Loading...
HomeMy WebLinkAbout03260 - Technical Information Report .fi..-�� American Engineering Corporation `— Engineers • Planners • Surveyors - O �9 � I � Technical Information Report '� "Ridgeview Court" I City of Renton Project Site Locarion: 327 Bremerton Avenue NE Renton, WA September 26, 2005 Prepared For: Ridgeview Court LLC c/o: Cliff Williams Consultin� En�ineev�s P.O. Box 2401 Kirkland, Wa. 98083-2401 Cz°ec�tive Solutions. . . Superior Service AEC Job #0312 , �32�0 , Ridgeview Court Technical Information Report City of Renton Project Site Location: 327 Bremerton Avenue NE Renton, W A Prepared For: Ridgeview Court LLC c/o: Cliff Williams P.O. Box 2401 Kirkland, Wa. 98083-2401 Prepared By: American Engineering Corporation Rob Stewart, E.I.T. / Cheryl Girard, P.E. September 26, 2005 � . � t;U,ht� .v�%'�'r!,�,S fr ,�.�.Sf. � � � ��< %�� / � ' 1' .:c ;�, � ,-r ���,= i. ��i�- � � ,�•���'��• � �r��_, ;Sj ,�.�_ ��5`� " 1__ -`.�H� - 9 z� a --------- , AEC Job No. 0312 � E�?RES �i�=r;5_20;:���_ __; , �32�0 King County Department of Development and Environmental Services DRAFT TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 1 PROJECT OWNER AND Part 2 PROJECT LOCATION AND PROJECT ENGINEER DESCRIPTION Project Owner: Ridgeview Court LLC Project Name: Ridqeview Court Address: c/o: Cliff Williams Location: Renton. Wa. (Kinq Countv) P.O. Box 2401 Kirkland, Wa. 98083-2401 Township: 23 North Phone: (206)933 - 1049 Range: 5 East Project Engineer: Einar Gundersen NW Y, Section: 15 Company: American Enqineerinq Corp. Phone/Address: (425) 881-7430 4032 148 Avenue NE Redmond.Wa. 98052 Part 3 TYPE OF PERMIT Part 4 OTHER REVtEWS AND PERMITS APPLICATION ❑ Subdivision ❑ DFW HPA ❑ Shoreline Management � Short Subdivision ❑ COE 404 � Rockery ❑ Grading ❑ DOE Dam Safety � Structural Vaults ❑ Commercial ❑ FEMA Floodplain ❑ Other ❑ Other: ❑ COE Wetlands Part 5 SITE COMMUNITY AND DRAINAGE BASIN Community: -- � Newcastle Community Planning Area j Drainage Basin: ' Cedar River Basin and Lower Cedar River Sub Basin Part 6 SITE CHARACTERISTICS ❑ River ❑ Floodplain ❑ Stream ❑ Wetlands ❑ Critical Stream Reach ❑ Seeps/Springs ❑ Depressions/Swales ❑ High Groundwater Table ❑ Lake ❑ Groundwater Recharge ❑ Steep Slopes � Other THIS SECTION N/A Part 7 SOILS Soil Type Slopes Erosion Potential Erosive Velocities AqC 6%-15% sliqht to moderate medium ❑ Additional Sheets Attached Part 8 DEVELOPMENT LIMITATIONS REFERENCE LIMITATION/SITE CONSTRAINT _ � Levet One Downstream Analysis ❑ See Section 3 for more details ❑ ❑ ❑ ❑ Additional Sheets Attached Part 9 ESC REQUIREMENTS MINIMUM ESC REQUIREMENTS MINIMUM ESC REQUIREMENTS DURING CONSTRUCTION AFTER CONSTRUCTION � Sedimentation Facilities � Stabilize Exposed Surface � Stabilized Construction Entrance � Remove and Restore Temporary ESC Facilities � Perimeter Runoff Control � Clean and Remove All Silt and Debris � Clearing and Grading Restrictions � Ensure Operation of Permanent Facilities � Cover Practices ❑ Flag Limits of SAO and open space � Construction Sequence preservation areas ❑ Other— ❑ Other ' Part 10 SURFACE WATER SYSTEM ❑ Grass Lined ❑ Tank ❑ Infiltration Method of Analysis Channel � Vault ❑ Depression 1998 KCSWDM � Pipe System ❑ Energy Dissipator � Flow Dispersal ❑ Open Channel ❑ Wetland ❑ Waiver ❑ Dry Pond ❑ Stream ❑ Regional ❑ Wet Pond Detention Brief Description of System Operation: Runoff from the road way improvements, roof areas, and vard areas will be collected and conveyed to the detention facility, and released at predeveloped release rates per the Citv of Renton requirements. Water quality treatment will be provided in the form of dead storaqe located below the live storaqe within the detention vault. Facility Related Site Limitations Reference Facility Limitation Part 11 STRUCTURAL ANALYSIS Part 12 EASEMENTSITRACTS � Cast in Place Vault � Drainage Easement ❑ Retaining Wall � Access Easement � Rockery >4' High ❑ Native Growth Protection Easement ❑ Structural on Steep Slope � Tract—Storm Drainage ❑ Other � Other— Sewer Easement Part 13 SIGNATURE OF PROFESSIONAL ENGINEER I or a civil engineer under my supervision my supervision have visited the site. Actual site conditions as observed were incorporated into this worksheet and the attachments. To the best of my knowledge the ' rmation provid ere is accurate. � �� �/ �� Srgned/Date ' TABLE OF CONTENTS SECTION 1 PROJECT OVERVIEW...................................................................................................1 Figure1: Vicinity Map............................................................................................................................................2 Figure2: Site Map...................................................................................................•---............................................3 SECTION 2 CONDITIONS& REQUIREMENTS SUMMARY.......................................................4 SECTION 3 OFF-SITE ANALYSIS.....................................................................................................7 Figure3: Existing Conditions Map.........................................................................................................................8 Figure 4: Upstream Contributing Area Map...........................................................................................................9 Figure5: SCS Soils Map.......................................................................................................................................12 - Figure6: Downstream Flotiv Map.........................................................................................................................14 Figure 7: Downstream System Table.....................................................................................................................15 SECTION 4 FLOW CONTROL& WATER QUALITY ANALYSIS AND DESIGN..................16 Figure 8: Developed Conditions 111ap...................................................................................................................17 SECTION 5 CONVEYANCE SYSTENi ANALYSIS AND DESIGN..............................................25 SECTION7 OTHER PER��iITS.........................................................................................................28 SECTION 8 ESC ANALYSIS AND DESIGN....................................................................................29 SECTION 9 BOI�'DS, SU11-11��1ARIES AI�iD COVENANTS...............................................................31 SECTION 10 OPERATIONS AND 1�iAINTENANCE:1iANUAL................................................35 L_: � ' .