th and South 359th streets. a Constructing a new two-lane flyover to replace the existing single -lane northwest loop ramp for westbound SR 18 to southbound 1-5 traffic. a Replacing the existing southeast loop ramp with a new flyover ramp to allow direct access for eastbound SR 18/ South 348th to northbound 1-5 traffic. a Reconfiguring the South 348th Street/SR 161 intersection to reduce left -turn movements and decrease congestion. ■ Constructing auxiliary lanes along 1-5 between the area south of the South 336th Street Bridge and the exit/entrance to the weight station/rest area. Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 I-5 — SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page 2 EXECUTIVE SUMMARY The Washington State Department of Transportation (WSDOT) proposes to improve safety, relieve congestion, and improve mobility in southern King County by reconstructing a major freeway interchange in Federal Way, Washington. The Interstate 5 (I-5)—State Route (SR) 161/SR 18 Triangle Improvements Project (Triangle project) will replace two existing cloverleaf loop ramps with direct access flyovers and add new roadway lanes in high traffic areas. Building a new SR18 to I-5 northbound access ramp as part of the proposed work will result in the unavoidable loss of 0.03 acre of Washington State Department of Ecology (Ecology) -rated Category II wetlands and 0.20 acre of Ecology Category III wetlands. Additionally, various portions of the project will result in the loss of 1.05 acres of forested and herbaceous wetland buffers extending from four separate wetlands within the project area. To mitigate for the planned impacts and ensure no net loss of wetland and buffer functions and values, WSDOT proposes to complete wetland and buffer mitigation measures at an off -site mitigation area approximately 2 miles from the project area. This 3.37-acre site, which is located in a relatively undeveloped portion of the city, adjoins the North Fork of West Branch of Hylebos Creek and is dominated by a large emergent wetland. The Corrington site is located in a large urban natural open space corridor, has wetlands supported by surface and ground waters, and provides several excellent opportunities for wetland, stream, and riparian mitigation. The project's wetland mitigation measures will create 0.32 acre of emergent and forested wetlands and enhance 1.37 acres of emergent wetlands degraded by dense stands of reed canarygrass (Phalaris arundinacea). Of this, 0.77 acre will apply to wetland mitigation and 0.60 acre within the paper buffer will apply to buffer mitigation. The project will enhance 1.03 acres of wetland buffer by installing a native tree and shrub community. In addition, the project will increase off -channel habitat for resident and migrating fish in the North Fork of West Hylebos Creek by constructing a side channel that will meander through the mitigation site. The Category I created and enhanced wetlands will be vegetated with diverse emergent, shrub/scrub, and forested plant communities. Compared to existing wetland conditions, the created wetlands will provide improved flood flow alteration and water quality function and increased wildlife habitat functions, and the enhanced wetlands will provide greater habitat interspersion, species richness, and improved vegetative structure. The proposed mitigation measures will increase wetland and wildlife habitat functions dramatically and improve water quality conditions in the Hylebos Creek watershed. Table 1 summarizes the impacts and mitigation measures. Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 I-5 —SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page iv Table 1. Summary of Protect Wetland Impacts and Compensatory Miti�atiort Region Northwest Region 1-5/SR 161/SR 18 Interchange Improvements - Contract #Y-8742 Project # OL3493 UCO Region Township/Range/Section (impact) Township 21N, Range 4E, sections 21 and 28 Permanent Wetland Impact 0.23 acre Temporary Wetland Impact 0.02 acre Permanent Buffer Impact 1.05 acres (0.79 acre herbaceous and 0.26 acre forested) Temporary Buffer Impact 0.6 acres Jurisdictional Wetland Impact Areas 0.23 acre 0.0 acres Regulated by Corps and Ecology Regulated by Ecology (Isolated) Mitigation Location Southwest of project site on South 364th Street, City of Federal Way, WA T21N. R 4E. sections 21 and 28 Total Area of Mitigation Site 3.37 acres Area & Type of Mitigation 0.32 acre of wetland creation 1.37 acre of wetland enhancement (0.77 acre wetland enhancement credit and 0.60 acre paper buffer credit) 0.06 acre upland preservation 1.03 acre of buffer enhancement Total Area of Mitigation 2.78 acres Years of Monitoring 10 years WSDOT will monitor and maintain the completed mitigation measures for 10 years according to a comprehensive monitoring, contingency, and adaptive site management plan. Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 I-5 - SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page v LIST OF APPENDICES Appendix A —Wetland N Memo Appendix B — Wetland Impact Plan Sheets Appendix C — Mitigation Site Wetland Delineation Memo Appendix D — Mitigation Site Plan Sheets Appendix E — Wetland Rating Form for Anticipated Conditions of Mitigation Site at End of Monitoring Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 I-5 — SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page iii 7.3 Performance Criteria.......................................................................................................... 52 7.4 Monitoring...........................................................................................................................54 7.5 Contingency Plan................................................................................................................ 55 7.6 Site Management............................................................................................................... 56 CHAPTER8 — REFERENCES.............................................................................................................. 57 LIST OF TABLES Table 1. Summary of Project Wetland Impacts and Compensatory Mitigation ................................. v Table2. Wetland Summary...................................................................................................................7 Table 3. Permanent Wetland Impact Summary by Classification...................................................11 Table 4. Wetland Size, Classification, and Area Impacted by the Proposed Project .....................1.4 Table S. Wetland Buffer Size, Classification, and Area Impacted by the Proposed Project .......... 15 Table 6. Impacted Wetland Functions..............................................................................................19 Table 7. Wetland M Impact Summary............................................................................................... 20 Table S. Wetland N Impact Summary ................................................................................................ 21 Table 9. Wetland Buffer Function Impacts....................................................................................... 22 Table 10. Summary of Wetland Mitigation Measures...................................................................... 24 Table = Recommended Mitigation Ratios for Projects in Western Washington ......................... 25 Table 12. Mitigation Area Required per City of Federal Way City Code* ....................................... 25 Table 13. Mitigation Site Wetland Summary .................................................................................... 35 Table 14. Project Impacts and Mitigation........................................................................................ 39 Table 15. Seed Mix for Wetland Creation Areas.............................................................................. 46 Table 16. Plant List Proposed for Wetland Creation and Enhancement Areas .............................. 46 Table 17. Plant List Proposed for Upland Buffer Enhancement Areas ........................................... 47 Table 18. Wetland Functions Provided by Various Areas of the Mitigation Site ............................ 50 Table 19. Comparison of Impacted Wetlands and Buffers to Mitigated Wetlands and Buffers.... 50 Table 20. Monitoring Report Recipients........................................................................................... 54 LIST OF FIGURES Figure 1— Project Area Vicinity Map Figure 2 — Proposed Project Figure 3 — Project Area Aerial Photograph Figure 4 — Wetland and Wetland Buffer Impacts Figure 5 — Wetland and Buffer Photographs Figure 6 — Wetland Buffer Photographs Figure 7 — Preserved Areas Figure 8 — Mitigation Site Baseline Conditions Figure 9 — Corrington Site Photographs Figure 10 — Mitigation Activities Wetland Mitigation Plan BERGER/ABAN4, FAPWT4)4-064 I-5 — SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page ii WETLAND MITIGATION PLAN 1-5 - SR 161/SR 18 Triangle Improvements Project Washington State Department of Transportation TABLE OF CONTENTS SECTION PAGE EXECUTIVESUMMARY......................................................................................................................... iv CHAPTER 1- INTRODUCTION..............................................................................................................1 CHAPTER 2 - PROPOSED PROJECT.....................................................................................................2 2.1 Location..................................................................................................................................2 2.2 Purpose and Description.......................................................................................................2 2.3 Project Schedule....................................................................................................................5 2.4 Responsible Parties...............................................................................................................5 CHAPTER 3 - WETLAND IMPACT ASSESSMENT.................................................................................5 3.1 Landscape Setting.................................................................................................................5 3.2 Existing Conditions of Wetlands and Buffers to be Impacted.............................................9 3.3 Permanent Wetland Impacts.............................................................................................11 3.4 Temporary Wetland Impacts..............................................................................................14 3.6 Wetland Buffer Impacts......................................................................................................14 3.7 Riparian Area Impacts........................................................................................................17 3.8 Wetland Functions Impacted.............................................................................................17 3.9 Wetland Buffer Functions Impacted.................................................................................. 21 CHAPTER 4 - MITIGATION STRATEGY.............................................................................................. 22 4.1 Avoidance and Minimization of Wetland Impacts............................................................. 22 4.2 Compensatory Mitigation................................................................................................... 23 CHAPTER 5 - COMPENSATORY MITIGATION SITE........................................................................... 26 5.1 Site Location....................................................................................................................... 26 5.2 Landscape Perspective....................................................................................................... 26 5.3 Rationale for Site Selection............................................................................................... 29 5.4 Mitigation Site Existing Conditions................................................................................... 30 CHAPTER 6 - MITIGATION ACTIVITIES.............................................................................................. 36 6.1 Mitigation Accounting........................................................................................................ 36 6.2 Mitigation for Temporary Impacts..................................................................................... 39 6.3 Mitigation for Permanent Impacts..................................................................................... 39 6.4 Site Hydrology.....................................................................................................................43 6.5 Invasive Species Control Strategy..................................................................................... 43 6.6 Grading Design.................................................................................................................... 44 6.7 Planting Design................................................................................................................... 45 6.8 Habitat Features................................................................................................................. 47 6.9 Buffers.................................................................................................................................48 6.10 Site Protection................................................................................................................ 48 6.11 Implementation Schedule.............................................................................................. 48 6.12 Ecological Benefits......................................................................................................... 49 CHAPTER 7 - MITIGATION GOALS, OBJECTIVES, AND PERFORMANCE CRITERIA ........................ 52 7.1 Goals....................................................................................................................................52 7.2 Objectives............................................................................................................................52 Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 I-5 - SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page i Wetland Mitigation Plan 1-5 - SR 161/SR 18 Triangle Improvements Project Submitted to Washington State Department of Transportation February 2009 Submitted by BERGER/ABAM Engineers Inc. 720 Olive Way, Suite 1100 Seattle, Washington 98101 Job No. FAPWT-04-064 MAR 0 2 2009 CIS " fE4��R�'L SAY SUS Kn, 1-5 — SR 161/SR 18 intewcha.r?.�e Improvements Draft Wetland Mitigation Plan February 2009 Adw MWashington State ', Department of Trarssxrtation 4- - OjU.S" Department of Trarsportat,ci Federal Highway Administration L ownd Project Limits i� Iditip i on Area Draft Wetland Mitigation Plan 1-5 — SR 161/SR 18 Triangle Improvements Project Washington State Department of Transportation Figure 1 Project Area Mcinity Map 1-5/SR 16VSRIS Triangle firVra ema►ts 0 0 1000 2000Fed l 1 e * 1 BERGER/ABAK FAPWT-04-064 January 2009 Page 3 Legend Psojed Urnks �iwayEtedes� Draft Wetland Mitigation Plan I-5 — SR 161/SR 18 Triangle Improvements Project Washington State Department of Transportation Proposed Project 1-5/SR 161/SR18 Triangle Improvements p Soo l,(NM Fed () I I I I I BERGER/ABAM, FAPWT-04-064 January 2009 Page 4 M 2.3 Project Schedule Pending approvals from the appropriate agencies, construction will occur in multiple phases, with the first phase beginning during spring 2010 and finishing at the end of 2013. The first phase would address the weaving pattern of the northbound I-5/westbound SR 18 loop ramp, 1 and reduce congestion and improve safety at the South 348th Street/SR 161 intersection by providing a direct access ramp between 1-5 and SR 18 to SR 161. The second phase of the project . would complete all the remaining improvements of the build alternative. 2.4 Responsible Parties WSDOT will be the primary party responsible for the oversight of the construction of the proposed project, work that includes the completion of the proposed mitigation and required monitoring and maintenance. CHAPTER 3 — WETLAND IMPACT ASSESSMENT 3.1 Landscape Setting The area of the Triangle project is in the City of Federal Way and is bounded roughly to the north by South 336th Street, to the east by Weyerhaeuser Way, to the south by SR 161, and to the west by Enchanted Parkway South. The entire project area is located within the Hylebos Creek Basin and is drained by the East and West Branch of Hylebos Creek. Land uses within the surrounding area consist of (1) high - intensity commercial and residential development that is primarily concentrated in the western portion of the project area, and (2) relatively undeveloped urban open space in the eastern half of the project area (Figure 3). Conditions in the general vicinity of the project are typical for highly developed areas. They include large amounts of paved surfaces and traffic, fragmented natural resource systems, and extensive stormwater management. In terms of recording the existing conditions and assessing the potential for direct project - related impacts, project staff determined that the project area extends 200 feet outward from the existing edge of pavement. 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V ill:. 1 ales / ales Ia1>< •,� ALL ,u. /♦J■ 1DP J 1 -.� Ii 1 r ' ` / r I! 1 r OF BANK r • ■ I 4v� / J + ORDINARY FCON NNTER OHW — I I I / / / !/ r1 1 ! / ! t ■ . ! / y 1 t 1 I ; I STREAM BUFFER ZONE r♦li sl... y&-TLIND `.- - an .. ,sJt.r aL. ' alp aw alt< il16. /;sL ar;! aL. ale..£1? alr. t /` s Jyg // i \ \ . �, ►I nE:1LAH6 BUFFER ZONE -J • \_ „i,. aLl� I ,!• ilL I au. pL. ► afr. I alt. / aw a[t� ,rut. Al yr' 1 I I ► I /! r r ♦� ram~ r I IXy v JAN 2 6 2010 PROPERTY -� Y LINE ----_---�rr S i 0 20 40 [ I I ;i I ! Tt ■ r1 r- R - SCALE IN FEET FILE NAME aLSeatde120OAFAPWi-04 0841CAD n1Qft013.d n TIME 2:03:17 PM FED.AID PROJ.NO. DATE 1112[2009 10 AS PLOTTED BY }ake.laWing DESIGNED BY J. SUAZO 09A802 ENTERED BY N. VU CHECKED BY J. JIM NEZ CONTPA" NM fOCAT10N NIL PROD. ENGR. B. NEBBITT REGIONAL ADM. C. STONE REVISION DATE BY 0), BergerABAM BLIIL,.�iNG DEFT_ rlo3: No SR 161/SR 18 GR13 Washington State INTERCHANGE IMPROVEMENTS488 Depatfinent of Transportation 4108 GRADING PLAN warm J �j EXISTING NEW GATE / \— GRADING NOTES CONTOUR (MAJOR) 60 FENCE -X— —X— —X— —X— - O PRIOR TO THE INITIATION OF EARTH DISTURBING ACTTVTTIES,ALL CLEARING UMITS, TREE CONTOUR (MINOR) 79 MSEMENTS, WETLANDS AND BUFFERS WILL BE CLEARLY MARKED TO AVOID INCIDENTAL TREE TO BE REMOVED X GRAVEL (PLAN) © i2 ALL GRADING ACTnES WILL TAKE PLACE DURING THE SUMMER CONSTRUCTION WINDOW - TO M TO AVOID COMPACTION AND DAMAGE TO SOIL STRUCTURE SANRATED SOILS WILL NOT BE WORKED. TOPSOIL WILL BE MANIPULATED AS LITTLE AS POSSIBLE TO AVOID COMPACTION. PROPERTYURA.W. LINE CENTERLINE OF ROAD GRAVEL (SECTION) ® O HEAVY EQUIPMENT WILL HOT BE PARKED, STORED, OR OPERATED WITHIN THE MITIGATION AREA UNLESS NECESSARY TO COMPLETE THE PROPOSED WORK ANY AREA WITHIN THE GRAVEL PAVEMENT SILT FENCE WnGATTON SITE THAT HAS BECOME COMPACTED DUE VEHICLE TRAFFIC WILL BE RIPPED TO A DEPTH OF Ir PRIDR TO THE PLACEMENT OF COMPOST. POWER POLE — P — O BMP'S TO LIMIT EROSION WILL INCLUDE BUT ARE NOT LIMITED TO THE INSTALLATION OF SILT FENCES (STANDARD MATERIALS) AROUND THE OUTER PERIMETER OF THE SITE GUY WIRE F O ALL EXPOSED AND UN -WORKED SOULS WILL BE STABILIZED BY APPLYING EFFECTIVE BMPS ==__=_==-=- B E SOIL FROM THE EROSIVE FORCES OF RAINDROP CONTACT AND CULVERT FLOWING WATER, CONTOUR (MAJORI — 79 — SOL STABLZATION MEASURES WALL BE APPROPRIATE FOR THE TIME OF THE YEAR,SITE CONDMONS,ESTIMATED DURATION OF USE,AND POTENTIAL WATER QUALITY IMPACTS THAT CONTOUR (MINOR) — so — STABLMATION AGENTS MAY HAVE ON DOWNSTREAM WATERS WETLAND BOUNDARY MAINTENANCE AND REPAIR OF HEAVY EQUIPMENT AND VEHICLES INVOLVING OIL CHANGES, HYDRAULIC SYSTEM DRAIN DOWN, SOLVENT AND DE -GREASING CLEANING OPERATIONS, FUEL WETLAND © TANK DRAIN DOWN AND REMOVAL,AND OTHER ACTIVITIES WHICH MAY RESULT IN T, DISCHARGE OR SPILLAGE OF POU.UTANTS TO THE GROUND OR INTO STORMWATER RUNOFF WILL BE CONDUCTED AT LEAST 200 FEET FROM THE OUTER EDGE OF WETLAND BUFFERS PONDNAULT AND BE COMPLETED ON IMPERVIOUS SURFACES. THESE SURFACES WILL BE CLEANED IMMEDIATELY FOLLOWING ANY DISCHARGE OR SPILL INCIDENT STREAM NAME 0016A ALL TEMPORARY AND PERMANENT EROSION CONTROL AND SEDIMENT CONTROL BMPS WILL OBE MAINTAINED AND REPAIRED AS NEEDED TO ASSURE CONTINUED PERFORMANCE OF THEIR INTENDED FUNCTION.ALL MAINTENANCE AND REPAIR WILL BE CONDUCTED IN ACCORDANCE WITH BMPS. ALL TEMPORARY EROSION AND SEDIMENT CONTROL BMPS EXCEPT THE SURROUNDING SILT FENCE WILL BE REMOVED WITHIN M DAYS AFTER FINAL SITE STABILIZATION IS ACNIE�-ED OOR AFTER THE TEMPORART BMPS ARE NO LONGER NFEDED.TRAPPED SEDIMENT WILL BE REMOVED OR STABLIZED ON SITE. OISTURSIED SOL AREAS RESULTING FROM REMOVAL OF BMPS OR VEGETATION WALL BE PERMANENTLY STABILIZED PAGE ,,.I.--_O F -2 --F. . FILE NAME ,.V004%FAPWYT•04064%CAD0 MEV00i.d n PIOt i TIME 1:15.12 PM _ _ fREOM STk7EFEDAID PROJ.NO. �► I-5DATE 2A012009 EV1 PLOTTED BY brlen.bollen WAS SR 1611SR 1S DESIGNED BY M.PERFETTI ER B�0R /ABAA! NENTERED BY N.vu l f Washington State INTERCHANGE IMPROVEMENTSCHECKED BY J. JIMENEZ ACT Ro. LO Tm NQ `r Oepartment of Transportation Z9� PROD. ENGR B. NEBBIrr ,,� _ OTES L ENLi - 491 REGIONAL ADM. C. STONE REVISION DATE BY P.LSTAIP Box PLsw. Ear CORRINGTON .Ty �. I -f it a i„� •x: '?- � '�+: ` - -• r Wx ^•�h. , � �.- - N 1. Y �+IN uc .. - -.. - x� f 3.ii Wetlands Project scientists delineated the wetlands in the project area in May and June 2005 and identified 16 wetlands. The I-5—SR 161/SR 18 Triangle Improvements Discipline Report (Appendix J, April 2006) contains detailed information about these wetlands. Subsequent visits to the project area by project staff resulted in the identification of an additional wetland — Wetland N—in the eastern portion of the site. This depressional small shrub/scrub wetland is located immediately east of Wetland M. The details of this wetland are provided in Appendix A. Table 2 below presents a summary of wetland classifications, sizes, and buffer requirements. Thln 7 Wa4land Ciirnrnary Wetland Name Acres Cowardln Classification Ecology Rating Federal Way Rating Base Buffer Width Wetland AB 0.42 Palustrine emergent shrub/scrub III III 50 ft Wetland D 0.05 Palustrine shrub/scrub III Not rated * — Wetland E 0.77 Palustrine shrub/scrub II II 100 ft Wetland F 0.01 Palustrine unconsolidated bed Shrub/Scrub III Not rated * Wetland G 0.74 Palustrine emergent shrub/scrub forested 1 I 200 ft Wetland H 0.06 Palustrine shrub/scrub III III 50 ft Wetland J 0.02 Palustrine shrub/scrub III III 25 ft Wetland K 0.13 Palustrine shrub/scrub III III 25 ft Welland L 0.02 Palustrine shrub/scrub HI III 25 ft Wetland M >1.16 Palustrine shrub/scrub forested II II 100 ft Wetland N 0.20 Palustrine shrub/scrub III III 25 ft Wetland 0 0.75 Palustrine shrub/scrub II II 100 ft Wetland P 1.91 Palustrine emergent shrub/scrub forested II Il 100 ft Wetland Q 0.24 Palustrine forested II II 100 ft Wetland T 0.05 Palustrine shrub/scrub III Not rated * — Wetland U 0.13 Palustrine shrub/scrub III III 25 ft Wetland U-1 0.01 Palustrine shrub/scrub III Not rated * — 'Category III wetlands under 0.10 acre in size are not regulated by the City of Federal Way M-2. Streams The project area is situated in the upper reaches of the Hylebos Creek basin and is further divided into the West Branch of Hylebos Creek sub -basin, generally located west of I-5, and the East Branch of Hylebos Creek sub -basin, situated for the most part east of I-5. For most of the project area, Tributary 0016A flows parallel to the west side of I-5 and is located in the East Branch of Hylebos Creek sub basin (Figure 2). Tributary 0016, located east of I-5, is also located within the East Branch of Hylebos Creek sub -basin (Figure 2). Both are tributaries to the East Branch of Hylebos Creek, which eventually combines with the West Branch of Hylebos Creek and continues to flow south before draining into Commencement Bay. The high proportion of impervious surfaces in the developed portions of the basin and the associated stormwater controls affect the hydrologic cycle of Tributary 0016A substantially, and reaches of it are dry for most of the year. Tributary 0016A has a limited capability to support Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 I-5 — SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page 7 fish and other aquatic life because of its intermittent and flashy flow (WSDOT 1997). These stream characteristics could result in fish stranding and high stream temperatures during low or zero flows and channel scouring, increased turbidity, and lack of spawning substrate as a result of high flows. Tributary 0016 starts at North Lake and flows into Weyerhaeuser Pond. From there, the stream is routed under the Weyerhaeuser corporate headquarters building and a grass field in a culvert about 0.5 mile long. Downstream of the culvert outlet is a short reach of channel that flows through a thick riparian corridor down to the culvert under SR 18. The SR 18 crossing consists of two culverts. Analysis of velocity and depth guidelines for fish passage indicates that the SR 18 culverts are velocity barriers for adult migration and depth barriers for downstream migration (BERGER/ABAM 2008b). Below SR 18, the channel is fairly low gradient and dominated by silt. The stream condition within this reach is dominated by shallow pools or slow water conditions. The riparian area is generally wide, except where houses have encroached down to the stream channel. Shading is generally good. A local resident reported seeing a dead 5-inch trout. Farther downstream at the 354th Street crossing, the stream channel is covered by a narrow strip of dense riparian growth. This stream reach resembles the riparian corridor in the previous reach. The culvert under SR 161 is perched and impassable. While both tributaries are fish -bearing and at one point supported healthy runs of anadromous fish, several fish blockages downstream of the project area now prevent migrating salmonids from reaching the stream reaches in the project area. Culverts on Tributary 0016A in the project area prevent the upstream passage of salmonids into the project area. These fish passage barriers are culverts just north of SR 161, the I-5 cross culvert, and culverts associated with the I- 5/SR 18 interchange. Analysis of velocity and depth guidelines for fish passage indicates that the I-5 culvert is a velocity barrier for adult salmon migration and a depth barrier for downstream salmon migration (BERGER/ABAM 2008b). Stream survey results reported in the fish, vegetation, wildlife, and habitat discipline report (BERGER/ABAM 2007) indicate that the average channel width of Tributary 0016A ranges from 5 to 15 feet and that it has an average depth of 0.5 to 1.25 feet. An electrofishing study by King County staff in 1996 and 1997 identified no salmonids in Tributary 0016A. The study report noted that even insect life was "limited" (WSDOT 1997). Project -related stream surveys also noted the absence of aquatic insects (BERGER/ABAM 2007). Tributary 0016 has a history of coho salmon use and current use by cutthroat trout (WSDOT 1997; WSDOT 2007). An electrofishing study by King County staff in 1996 and 1997 identified no salmon in Tributary 0016 (WSDOT 1997). 3.J-3. Uplands While the surrounding area has been subject to extensive high -intensity commercial and residential development, u e uplands immi ediatel-y adjacent to most of the project aligrunents are maintained highway ROW, urban forestland, and open space (Figure 2). These uplands Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 I-5 - SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page 8 have been subject to manipulation in the forms of historic logging and agricultural practices, disturbance from past road construction activities, and on -going road ROW maintenance. Except in a few locations, the first 50 feet of area adjacent to the existing roadway and gravel shoulders is a regularly mowed and maintained lawn area. Outside this immediate ROW, vegetation varies greatly, ranging from heavily impacted areas dominated by monotypic stands of Himalayan blackberry (Rubes armenicus) to relatively undisturbed upland forestland with an overstory of Douglas fir (Pseudotsuga menziesii), big -leaf maple (Acer macrophyllum), and red alder (Alnus mbra). Understory vegetation here is typical of this region and is dominated by snowberry (Symphoricarpos albus), osoberry (Oemleria cerasiformis), thimbleberry (Rubus parviflorus), salal (Gaultheria shallon), beaked hazelnut (Corylus cornuta), swordfern (Polystichum munitum), and bracken fern (Pteridium aquilinum). 3JA Land Use History Historically, the 18-square mile Hylebos watershed was a small but productive salmonid- bearing watershed. Before urbanization, the watershed supported substantial runs of coho, Chinook, chum salmon, and residential cutthroat trout. Early land uses were limited to timber harvesting. With the completion of Highway 99 in the 1920s, the population and commercial opportunities increased. Steady residential and economic growth in the 1980s brought rapid growth in population and commercial and retail development. Increased development activity resulted in large-scale negative impacts to the surrounding landscape and watershed that included filling and draining wetlands, installing poorly designed culverts, channelizing natural stream channels, the loss of riparian vegetation, and increased impervious surfaces without proper stormwater treatment. 3.2 Existing Conditions of Wetlands and Buffers to be Impacted Figure 4 illustrates the locations of both temporary and permanent wetland and buffer impacts. The conditions of the impacted wetlands and buffers vary greatly, ranging from relatively undisturbed forested wetlands to heavily manipulated wetland buffers in maintained ROWS. Refer also to the I-5-SR 161/SR 18 Triangle Improvements Wetland/Biology Report (BERGER/ABAM 2006) for more details about each wetland, including rating forms and field data forms. Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 1-5 — SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page 9 Legend 1+'l2D 4 Project Limits �11 Permanent Wetland Impact Wetland & Wetland Buffer Impacts �l Delineated Wetand Temporary Wetland Impact 1-5/SR 161/SR18 Triangle Improvements Wetland Buffer r Permanent Wetland Buffer Impact Temporary Wetland Buffer Impact 0 500 1,000 Feel Wetlands were classified using: ■ USFWS system (Cowardin et al. 1979). • Hydrogeomorphic Classification system (Brinson 1993). ■ Washington State Wetlands Rating System for Western Washington (Hruby 2004) ■ City of Federal Way City Code, Chapter 22 (City of Federal Way 1990) These criteria were used to assess the condition of wetland buffers qualitatively: ■ Dominant land use (e.g., agriculture, residential, commercial, industrial) ■ Dominant buffer vegetation type (tree, shrub, herb, vine, un-vegetated) ■ Estimated percent cover of invasive plant species 3.3 Permanent Wetland Impacts The proposed project will permanently impact a small portion of Wetland M and Wetland N in its entirety. These impacts will result in a net loss of 0.23 acre of wetlands. In addition to these permanent impacts, the project will temporarily impact 0.02 acre of Wetland M to allow for construction access. The following table summarizes the proposed impacts by classification (Table 3). Table -_ Permanent Watlnnrl Impact Summary by Classification ----- -- ------------- --------- Wetland Classtflcation ---- - - - - Class Wetland Impact Area acre Percent of Total Wetland Area } USFWS PSS 0.03 13% PSS 0.20 87% Total 0.23 Washington Department of Ecology (Hruby 2004) i l 0.03 13% l it 0.20 87% Total 0.23 Local Jurisdiction City of Federal Way III 0.20 13% I I 0.03 87% Total 0.23 Hydrogeomorphic ' Class De ressicnal 0.23 100% • Total'.. • Percentage of total in wedand class. Wetland M is a palustrine shrub/scrub-forested depressional wetland with riverine influenced J portions of the wetland located adjacent to Tributary 0016 (Table 2). The construction of the new i SR 18 to northbound I-5 onramp will impact the southernmost portion of the wetland, which is j regulated on federal, state, and local levels by the Corps, Ecology, and City. Direct wetland J impacts totaling 0.03 acre will result from grading and construction of a large retaining wall. The proposed impacts will result in a loss of wetland area and the permanent loss of wetland vegetation, primarily mature shrubs. These impacts will result in the permanent loss of associated wetland functions and values. Sheet 8 of Appendix B shows project plans for the proposed road alignment and wetland impacts. _ Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 I-5 — SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page 11 Wetland N is a depressional Category III wetland dominated by shrub/scrub vegetation. The wetland is located within a prominent depression at the base of the SR 18 fill slopes. Hydrologic inputs from seasonal interactions with elevated ground water levels and precipitation sustain Wetland N. In addition, the wetland likely receives a small amount of surface runoff from the SR 18 fill slopes. This small wetland was likely part of a drainage system that connected historically but no longer connects to Tributary 0016. Douglas' spirea (Spirea douglasiz), willow, and thimbleberry dominate the vegetation in the shrub/scrub portion of Wetland N. Its easternmost portions are forested and have a canopy layer of red alder, black cottonwood (Populus balsamifera), and willow. The size of the forested area is too small for the wetland to be divided into both shrub/scrub and forested vegetation classifications under the Cowardin system. Wetland N's 25-foot buffer has been subject to past land disturbances and ongoing ROW mowing. Mixed upland pasture grasses, non-native weed species, and Scotch broom (Cytisus scoparius) dominate the buffer areas. Direct permanent wetland impacts to Wetland N will result from the construction of fill slopes necessary for the expansion of SR 18 in addition to impacts to the wetland resulting from construction access. Direct wetland impacts will result in the loss of 0.17 acre of Wetland N. This represents a loss of 85% of the total area of Wetland N. It was determined that the proposed fills would likely cause the hydrology of the remaining portions of Wetland N to be indirectly impacted to such an extent that the remaining portions of the wetland would not function properly. To ensure that the project completes sufficient mitigation to offset all direct and indirect wetland impacts, the impacts to Wetland N have been calculated as if the entire wetland were impacted. Under this plan, mitigation requirements and calculations indicate impacts to Wetland N totaling 0.20 acre. Photographs of the areas of impact are provided in Figure 5. Sheet 9 of Appendix B shows project plans and details of the proposed Wetland N impacts. Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 I-5 — SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page 12 ' _ l..= 4 '8• .- �� - � _ 1y�. aC a '��•�F -ram.. � � 'wr � Via, '%•_ � � ; �";= ;. ��-'•�' _ 4 _ P • 1 l ' .