__ i � � American Engineering Corporation Page i APPENDIX A King County Community Planning Area Map King County Drainage Basin Map Table 3.2.2. - Soil Types Drainage Complaint List APPENDIX B Wetland Study by Alder NW dated March 13, 2003 APPENDIX C Geotech Report by GeoGroup North���est dated October 4, 2004 APPENDIX D - Rainfall Regions and Regional Scale Factor Figure 5.3.4H from KCSWDM, riser inflow curves King County Back Water Excel Spread Sheet King County Back Water Outputs (Systems l to 8) Detailed Breakdown of Developed Area Table APPENDIX E Operation and Maintenance Manual � ; American Engineering Cor-poration Page ii Technica!Informatio�� Rc�ort for Ridgertetiv Court Septe»Tber 26, 2005 SECTION 1 PROJECT OVERVIEW Project: Ridgeview Court AEC Job No. 0312 Site Information: The proposed project is to subdivide approximately 2.4 acres into 20 single-family residences. The rectangular site is located within the City of Renton at 327 Bremerton Avenue NE (KC Parcel No. 5182100042), see Figure 1: Vicinity Map. More generally, the site is located «�ithin the Northwest Quarter of Section 15 of Township 23 North, Range 5 East, W.M. The site is bordered by undeveloped parcels containing single family residences to the north, south, and west, Bremerton Avenue NE to the i east, and the Post Office to the north�vest. Pre-developed Site Conditions: The site contains a single-family residence, rivo detached buildings, and a gravel drive. The single-family residence and detached buildings will be demolished as part of this project. Runoff patterns for the site are generally from northeast to southwest with slopes ranging from 2% to 25°/o. Ground cover on-site consists of pasture on the southern portion of the site and forest on the northern portion on the site. Post-developed Site Conditions: The proposed development consists of 20 single-family lots with associated roads and utilities and a separate tract for the stormwater detention facility, see Figure 2: Site 1��1ap. Runoff from the roofs, driveways, upstream areas and frontage improvements ���ill be collected and conveyed to the stormwater detention facility and released at predeveloped rates per the City of Renton requirements. .Antc�rrcurr F:u�i�reerin� C'orj�w�utiun Yagc I � �b� �1 �6M a ` = NE � z � �_i z 6TH N z v`�'i �V�' �j 5I � z . nt s x rrK�"����STII a K;'Ssn c� ..-$T ��.INnI 57 j� . . � �.> W �+c`' � 4' v� � �.�� > < I SE :a 1 iW. . ;5jh a z �- '���AYNFQ� qy��s'S���a -- - .snn,Qa�� x �. - .;z. �z.'` � .�1 .�' ,5 . qp Nr SINa ` � NE S� i. x �}.�, SE__126TN �, . > �SM�� �. ��1.y�,Q : , bf . � � n=s �nii"s � S7 ..�. � a��� } ,,,.,`�� >; REMQ4 W; �' � p � �'W�e`2� t�� NE z ��sr <� � � �' a� T£pYIlU1 w; � � z f-� w��aN f� a�c-`1m cr '`:' NE , ca�rcc o� 4TH �� ' ' "'� $T ��a�„� s" �� ;i< P ' G r--1�. .._. . ..- fiRfFN1+qDD ; � ; ��� Wi i S� ' � : ? �� tn� � ._ . Z METK)RIAC ¢ NE,3RD LT �' ' m ; �SE 129 . . �i . p � �.. , . . � . � .nurn.rou/a�� . .—�---- --- s .___ {...� . . PARK N:� vra tstru�2ND PL i �� _-- --�--� NE 2ND ST , •� ,,y� � � E �3i57 5� 132ND ..,- - - � �.'2N0_.?1� � ~ � .. � - -- — � . : t g��- + = SITE � CT}I ' NE IST ¢, 3:<`p �. � '1.7JRD� 51 . � ��o. !�a'� -- i .. � CEISURE _ � Q.��� � ���.�s: . SE 134T11'�' ESTATFS • . °' I SE - �. 51 - _ 5[(1St tC�,;:�- � 135TH: � 5� 17stu � . � � . � �.�PY . � �- - _ ,. i , SE 2ND�;�p I ' Si SE� St 136TN u �N z �. �St.'x,� QL ;q � I�sM� � �a � - 5lbYYVDAI E, . , z;.¢ ����•- '('��� ��� St. 138iH:si . � SE S f � . I61P . . yL�'y� . Q��J r� SE 4'�' s���At� f' �'SF 3 p w Y SE STH SE i�nrF, a - -- _i �cau�s' 'tc •—"-- --- -- tiv f 1a1S1 � �� ,..s�S=Po� � '��HAplEIR7Dp u "'v, �ARK r ��far $- q-~� �$T t'___'_ � � ,^�,i' Q � 142N0 $T .. .. .Pe�.,� y,t:rta �`�,dr`' '. i �E. LL ia�J � u ���.. . 2P�� .o�5ryn •SF. �yr��` t '^� c 5 6� � � - �.SF.-��I VICINITY MAP (PJOT TO SCf;Lt) American Engineers • P'�onners • Sur.eyors RIDGEVIEW COURT Engineering �o3z ,.e�h F.e •,E __ —__ — - Corporation Redi'°�'d "�` `�0�„ ,/���� VICINITY MAP c�Hct�e lczs' an, � � r,. �;a25) sei � c��_,i .i . ��,:�:. t _----�cR�[ 'rn;cF: — _ - - 0311 �"� ' ,-�?-04 AS NOTFD 1 r rca��n2r- �.a� ;�.c.��.Ecnr�c,ia.� i[:�oi � r�, �_ya ,i , •, , _ _ ___ _ NE 4th ST I -- - - - -�-- - - - NI I _ ; _ { � � �,� , _ � .- :-- jl I ..: ! � N88'06'17"W. ,323.52' �I I — — -+ _ '� � _ � � ,,�J '9' SO' _� g0� II I � � � I � W �� A N f � I N A • U. '� � � O '2.) .30 "'{ �-i � 90' "'- � , � 1 16' � ' I � 94' �I - 5�' S� I I y � _, o J I ,., "'. � N ' �D� i CDN mJ � . , � i �C]O �p ��A � �U!p �'— r�^ m� (0 ➢ O C➢N I I y/J -Cin!J <Nz 2O mV1� _ O < o� �<�a � r��� ynn � yZy 9C' �� II � m� �� � <N,�� mor^ � mo�^ � I � '`^< o D � � ryt" m � z I 17 �� �'=,> � �'�'`v'� q, � r.� ;om � I m ti °' m �,,. �Z 45 � I � � � � - zb' � Z .�m7 I o O o' ` S,'s. R. Sg' ,y,j �� � o . II .� • ' � RS• �� j� Z •-i 96 6 ROAD "A" ;, ^' m D I � w — — � � C o � � �• � J W m ... �r. o I ----—� , 5�m1� . J ,P\\JS o Z I �o�' I6 5' g� m x � I _ I / �� rn� � � ._— N(N ` ' � ' Vr � 1 � .