�� J r• C - �Zyar k J� N � Bey j 3.4 Temporary Wetland Impacts Temporary impacts to Wetland M may result from clearing vegetation on the northern side of the proposed retaining wall. The clearing is not expected to extend further than 10 feet from the edge of the permanent wetland impacts. Based on this 10-foot wide disturbance zone, project scientists calculated temporary wetland impacts at 0.02 acre (Sheet 8, Appendix B). These temporary impacts may be necessary to allow equipment access for constructing the retaining wall. To the greatest extent practicable, the project will remove vegetation only to the base of the plant and the roots will not be grubbed or removed with machinery. Vegetation that will be temporarily impacted by the project will include red alder saplings, willow (salix sp.) shrubs, red -osier dogwood, reed canarygrass and Douglas spirea. Temporary impacts will be mitigated through the restoration of the temporarily impacted areas. Restoration will include reseeding and planting of native vegetation and is covered in the sections below that discuss mitigation activities. Table 4. Wetland Size. Classification, and Area Impacted by the Proposed Project Wetland Wetland Classlficatlon Wetland Size (acre) Wetland Impact Area (acre) Cowardina HGMe Ecologyr Local n Permanent Temporary M PFO Dp/Ri 11 11 >1.16 0.03 0.02 N PSS Dp Ill III 0.20 0.20 none Total - - 0.23 0.02 Notes: A) Cowardin, et al. (1979) or National Wetland Inventory (NWI) Class based on vegetation: PEM = Palustrine Unconsolidated Shore; PEM = Palustrine Emergent; PSS = Palustrine Scrub -Shrub; PFO = Palustrine Forested. B) Brinson, Mark (1993) Hydrogeomorphic Classification for Wetlands Dp=Depressional; Ri = Riverine C) Ecology rating according to Hruby (2004). D) Crty of Federal Way 3.6 Wetland Buffer Impacts Constructing the westbound SR 18 flyover, proposed road widening activities, and associated grading will result in impacts to the buffers of wetlands AB, K, M, P, and U through a loss of both vegetation and buffer area (Figure 4). Wetland buffer impacts are shown in the project plan sheets in Appendix B. The wetlands and their associated buffers represent a broad continuum in terms of quality and wetland/habitat functions. They range from low quality wetlands and buffers subject to historic disturbance and largely dominated by non-native invasive species, such as Wetland AB, to higher quality wetlands vegetated with a structurally- and species -diverse assemblage of native plants, such as Wetland G's buffer. 3.6.1 Permanent Wetland Buffer Impacts The proposed project will permanently impact 1.05 acres of wetland buffers that are roughly divided into two types, herbaceous and forested. Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 1-5 — SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page 14 i The buffer impact areas of Wetland M and Wetland AB are dominated by non-native grasses and forbs. Dominant species include sweet vernalgrass (Anthoxanthum odoratum), meadow foxtail (Alopecurus pratensis), reed canarygrass, tall fescue (Festuca arundinacea), Canada thistle (Cirsium arvense), oxeye daisy (Chrysanthemum leucanthemum), English plantain (Plantago lanceolata), and Scotch broom. _ A dense canopy of medium -aged Douglas fir trees characterizes the buffers extending from 1 Wetlands K, P, and U. Understory vegetation in the buffer impact areas ranges from wetland to 1 wetland, but in general includes Himalayan blackberry, osoberry, vine maple (Ater circinatum), beaked hazelnut, and red alder seedlings. Photographs of the wetland buffers that will be impacted are presented in Figures 5 and 6. Table 5 below summarizes buffer impacts. Table 5. Wetland Buffer Size, Classification, and Area Impacted by the Proposed Project Wetland Wet€and Classification Buffer Width (feet) ° Impacted Vegetation Buffer Impact Area (acre) n Ecologya Local Jurlsd€ctlon a Permanent Temporary Wetland M II II 100 Herbaceous 0.56 0.17 Wetland AB III Ill 50 Herbaceous 0.23 0.14 Wetland K III III 25 Forested 0.00 0.01 Wetland P II II 100 Forested 0.12 0.24 Wetland U III III 100 Forested 0.14 0.04 Total — - 1.05 0.6 Notes A. Hruby (2004). B. Wetland rating according to City of Federal Way City Code (City of Federal Way, 2005). C. Wetland buffers according to City of Federal Way City Code (City of Federal Way, 2005). Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 I-5 — SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page 15 r' �� t • Outer edge of Wetland U-1 buffer Outer edge of Wetland P buffer I rP• .Fr. tiz -� •- r outer edge of northern wedand AB buffer (northernTypical portion). Figure 6 Wetland Buffer Photographs 1-5 /SR MUMS Triangle Improvements 3.6.2 Temporary Wetland Buffer Impacts The temporary impacts to a total of 0.6 acre will result during the construction of the project. Temporary buffer impacts are necessary to provide construction site access. Temporary impacts to herbaceous vegetation from impacts to wetlands M and AB will total 0.31 acre. A total of 0.29 acre of forested buffers on wetlands P, K, and U will be impacted. All temporary impacts to woody vegetation will be minimized to the maximum extent possible during construction. Mitigation for temporary wetland buffer impacts will take the form of revegetation of all the impacted areas. These revegetation efforts will include hydro -seeding or the planting of herbaceous vegetation and native woody trees and shrubs. Information about the proposed temporary buffer mitigation measures is included below. 3.7 Riparian Area Impacts The proposed project will include impacts to riparian habitat along tributaries 0016 and 0016A. The Draft Stream Mitigation Plan (BERGER/ABAM, 2009) gives details of the proposed stream impacts and restoration activities. The Triangle project will not directly affect the stream channel of Tributary 0016. Minor temporary alteration of vegetation in the setback area of Tributary 0016 may accompany the construction of a retaining wall at the stream crossing of SR 18. All temporarily disturbed areas will be restored by planting appropriate native trees and shrubs. The Triangle project will result in various impacts and restoration activities to Tributary 0016A. Construction of the project will have the following impacts on the stream channel of Tributary 0016A and its associated riparian area within the regulated 100-foot setback The project will: ■ Enclose 250 feet of Tributary 0016A in new culverts (65 feet) and culvert extensions (185 feet) w Fill 495 feet of Tributary 0016A and relocate the stream a Encroach into an estimated 4.44 acres of riparian habitat, principally mixed deciduous/conifer forest, Himalayan blackberry thickets, and roadside grass fields ■ Temporarily impact an estimated 1.28 acres of riparian area along Tributary 0016A In addition to these direct impacts, the Triangle project will cause a small amount of indirect impacts by not alleviating fish passage issues that occur at several culverts in the project area that convey Tributary 0016A flows. Reconstruction of these culverts in their present locations (deep, under the entire width of I-5) would entail significant construction difficulties and increase project costs and traffic delays. Repairing these culverts would not allow fish to access usable habitat because the upper reaches of Tributary 0016A lack sufficient water levels and suitable fish habitat and are subject to flashy stream flow. 3.8 Wetland Functions Impacted Wetland functions were evaluated using the functional groupings and assessment methods detailed in the Washington State wetland rating system for Western Washington — Revised Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 I-5—SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page 17 (Hruby, T, 2004). The only wetlands that will be directly impacted by the project are Wetland M and Wetland N. Wetland M is a palustrine shrub/scrub and forested wetland provides a variety of wetland functions that include hydrologic functions, water quality functions, and wildlife habitat functions —most of these based on the wetland's depressional/riverine hydrogeomorphic rating, mature and species -diverse vegetation layers, and the diversity and size of buffers to the west, east, and north of the wetland. Wetland M's hydrologic functions include flood flow attenuation, shoreline stabilization, and sedimentation control. The wetland has the potential to provide these functions because of its location adjacent to Tributary 0016, its depressional characteristics that allow for the ponding of water, and its well -established emergent and shrub/scrub vegetation layers. These characteristics also provide water quality functions that include sediment removal, production and export of organic matter, and uptake and sequestration of toxicants and pollutants. Finally, the wetland provides a relatively high degree of wildlife functions relative to the surrounding areas that have been subject to high intensity developments. Wetland vegetation in Wetland M consists primarily of diverse, structurally complex native plant communities that provide emergent, shrub/scrub, and canopy layer habitats. Habitat functions include native plant richness and habitat for wetland -associated mammals, resident and migratory birds, and aquatic invertebrates. The impacts proposed will result in the loss of a small amount of shrub/scrub plant community along the southern edge of Wetland M and a small reduction in wildlife habitat values. Project scientists identified the hydrologic source of Wetland M as interactions with the seasonally high water table and periodic flooding from Tributary 0016. Since the impacts will occur along the southern edge of the wetland, no hydrologic impacts to Wetland M are anticipated to occur. In addition, the portion of the wetland to be impacted does not he in a depression and does not adjoin Tributary 0016. Therefore, loss of hydrologic functions such as sediment removal, toxicant removal, and attenuation of flood flows, is not anticipated. Anticipated loss of vegetation will increase the edge effect along the southern portion of the wetland and decrease the visual attenuation functions of well -established woody vegetation, although it is not anticipated that the edge effect impacts will be significant because no canopy vegetation will be removed that may cause injury to shade -tolerant plant species. The proposed 10-foot high retaining wall will mitigate the loss of the sound attenuation functions of the wetland vegetation. At this height, the new roadway will be elevated to such an extent that traffic -generated noise will be commensurate with existing noise levels. Wetland N is a small (0.20 acre) depression class wetland that is vegetated with both shrub/scrub and forested vegetation. The amount of functions that the wetland provides is limited due to its size, character and position in the landscape. The wetland is located directly adjacent to maintained ROW to the south and west and routinely mowed fields to the north. Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 I-5 — SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page 18 The lack of a connection with other wetlands or surface waters severely limits the ability of Wetland N to provide benefits to water quality and the export of organic material. This is { because pollutant -laden surface waters that could be treated by vegetation within Wetland N have no clearly defined outlet by which to leave the wetland. Wetland N does have some potential to alleviate localized flooding by preventing surface water runoff from continuing ' down slope; however, the small size of the wetland limits this function. The proposed impacts will result in a loss of shrub/scrub and forested vegetation communities and the associated wildlife habitat values associated with Wetland N. Birds and small mammals likely use the habitat provided by Wetland N; its closeness to SR 18 limits its usefulness as habitat for other species. Wetland N's loss of water quality and hydrologic functions will be very limited because it is small and because it experiences only minimal surface water inputs that provide the potential for the sequestration of sediment and uptake of toxicants. Table 6 summarizes the existing wetland functions and anticipated impacts. Tahla F. Irnnarted Wetland Functions Function/Value, Wetland M Wetland N Exlsting Anticipated Existing Anticipated Flood Flow Alteration + No change Sediment Removal X No change - Nutrient and Toxicant Removal + Small decrease X Complete Loss Erosion Control & Shoreline Stabilization X No change Production & Export of Organic Matter + No change General Habitat Suitability + Small decrease x Complete Loss Habitat for Aquatic Invertebrates + No change - Habitat for Amphibians - - Habitat for Wetland -Associated Mammals + Small decrease - Habitat for Wetland -Associated Birds + Small decrease General Fish Habitat - Native Plant Richness + No change x Complete Loss Educational or Scientific Value - Uniqueness and Heritage - -" means that the function is not present, "X" means that the function is present is of low quality, and "+" means the function is present and is of high quality. Table 7 summarizes the impacts to Wetland M and its associated functions that would result from the proposed project. Table 8 summarizes impacts to Wetland N. Wetland Mitigation Plan I-5 - SR 161/SR 18 Triangle Improvements Project Washington State Department of Transportation BERGER/ABAM, FAPWT-04-064 February 2009 Page 19 AI Tattle T. Wetland M ImDact Summary Wetland Im acb Summary Sheet Local Jurisdiction Cit y of Federal Wa WRIA 10 Ecology Rating II Hrul} 2004 Local Jurisdiction Rating If Local Jurisdiction Buffer 100 feet Width Wetland Size > 1.16 acres Cowardin Classification Palustrine forested- shrub/scrub HGM Classification 0 Ri Wetland Ratin System Pts. Water Quality Score 24 Hydrologic Score 6 Habitat Score 21 Total Score 51 Wetland and Buffer I pact Summa ry Permanent 0.03 acre (< 3% of Wetland M) Wetland Impacts Temporary 0.02 acre Indirect 0 Buffer Impacts Permanent 0.56 acre Temporary 0.17 Dominant Vegetation Mature shrub/scrub vegetation will be impacted within the wetland. Primary species include Impacted willow, red -osier dogwood, and Douglas spiraea. Wetland buffer impacts will be limited to non-native grass species (reed canarygrass, tall fescue, velvet grass, and small clump of Scotch broom). Soils Series Impacted Alderwood san ravelly loam Hydrol2& Impacted De ressional wetlands- no indirect hydrology impacts anticipated Wetland Functions Impact Summary The portion of the wetland that will be impacted provides a small amount of water quality Water Quality functions due to interactions with the seasonally high water table which is the primary source of hydrologic inputs for it. The impacted portion of the wetland is not adjacent to Tributary 0016 and no anticipated effects to Tributary 0016 are anticipated. The impacted portion of the wetland does not store surface waters during normal years and Hydrologic has no direct connection with Tributary 0016. No hydrologic impacts are expected to occur from the erocosed wetland fill activities. Wetland M provides significant wildlife habitat, although the habitat value of the impacted portion of the wetland is significantly lower than the rest of the wetland due to its location. The impacted area is located approximately 50 feet from SR 18 and the buffer in this area is Habitat subject to periodic mowing and other disturbances. A small amount of habitat for resident and migratory birds and some small mammals likely will be lost with the loss of shrub/scrub habitat. The planned retaining wall in this area should alleviate noise impacts and reduce traffic fatalities for resident terrestrial wildlife. Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 I-5 — SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page 20 Tnhla R WatinnA N IrnnnrF Cnmmary Wetland Im acts SumrnaTy Sheet Local Jurisdiction City of Federal Way WRIA 10 Ecology Rating II[ Hrub 2004 Local Jurisdiction Rating III Local Jurisdiction Buffer 25 feet Width Wetland Size 0.20 acre Cowardin Classification Shrub scrub HGM Classification D Wetland Ratan tern Pts. Water Quality Score 18 Hydrologic Score 16 Habitat Score 10 Total Score 44 Wetland and Buffer impact Summary Permanent 0.20 (100%) Wetland Impacts Temporary 0 Indirect 0 Buffer Impacts Permanent 0 Temporary 0 Dominant Vegetation Mature shrub/scrub and medium aged forested vegetation will be lost because of the Impacted proposed wetland impacts. Dominant species include Douglas spirea, Nootka rose, red alder, black cottonwood, and thimbleberry. Buffer vegetation is limited to common mixed asture grasses and invasive scotch broom. Soils Series Impacted Alderwood sandy ravel) loam Hydrology Impacted Depressional wetlands- hydrologic impacts to the remaining portions of the wetland are expected. Mitigation calculations will assume that the entire wetland was directly impacted. Wetland Functions Im pact Summa ry The primary source of hydrologic inputs for this wetland is interactions with the seasonally high water table. It is anticipated that during storm events, the wetland could receive surface water inputs from the adjacent road fill slopes of SR 18. These surface waters would likely Water Quality be pollutant -laden, thereby providing the opportunity to improve water quality. However, little loss of water quality functions is anticipated, as the wetland has no defined outlet to discharge "treated" water. The wetland provides a limited amount of hydrologic benefits through impoundment of surface runoff from adjacent SR 18 slopes that would otherwise continue to flow downslope. Hydrologic The hydrologic benefits provide by the wetland are very limited due to its small size and limited retention potential. Wetland N provides little wildlife habitat outside of forage opportunities for resident and Habitat migratory birds and perhaps opportunistic hiding cover for small mammals. The wetland is too small and located too close to SR 18 to provide significant habitat value. 3.9 Wetland Buffer Functions Impacted Buffers are vegetated areas adjacent to an aquatic resource that can, through various physical, chemical, and/or biological processes, reduce impacts from adjacent land uses. Buffers also provide the terrestrial habitats necessary for wildlife that use wetlands to meet their life -history needs. Sheldon et al. (2005) identified the following buffer functions: e Water quality —Removing sediment, excess nutrients and toxics (bacteria, metals, pesticides) ■ Influencing the microclimate a Maintaining adjacent habitat critical for life needs of species that use wetlands Wetland Mitigation Plan I-5 — SR 161/SR 18 Triangle Improvements Project Washington State Department of Transportation BERGER/ABAM, FAPWT-04-064 February 2009 Page 21 • Screening adjacent disturbances (noise, light, etc.) a Maintaining habitat connectivity The project proposes to impact buffers that provide some of these functions. For this project, the forested buffers (0.29 acre) provide most of these functions, but herbaceous buffers (0.79 acre) provide only water quality functions (Table 9). All of the buffers filter stormwater runoff and help maintain the quality of water that reaches the wetlands. None of the buffers function to maintain habitat connectivity between wetlands because that connectivity is already blocked by I-5 or SR18. Forested wetlands alter microclimate by providing shade and screening the wind, while herbaceous buffers do not have the structure to shade or block the wind. In the Pacific Northwest, most wetland -dependent wildlife that use adjacent terrestrial habitats rely on forested areas for part of their lifecycle. Few, if any, wetland -dependent species in the Pacific Northwest rely on herbaceous buffer, especially along a highway, for critical life needs. Forested buffers can screen wildlife in the wetland from movement and light that could disturb breeding or feeding. Herbaceous buffers do not screen light or visible movement from wildlife using the wetlands. Table 9 below summarizes the wetland buffer impacts and the losses in wetland buffer functions that are anticipated. Table 9. Wetland Buffer Function lmQacts Permanent Buffer Vegetation Extent of Wetland Name Impacts (acres) Composition Anticipated Buffer Buffer Function Impacts Function Loss Wetland AB 0.23 Herbaceous Moderate Water quality Wetland M 0.56 Herbaceous Moderate Water quality Wetland P 0.12 Forested Moderate Wildlife habitat, water quality, vegetation diversity Wetland U 0.14 Forested I Low I Water quality CHAPTER 4— MITIGATION STRATEGY 4.1 Avoidance and Minimization of Wetland Impacts WSDOT has avoided and minimised impacts to wetlands and wetland buffers to the greatest extent practicable. During the design process, the project team used a two-phase WSDOT screening process to examine the different build alternatives as they were developed and analyzed. Eleven different build alternatives were analyzed during this process. The current build alternative was chosen for its top scores in minimizing environmental impacts as well as in four of the six categories that were reviewed. Total avoidance was not possible due to constraints associated with safety and design guidelines. By using site -specific design techniques —primarily mechanically stabilized earth (MSE) retaining walls to limit fill slopes and associated impacts —the project team was able to minimize critical area impacts. Adjacent to Wetland M, the project will construct a 10-foot high wall to limit fill slopes and resulting wetland impacts. The construction of this retaining wall will reduce wetland impacts by 0.15 acre. A retaining wall is also proposed along Wetland AB, also reducing wetland impacts. Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 I-5 — SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page 22 New stormwater detention and treatment facilities will treat and detain additional runoff created by new road surfaces and provide a higher level of treatment and detention for as portion of the existing road surfaces. Runoff from a total of 14.7 acres of new pavement and 34.10 acres of existing pavement will be treated and detained in accordance with the WSDOT Highway Runoff Manual M 31-16 (WSDOT, 2006) and the WSDOT Hydraulics Manual M 23-03( WSDOT, 2007). Ecology embankments or media filter drains, modified bio-infiltration swales, and detention/water quality ponds will provide water quality treatment, and the expansion of two existing detention ponds and the construction of two additional ponds and a detention vault will provide detention. These stormwater treatments will prevent incidental wetland impacts by providing/ supplementing the water quality functions of the wetland buffers. 4.2 Compensatory Mitigation 4.2.1 Mitigation Overview To prevent the loss of wetland and wetland buffer functions and values, the project includes comprehensive wetland mitigation measures such as creating wetlands and enhancing wetlands, riparian habitat areas, and wetland buffers. Temporary wetland and buffer impacts will be mitigated through restoration of impacted plant communities following construction activities. Permanent wetland and buffer impacts will be mitigated off site. An off -site 3.37-acre parcel (the Corrington site) will be the location of wetland mitigation. The Corrington site is approximately 2 miles southwest of the project site along South 364th Street. This rural residential lot is mostly undeveloped, except for a mobile home trailer and garage located in the northern portion of the property and a small pump house located in the east - central portion of the site. Much of the wetland on the Corrington site has been degraded by the establishment of invasive, non-native reed canarygrass, a species that can colonize wetland areas aggressively and out -compete native vegetation, ultimately resulting in the loss of wildlife habitat and vegetation diversity values. Removing this species and re-establishing a native plant community represents an opportunity for wetland enhancement. WSDOT has taken a watershed approach to mitigating wetland and stream impacts. The overall intent of the proposed mitigation is to preserve, protect, and enhance a significant contiguous wetland and wildlife corridor within the Hylebos Creek watershed. The Corrington site is close to other wetland and riparian habitat enhancement sites, and the surrounding area has not been subject to extensive development. Compared to potential on -site mitigation opportunities that would result in isolated enhancement projects in highly developed areas with limited wildlife habitat potential, the proposed off -site mitigation will provide a greater increase of wetland and wildlife habitat values for the watershed. The mitigation activities will restore temporarily impacted wetlands and buffers on site. Off - site, they will create a large contiguous tract of highly functioning wetlands and wetland buffers characterized by high amounts of native plant diversity and diverse fish and wildlife habitat. Table 10 below summarizes the mitigation activities for the Triangle project. Wetland mitigation for the proposed buffer impacts will take the form of increased storlwater treatment to replace lost water quality buffer functions and off -site buffer enhancement Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 I-5 — SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page 23 activities to offset the loss of a small amount of native vegetation and associated wildlife habitat functions. Project staff determined that off -site buffer enhancement in an area with a higher potential for wildlife usage would serve the watershed better than buffer enhancement in the project area The wildlife habitat potential for many of the wetlands and buffers in the project area is severely limited because they are close to the freeway and other high intensity developments. Table 10. Summary of Wetland Mitigation Measures Impacted Critical Area Corresponding Mltilation Temporary wetland and buffer impacts Restoration of affected areas within the road ROW Permanent wetland impacts Creation of additional wetlands, enhancement of existing wetlands on the Corrington site Permanent herbaceous wetland buffer impacts Added detention of project stormwater as part of a larger watershed approach Permanent forested wetland buffer impacts Wetland buffer enhancement on the Corrington site Riparian Area Impacts Enhancement of riparian area, creation of off -channel fish habitat 4.2.2 Regulatory Requirements Local Permits The City regulates wetlands and wetland buffers under Chapter 22 of the Federal Way City Code (FWCC). Under the FWCC, initiating construction activities that would impact wetlands or wetland buffers requires prior authorization. Federal Permits The project will result in direct impacts to wetlands under the jurisdiction of the Corps. Therefore, the applicant will apply for a Nationwide Permit (NWP) from the Seattle District of the Corps under Section 404 of the Clean Water Act. The project would likely be permitted under the guidelines of NWP 14 (Linear transportation projects). Under NWP 14 guidelines, formal mitigation to offset the planned wetland impacts will be required. State Permits Under the Nationwide Permit 14 guidelines, a Section 401 individual water quality certification from Ecology will be required, as will an HPA from WDFW because the proposed project will also include work below the ordinary high water mark (OHWM) of waters of the state. (All in - water work is addressed in a separate stream mitigation plan.) 4.2.3 Recommended Mitigation Ratios Wetland mitigation recommendations were determined using guidance from the Corps, Ecology, and the City code. Table 11 below summarizes the wetland mitigation ratios recommended by Ecology in Wetland Mitigation in Washington State — Part 1: Agency Policies and Guidance (Version 1) (Ecology et al., 2006a). These recommendations assume impacts occur to wetlands within a similar wetland category. Ecology guidance provides for the adjustment of ratios for an increase or decreases in category from the impact to the mitigation site. Ecology guidance also provides for the adjustment of mitigation ratios when either the probability of success is high or temporal impacts are low. Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 I-5 — SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page 24 Tahlc 11_ Recommended Mitigation Ratios for Proiects in Western Washington Category and Type of Re Rehabilitation Reestablishment or Re-establishment or Enhancement Wetland establishment Only Creation (R/C) and Creation (R/C) and Only or Creation Rehabilitation (RH) Enhancement (E) Impacts All other 3:1 6:1 1:1 R/C and 4:1RH 1:1 R/C and 12:1 Category II 8:1 E Category III 2:1 4:1 1:1 R/C and 2:1 RH 1:1 R/C and 8:1 4:1 E * Ecology et al. (2006a) According to the FWCC (City of Federal Way, 2005), the following standard ratios apply to creation/restoration/enhancement of wetlands disturbed by this project. ■ Shrub/scrub, Category II wetlands: 2:1 creation, 2:1 restoration, 4:1 enhancement ■ Shrub/scrub, Category III wetlands: 1.5:1 creation, 1.5:1 restoration, 3:1 enhancement only It should be noted, however, that the City's planning director has the authority to decrease wetland mitigation ratios (in no case will the minimum acreage replacement ratio be less than 1.25:1 as authorized in Section 22-1358(e)(3)) of the FWCC based on the following criteria: ■ Probable success of the proposed mitigation ■ Projected losses in functions and values >. Findings of special studies coordinated with agencies with expertise which demonstrate that no net loss of wetland functions or values is attained under an alternative ratio. Table 12 below summarizes the amount of creation required by the City. Table 12. Miti ation Area Re uired per City of Federal Wa C Code* Direct Creation or Restoration Enhancement Wetland Im acts Local Proposed Proposed Jurisdiction Area Ratios Creation Ratio''' Enhancement Wetland {acres] Cate o Area (acres) Area 00 II 0.03 1 2:1 0.06 4:1 0.12 111 0.20 1.5:1 0.30 3:1 0.60 Total 0.23 0.36 1 L 0.72 * Federal Way, 2005 4.2.4 Buffer Mitigation Wetland buffer requirements are regulated on a local level by the City. As per the FWCC, wetland buffer impacts for essential public facilities, public utilities, and other public improvements may be approved by the planning director. Buffer impacts were unavoidable fo*— the Triangle project based on the existing alignment of the roadways and current design limitations. The FWCC does not set out exact wetland buffer mitigation requirements when buffer impacts are authorized. 4.2.5 Surplus Mitigation The rn4tigat..ion project iS designed tC; have a Small ar.nount of surplus Ylus mitigation to address a.^. unforeseen wetland impacts associated with final design. These final design changes are often Wetland Mitigation Plan I-5 — SR 161/SR 18 Triangle Improvements Project Washington State Department of Transportation BERGER/ABAM, FAPWT-04-064 February 2009 Page 25 associated with utility boxes, utility lines, stormwater outfalls, or sign placement. By providing a surplus of mitigation, WSDOT will not have to redesign the mitigation site to address these impacts. WSDOT will notify regulatory agencies if impact areas should change as a result of redesign and if they wish to use the surplus mitigation. The Corrington mitigation site provides more buffer mitigation than is needed for the project. The surplus buffer mitigation provided includes upland buffer and wetland enhancement within paper buffers. WSDOT would like to preserve this buffer mitigation for use on future projects. Two likely projects include the SR 509 Freight and Congestion Relief Project and the SR 167 Stage 5 Project. Both have buffer impacts that are not fully addressed. Any use of the site for mitigation for any other WSDOT project would require regulatory review and approval. For the agencies to consider a project that might use the mitigation site, the project will have to follow avoidance and minimization procedures, provide a report of project impacts and mitigation, and evaluate functional replacement. CHAPTER 5— COMPENSATORY MITIGATION SITE 5.1 Site Location To prevent the loss of wetland and wetland buffer functions and values, comprehensive wetland mitigation activities will be completed off site on a parcel known as the Corrington property. The Corrington site is located approximately 2 miles southwest of the project site along South 364th Street with a street address of 933 South 346th Street (Figure 1). This gravel road serves as access to five single-family homes and terminates at a single-family residence approximately 400 feet west of the Corrington property. The property consists of two separate tax parcels (2921049110, 2921049081) totaling 3.37 acres. 5.2 Landscape Perspective 5.2.1 Landscape Position The US Geologic Survey (USGS) Poverty Bay topographic map of the area illustrates that the property is situated on the eastern edge of a large drainage basin that contains the West Branch of Hylebos Creek (USGS, 1997). The North Fork of West Hylebos Creek flows south along the western boundary of the site. In addition, a small perennial channel flows east across the central portion of the property, into a small man-made pond, and eventually outfalls to the North Fork via a small corrugated metal culvert. The Corrington site is in an area which has not been subject to the types of high intensity development that characterize the project area. Land use in the surrounding area is limited to low density residential developments, public parks, and urban open space. Large tracts of undeveloped forestland are located north and west of the property. 5.2.2 Ecologlcal Connectivity The Corrington site is located in the upper portion of the approximately 18-square mile Hylebos Creek watershed. Hylebos Creek eventually drains into the Hylebos Waterway and the navigable waters of Commencement Bay. Although the watershed is rather small, it was once a productive salmon rearing and spawning watershed. Unfortunately, the negative effects of Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 I-5 — SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page 26 urban development and deforestation have resulted in dramatic declines in salmonid numbers and an overall decline in water quality parameters. In the immediate area surrounding the Corrington site, the hydrologic conditions are characterized by large tracts of wetlands likely supported by high ground water tables, precipitation, and surface water inputs. Emergent, shrub/scrub, and forested wetlands are located to the north, south, and west of the Corrington site. In addition, several ponds with permanently open water are located on the Corrington property as well as in the immediately surrounding area. Based on the relatively undeveloped nature of the surrounding area, the Corrington site is located within a broad forested corridor that stretches roughly from South 348th Street all the way to the northern edge of Commencement Bay. Except for the occasional single-family residence and Highway 99, this corridor is relatively unbroken and serves as an important migration corridor for resident wildlife. 5.2.3 Historic and Current Land Use Like many forested areas adjacent to urban centers, the Corrington site and adjacent lands have been subject to timber harvesting activities. Federal Way was originally settled as a timber outpost in the early 1800s. It was not until the 1950s that the city began to transition from an economy based on natural resource extraction to one based on providing services. Therefore, the Corrington site and surrounding areas were likely subject to several cycles of timber growth and harvest. The Corrington site and adjacent lands are zoned as rural residential (R35) which equates to one single-family residence per 35,000 square feet. The property to the north of the Corrington site is designated as open space by the City (Spring Valley Open Space). Land south of the Corrington site is undeveloped wetlands. To the east and west, the mitigation site is bordered by low -density residential developments characterized by grasslands and small tracts of forestland. On a larger scale, the Corrington property is located within a large tract of undeveloped land owned by the City, WSDOT, and other public agencies. Figure 7 is an aerial photograph of the Corrington site and shows its relation to the forested areas of the watershed and the locations of publicly owned property slated for conservation that will remain as open space. The West Branch of Hylebos Creek subbasin has been the focus of several wetland and watershed improvement projects. These have included wetland restoration, fish enhancement and riparian habitat improvements. Their goal has been to restore and increase overall wetland and wildlife habitat functions within the West Branch of Hylebos Creek watershed. Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 I-5 — SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page 27 � � . t. • ilr �'� ..III i �y ' * � + _;L�_ rts ; • =; � r Ste: •t ��� ,,.�, •': AMN 5e3ected h itEga'tton Sst " 1 = Spnirg iMlley j ;? 1 f 5 ` - f ; • Y _ice---� r. EN 2, H iehos West Hy iebas East r f ._$�~._L . � I � 4�1ac ,r,. yam_: •. � ! �r��^"'Y-- r �•�' �'F �� a� fir. •'�[_J�.' _l �i,, '_: ti __ +�.•.�T'u 1 � ,may �•_. VF r r - r � ~~ , ' � ±. w �- � -. I... � - �_ _r►•' _� a ._. � ]'L"Tri{S �wL'i:'lY�:al -1 5.3 Rationale for Site Selection Before selecting the Corrington mitigation site, WSDOT biologists used a formal evaluation process to review a number of potential sites. Screening criteria of the review and selection process included: ■ Sites located in same sub -basin as impacts ■ Sites with adequate area for wetland and buffer mitigation ■ Sites with appropriate construction equipment access and equipment/materials storage capabilities ■ Sites located outside of WSDOT ROW ■ Sites that are not dominated by forested vegetation a Sites with an adequate source of hydrology ■ Sites capable of replacing wetland functions lost by roadway impacts Details of the preliminary mitigation site reconnaissance are provided in the WSDOT I-5 — SR 18/SR 161 Triangle Project, Wetland Mitigation Site Selection Preliminary Field Reconnaissance memo (WSDOT, 2006). Following the review of 11 different potential mitigation sites, a more detailed review of the mitigation potential of the Corrington site was conducted and a summary of these findings was supplied to WSDOT (WSDOT, 2007). The team subsequently chose the proposed mitigation site for its high potential for the successful design and completion of mitigation and because of thely— relatively low development and large tracts of forestland and wetlands that surround it. Thes increase the potential for wildlife habitat benefits by enhancing an existing vegetated corridor. In addition to the surrounding area's undeveloped nature, the property directly north of the site is designated as urban natural open space and is protected from further development activities. The mitigation site is also adjacent to the North Fork of West Hylebos Creek The existence of this creek, which is designated habitat for ESA -listed fish species, provides the potential to increase water quality benefits and off -channel habitat. The presence of permanently open water sources in the form of the man-made pond and associated inlet and outlet channels coupled with high water table elevations will ensure adequate wetland hydrology and a high potential for success for planned wetland creation areas. Lastly, dense stands of reed canarygrass have become established in most of the wetlands on the site. This invasive weed 1 species is outcompeting native emergent plant species, resulting in less plant diversity and loss 1 of wildlife habitat, and presents a prime opportunity for wetland enhancement. Because of its landscape position and the fact that the surrounding land use is limited to low - density residential development, the Corrington site has high potential for providing significant wildlife habitat functions. Compared to potential mitigation on the project site, on the Corrington site, enhancement efforts can be carried out that will complement the ongoing Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 I-5 — SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page 29 restoration efforts in the surrounding area. The combination will make for a more substantial increase of wetland and wildlife habitat values in the watershed. 5.4 Mitigation Site Existing Conditions WSDOT staff completed a preliminary wetland assessment of the mitigation site in November 2007 and BERGER/ABAM staff performed a routine wetland delineation of the site in spring 2008 (Appendix C). Development on the mitigation site is limited to a mobile home site and detached garage located in the northern portions of the property and a small pump house located in the east -central portion of the site. The mobile home sits on a broad shelf of obvious fill material that gently slopes down to what appears to be a constructed pond. The garage is located in the northwest corner of the property and is accessed by a narrow driveway constructed of a thin layer of gravel and fill material. Except for the areas immediately south of the man-made pond, mature trees are primarily located along the eastern and western boundaries of the property. BERGER/ABAM biologists delineated the wetlands on the Corrington site in May 2008, identifying one large Category I wetland in the central and southern portion of the property as well as a small Category IV wetland and a small portion of a Category H wetland located in the site's northern portion (Figure 8). 5.4.1 Uplands The only uplands located on the site are in the northern portions of the property close to the existing garage and mobile home. These portions of the property have been regularly maintained and are dominated by typical upland pasture grasses, scattered coniferous trees that include Douglas fir and western red cedar (Thuja plicata) and deciduous trees that include red alder, black cottonwood, bitter cherry (Prunus emarginata), and Oregon ash (Fraxinus latifolia). 5.4.2 Wetlands There are three separate wetlands within the Corrington mitigation site although all the proposed mitigation measures will take place within the largest — Wetland C, which is a small portion of a much larger depression/riverine wetland that includes emergent, shrub/scrub, and forested components. On the subject parcel, most wetland is emergent, although scattered red alder, black cottonwood, western red cedar, and a few Oregon ash trees are located along the western boundary of the wetland adjacent to the North Fork of West Branch of Hylebos Creek and immediately south of the man-made pond (Figure 8). Common pasture grasses and forbs subject to routine mowing characterize the wetland's northern portions, and the dominant vegetation here is limited to tall fescue, meadow foxtail, colonial bentgrass (Agrostis capillaris), reed canarygrass, common dandelion (Taraxacum officinale), English plantain, and creeping buttercup (Ranunculus repens). Figure 9 presents photographs of this area. This portion of the wetland receives hydrologic inputs from subsurface water movement and overland flow from adjacent slopes. The wetland boundary in this area was clearly identifiable through a marked change in soil saturation in conjunction with subtle changes in soil color. Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 I-5 - SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page 30 The southern portions of the wetland are dominated almost entirely by reed canarygrass, although a few small patches of soft rush (Juncus effusus, FACW+), Nootka rose (Rosa nutkana, FAC), Himalayan blackberry and Douglas spiraea are scattered throughout the wetland (Figure 9). Small upland islands were identified directly south and southwest of the man-made pond. Vegetation within the southwest upland island adjacent to the North Fork of West Branch of Hylebos is dominated entirely by Himalayan blackberry, while the upland island directly adjacent to the man-made pond is dominated by common mixed pasture grasses and forbs. Wetland Mitigation Plan I-5 — SR 161/SR 18 Triangle Improvements Project Washington State Department of Transportation BERGER/ABAM, FAPWT-04-064 February 2009 Page 31 Figure 8 ie-egs Mitigation Site Baseline Conditions l-5/SR 16I/SRIS Triangle Improvements bfitiption Site Boundary OEEVU%E Delineated Wetland Boundary ••• Culvw as.aaa� �� Sttemn 4 50 100 Feet Sling S&cmn t t 1 1 Pond inlet channel and pond -facing west Northern portion of Wetland C- Facing south Southern portion of Wetland C- Facing south Legend — — — Ddtneaedweamideoa,dry Draft Wetland Mitigation Plan I-5 — SR 161/SR 18 Triangle Improvements Project Washington State Department of Transportation North Fork of Flylebos Creek -facing south Corrington Site Photographs Figure 9 1-5 - SR 161/SR1S Triangle improvements BERGER/ABAM, FAPWT-04-064 August 2008 Page 22 The hydrologic source for Wetland C is a combination of interactions with the seasonally high water table and periodic flooding from the North Fork of West Branch Hylebos Creek. The southern portions of Wetland C appear to have a slightly higher degree of saturation and seasonal inundation owing to their lower elevation and reed canarygrass monoculture. At the time of the delineation, the southern portion of the wetland had higher levels of soil saturation between 2 and 8 inches from the surface. The northern portions of Wetland C are located at a slightly higher elevation and are not subject to seasonal flooding from the North Fork of West Branch of Hylebos Creek The northernmost portions of Wetland C form a lobe located on the moderate fill slopes that descend from the mobile home plateau in the northernmost portion of the site. The wetlands within this lobe likely receive hydrologic inputs from surface runoff in addition to subsurface flows. Based on the delineated wetland boundary in this area, subsurface flows east of the lobe may have been interrupted during site preparation and grading for the placement of the mobile home. The wetland buffers are primarily located in the northern portion of the site, as Wetland C extends all the way to the property boundaries to the south. Mixed non-native upland pasture grasses and forbs commonly associated with maintained lawn areas and pastures dominate the wetland buffers; invasive plant species in the buffer area are limited to a few scattered Canada thistle (Cirsium arvense) plants. 5.4.3 Streams/Surface Waters The North Fork of West Branch of Hylebos Creek enters the property after passing through a culvert under the graveled South 364th Street. The creek flows south along the western edge of the property for approximately 400 feet. Average water depths at the time of the site visits varied from 8 inches to almost 2 feet. The North Fork currently exists as one long riffle with little channel form diversity. Small -sized cobble and areas of sand/silt dominate the substrate. The other surface water feature on the property is a medium-sized man-made pond in its central portion. The pond receives water inputs via a small inflow channel that drains west from the adjacent property (Figure 4). The inflow channel has an average width of approximately 2.5 feet and an average depth of 1 foot. The input water comes from ground water discharge from the large wetland complex north and east of the Corrington property. Flow leaves the pond through an outflow channel similar to the inflow channel and eventually outfalls to the North Fork of West Branch of Hylebos Creek via a small corrugated steel culvert. Table 13 below summarizes information about the mitigation site wetland. Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 I-5 — SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page 34 Fable ll Mitigation Site Wetland Summary Location Tha southern and central portions of the property are dominated by the.. wetland. The wetland continues off site to the south, east, and west. Local Jurisdiction City of Federal Way WRIA 10 Ecology Rating Category I : (Hruby 2004) Federal Way Rating CategoryI Federal Way Buffer 200 feet Width Wetland Size 2.4 acres Cowardin Palustrine emergent Classification (PEM) HGM Classification Riverine/Depressional Wetland Rating System Pts. Water Quality Score 20 32 Hydrologic Score 19 Habitat Score 71 Total Score Dominant Vegetation Emergent in nature, most of wetland dominated by reed canarygrass Soils within the wetland vary depending on location. Most common soil profile was identified as silty clay loam material with soil matrices colors Soils of 10YR 2/1 This soil typically extended to depths of 18 inches. Below this level, soil matrices included the presence of common distinct 10YR 5 6 mottles. Hydrology Seasonally saturated, temporarily flooded Rationale for Local Rating Presence of ESA -listed salmonids = Category 1 rating as per the City of Federal way development code. The existing wetland provides wetland functions including flood flow attenuation, sediment removal, toxicant and nutrient uptake, habitat for Functions of Entire Wetland amphibians and aquatic invertebrates, and general fish habitat. Buffer Condition Buffers on the property are a mixture of forested areas and maintained lawn areas dominated by common non-native grasses and forbs. 5.4.4 Wildlife Habitat and Use The potential for wildlife usage of the site is largely a function of the rural nature of the property and the large tracts of adjacent open space (Figure 7). Vegetation diversity and structural complexity are relatively poor. Overall, vegetation is best characterized as uplands vegetated with common non-native pasture grasses and forbs and wetlands dominated by monotypic stands of reed canarygrass. Canopy -level trees are limited to a small row of trees adjacent to North Fork of West Branch of Hylebos Creek and a few scattered cottonwoods adjacent to the man-made pond. Shrub layer vegetation is limited to a few small stands of Nootka rose and Himalayan blackberry shrubs. Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 I-5 — SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page 35 The need for buffers around the Corrington site to ensure protection of wetland functions and values will affect the mitigation accounting for the project dramatically. Consultation with Rebecca McAndrew, Senior Scientist for the Seattle Corps, resulted in the determination that the Corrington site should have 75-foot buffer zones to prevent incidental impacts to the mitigation site. Because WSDOT does not own the adjacent properties and because these areas are subject to routine disturbance in the form of periodic mowing and traffic, the first 75 feet of the mitigation area adjacent to the east and west property lines will act as a paper buffer. The road 1 along the northern edge of the property is also a vector for disturbance and the first 75 feet of the property that adjoins the road will also act as a paper buffer. These paper buffers will protect the wetlands on the Corrington site, although the areas covered by them are themselves ] wetlands. Ms. McAndrew, in a January 15, 2008 email to WSDOT staff, stated that the wetland enhancement activities within the 75-foot paper buffers will not count towards eliminating the wetland mitigation debt as the wetland enhancement areas within them are not properly buffered. The enhancement areas within the paper buffers should be calculated as wetland buffer enhancement areas when determining mitigation credits generated by the project because the functions provided by the wetland enhancement areas within the paper buffers may be degraded by impacts from the adjacent properties. However, WSDOT will receive full credit for the wetland creation activities taking place within the paper buffers along the stream, although not for those within the paper buffer for the road. Wetland enhancement area and creation areas within the 75-foot paper buffers total 0.60 and 0.03 acre respectively (Figure 10). Therefore, WSDOT will get credit for completing only 0.77 acre of wetland enhancement (1.37 minus 0.60) and 0.28 acre of wetland creation (0.32 minus 0.04) for the purpose of mitigation accounting. The wetland creation and enhancement credits inside the 75-foot paper buffer (0.63 acre) will be counted as wetland buffer enhancements. Therefore, for the purposes of mitigation accounting, the project will receive credit for enhancing 1.67 acres of wetland buffer. In addition to the paper buffer calculations, it was agreed that WSDOT will get credit for f preserving the small upland forested island located immediately south of the pond. In addition to preserving the existing mature trees in this area, blackberry stands will be removed and the understory enhanced (Figure 10). This preservation credit will be calculated as wetland mitigation at a 5:1 ratio. Table 14 below explains the mitigation accounting for the project. The mitigation debt for each impact is zeroed out by the creation, enhancement, and preservation activities. The credit for each mitigation activity is calculated by dividing the area of each mitigation activity by the corresponding mitigation ratio. As per Table 14, the project will result in a surplus of wetland and wetland buffer mitigation credits. Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 I-5 — SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page 38 Table 14. Project Impacts and Mitigation Im act I Mitigation Type Area (ac) Debt Type Area (ac) Credit Ratio Credit Generated Balance Category II Wetland 0.03 -0.03 Wetland Creation 0.09 3:1 0.03 0 Category III wetland 0.20 -0.20 Wetland Creation 0.19 2:1 0.10 + 0.01 Wetland Enhancement 0.77 8:1 0.10 Upland Preservation 0.06 5:1 0.01 Forested Buffer 0.26 1 Buffer Enhancement 1 1.6 1 1:1 1.67 6.2 Mitigation for Temporary Impacts Mitigation for the temporary wetland and wetland buffer impacts that will result from the necessary clearing and grading activities will take place on site. This mitigation will restore the areas to their original condition by planting trees and shrubs and reseeding herbaceous vegetation. Only native species suited for the conditions of each individual restoration area will be planted/seeded. 