� � , � ' � � �; '' � � Qo I ;_{ 20, _ I m�� i,. 0� �. 50 o N " -i _. � Z C� � 50' � � �_ ��--I � I � carv CDN 90' O ��q 1 �'n'- , �_ -m � K N� I �N A i �.. x < I cP TmD D m /^ rn y(�DD V/�p� � v, I+I�m � A . �__ ; � � x b ti �—�- —? 2 1 � nN � � �_ 65' �N� ��6�' S�' �-��—, 90' ^� N88'09'35'W 323.83" � —I —— �ri , s� _�� __{ _ - i�- _A I � << m T �� I ". ; ~ � I 0 n � NS � �� � � � � 0 Dals ReNalo�s � � RIDGEVIEW COURT = �' ��-04 "° o"` BY �y ,� ctU71gT� . . ,�..r o Q�. •or��+a,y�:�'s American Englneers Plonnan vavors kO1e AS SHOWN h� UY'4 N'.�J. SITE MAP ;. Engineering w3��.e=��b N� r _ � � .�'" � 9:� Corporatlon R�amono,w�eeo5 � •�� orow+ NEB .?o. �' � ��n'. Soa�� '�"i PC5 _" �- ��. �'�"'�^ D�slqn�d � 'r'y.�A,o��q�F,�t Q��' PHONE(425)881-7�30 Fcr(425)s61-7751 ' RWS � r�NAL LANaS . _ . _ .-... Cneckee ExPiRES:�Ltr�0. Flle Da<�h Nome EC 7�\2003�0312�E�pino¢�in9\D.p�E0312F,2.tl•p OS/l2/2003 03�3a��4 VM P01 Technical lnforn�ation Report for Ridgeview Court September 26, 2005 SECTION 2 CONDITIONS & REQUIREMENTS SUMMARY The 1998 King County Surface Water Design Manual Core and Special Requirements and Hearing Examiner's Conditions are being met in the following manner: King County Surface Water Design Manual Core Requirements: 1. Discharge at the Natural Location Runoff produced by the developed site will discharge at its natural location. 2. Off-site Analysis See Section 3 of this TIR. 3. Flow Control Calculations provided in Section 4 of this TIR conform to the reyuirements set forth in the 1998 KCSWDM per City of Renton requirements. 4. Conveyance S s� All conveyance systems proposed conform to the 1998 KCSWDM per City of Renton requirements, see Section 5 of this TIIZ for additional information. 5. Temporary Erosion & Sediment Control All TESC measures proposed conform to the 1998 KCSWDM per City of Renton requirements, see Section 9 of this TIR for additional information. 6. Maintenance & Operations A maintenance and operations manual will be provided after first review of the construction/ final engineering drawings. Refer to Section 10 of this TIR for more information. 7. Financial Guarantees & Liabilitv A bond quantity worksheet will be provided after first review of the construction/ final engineering drawings. The project owner will provide bonding as necessary. 8. ��'ater Quality Water quality calculations provided in Section 4 of this T1R conform to the 1998 KCSWDM per City of Renton requirements, see Section 4 of this TIR for additional infonnation. .4�rrericait Fnginec�rrng Cn�J�urution Page a Technical Information Report for Ridgeview Court September 26, 2005 _ King County Surface Water Design Manual Special Requirements: � l. Other Adopted Area-Specific Requirements There are no area-specific requirements for this project site. 2. Floodplain/Floodway Delineation There are no King County classified streams or wetlands on-site (per the 1990 KC Sensitive Area Map Folio). 3. Flood Protection Facilities There are no flood protection facilities located on or directly adjacent to the site. 4. Source Control This site does not meet the threshold for source control requirements. 5. Oil Control This site does not meet the threshold for oil control requirements. i ; i i American Engineering Co►poration Page S Technical Injormation Report j�or Ridgeview Court September 26, 2005 _ Hearing Examiner's Conditions: All City of Renton Conditions as they pertain to the Ridgeview Court Project have been addressed and accounted for in both this Report and the accompanying Engineering Plans. I I �I ;�- ' �_ _� ' ; � ! I ' . � ' �� . American Engineering Corporation Page 6 Technical Information Report for Riclgeview Court September 26, 2005 SECTION 3 OFF-SITE ANALYSIS TASK 1 — STUDY AREA DEFINITIONS AND MAPS Overvie�� This section of the TIR is a Level 1 Downstream Analysis per the King County Surface Water Design Manual Section 1.2.2.1 and 2.3.1.1 as required by the City of Renton. The proposed project (Ridgeview Court) is the subdivision of 2.5 acres into 20 new single family residences. The site is located in the City of Renton at 327 Bremerton Avenue NE (KC Parcel No. 5182100042), see Figure 1: Vicinit,y Map. More generally, the site is located within the Northwest Quarter of Section 15 of Township 23 North, Range 5 East, W.M. Topography of the _ site area generally slopes from northeast to southwest, see Figure 3: Existing Conditions Map. There is one point of surface water outfall from the site. Therefore, the site consists of a single basin. Please refer to Task 4 for more detailed information regarding runoff downstream of the site. Upstream Drainage Analysis / Upstream Contributing Area Per the surveyed topography there are approximately 0.26 acres of upstream area tributan ��, ,},�, site. The field investigation also confinned the u�strevl� contributin�� area. see FiQure 4: Upstream Contributing Area ]�1ap. ,-lntericuii F_n��inc�t�ring C�o�J�orutio�t Pnge ' �t;STtR��(F. � :-. I . � o \� q� CWSTER / � FX trP!1 C8 \ � ORANCE �: � ` I ' I S 4�MFL�1Q4ti . � f•` �7"��µ,=���. PI11NT �� El(ISTING CARACE �'� 1' � � �, GRAPHIC SCALE �Y n+Y E=�as.or �� � / 1 '' I \ � I I , �s o is ao so rce eaw��w� �,• A� �-� � � �/ \ i ^' � � � r � wcn=ao rr. — — — — — \�e Hro @ `'� '6 e � / "� ( � i � g�. ,�`. PP W/UC PMR ���, •� _ � --_ � 4�1 . ! _ 6.'" I n' � . c�'_...� -?--s,.� AYP � �/1 . R i� ' ,` }�` �r . .'-. �N/$ __ A�1rCA WAZR WALK I 40.,(t?�' �,.�. TYa �10� _, h�' LOCAT1pJ �� ' � APPOM. W.17FR � ` `.��t � re �', ! % �. BREMERTON AYE. N. E_ ��' � _ _ LT/RB l£RT FAC£ lB0% 1 UGP PAMT qSPNAL J ROM.STIPf�C[ • WATER P IN - - �3GTH AVE. 5. E. >£LCN'S17.'PE J _- ASPHALT PAR7/ —"—T �, I_ ' _ � NOO'4 E NPN S7LN 4•31• �o 330.03' � __ ..t'...40CWALN. ' .:' • �. .`� , - "__ ' ay I _604- )2 �� \ APPoX. WA�R �a z �, ' � �� �\ `. �,, — - � - � ._ , .._ \ ___' ` � CQCAPQV ' . � 3 _��D_ � �\ , o _ _ _ _ _— \ ' ` i�'I - _ _ � 4�2 _ _. . '.` . .v LYA4C PAD' __ 1 GRC�OSEO DEY 9QY o � � �� 1` � r � 'c � � —� \ _ — � � _ -_- �, -�oe— - ' — — — — — � v=i c y T�'�.. �. m N / �..A��.�o s�:.��— ,u r sx�s � i � � � _ 'P I � ' / �- � � ^� �s��— — � a z � w .�H"f<�.:J42'F.;£ ' 17"C'✓�E 4:67E � �� 1 1, .:� _Ci - 40�} 1 ( S \ " � ���- �a �_ — � X 1�� � 1 ,, ` , ; ,o�� � �P������,.,f / 1 ' � I :�s�� - o — �' , � ' �:�k��,�, � x a I \ I 1 , ` - -- - � o � ' ' ��° � � ''° � / J �'; i �� `.( a �`, x r' � 1 ' .�+ `,. / � � / /'', ��� ) � �' ,I; .., I �- 4 � 1 / . =--� \ /'O+ � IZ f ''m i i � � `O6 �'aN 6� J X', ' � ��, '`, ''�--� i` \ PASTUR� � t � " - n "� . , ; GRAVEL DRIVE � � i � � � y,"aW�°";, ' \ 1.21 q�C I � I � . ' ^ I" �, '','� MODELED AS LAWN , I ', �; { �,. '�-`°'`� ;;p1.� I I 3 I « � 0.07 AC � xIi , � � �� 40 � ��;�1' '$�_ � � �/�� 1�•�� I1 i Q a <; . =o I � I I�1�- � � � 5� /0�- , �. i � m I ' � j �: I xIi 1 i 1. -� � ;� �` . � ' `� . Z x a E {{ � i � ; , ����. ` , It , � ` S� . v ;I� < < 7/ I � ,� I � , ' /4I,�� ��—X- w 106 _ . � r f. �\ � ,,, 1 ' i / � � ' , W 4 i;�, �, ; � � � J , , f (; , „� �,� tl . t � � ; p° p ' � ,,,• 'O ' � .� ��I�'._ I i - �N `� � " ��,�.! \ '`� �� � ' •'r � � \`\'I� \ `� J1� ! I ` � m o . i � � ���a� I �' �- � ,, ( i i � il 5� m c a p� I j i � i •., � i � '+' ` � � �� i ' � �� � .R ' � 1 / �� < I \ ; - \ 1 �I 11 i � i e� � � Q W U a - x ` 1 e �K�° l � ,� 3- �-,��F �.�FOREST �, � � �,� : 1 � I � � � ;i�l� � �� ^ �" � � 0.94 .AC _�':, , �I � ' I I � �N`a` � --- - - - ------- - -----o � 1', '�, , -, � 1'i - _ 1.` ,} ' . � i '°�� �� TOTAL AREA= ONSITE + OFFSITE ���j4 °W?�'. � �x `. _ ,_ � , - I ' i� �,� • W; - 2.91 AC � � � � a � � . - � � i � �,_ - ";�'Q��,,, „I 11`.\:i I - � . �,, -. - I II1� II� ' Z< bbti�,'`���.�F`'�'� �K i I - �t► , - '� I y,� � �Q IMPERVIOUS: 3 °0. �` ,. � � , . � '� 1 , I ONSITE=0.08 AC �` ' �� '�'��� I �� OFFSITE=0.06 AC a ,' , ,� •� , �� .�a i •°�;9, � � � „ a • ��' � ,.� � a� '� � �,� �,`� , ��_" TOTAL=0.14 AC � �p �� �,��� ��� � - - � E-' •a���a�w,rerocc -+ . �`�T � a ' ' ' PERVIOUS: f� � -- - -- - — — �=--� _ _ � + t 90 I , .�N� -_ �� _ �o, Z --- --- - _ � ' y s -- a��-��' - " - " .�� . �so.a2- � Hoo-.r<se : ONSITE PASTURE=1.21 AC � O .� - �, Ex,�,�o�, �� � �'''' � ONSITE FOREST=0.94 AC �, ��. � �•pzx� � � � ;�'\\V`�+ ' U � I i $ ONSITE LAWN=0.17 AC �o``� ' �` ; o,o w�P°�� J�B J�P '�' �`���•�'� OFFSITE FOREST-0.20 AC � A P,�� i I OFFSITE PASTURE=0.25 AC � � I _ I ; ' TOTAL=277 AC W v ., i i � � I ,.`', ' A Z ( , I t� F, � � , � � � W JOB NO 0312 1 �,EET FIG 3 i � i � � I a a I [+�i I i � ? � . � z,. � � O � m I � e��� � � D � �, � � J, � � � � I �I � ' � Z D �� � I - � � G7 � g .. , c �i � I ' o '� � � �Q� � ', � I , 9�I � g e �� I � i ' �� � � � � I� ��tl � -� ; �-, - �- � � ¢ � � � � � . � , ��J, � 00 \ \ � � �"��. / —_ g II — _� � / — _ a �i�G II �II' S� I � �� -` --- _ - �� ` i;��/� ( +�. � 9 - - — -- �J _ ,� '� / � p _ � I / � A 1 p I ` / p i � � � /� `` C � \ / � � O � � `. 9A I � � o" N � T� % / -� I �� � � :I7 TI �/� % � /oa ',o �,. � / fTl (/) — 6 I/' % � ,, a p tl P \ •. D �'� d � I \ ��� I �'i � � � - - — -- -�on— — � D � �[Z, � 1 � ��� � .� �[7 �� � � � �� � �� � /� � ���� f �9 ,D � ^i� 4q \` ! �.qo" . I \ C- ` � i � �� � / ' � ' \�� �/ ,�d� / � � i �i a �oa,I ,tW� _I � � � 1 � o o � � � � / = � D. �� � g: _oqY �/ _ ' / — ` � , // � �DCmN i � � m ti , � � ' r II � <�r i % , � -s� , ----------Q-- - � '' �,. — - - � � � ��� � / �OrrtO �i w _ -- , � � � �c�' oc�n �� o °— °� zo, ' --- % 1 � �� m u - / _ R �„ ✓ D CNJ� O f�Tll � __� o` ���+� � � � � `� � � � � � � �����V --zu� � -N � i \ � c�, p� � � ------- � I �, \ `\ � z,' i e�`� g � ' - �� � �\� �\� �� �'������ ��'�� -, �� N � - � �i _ _1 ��� �'� , � � �, / A I � /� � � �9.. � ' / / ` ' / = ! — -� � ' `_10�, '/ � �. I �_ �_'__ � —._ � ,. \ � D, � �` — -- . , _ _ � i , '� - -- - - - =- � ; ti� — — _ _ _ .=� � _ _ _ \ 4 � I f I� a \ gbf '-'.� _ ' �i=_ = —� _ � ��. :=` . � � .. 1 ` / ( _ JI I I � R� /�. ' ,,y�' _ _ ` � � A' a/ �� _412-. '-_ _ _ ' _ - \ � � I k oo`. ;_`-- �,o ; a�, — _ _ -- � -- _ _- - g �i Qo, -- 1 _ - -_ -- -- — ^� \ � ' — - � � - — — — - — — / N88'09'35'W 316.33' � i -90b- — — '._ _ - ' 'aC> tC�_ —. . .- _ — _ — _- '' -� _ . _. .- __' _.�P � �" _�_��_' �0,,�"--, ?.`_'� �n I � O ���410��� I � I � I o� � , b C � I � W I � 30' � I I bi I I G+7 � ' 0 n � "S � �� � � � � 0 � � RIDGEVIEW COURT °°" R."„°�. 4�-��-�4 "'JNp No. Dots By � ~ � �W�� WASN p�i" American Engineers • Plonne�s • ,urveyors �ol� � p UPSTREAM CONTRIBUTING `�� ��" Engineering WJ4 168t�Aw.N.E AS SHOWN �I R�dmond,WA 98052 Drown �'' AREA MAP a Corporatlon z � NEB � �� a,;N ,^ ~7�, A�"����T�a�° �'`" ,.. — o.,�,�.a T `v SS�ONAL �NG P�ONE(425)6E1-7aJ0 FaR(a25)BB1-77�t - RWS f'lle potn k Nome C�eCksO ExviRES 0�-OS-2006 p,�p003\031��Cnglneering\�Wg\f0312�G1,tlwp OS/12/2003 03�13�35 PN POT E� Technical Injormation Report for Ridgeview Court September 26, 2005 __ TASK 2 —RESOURCE REVIEW Adopted Basin Plan The site is located in the Lower Cedar River Sub-basin and Cedar River Basin (see King County Drainage Basin Map in Appendix "A"). Community Plan The site is located in the Newcastle Community Planning Area (see Community Planning Area Map in Appendix "A"). Basin Reconnaissance Summary Report - A basin reconnaissance summary report could not be obtained for the Lower Cedar River Sub- basin. Critical Drainage Area The site is not located in a Critical Drainage Area as defined by the 1998 KCSWDM. I Sensitive Area N7ap Folio (FEMA Maps) The King County Sensitive Area Maps from the internet did not show that the site contained any wetlands, 100-year floodplains or seismic hazard areas, coal mine hazard areas, erosion hazard, landslide hazard, and