6.3 Mitigation for Permanent Impacts WSDOT will mitigate for permanent impacts to wetlands using standard mitigation ratios (Table 14 and Ecology 2006). The mitigation plan includes creation of additional Category I wetlands, enhancement of wetlands, and enhancement of wetland buffers that will occur at the Corrington site and these are shown individually below. This results in an increase in wetland quality from impacts primarily to Category III wetlands with creation and enhancement of Category I wetlands. Water quality treatment to mitigate for buffer impacts to herbaceous buffers will occur as part of the larger watershed approach to mitigation. Lastly, the Corrington mitigation site includes stream mitigation, including off -channel fish habitat and riparian enhancement. 6.3.1 Wetland Creation The primary wetland mitigation measures will consist of wetland creation and wetland enhancement. The wetland creation activities will increase the amount of Category I wetlands on the site by 0.32 acre (Figure 10). Wetlands will be established through excavation of upland areas in order to lower the base elevation sufficiently to induce interactions with the seasonally high ground water levels. Excavation amounts range from 6 inches to 4 feet. Grading and construction sheets for the Corrington site are provided in Appendix D of this report. Four separate areas, totaling 0.32 acre, will be created within the mitigation site. Two creation areas adjoin the permanently flowing waters of the man-made pond and outflow channel. In addition to these two areas, the area previously covered by the garage and driveway will be converted to wetlands and a small section of the off -channel fish habitat channel will pass through a small section of upland (Figure 10). The largest creation area is located directly north of the man-made pond. Wetlands in this area will be created through excavating down to a level that will induce prolonged saturation and seasonal flooding (Sheet EV3, Appendix D). The proposed excavation will create a broad flat bench that begins at the elevation of the water level within the man-made pond. From this Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 I-5 - SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page 39 point, the created wetland will gradually rise, eventually matching the existing grade of the hillside (Sheet EV3, Appendix D). The second creation area is located north of the outflow channel (Sheet EV3, Appendix D). This creation area was designed so that all surface waters would drain back to the pond, thereby preventing stranding of fish that enter the creation area during flood events. All of the creation areas will receive hydrologic inputs through surface runoff, capillary saturation of soils from adjacent open waters, and periodic flooding. The northernmost wetland creation area will receive hydrologic inputs from seasonally high ground water interactions and through surface runoff from adjacent slopes. To increase shading of surface waters and increase wildlife habitat values, native emergent, forest and shrub/scrub plant communities (deciduous and coniferous trees) will be planted in these wetland creation areas. The wetland creation activities will offset some of the losses due to impacts to wetlands M and N by increasing the following wetland functions: native plant richness, nutrient and toxicant uptake and sequestration, production and export of organic matter, flood flow alteration, and habitat complexity and diversity. 6.3.2 Wetland Enhancements Enhancement of existing wetlands will be the largest form of mitigation on the site, with the project removing invasive vegetation and establishing a diverse native plant community to enhance a total of 1.37 acre (0.77 beyond the paper buffer, with 0.60 acre within the paper buffer) (Figure 10). Wetland enhancement activities will result in an increase in wetland functions, thereby eliminating the remaining amount of wetland mitigation debt. Wetland enhancement will take place in the southern portion of Wetland C where reed canarygrass has become established and in the northern section of Wetland C that is dominated by emergent vegetation. The invasive weed control section below discusses invasive weed eradication and control methods. Ultimately, the enhancements will establish a complex matrix of emergent, shrub/scrub, and forested wetland plant communities with a high degree of vegetative interspersion. The enhancements are projected to increase numerous functions (native plant richness; habitat complexity and diversity; sediment capture; habitat for amphibians, mammals, and birds; and production and export of organic material) and to reduce the source of invasive seeds for downstream watersheds. 6.3.3 Wetland Buffer Enhancements In addition to the various wetland creation and enhancement activities described above, the mitigation strategy includes 1.03 acre of wetland buffer enhancements (Sheet EV5, Appendix D). The buffer enhancements will increase wetland buffer and riparian buffer functions along the North Fork of West Branch of Hylebos Creek and offset the impacts to 0.26 acre of permanent forested wetland buffers in the project area. Enhancements will install a native forested plant community and habitat improvement structures, such as LWD and wildlife habitat brush piles. These enhancements will increase wetland buffer and wildlife functions by increasing plant diversity, foraging and nesting habitat, overall habitat complexity, and plant structure diversity. Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 I-5 — SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page 40 6.3.3 Wetland Buffer Preservation A small (0.06 acre) upland island located immediately south of the man-made pond is currently vegetated with mature trees with an understory of native and non-native shrubs. This area will be preserved, the non-native plants removed, and the understory enhanced through the planting of native woody shrub species (Figure 10 and Sheet EV, Appendix D). 6.3.4 Stormwater Treatment and Control To mitigate for the loss of 0.79 acre of herbaceous wetland buffers and their associated water quality functions, the project will provide water quality and stormwater control for 34.10 acres of existing I-5 and SR 18 impervious surfaces. This infrastructure will collect and treat pollutant -laden surface runoff that would otherwise enter the wetlands and buffers. Therefore, the water quality functions that these buffers currently provide will be augmented/replaced by the construction of stormwater collection, treatment, and detention facilities. 6.3.5 Off -Channel Fish Habitat Creation To mitigate for the lack of fish passage improvements along Tributary 0016A, in -lieu mitigation will be performed at the Corrington site. Because of the low base flows and flashy nature of Tributary 0016A and the poor habitat of the stream reach above the existing fish barriers, removing the existing fish barriers will not improve conditions for fish species significantly. Therefore, the project will create off -channel fish habitat in the southern portion of the site in the form of a permanently flowing channel (Sheet EV3, Appendix D). Since the Corrington site adjoins the North Fork of West Branch of Hylebos Creek, which has better habitat than tributaries 0016 and 0016A, the added channel will be a greater benefit to fish species than removing the fish barriers on tributaries 0016A and 0016. New off -channel habitat will increase the amount of available fish habitat in the reaches of North Fork of West Branch of Hylebos Creek used by anadromous and other resident fish species. The project will excavate a channel averaging 3 feet wide and 2 feet deep in the wetlands (Sheet EV3, Appendix D). Sheet EV4 of Appendix D details the proposed cross-section of the stream. Water depths within the channel are expected to be relatively constant between 18 and 24 inches. This channel will start near the pond outfall channel in the central portion of the Corrington site, meander through the enhanced wetlands, and ultimately outfall to the North Fork of West Branch of Hylebos Creek (Figure 10). The channel will receive flows that currently flow through the pond outfall channel and outfall to the North Fork of West Branch of Hylebos through a small corrugated culvert. The water source for the pond is perennial and is composed of cool and clean ground water discharges from the wetlands east and north of the project site. This water source flows year round and water levels were observed to remain constant throughout the year. The proposed channel and wetland creation areas adjacent to the pond are not anticipated to change the level of water in the pond. The outflow channel will be created in wetland areas where the soils are listed as Shalcar muck Shalcar muck soils are moderately permeable soils that are very poorly drained and high in organic content. Soil samples taken during the wetland delineation of the Corrington site confirmed the presence of Shalcar soils within the channel creation areas. The upper 5 to 10 inches of the soil are very high in decomposed organic matter mixed with a matrix of silt loam Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 I-5 — SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page 41 material. Deeper in the soil profile (below 12 inches), the soil transitions to a sandy loam material with inclusions of clay. Below approximately 18 inches, the soil is a mixture of sandy silt loam and sandy clay loam more similar to Snohomish silt loam soils that are listed by the NRCS as a minor component to the Shalcar series. The proposed channel will result in excavation within the wetland areas to depths approaching 3 feet (Appendix D, sheet 3). It is anticipated that the dominant material within the created streambed will be the clay loam material encountered below 18 inches. Erosion is not expected within this soil due to the very low overall slope of the created channel (0.98%). The construction of the channel will be completed in stages in coordination with the grading and other enhancement activities. Following the mowing and spraying of the reed canarygrass stands, the grading of the stream channel will be completed in conjunction with the other required grading on the Corrington site. The beginning and end of the stream channel will be isolated from the surface waters of the pond and North Fork of West Branch of Hylebos with temporary cofferdams constructed from plastic sheeting and sandbags. Once herbaceous vegetation has become established within the creation areas minimizing the risks of erosion, the cofferdams will be removed and surface waters allowed to flow through the new channel. The last stage of the channel construction will be the removal of the existing culvert on the pond outflow channel. A small backhoe or similar equipment will remove the existing culvert, and the area previously occupied by the culvert will be backfilled with compacted soil. Prior to removal, the area will be isolated with cofferdams similar to those used for the new stream channel. This plan will allow surface waters to continue to circulate through the pond while at the same time providing valuable off -channel habitat for resident and migratory fish. It is anticipated that, over time, the backwater area between the entrance to the created channel and the old location of the culvert will silt in as suspended sediment settles out. The open water channel will make it easier for fish to access the resting and feeding opportunities in the pond. To enhance the amount of available fish habitat within the pond, several large softwood logs will be placed within it. In addition to providing egg laying opportunities for amphibians and basking habitat for turtles, these logs will provide cover opportunities for fish. When the channel is constructed, the project will plant the floodplains adjacent to it with native wetland emergent vegetation. These plantings will increase water quality functions by trapping sediment during high flow events. The plantings also will increase exports of insects and organic matter to the stream. Creating the channel and enhancing the pond will add or enhance 0.19 acre of off -channel fish habitat. It should be noted that the construction of the fish channel will result in the creation of 0.01 acre of new riverine wetland and the conversion of 0.05 acre of palustrine emergent wetlands to riverine wetlands. 6.3.6 Riparian Area Enhancements To mitigate for the negative effects of lost riparian area, the entire riparian area east of the North Fork of West Branch of Hylebos will be enhanced (Figure 10). Because of the location of the wetlands and wetland buffers on the site and the overlapping nature of their setbacks, the Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 I-5 —SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page 42 riparian enhancement area is composed of wetland creation areas, wetland enhancement areas, and wetland buffer enhancement areas (Figure 10). For the purposes of accounting, the riparian area was presumed to extend 100 feet from the OHWM of the North Fork of West Branch of Hylebos Creek. The total amount of riparian area that will be enhanced equals 1.08 acres. 6.4 Site Hydrology The hydrologic source for the existing wetlands on the site is interactions with the seasonally high water table; for the wetlands adjacent to the surface waters on the site, the source is periodic flooding from the North Fork of West Branch Hylebos Creek. These sources of wetland hydrology will not be altered by the proposed mitigation activities. Data collected during the delineation of the Corrington site wetlands reveled soil saturation levels that ranged from the surface to a depth of 8 inches. Depth to standing water ranged from 12 to 18 inches in wetland sample plots. The current hydrologic regime for the existing wetlands on the site (that will be enhanced) is best described as semi -permanently saturated to seasonally flooded. Hydrology for the wetland creation areas will come from surface runoff from adjacent slopes, capillary saturation of soils from adjacent open waters, and interactions with ground water. The entire site sits in an area with high ground water levels. Test wells were dug within the anticipated wetland creation areas in January of 2009 to record standing water elevations. The location of these wells and the observed standing water levels are provided in Sheet EV3 of Appendix D. In general, standing water was observed within 2-3 feet of the surface of the soil within the creation areas. Based on the results of the sample wells, winter ground water elevations appear to be approximately 81 feet. Although a decrease in the elevation of the water table is expected to occur during the latter portions of the summer months, the fairly static water level within the pond, presence of large amounts of springs in the general vicinity of the project area, and saturated soil conditions observed during the summer within wetland areas dictates that fluctuations of ground water levels will be fairly minimal. With ground water elevations generally occurring at 81 feet, the excavation within the creation areas was designed to create hydrologic regimes that will include seasonally saturated, semi - permanently saturated, and seasonally flooded. The existing water sources flowing through the man-made pond will supply hydrology for the planned perennial, off -channel habitat. After the channel has been graded, the existing culvert will be removed, allowing the pond's surface waters to drain through the created channel and eventually outfall to the North Fork of West Branch of Hylebos in the southern portion of the project area. The dimensions of the created channel are similar to the existing pond outlet channel (Sheet EV3 and EV4, Appendix D). Based on the designed volume, the created channel will flow year-round and be subject to periodic flooding. 6.5 Invasive Species Control Strategy Invasive reed canarygrass dominates the entire wetland enhancement area. This aggressive colonizer of wetland areas reproduces by both seed and rhizome, making its control difficult. Without continued annual application, chemical control is not very effective and the annual Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 I-5 — SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page 43 application of broad-spectrum herbicides can damage mitigation plantings. Therefore, a comprehensive eradication plan will be executed. Physical as well as chemical control methods will be used to eliminate reed canarygrass from the site. At a minimum, WSDOT will remove the reed canarygrass by mowing and spraying with herbicide. Typically, this involves mowing followed by spraying, followed by another mowing and another spraying. Excavating the top foot of soil and roots, which was considered, was rejected because the site's soils, especially when wet, are unsuitable for the extensive use of heavy equipment. All herbicide application will be completed by a qualified professional to minimize overspray. All applicable WSDOT guidelines for applying herbicides will be followed WSDOT is considering using tarps, but questions remain about whether there is enough time in the schedule. With this option, heavy tarps will remain in place for an entire growing season as the principal method of reed canarygrass elimination. Installing the tarps will prevent light and water from reaching the stands of reed canarygrass and will cause elevated soil surface temperatures that should result in increased mortality to reed canarygrass seeds and rhizomes. If the tarps are used, the sequence of controls will be as follows: 1. Mow all reed canarygrass stands in early spring (March) to expose new growth. 2. Spray all new growth with an appropriate concentration of glyphosate. 3. Following the excavation of the new stream channel, install heavy tarp material over the entire enhancement area that is infested with reed canarygrass. 