landslide hazard drainage area. Therefore, no mapped sensitive areas are on or adjacent to the site. The City of Renton maps sho�v a small stream meandering down the center of the site. However, field reconnaissance did not show any streams, channels, standing water or flowing water at the time of the site visit. Therefore, no streams are present on the site. Furthermore the wetlands report by Alder NW dated March 13, 2003, concluded that no wetlands or streams are present on or adjacent to the site. � il �, � American Engineering Corporation Page 10 Technical lnformation Report for Ridgeview Court September 26, 2005 _ SCS Soils Survey The SCS Soils Map of King County shows the soil on-site to be Alderwood Gravelly Sandy Loam (AgC), see Figure 4: SCS Soils Map. This soil type is classified as till per Table 3.2.2.B in the 1998 KCSWDM, see Appendix A for Table 3.2.2.B. The Soils report by Geogroup Northwest dated October 4, 2004 generally agrees with the above mentioned soils description, see Appendix C for more information. Wetland Inventory There are no wetlands on or near the site. This is also confirmed by the wetland analysis by Alder NW dated March 13, 2003, see copy of Wetland Study in Appendix B for more information. Drainage Complaints - Cindy Torkelson at WLR Stormwater Services Section was contacted regarding drainage complaints within the downstream area. These findings are described in further detail below. `�'LR Stormwater Services Section found several complaints within the area. However, none of these complaints were located on or near the dow�nstream flow path from the proposed discharge of the site. Therefore; the developed runoff from this project should not create adverse downstream effects. Please refer to Appendix A for the complaint list. �1n���ricun f:��r,�ixc�t�rin� C'n�f�urutrnrt P�rge 11 fi : ' �� �- � g';'�, �t� "�;� � .I: " '-� ' I � " *�,i� �t .,� ,'. �i - � . `"� � ',.o. �� � i ' '��'�`��,� I � •• • �'� . • � % ;� .� w� *�t � � �"�'��'',�,, •` '��_- __���' � , �` � a .' � ; . ' �' �'$ '� - �,.„ ' • / f� �\�Q ���t"���`'�, 1 �n ^�� iler ��?��;' 4 = �• '�'" X��' � � ' � �.g� � ■� ■' n� � ' '. �>. - ��. ,�•*.� � � � '� k�• ' n i�' ,� �iBM 3 � .�'' $� �. t F.... �� � a�'.' ' i--��- �'..� 3� n ti+ • 3' '424x '` . r ' _ t I �� 7 �'' ••=� --r � •� r _y� � *� �C . � . -c , ��,• ,`.' �� ' reenwood 4� �` � • s ���,s� ^ . �s �� ' , '�-*� .- v��� � ��.- i x... -I -.�'�,e�^�t�::� •.� a'' �' � �y',Y� �3 � � _ i �: y', � :.� 3� � �+`.r `�q, � � ,re _ %� � � u�� " . � .� �a�t��� .a � eY � . !_ r1 _.i i.. t 3y;7` . �`' �� a,^.'r t.i.-��� _.s x F `� J�� r _p -�\i� � - - � . .„�. f--i �' � � '. (1 :p `� 4 > : L� '�e � •�.�. , EvC�� :, II - � 'Y ,, � �� , ..'a k ' ! ��� �� F; ��� i.ert� 1'S 3 : ' �l An �' r°�,, `'� � � :rs-�.4 '*.�' � , n t .34 eGRAVEt 'P�T `` �y.� . � �':..`t'� `r '�T'n� _- '�4 ; �` � .L�a . � �@,' Y., 'L �-��: "•�.��i 'l� � �,�r� � •�� � .w�`�� `at- � �ZS. , �� �� �Cw M Y-t� �-`. H v�'� � '•= ♦ __ �4 .t;. ` �C�,.�� �i ���IA � ia�\ t �.X��� r� .�"���' �15•- _� T�1 - �iE£s'�i� -14� ' '1 x�' �^ �� ... � ��L�.�a.'�I �,i' P,t�G _�\• �� :'� r���� .xi����{�,� .,�,. '�a.`_ '�y� t � � �"qF��� Evc , `� ' .t?�kE k =- ��;�li = �' � �7� .��� t '� - � � G- - +,F'� .e�.. ", a',�"�,�,�a'�' ,� Jl� '�"f "�^ ���j��'�..Y a � � a`� ' ..y �*_ .,x�+:�T�.� Ta �nSsl� �� 'r �r.3 _� ,r./ +�""'�€S�' .".-'�'�'x'`"',�r .�.i • , , ;� �-'-.,. ; � L i?�'x ' + `� `f' y +� _ s �` '- , -" e:s-�*SFb"'a :3jw s��r ����,�� , -.t �'�-,i r�.� l- ��� T� ..;,r�.�"i�"�/� � c�'#� ' y>� {l1i py ~ �.' M y �.. � ts•� �3��"�, K e F•�. 3 •'� �r�� : �� _ !•�. ��' • ,,,5 . .t ':l; '�',�+�..�a;{ �y�' � -� � i_.�.. .�� y`s..� t�' , ': �•t �S' 4 �'��,.� ' ,��: 7 *� ' s r'°�..�.�.� _.- • , � -�+ �.� '; �, r B[•f , ,te N w � ; � 4,- Fc."4: �, ��.s��`�i.3 ,�•• `•-� t �� 1� ;ij�}� ��7 x . � .4+F�$ y�. � _:�Y,��rp �j'. � .ry '. •`�• s�� `�I �-- '�"� \ ��. s'44''a� ':�s'��YS�.-���'�'_y,�.'��,� .� �° T_. .� I ,a' �.�''�r�f� +,. �'a � -4.� a BM 37 "-• " � � ' �•� �-�PYPh.� ` '�.� �" � � r r.�°�� :-C: �� ��ta �'��.�fi' C°�fC'�: is} �`�,`'���� ����� � � ��k�'�rs�±` �.�-� �:a- 1,_ �:.+ ..� A C '�" #.! .:. .�i. '� ���5 t z, r""'. � . ... � �.�� 'tr'r.= �.a-:��t �g ~` i `� g s.���� � �e K",� '� `"��.3._ P�� S =�` !' ' 'I- `��_- ��aF .�� ,t='}� s �'ru- ' � ,.s,�-k��,,,,.��. ..,� �, .. �. G• � '"� �"� ;" '�>-. � a�,w-� •� G;' " � f a.�•`i r�s��• � i � A4�'�''� -s'6� !'6 '� I � .. . - � .5 �� Q .w •Xr� t i � ..{.. � �` �" �. � . t: X C p�� S/�` I ���. \\` g�`�:/�I�` . •i �� i �. \ •S , �V��,q'��'^�i�V-"r•�.� 'i � �� A . _ _ _ s �• � �E •• • • � . a C M �� , __ � � ��,. - I ct ,.�/_l . AkF _ . `: - 8B _ d,�'j�„i u � '" � ,cNg � o c� � �_.._ `� �� .. �u. :�' `\ � iit, '� h � _a55 SOIL LEGEND �`'*' �"a "- 4 g�, •4 E `^a :: =jl ,,��^ ,�r� i- 1 \ �g'�x-: �. ��rf Ur P. ��, ". � `ParTc. Ng � � The flrsr co -rc lerrer s rhe .nir al�n p� � P � e of rhe so�l narne A second co rol lerrer, �K�- t � �+, 3, �" E, ar F i�dlccres rhe c'oss of slope. Sy�.•ools wi�ho�t�slope lerrer °`-^�"Sz- � y i�` '���' � ��� �re rhose of reor v level soils "`;-e.'�''� ^ '�-.,'� � m � AgC� 3 . i'�':e- ' �: � • ' s -����'��'� �y,, .�a�: � SYMBOL ^IAME i aqgD q Y�' � ;: � £` ;�.r��=, t .:a �, �- . � . _:�,f:��.` •: . Z6 T ag8 Alderwoco cr�velly sandy�oam,��to 5 percenr slopes -_-_-_-- _--� _ �'_i_�..-- ---- � ' AqC 4lderwooc y-r�velly sandy :oom,6 ro IS oe.cent slopes - ' --�'-- ,_� ___ '_--___`a � � � AgC Alderwcod��a�elly sond loom, IS ro„0 � `� � r '- v � percent slopes A B �' , AkF qlderwooc a�d Kirsoo soils,very steeo >} Am6 Arents, Alderwood morer��l,0 ro 6 percen•slopes• �� y� �} - AmC Arents, Alder«ood�ncteriol, 5 to 15 percenf slopes• � ` t�fi;� ` - `' A� Arents, Evereit mofenol• �.. y ���;� � ... � � � �— '' AkF.,� v !-�r . 6eC Beausite g-ovelly sondy�oam,E ro 15 percent slopes O�.''+> � � ' �'. • 9eD Beous�te grnvelly sond 1 � I �:.- ;� y oam, 1�ro 30 percenr slooes �. �. � .^ � - . ;�iy�` a�� Lec�s�re y.a�.i. " . ." , ,.. _ _� _e. �.o��_ l . � � � b � - " �, 3^ 6eilingham s-I; �m J � Pmg � � I _�g8 �,_. ' �r '27 ' � y � r �B 3u Briscot s�it loom � 1i� t�,i` �` B�ckley sfk loom � •`�''" 492 l '�� � ' �`I� �4�J2 � Q� .�---JLJ � �` � � �.l rp - � 'I '1 t, �� ��- �1- �C. . u\/ � ..i. � . ..�''¢' � � ��'�4 � l� "� rL �I`l4� 1;a.r. , 4 > � . 'P� . e � ' —R-� � z' _ � . �I �o .;,�- ., , ti ��'^ ` "�i!!'d� 5 .F � U . ' ��., ^Sk.r�, ''1 .sc.�� .�.�� ` � �;� '� .�. '�q � � � ♦ s r�c 7 , 3 - � j� ��.���$, �+. � �Ar .4'h��;� �S I �'° '�„�,�'-C42 F � �% Q •i ���`�.�� 1 ' a� ...�; „t �- `� - +�y±�{",r��... Bb1 �,`- � ��+1 ;•`� . \' 'I� o� �� � ;'d��i�'� '� �i ii .... Ameriean Engineers • Pianners • Surveyors R I D G E V I E W lr O V� I II Engineering �o�z ,<e�h ,.e �,r - - — I Corporation Feom�.,a, +�A 9ao�� � ;, S C S S��LS M A P I --=== - - -- - - -- � PNC��E (42S B8'-:e�p Fai ia£51 891 .,i� �_� _- _-- :F�. � -- n".1ff'9 C:•'E SCALf flt�C�E �� =„��03.�3«.E�,,,�F���.�,3,E�_��F«ti., �-;��;�_�: ����os :.M �:�� G31: �7-20-04 AS NOTED 5 I Technical hllormation Report ror Ridgeview Court Septemher 26, 200.i TASK 3 — FIELD INSPECTION A site visit ��vas made on July 8, 2004, during a partly sunny day with temperatures around 65 degrees. There had not been much rain in the previous few days. The site is currently undeveloped and consists primarily of sparse forest on the northern portion of the site and pasture type of vegetation on the southern portion of the site. The site can be accessed from 136`h Avenue SE. The topography of the site generally slopes in the southwesterly direction into a low point. There were no visible drainage problems or recent unstable ground activities observed on-site at the time of the field investigation. The northern portion of the adjacent parcel east of Bremerton Avenue NE, has elevatoipns lower than the new proposed road grade. At the time of the field reconnaissance, this area appeared to slope to the east. Therefore raising the road in this area will not cause a low point/depression on the adjacent parcel. All runoff on the adjacent parcel will flo�v a��-ay from Bremerton Avenue NE, no ponding should occur in this area. TASK 4—DOWNSTREAM ANALYSIS DESCRIPTION Drainage System Description Runoff from the site sheet flows southwesterly into the low point of the site (Point A). Runoff continues in the westerly direction in a very broad ditch (Point B) until entering a wetland (Point C). Runoff leaves the wetland in the southwest direction and enters into a drainage channel (Point D). The drainage channel originates in a larger wetland��vesterly of Point C. This larger wetland is denoted as Point E on the map and is located near the intersection of the Union Avenue NE and NE 4`h Street. However,once runoff from the site leaves the wetland downstream of the project (Point C) and enters in the drainage channel (Point D), runoff flows in the southerly direction. Runoff continues flo�ving southerly in this drainage channel (Point D) until reaching a culvert (Point F). Runoff is directed into a 60-inch diameter structure (Point G) and then under Bremerton Place NE to the east via a CMP culvert (Point H). This is where the downstream analysis was terminated. However, runoff discharges on the southeast side of Bremerton Place NE (Point I), entering Maplewood Creek (Point J), and appeared to continue flowing in the southerly direction. Please reference Figure 6: Do�vnstream Flow n'[ap and Figure 7: Do�rnstream S��stem Table more details on the downstream field investigatic�n. No downstream problems were observed at the tin�e ��Cth� li�l�i in���5ti�atiun. American Engineering Corporntion Page J3 i �" f - - -' `��`1'`"� � iy..� �..� �. ... ,/� �99rYl�o�L a 6 � � �<��ou�ev \/y. �f.�� � � �r v ` Yb �Vibl ..Q � _ __ M i►' o � ° � ; � . �,.��'a � � �� 69���i-r �r� 9S � ~� Ob�-�.. ____ _ --- ---�_ _..�tc � q6 hi��----� -- IY'9� � ;� ,�, 6�7� �19_'. m l ti 8S �S .i �r or ti a6tD Bf o !£ � 9£ �_ S{- b£ _ ££ ,:, 2f � - � Z y:� `�y -.: [�` 9 �,� �� , ; � � W �Q� `,/ 4 �ri w .VO �« QS p � Ucl � _' S� 2�� �� �Z� S 6 � k� o r Uv o17'UC9 �. `C' r"'a' '"'1� �' � ___ - �.; ,�4' st�z — � °6� � - - 1S1 �3�5 �� G(�fl �` �� �.I I g�,, yc � � - � u 5r . . . a; • � � ue �� �� ,, . .-yt,� � <h _ 6:- •� � ' SI � --''�` � V dl`�3 21 " � fl �" �I SI • 91 � LI BI 61 Ol E� Id 2d fZ . S: S€� yp._ s� s ---SL_ _-- _ _ - --I�uC9 - - -��i '_�69- •-�ao� 4cu �9�1� 5oi u 2oi v ta ,�. �---3�-�, \ �u � ._ - �-----= <<� �' ' � �z � iz or s� e� ���I � o� s - � ak �,� (a� ( —<—v ai .., �1244 ,� . �� se e�,� ,, <x ; ,,. ;� �o��� f6Zfl� �� l a � `�� `�� ' �� ' �`� ZI ' �� �� `� ��`'\ c. s 9� u67, � � �s� � � ��l; � � - J1j �� � 1 1 w �;.._ �4�iSF� �,�. 0 si�.,.i�i �, g �b�r m � p � },` c�, "�..as• .- � .. _ 2 �,, t� � ,,i � �,� 4Z �,�4 y= 2,�62�a� o 'a� ,� Z w � �" _ L .)� ��j � w � �pu � � r � � � _60( � z I ' sd �ZZ .+ � n��/ R LI N41 ± O�UIi �.�16` . . SfBt� ` n " L Z �, "a '�° 2a �, � - �zoi �6 � �� �. ` �- - �V I� � uv�i= ,t. � l �s�f��'�i r.r � d �[9 aC►n-Y�i bu Q'� ~ Q .�C �r Q � - -- -- u�z S�l ( uiit � f, �� pU� c�' pyrr 91 ,� bl � '' r. .v2�, i��c, A � - oic ��� ez ' rn �� •r s� a s�if � s� fm �y .t :� �s, Szr � � � g Sk�c�9 n ero�9, zo ��IV a' , � '��9 0 �° -- —�lf---- � p �c �c+� �' �c H e a �„ — . - - - 8� , G e, °j �. _�;. � i ._ -_ If bIE 6C _r Z �n � � � �� :: a S9 fy.�` ll��� \C'+ r`9 ,w 6 i f I ._-_. . __�.___ ---.._.. .._...-- � CLV�GZ9 `� ;8 � �' q�' yE�fS S��' yl +' �9 b9;;' �c�,l - -- __.--81T-;�• � rF�. 7.b � £h �' � �y 'g -f. g �i5`? ---so`� CQ �% ' H4' � i t' y! �, = ? Z�� 'f=' - ._ st� OC � `.