4. Keep tarps in place and inspect them periodically throughout the summer. 5. Remove the tarps in the early spring of the following year and hydro -seed the entire area with a native emergent wetland seed mix. 6. Complete the woody enhancement planting in the early spring as conditions permit. All herbicide application will be completed by a qualified professional to minimize overspray. All applicable WSDOT guidelines for applying herbicides will be followed. The tarp material that will be used must be sufficiently thick and constructed to prevent solar degradation and subsequent failure of the material. All tarps should be at least 50 feet by 50 feet and installed with at least 5 feet of overlap. Tarps will be secured with sandbags or similar material so that the tarps are not affected by the wind and the pressure of the growing reed canarygrass. No stakes or similar hold-down devices should puncture the tarps. Darker tarps are preferred to maximize the temperature beneath them. Blackberry patches in the mitigation site will be removed using hand or mechanical methods. The work will include removing the entire root mass of the shrubs while minimizing ground disturbance to the greatest extent practicable. Future invasive species control will include monitoring and the methods specified in the monitoring and maintenance section below. 6.6 Grading Design The project team determined the proposed grades for the mitigation site by analyzing soil test pit data collected during the delineation, measuring surface water elevations during several site Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 I-5 — SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page 44 visits, and correlating this data with 2-foot contour maps. The dominant soil type within the wetland enhancement and creation areas is very poorly draining Shalacar muck Soil samples revealed clay/silt loam soil texture with large amounts of decaying organic matter and a soil matrix color of 1OYR 2/1. The depths of this soil within the enhancement site range from 12 to >18 inches. Based on the excavation depth of 12 inches in the enhancement areas, the remaining soils should be of suitable depth and texture to support the enhancement plantings (Sheets EV5 and EV7, Appendix D). The enhancement area will have a hydroperiod that is primarily semi - permanently saturated with areas experiencing seasonal inundation. Following the proposed grading, the contractor will cover all graded areas with a 3-inch layer of mulch to inhibit weed establishment and nourish future plantings. No additional soil amendments should be necessary. The wetland creation areas will be graded to the contours shown in Sheet EV3 of Appendix D. This elevation will allow seasonal inundation of the created wetlands from the adjacent open water sources of the man-made pond and outflow channel. The only other areas of the mitigation site that will require earthwork or soil manipulation are those close to the existing trailer home and garage. The areas directly north of the garage have been compacted by vehicle traffic and small amounts of gravel. The gravel areas around the mobile home are similarly highly compacted and probably not conducive to establishing trees and shrubs. In order to prepare these buffer enhancement areas for planting, any gravel material and the upper 3 inches of topsoil will be graded away and removed from the site. Afterward, the contractor will spread 4 inches of compost evenly over the area, till the compost into the upper 12 to 18 inches of the soil, and dress the exposed areas with 3 to 4 inches of mulch. A native forested plant community is identified in the planting section below. 6.7 Planting Design The plan calls for planting several different plant communities in the wetland creation and wetland enhancement areas. Plant communities were chosen based on soil and anticipated hydrologic conditions. The dominant soil type within the wetland enhancement and creation areas is very poorly draining Shalacar muck. Soil samples revealed clay/silt loam soil texture with large amounts of decaying organic matter and a soil matrix color of 10YR 2/1. The depths of this soil within the enhancement areas range from 12 to >18 inches. Since only minor excavation to produce several small hummocks will occur within the enhancement area, the existing semi -permanently saturated hydroperiod will be maintained while the hummock areas will likely experience seasonal inundation. Following the proposed grading, the contractor will cover all graded areas with a 3-inch layer of mulch to inhibit weed establishment and nourish future plantings. No additional soil amendments should be necessary. Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 I-5 — SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page 45 The wetland creation areas will be graded to the contours shown in Sheet EV3 of Appendix D. Based on observed ground water levels, these elevations will create hydroperiods ranging from seasonally inundated to seasonally ponded. The creation areas adjacent to the man-made pond will receive hydrologic inputs from surface water as well as interactions with seasonally high ground water levels. Soil test pits in this area indicated the presence of highly organic muck soils to depths of 48 inches. Soil amendments will not be required in the creation areas adjacent to the pond for proper seed establishment/plant growth. Tables 15 and 16 list the contents of the wetland emergent seed mix and the woody vegetation species that will be planted throughout the creation and enhancement areas. Table 16 and provide details on woody vegetation species that will be installed within the wetland buffer enhancement areas. Sheet EV5 of Appendix D shows the boundaries and locations of each specific vegetation community. Tahla 15. Seed Mix for Wetland Creation Areas Common Name Scientific Name % composition of Mix Slough Sedge Carex obnupta 35% Small -fruited Bulrush Scirpus mlcrocarpus 25% Saw Beaked Sedge Carex stipata 20% Slender Rush Juncus tenuis 10% Spike Rush Eleocharis palustris 10% Tahiw U. Plant LLst Pronosed for Wetland Creation and Enhancement Areas Common Name Scientific Name L Indicator Status Emergent Wetland Community (PEM) Small -Fruited Bulrush Scirpus microcarpus OBL Hardstem Bulrush Scirpus acutus OBL Awl Fruited Sedge Carex stipata OBL Scrub -Shrub Wetland Community (PSS) Nootka Rose Rosa nootkana FAC Scouler Willow Salix scoulerana FACW Pacific Willow Salix lasiandra FACW Pacific Ninebark Physocarpos capitatus FACW W. Crab Apple (Pyrus fusca) FACW Black Twin berry (Lonicera Involucrata) FACW Salmonberry Rubus spectabalis FAC Forested Wetland Community (PFO) Black Cottonwood Popu/us balsamifera ssp. trichocarpa FAC Oregon Ash Fraxinus latifolia FACW Western Red Cedar Thuja plicata FAC Pacific Willow Salix lucida FACW+ Douglas Hawthorn Crataegus douglasii FAC Scouler's Willow Salix scouleriana FAC Pacific Ninebark Physocarpos capitatus FACW Salmonberry Rubus spectabalis FAC Nootka Rose Rosa nootkana FAC Red -osier Dogwood Cornus sericea FACW+ Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 I-5 — SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page 46 Table 17. Plant List Proposed for Upland Buffer Enhancement Areas Common Name Scientific Name Western Red Cedar ThuJa plicata Black Cottonwood Populus balsamifera ssp. trichocarpa Red Alder Alnus rubra Douglas Fr Pseudotsuga menziesii Big Leaf Maple Acer macrophyllum Vine Maple Acer circinatum Evergreen Huckleberry Vacinium ovatum Snowberry Symphoricarpus alba Ocean Spray Holodiscus discolor Serviceberry Amelanchier alnifolia Cascara Rhamnus purshiana Beaked Hazelnut Corylus cornuta Tall Oregon Grape Berbaris aquifolium Indian Plum Oemleria ceraslformis 6.8 Habitat Features The plan describes three habitat features: LWD, snags, and wildlife habitat brush piles. 6.8.1 Large Woody Debris LWD will be placed within the wetland and wetland buffer enhancement areas and the man- made pond to provide cover, food, and breeding habitat for small mammals, amphibians, and insects (Sheet EV3, Appendix D). All LWD will be at least 20 inches in diameter at the butt end and at least 15 feet long. If possible, root wads should remain on the LWDs. This plan includes the placement of a minimum of 10 pieces of LWD in the buffer area. Several LWD pieces will be placed in a way that will protect the outside banks of the perennial channel. In addition, at least two LWD pieces will be placed in the man-made pond. A qualified biologist will be on site to supervise the placement of LWD. 6.8.2 Snag To provide habitat for cavity nesting birds and mammals, four upright snags will be installed in the mitigation area. They will be at least 16 inches in diameter and at least 20 feet long. The plan calls for placing snags upright in an excavated hole with a depth that is approximately equal to one -quarter of the total length of the snag, backfilling the hole with native material, and compacting the soil to ensure stability of the snag. Snag locations will be determined in the field at the time of installation by a qualified biologist.. To avoid property damage, the installer should exercise best professional judgment in the field during installation Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 I-5 — SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page 47 6.8.3 Wildlife Habitat Brush Piles To further increase available habitat for small mammal and insect populations, the project team will oversee the construction of five brush piles in the mitigation site to provide cover from predators, assist thermal regulation, provide nesting areas, and increase insect populations for 1 birds and other insectivores. Brush piles will be at least 10 feet in diameter and 5 feet high and constructed of native woody debris layered in a criss-cross pattern with the largest debris on the bottom and smallest debris set on top. Typical Brush Pile Bottom Typical Brush Pile Top _1 1 The illustrations above are a general guideline. To ensure proper construction and placement, brush pile construction in the field will be assisted by a qualified biologist. 6.9 Buffers To increase wetland buffer functions, the project will install a native forested plant community in the buffer enhancement area. The buffer width in the project area varies from 60 feet along the western boundary of the wetland to 150 feet along the northern portion of the existing and created wetlands (Figure 10). These buffer widths are consistent with the existing conditions of the site. Upon maturation, the forested plant community described in Table 16 will result in a structurally and species -diverse vegetation community typical of the Western Cascades bioregion. Project scientists observed similar plant communities in upland areas that have not been subject to recent land use disturbances. The team has not yet determined the specific abundance numbers and community composition of this forested plant community, but anticipated spacing for woody vegetation will be 5-foot centers or less. The proposed enhancements will increase wildlife habitat, support characteristic vegetation, l provide thermal regulation, and assist production/export of organic material. 6.10 Site Protection To protect the site from future development, the entire parcel will be placed in a conservation j covenant running with the land. WSDOT anticipates placing a three -wire fence on the north, west, and south sides to limit human disturbances, neighbor encroachment, and dumping. The stream side of the property will not be fenced. 6.11 Implementation Schedule l The site preparation and installation of erosion control BMPs will be the first steps in J completing the proposed mitigation. Sheet EV1 and EV2 in Appendix D presents information Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 I-5 — SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page 48 about site access, staging areas, and erosion control. The existing gravel access drive in the northern portion of the site will provide access to the site, while establishing a temporary path along the site's eastern boundary will give access to the wetlands in the southern portion of the site. A large steel plate will facilitate crossing the pond inlet channel. Grading of the mitigation site will begin during the spring/summer and will last for approximately 3 weeks. The site will be prepared and the soil remediated in the northern portions of the property after grading has been completed. The installation of the proposed wildlife habitat enhancement features will follow grading. Afterwards, the contractor will cover all bare ground in the mitigation site with a 4-inch layer of weed -free mulch and hydro -seed the wetland creation, enhancement, and restoration areas with the specified seed mixes. Hydroseeding mixes will contain appropriate amounts of tactifier to ensure proper seed adhesion through fall and winter precipitation events. Lastly, the contractor will install woody vegetation and aquatic plugs in the locations specified in the planting plan (Sheet EV5 and EV7, Appendix D). Woody vegetation will be planted between December 1 and March 31 when plants are dormant. 6.12 Ecological Benefits 6.12.1 Wetland Functions The mitigation design will create a total of 0.32 acre of Category I wetland and restore and enhance a total of 1.37 acres of Category I wetlands now dominated by invasive species. These activities will improve water quality, hydrologic, and habitat functions (Appendix E). Functional attributes of the mitigation wetlands that will be improved and added compared to the existing impacted wetlands are shown in Table 18. The table shows which functions and values will be present at the mitigation wetland as well as which type of mitigation provides which functions. For this table, the off -channel habitat creation was treated as wetland creation. Table 19 compares, in more specific terms, the characteristics of the wetland and buffer areas of the impacted versus mitigation sites. Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 I-5 —SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page 49 Table 19. Wetland Functions Provided by Various Areas of the Mitigation Site Function/Value Creation Enhancement Flood Flow Alteration + + Sediment Removal + + Nutrient and Toxicant + + Removal Erosion Control & Shoreline x + Stabilization Production & Export of + + Organic Matter General Habitat Suitability + + Habitat for Aquatic + Invertebrates Habitat for Amphibians + + Habitat for Wetland- + Associated Mammals Habitat for Wetland- + x Associated Birds General Fish Habitat + Native Plant Richness + + Educational or Scientific Value Uniqueness and Heritage a "-" means that the function will not be present; "X" function will be present and will be of high quality. means that the function will be present is of low -quality; and "+" means the T..r.i.. 4 a n.,... —ii—n ni 1—ny&+o ri WaHnndc and RuffPrs to Mitigated Wetlands and Buffers Item Typical Wetland Impact' MItl ation Site Functions Improved Wetland Dominant Reed canarygrass Native species Wildlife habitat, support of Vegetation characteristic vegetation Geomorphic Adjacent to highway Adjacent to stream Higher wildlife habitat potential Setting Habitat Moderate Interspersed emergent, General, bird, amphibian, and Interspersion scrub -shrub, and forested mammal habitat habitats Species Relatively low within impact Diverse -several General, bird, amphibian, and Richness area dominants in each habitat mammal habitat Vegetative Shrub/scrub Trees, shrubs, emergent General, bird, amphibian, and Structure vegetation mammal habitat Buffer Width Narrow -subject to mowing Range from 60 to 150 All buffer functions improved adjacent to impact area. feet Vegetative Moderate -shrub -scrub and Trees, shrubs, and Screening and cover, increased Structure emergent emergent layer sediment capture Species Low -approximately four Diverse -several Habitat Richness I species in impact area. dominants in each habitat Wetland Mitigation Plan I-5 - SR 161/SR 18 Triangle Improvements Project Washington State Department of Transportation BERGER/ABAM, FAPWT-04-064 February 2009 Page 50 6.12.2 Stream and Riparian Functions Stream and riparian functions will be improved by enhancing the wetlands adjacent to the stream and the riparian buffers on the site and creating off -channel fish habitat Establishing a native forested plant community within the wetland and riparian buffer enhancement areas will provide a large amount of riparian functions. Upon maturation, this plant community will lower surface water temperatures by preventing direct solar radiation, create a cool microclimate within the riparian area, increase woody debris and nutrient inputs to West Branch of Hylebos Creek, increase water quality parameters during storm events through entrainment of sediments, and increase the amount of wildlife habitat through a more structurally and species diverse vegetation community. In addition, the proposed surface water channel will increase stream functions by increasing the amount of off -channel habitat available for migrating salmonids. Creating the channel and channel side floodplain areas also will increase habitat for a variety of macro -invertebrates, and this habitat will be further enhanced with LWD and habitat brush piles in the riparian floodplain areas. 6.12.3 Buffer Functions Common non-native grasses and forbs characterize the wetland buffers on the site. The installation of a native forested plant community and the construction of wildlife habitat structures in the form of snags, brush piles, and LWD placements will enhance these buffers. The mitigation site has the potential to provide a wide variety of wetland buffer and wildlife habitat functions. This potential is largely a function of the site's location in a relatively undisturbed vegetation corridor, its closeness to different wetlands and open waters, and its adjacency to the North Fork of West Branch of Hylebos Creek. The installation of the forested plant community and wildlife enhancements will help the wetland buffers reach their full functional potential. Dense woody vegetation plantings will better screen adjacent land uses and associated disturbances and create a more structurally diverse vegetation community, which in turn will provide more habitat for a wider variety of species. The eventual canopy layer will help induce a cool microclimate adjacent to the stream and lower overall surface water temperatures; these effects also will increase wildlife habitat values by providing opportunities for thermal regulation. Creating a forested floor with a thick layer of leaf litter and many woody stems will increase water quality values, decrease surface runoff during storm events, and trap sediments that otherwise could enter the surface waters of the site. Lastly, the proposed snags, brush piles, and placement of LWD will directly benefit a wide variety of birds and small mammals that use the area by providing feeding, nesting, perching, and denning opportunities. Wetland Mitigation Plan BERGER/ABAK FAPWT-04-064 1-5 — SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page 51 CHAPTER 7 — MITIGATION GOALS, OBJECTIVES, AND PERFORMANCE CRITERIA 1 The proposed mitigation site will be monitored for 10 years to demonstrate that the intended goals and objectives are established. Goals describe the overall intent of mitigation efforts, and objectives describe individual components of the mitigation site in detail. Performance measures and standards describe specific on -site characteristics that indicate a function is being provided. Performance measures are intermediate steps used to guide management of the mitigation site. Performance standards are the finish line used to evaluate compliance with I regulatory permits in the final year of monitoring. Contingency plans describe what actions can ` be taken to correct site deficiencies. WSDOT uses the adaptive management process to improve mitigation success. Adaptive management involves learning'from monitoring and implementing management activities, such as implementing parts of the site management or contingency plans. Information from monitoring is used to direct subsequent site management activities. 7.3. Goals The goal of the proposed mitigation is to ensure that no net loss of wetland functions and values occurs as a result of the proposed wetland and buffer impacts. 1 7.2 Objectives The plan proposes to reach the goal by achieving these objectives: 1. Increase wetland area at the mitigation site by excavating upland area to create an 1 additional 0.32 acre of wetland. 2. Enhance 1.37 acres of emergent wetlands degraded by a dense monoculture of invasive reed canarygrass. 3. Enhance 1.03 acres of wetland and riparian buffer area through the installation of a native forested plant community. 4. Preserve and enhance 0.06 acre of existing forested wetland buffer. 1 5. Improve hydrologic functions by increasing wetland area and flood storage capacity, 1 extending wetland hydroperiod, and increasing cover of woody vegetation 6. Improve water quality functions by increasing wetland acreage, adding additional vegetation classes, and increasing the connectivity of wetlands to the North Fork of West Branch of Hylebos Creek 7. Improve habitat functions by increasing the numbers of vegetation strata, water depth Jclasses, hydrologic regimes, native plant species, and plant assemblages by increasing vegetation class interspersion and canopy closure over the wetlands and by improving i buffer condition by placing LWD, snags, and brush piles within the mitigation area. 7.3 Performance Criteria i The performance standards described below provide benchmarks for measuring achievement of 11 the goals and objectives of the mitigation site. Mitigation activities are intended to meet these performance standards within a specified period. The performance standards are based on function characteristics described in Method for Assessing Wetland Functions (Hruby et al., J 1999). These function -based performance standards measure structural attributes that provide a Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 I-5 —SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page 52 reasonable indication of wetland functions. Methods to monitor each performance standard are described in general terms. 7.3.1 Hydrologic Performance Criteria The hydrologic performance measures/standards help to document and verify that wetland area and ground elevations within the wetland creation areas are established according to the criteria specified during the design. The hydrology performance criteria directly relate to Objectives 1, 2, 5, and 6. Performance Measures Years 1, 2, and 3 The soils in the created wetland will be saturated to within 6 inches of the surface, or standing water will be present within 12 inches of the surface, for at least four consecutive weeks (10%) of the growing season in years when rainfall meets or exceeds the 30-year average. Performance Standard Year 10 The wetland area at the mitigation site will be delineated using current methods to assure that the mitigation site contains 0.32 acre of created wetland. 7.3.2 Wetland and Buffer Vegetation Performance Criteria Many of the anticipated increases in wetland and buffer functions are directly related to the establishment of diverse plant communities throughout the mitigation site. The wetland and buffer vegetation performance criteria help to verify that the proposed increases in wetland and buffer functions and values are attained. The wetland vegetation performance criteria directly relate to Objectives 2, 3, 4, 6, and 7. Wetland and buffer area performance measures and standards should be set separately. Performance Measures Year 1 and Year 3 Native, wetland (facultative and wetter) woody species (planted and volunteer) will achieve an average density of at least four plants per 100 square feet in the scrub -shrub and forested communities of the created, enhanced, and restored wetland areas and the buffer enhancement areas. Year 3 Aerial cover of native, wetland (facultative and wetter) herbaceous plant species will be at least 30% in the emergent community of the created and enhanced wetlands. Year 5 Aerial cover of native, wetland (facultative and wetter) woody species will be at least 35% in the scrub -shrub and forested communities of the created, enhanced, and restored wetland areas and the buffer enhancement areas. Year 7 Aerial cover of native, wetland (facultative and wetter) woody species will be at least 50% in the scrub -shrub and forested communities of the created, enhanced, and restored wetland areas and the buffer enhancement areas. Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 I-5 — SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page 53 Years 1, 3, 5, and 7 State listed Class -A noxious weeds and non-native blackberries (Rubus spp.), purple loosestrife (Lythrum salicaria), Scot's broom, thistles, and non-native knotweeds (Polygonum cuspidatum, P. polystachyum, P. sachalinense, and P. bohemicum) will not exceed 25% aerial cover in the created and enhanced wetlands. Performance Standard Year 10 Aerial cover of native woody species will be at least 60% in the scrub -shrub and forested communities in the created, enhanced, and restored wetland areas and the buffer enhancement areas. State listed Class A noxious weeds and non-native blackberries (Rubus spp.), purple loosestrife (Lythrum salicaria), Scot's broom, thistles, and non-native knotweeds (Polygonum cuspidatum, P. polystachyum, P. sachalinense, and P. bohemicum) will not exceed 25% aerial cover in the created and enhanced wetlands. 7.3.3 Wildlife Structures Performance Criteria The wildlife structures performance criteria will document that the proposed placement of various wildlife structures has been completed. The wildlife structures performance criteria directly relate to Objectives 1, 2, 6, and 7. Performance Standard Year 1 Ensure that all of the proposed wildlife enhancement structures have been placed within the wetland and buffer areas and meet the specific size requirements detailed above. These include 10 LWD, four snags, and five habitat brush piles. 7.4 Monitoring WSDOT staff will monitor the mitigation site for 10 years after installation. If all the performance standards are achieved in less than 10 years, WSDOT may terminate monitoring with approval of the review agencies. Quantitative monitoring will be completed and documented in the 1st, 2nd, 3rd, 5th, 7th, and loth years after initial acceptance of the mitigation construction. The site should be evaluated informally during the summer following plant installation to assess survival rates and document the presence of non-native invasive species. WSDOT HQ Wetland Assessment and Monitoring Program will also complete informal (qualitative) assessments of the mitigation sites in the 1st, 2nd, 3rd, 5th, 7th, and 10th years for adaptive management purposes only. Monitoring will be designed to determine if the performance measures or performance standards have been met. Monitoring reports will be submitted for review and comment to the recipients listed in Table 20 by April following the formal monitoring activities conducted the previous year. ,r Fkie gn KAnnt+nrlr!0 Re ort Reclnlon4s Permitting Agency or Organiratlon Contact Name and Address US Army Corps of Engineers WSDOT Liaison Department of Ecology WSDOT Liaison City of Federal Way City of Federal Way Planning Staff Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 1-5 — SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page 54 WSDOT has established a comprehensive set of monitoring methods that are based primarily on Elzinga et al. (1998). The actual methods used to monitor each site are documented in annual monitoring reports prepared by WSDOT's Wetland Assessment and Monitoring Program, which is based in the Environmental Services Office in Olympia, Washington. Some variation of the methods occurs as techniques are improved, or standards change. 7.5 Contingency Plan WSDOT anticipates the mitigation goals will be accomplished with the construction and installation of the mitigation design as shown on the grading and planting plans. Contingency actions, however, may be needed to correct unforeseen problems. Contingency revisions will be completed following coordination with the permitting agencies. As necessary, contingency measures (site management or revisions to performance criteria with permitting agency agreement) will be implemented in order to meet performance standards. The following describes potential situations that may occur and the contingencies that might be implemented to correct the problem. Because not all site conditions can be anticipated, the contingencies discussed below do not represent an exhaustive list of potential problems or remedies. 7.5.1 Hydrology Hydrologic problems occurring on a mitigation site are typically the result of either insufficient water or excessive water. Insufficient water can occur seasonally during drought conditions or can be a long-term problem. Long-term problems can be the result of altered surface water flows for mitigation sites reliant on surface water flows as the primary source of hydrology. For ground water driven mitigation sites, typical long-term hydrologic problems that result in either excessive or insufficient hydrology can occur from a design based on insufficient ground water data, the establishment of incorrect final grade elevations, or an unperceived soil condition that alters ground water flows. Hydrologic contingency measures will be implemented based on observed conditions or monitoring data. Steps to address insufficient or excessive hydrology are: ■ Clearly identify the source of the problem. ■ Consult with the mitigation design team, including members of Biology, Landscape Architecture, and Hydrology, and the resource agencies to determine an appropriate course of action. it Adjust elevations or install water management structures to achieve appropriate hydrologic conditions. 7.5.2 Vegetation Problems related to vegetation include plant mortality and poor growth resulting in low plant cover. These problems could be the result of insufficient site management, particularly watering in the first few growing seasons, animal browse, competition from invasive species, incorrect plant selection, altered site conditions, and vandalism. Contingencies for plant mortality and poor plant cover may include: Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 I-5 — SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page 55 ■ Plant replacement — Additional planting may be required to meet plant survival and plant cover requirements. Plant species will be evaluated in relation to site conditions to determine if plant substitutions will be required. ■ Weed control — Control of non-native invasive species may be required to meet survival and plant cover requirements. Weed control methods could include mechanical or hand control, mulching, or herbicide application. ■ Herbivore control — If plant survival or vegetation cover standards are not met because of animal browse, the wildlife responsible will be identified and appropriate control measures will be attempted. This could include plant protection, fence installation, or the use of repellents. Implementing precautionary measures with design and placement will minimize unwanted species but likely not eliminate them. Wildlife damage and manipulation to plantings and structures should be expected to occur and, with exceptions, it may be necessary to accept the situation and allow the vegetation to mature under these conditions. ■ Vandalism — To prevent vegetation disturbance from vandalism, fence installation and sensitive area signage may be installed. ■ Review and revise performance criteria with permitting agency agreement. 7.5.3 Wildlife Structures Wildlife structures will be installed during construction activities, and will be monitored to verify presence/absence. A contingency for wildlife structures is to: e Replace or repair missing or damaged structures — If habitat structures become vandalized, are missing, or are functionally damaged, they will be repaired or replaced as necessary. 7.6 Site Management WSDOT will actively manage the site annually for the first 3 years. Site management activities will include noxious weed control and may include mulching, fertilizing, supplemental watering, maintaining access, repairing damage from vandals, correcting erosion or sedimentation problems, and litter pickup. The first year of plant establishment includes supplemental water and care of all replacement plants installed during the first year. j Reed canarygrass currently dominates the entire enhancement area with seed sources presumed to be plentiful within the West Hylebos watershed. Suppression/control of this invasive plant 1 will require careful site preparation and active site management. While complete elimination of reed canarygrass from the mitigation site may not be possible, the species should be managed sufficiently to ensure survival of the native planted species until they can compete effectively. Wetland Mitigation Plan BERGER/ABAM, FAPWT-04-064 I-5 — SR 161/SR 18 Triangle Improvements Project February 2009 Washington State Department of Transportation Page 36 CHAPTER 8—REFERENCES Azous, A. L., M. B. Bowles, and K O. Richter.1998. Reference standards and project performance standards for the establishment of depressional flow -through wetlands in the Puget lowlands of western Washington. King County Department of Development and Environmental Services, Renton, WA. BERGER/ABAM Engineers Inc. 2009. Draft Wetland Mitigation Plan I-5 - SR 161/SR 18 Triangle Improvements Project. Prepared for the Washington State Department of Transportation, January 2009 BERGER/ABAM Engineers Inc. 2008a. I-5 - SR 161/SR 18 Interchange Improvements Phase 1 Hydraulics Report. Prepared for the Washington State Department of Transportation. May 2008. BERGER/ABAM Engineers Inc. 2008b. I-5 - SR 161/SR 18 Interchange Improvements Fish Evaluation Passage Report. Prepared for the Washington State Department of Transportation. February 2008. BERGER/ABAM Engineers Inc. 2008c. I-5 - SR 161/SR 18 Interchange Improvements Conceptual Wetland Mitigation Plan. Prepared for the Washington State Department of Transportation. August 2008. BERGER/ABAM Engineers Inc. 2007. I-5 - SR 161/SR 18 Triangle Improvements Fish, Vegetation, Wildlife, and Habitat Discipline Report. Prepared by CH2M Hill for the Washington State Department of Transportation. March 2007. BERGER/ABAM Engineers Inc. 2006. I-5 - SR 161/SR 18 Triangle Improvements Water Resources Discipline Report. Prepared for Washington State Department of Transportation. October 2006. Brinson, M.M.1993. A Hydrogeomorphic Classification for Wetlands. Technical Report WRPDE-4. 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Washington State Department of Ecology. Publication #05-06-008.Olympia, WA. [April 20051 h www.ecv.wa.00v ubs 0506008. df. Hruby, T. 2004. Washington State wetland rating system for Western Washington — Revised. Washington State Department of Ecology Publication # 04-06-15. h www.e .wa, ov ubs/0406O25. df Null, W., G. Skinner, and W. Leonard. 2000. Wetland Functions Characterization Tool For Linear Projects. Washington State Department of Transportation, Environmental Affairs Office. Olympia, WA. [June 20001 http://www.wsdot.wa.gov/NR/rdonlyres/B92BEOD4- 9078-4EFC-99DA-3COEA4805E2F/O/bpjtool.pdf Sheldon, D., T. Hruby, P. Johnson, K. Harper, A. McMillan, T. Granger, S. Stanley, and E. Stockdale. 2005. Wetlands in Washington State - Volume 1: A Synthesis of the Science. Washington State Department of Ecology. Publication #05-06-006.Olympia, WA. [March 20051 hU://vrvvw.ecv,wa.gov/pubs/050600fi..pdf. US Geological Survey (USGS). 1997. 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