� � , ' -r "-' 1s , � FS„' - � � 4�a�`�� 1'„ 9 -OFi � z ,=St`�r� 0, y� d9 � Fa - /� bt� � p d Es�c,a: �l� ' 19 tlQ r--a,, ! � M �I � �-�2F�-�,sF �s � o ,�5� �, w _ W w � s �,� � � �> , ; �"'� �� -< w (�J N �N 91 � - I£ a - -- sa�`� r � "ie� ,ga�" o" ibi�-. o , ti !� � � al 1; Sy ti a� �-tio`a" - 6s R `na ,a �� � �� �� 9�`; � `� ,,,��^.�:=� m 06 �,� ,-.� 7 ,o'�.�y y �3� �,� bi__'2- _ $��S�b�Y� r 1�??` 4 ''�� �OFF C��E r� O�fi�--: �� 1 �� ��q y,. 25 ! �. � Y � b17�F�9t 9955 �SF'�� I. � . o, es� �9b � �" : i '�;� • V � z� r i� y �� � � r � � �� � Bb `� 6b �,e�'95 NO �5 `=8S`g�� 6Sf � � ` £� -3' � y S2 _06 � 0- 0 __ ! fOS I e 2B 29 t' a I`� G0� � ' b� � d.� � � - �-- -�,� � � � '1S ONZ ti ` S'L ,S'0 , �� _ , � � � �, �.� �� '� iS . , bl�Zl `� 4p4S_ � - - A r,ur�rv� cr �w (I) I j ����;.�-w �o�c ccs u� � � g � � U � � � I� N w � • w � 6H '�9 YL� '�9 �S 6 1� o � �; R � es�e ey o� '� � 9 _ Ir- �K �. v� �� ro , i� (� ' ' '�s' � ` , _ ,�, i: °' `° •� ; � , ,� � ---- ---- ----- ---- - -- .- � ,� . _ ___------ __ _ ____-- oE ----- �L- -- - ------ `.� _� iik •�rvzc _ ._ __'� � Y 92 � �y� 1, I OG� �9� `�J9 ti " ' I ,� � „ �J �� �; "- _ =-=-=�;- - _ _ b w � .........��� N (.+ (/y {✓� D. • -J �"� O 0 W �� P t �` ` - � S __._..___..'_"_'" __'___' u p � o �}—� � � --Y2i--- ----- — '_ w U �� �e � � �f� N �,z,z �£� ��� � -� ' � � � N (1 � � ~I � � 0918L9 d S r d --- � -t� o-� �rr�- E::-o-� q r-�-o� _�-�aL_� r�- � - - ----- - _____. ---�- tts�t�i c I etc . e'..�fe -z �.�=, zo•tizF ���ez� 1 rw n �� d 2lO�s�-- NOl Y� A , � �� � '�.V 9��1 I z� A � �oz, �I---- 6 -= � '� --- ----- - 1 � � S , N I 1 �i�C W � . , ., W � w �� , � I "___ P ��9�Eof � , _ 1�:� n � �' p f �.\ I � i� � ��'C 5I I ,�, _.---- \y � 4 � � • ..! S��Z� _._' ''. - - _ \ I _ �----- � � ` M1 � N �� ---- \�\� �' � w C� �,_i £8-44 .- '~ , 125Fof IZSCtf �v�� ... � w w�^; `' b< <_17.5451 �'.. OS �001 EUU�i _49212 ----_ . �9 � .�� _��� iF l;p� 66 I � �. �P 6906L01 d'S o ` (�) er �_�, ,,,,I.u° � F � '_ r Z � v, �m � i � �i � o` � t S � � E � � � `� � Y� 14['E'i- �-� -- .� � � n ^(�- q Zp i � �z) o ('�lp����, - -- _----- �:� i c� E; S 11�'N=�: (j, o � � I� �I) T? W v, o' c�� u ,�. U, I�n V� �. w �.' w pp ('� �i �7 �• bZl � i i�i D,.io�ji i " Q � Q � ��� 'r � ��(i I - � �. I �,i-1..,i �r `' � � �k�.� � � ` .7 `^ vis' o �i f- D n '� _.��u� G J9�n,vis' �i �.I 7 r � ��J� ( � J9 w �� � � I�\ �. 'o�-. .. .......�.�__�..,y� . uui iu r ��� _n`d� i:.�•�a..��SG�l�Ni 18' 1� 17�lE'L 1 q9 ��4�1 (7,Z�ElC ��If�_.......�..�4.JI`.�2 k'tl . ni� �♦ A Lez��y------••-- � �•T•---.�:T^N _- _•-------T:--.�:.-,^.--------- ..:-m::-.. —T—���� :;-,� --�„;;�3��:: _ ��- . =�._�.-�.,....—.-�.�.--. :.--r._-;�.: ;�l S:_�--�..=H 1 t�-:_ _� _"C_�__—.f J� _ _" LLua__—,� . .__ _______. '�.•�T.� �. ..... .' >.. .. .... ...... � � I I� 1y-}I i�t' pol. w � � . 4l�t6 I �.-�,.tF�u�..�t. — , _..��.�pt..-. �a.,,.." m i r�, tiV'C�Z I S. 001 °� � I I �i � i ; o �'��C�l �tl z�] � � �!/ ` i g.9 rU � I � I T a�F 6.I� � o � � �� ' Z - i w i �, � �., � `=' w �'', I `'^" p i i� w b i I :o '" �o sc ,� I I '.__-oci . . �� S��� rv � � � ��� � „i W I � "_ Z. 0�____ � � � P �I; L, I �� Iq J�'___-_.S2'F,hII �I�IC,�.I I' _ CZ� ' I�'i ; i iSl I ;I _' � '_ �v q9 T o oe ze �; --.._��f?��,� ,:,. ; --- �v sz�o �' ._. . N�C1 � .d 3 1 I Sj' J N I 0 N I 8 �IV �: � � �,l n,�, _.._ .._, I ..p.,� � , i ,�� � 1W �y . N C ���� I . . .� , . _ .._ ��r.,,�f�li—=1 N i -.1 ,- � � , 1� n ., � ,. �, �, .� `pm Dole RnN�lonf ►�y RIDGEVIEW COURT 07-2° °° P GUNp� No. Dat� By �J I' P � W�' H^ � � DOWNSTREAM FLOW MAP /�/� �"\2��' American E�9��a��s . P�����„ . ��r�e��.= 5���. AS 5„aWN � O /,'� ";\z" Englneering 4oas,<e�n n .Ne. I,� � � Redmond,WA 98052 ' DroWn C,J Corporatlon 0 NEe \ ��' "'L� �"'' o..�,��.�.uu.q;'„ - � - — o..iQnw � � `�.S�F;'SIEa`:�<�` PNONE(�25)BB1-74J0 Faa(425)881-77}7 ------ RWS ���NAL �' � Flla pot�R Nams C�ecke0 [xriHc;ua-�, _ I l���200:1�0]12�Enp�nvv�i�y�Dvq�E0J12�G6.d.g 07i20i200� :1�.'���5'an Nof EG DOWNSTREAM ANALYSIS DRAINAGE SYSTEM TABLE RIDGEVIEW COURT - CITY OF RENTON Basin: Cedar Rivcr Subbasin Name: Lower Cedar River Subbasin Number: n/a Symbol Drainage Drainage Slope Distance Existing Potential Observations of field Component Type, Component from site Probiems Problems inspector, resource Name, and Size Description dischar e reviewer, or �esident see map Type:sheet flow,swale, drainage basin,vegetation, % Y.ml=1,320 ft. constrictions,under capacity,ponding, tributary area,likelihood of problem, stream,channel, pipe, cover,depth,type of overtopping,flooding,habitat or organism overflow pathways,potential impacts pond;Size:diameter, sensitive area,volume destruction,scouring,bank sloughing, surface area sedimentation,incision,other eroslon A Dischar�e Point Runoff from site 2-25 0 none nonc No erosion problems from Site B Drainage Channel 4-6 ft Wide at top, +/- 2% 0-25U none none No erosion problems 2.5 ft Dccp, 2:1 SS C Wetland +/- 100 ft x lU0 ft n/a 250-350 none none No erosion roblems D Drainage Channel 4-6 ft Wide at top, +/- 2% 350 - 1650 none none No erosion problems 2.5 ft Dee , 2:1 SS E Wetland (not in 5 —6 Feet Wide, 4 n/a n/a none none No erosion problems flow ath) Feet Dee , 1:1 SS F Culvert 12"Diameter (pipe +/- 2% 1650 - 1675 none none No erosion problems type was not noted) G Structure 60-Inch Diameter n/a 1675 none none No erosion problems (2 - 12"pipes in from channel) H Culvert 36-Inch CMP +/- 2% 1675 - 1750 none none No erosion roblems I Outfall 36-Inch CMP n/a 1750 none none No erosion roblems J Creek (Maplewood) 24" diameter conc. ??? +1750 none none No erosion roblems Figure 7: Downstream System Table Technical lnformation Report jor Ritlgevic�i C�ourt September l6, 200.i SECTION 4 FLOW CONTROL & WATER QUALITY ANALYSIS AND DESIGN The calculations are based on the 1998 King County Surface Water Design Manual (KCSWDM) requirements, as adopted by the City of Renton. The site is located in the Cedar River Basin, which requires a minimum of a Level 2 Flow Control analysis. Water quality features for the site will be designed from the basic �vater quality menu. Existing Sitc Hydrolog�� The site slopes to the southwest ranging from 2% to 25%, and becomes steeper along the southern portion of the site. Vegetation on the site consists of sparse trees and underbrush in the northern portion of the site and shrubs and grasses in the southern portion of the site, see Figure 3: Existing Conditions Map. The soil on the site is AgC, Alder�vood Gravelly Sandy Loam and is classified as till soils by Table 3.2.2.B in the 1998 KCSWD�-f, see Figure 5: SCS Soils t11ap. Developed Site Hydrolog�� The proposed development will consist of 20 single family lots, an access tract with associated roads and utilities, and also a separate storm drainage tract for the detention facility. The Public Access Tract (Road A) will provide access to all of the lots from Bremerton Avenue NE. Runoff from the roadways and lots will be conveyed to the detention vault located on the southwesterly corner of the site. The detention vault will also include dead storage, which will provide water quality treatment for the project, see Figure 8: Developed Conditions Map. A runoff time series was created using the reduced 8-year data. The hourly series was used to size the detention facility. The site is located within the Sea-Tac Region and has a scale factor of 1.0, refer to the Rainfall Regions and Scale Factor Map in Appendix D. The soils on site are Alderwood, therefore, a soil cover type of till was used. ii � I � American Engineering Corporntion Page 16 S ,... '',; / I � � i -' '�t� °A�.��j� � 1 1 � � � � �R��� �� �. 1 Q �.M.�._..,.,A..� N �.. \ ! ( ,S Q ,5 30 6� / �. � t , - � — � , �_� n. — — — W � � � \ li �,,o � i ; �— - --a- —3w y ,po m � � -a;o— R �oa -_ _ � ' t � i� •safw.�K . 406 / -i!t' aars 7 BREMEKTON AVE. N. E. t2 �g - -_ �` --{- � UCP PAINT � P Nr. __�_ � 136TH AVE. S. E. YELLOW 5IR/P£� ' I \ . '44'31'E` 330.03' . .•5lOIEWALK. � . � __ ___ � _� _ � - _ = - _ � n 3 � -��D- J a07 �v ` _ �n O _ � � _._— '�1\ _ .4 _- _ ___ �'\ ` __`-_ - -a .- \ L� / • � � - `- -� �� � �4 � \ Ut mW 3 u - ; � 1 �, � � 6- �n Q Z � � '� r \\ op � '• � /�7� �� � o�l � — I � � $ � �s i i '1 g � i 8 � I ' I /� i i :� � � �) � � `"ge S �n o 0 5 � ii ` � i � i i :'� � i `-` � > '' 11 ; ; ; , I � : `� � x � � � 'M 9� ` � I � � I �� \ I � 1 j � t \ � � 4pM �- � J / ` � � � ` �I I !� � . � I I - � o � .. � � 't � � f � � - - - - -f--- -! - � �a , o ' � - _ � a f$ €P i -i � - • << _ _ � � a i ��. \ � � � � \ � p . ; � �; ��� � � � , � � s - � r a � �1 ' 17 , �.' 4 1 5 = �E $ gti i � . � ' / � \ �� l.\ o� o,S� '" �o . � '- : • / � 1 � �.y si�� �. aos W /I -- � ---- - ! -- _ � � � . � � ��7/ ��. i( C I 5t - I�� / _ ______ __ � ' C� � / � . � I � b�a 1 - �' � O > :� � ;l��� J) I� �' � o � . � � ��� o � a r .� 15 14 � . � v � � � ' ` , r' � � �� ��!1 �, �� I!I aw`U = � '�� ----` ' , \ � � ' I j , a . ( , � ` _- - - ' ',� � ^ __�_ . •r; �_-_ �1 � I� � I �II �cj��SON ��WI . � ,_ t J i /, m �_ ' - 1y�1{ 8 ` 1}1 � ��a �yd � I � I � � � � � �^ u � I 1 I� � �I '� �j o-�!a„? __--_ _ -------------- � .. _ ' c Z I � � I � I 1� � 1 I �_____ ' �� ; ,� II TOTAL AREA= ONSITE + OFFSITE ��a� eg9 a 13� i i 1 ' i 11 i i 10 i i ' 9 `� - � " � �� = 2.91 AC ��15-p� � f � ' J g li i i i � i i i i ` . � ' �� i �'i i i i � i i i i `1 _�'., I T R�F T � �'\'� ,a � I I IMPERVIOUS: - , , �_ - _� � __ _� �_ �__� _- „ ONSITE ROADS/STRUCTURES 1.73 AC ��, � • � . --- --� � . 1�, a_ � ;. -�- '� --- --- --- - _oETEraT v OFFSITE ROADS (BREMERTON�=0.21 AC �i � � 5s - - I ', `, ,A H - - - � - - ' ' TOTAL=1.94 AC a — .. 56 3 -- � � � — — �_---- � ( q ,�..� � - -- --=,z — _ . , .00� - — - - _�J.a� . �330.3; . N00'47'45'E ��,- � \,`�.�1 � P E R VI 0 U S: � W � �. i \ � �� EXiRJDEO ttrtte I ��g��I CAf�ED 9 ,o "� � —,�7 ' i „ �� \ ,`•\,;\ '�� � ONSITE LAWN=0.67 AC U O Z I � � � ��,�0,5 ' OFFSITE PASTURE=0.10 AC � I a,O•W�P_C� e s ` I OFFISTE FOREST=0.20 AC W W � I i TOTAL=0.97 AC � A A i I � � z I i A O i I � U i i � ��o 0312 SMEET FIG 8 Technica!Information Report for Ridgeview Court September 26, 2045 _ Facility Design Methodology The detention facility was sized by trial and enor in accordance with the KCRTS detailed routing method, see Tables and KCRTS flow outputs below. The design intent for the detention facility is to match the predeveloped peak durations for the 2-year, 10-year, and 50-year return periods to , half of the developed 2-year, 10-year, and 50-year respectively(Level 2 Flow Control Standard). ' Existing Conditions: Total Area to be detained = 2.91 Acres 'I Offsite Area(Bremerton) =0.31 Acres Offsite Area (Contributing) =0.20 ac On-site Area=2.40 Acres , Impervious Surface: � On-site Impervious (structures) = 0.08 acres Off-site Impervious (fronta�e) = 0.06 acres j Total Impervious = 0.14 acres Pervious Surface: On-site Till Grass = 0.17 acres On-site Till Pasture = 1.21 acres On-site Till Forest = 0.94 acres Off-site Pasture (Bremerton) = 0.25 acres Off-site Forest (Contributin�} = 0.20 acres Total Pen-ious = 2.77 acres Predeveloped KCRTS Output Flow Frequency Analysis Time Series File:predev.tsf Project Location:Sea-Tac --Annual Peak Flow Rates--- -----Flow Frequency Analysis------- Flow Rate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) Period 0 .211 2 2/09/O1 15:00 0. 360 1 100. 00 0.990 0 .094 7 1/05/02 16:00 0.211 2 25.00 0.960 0 .200 3 2/28/03 3 :00 0.200 3 10.00 0.900 0 . 044 8 8/26/04 2 :00 0.190 4 5_00 0.800 0 .115 6 1/05/05 8:00 0 . 177 5 3 .00 0.667 0.190 4 1/18/06 16 :00 0.115 6 2 .00 0.500 0.177 5 11/24/06 4 :00 0.094 7 1.30 0.231 0.360 1 1/09/08 6:00 0.044 8 1.10 0.091 Computed Peaks 0 . 310 50 . 00 0 . 980 ,-1mc�ri���n� f ngi�rrc°riit�C'r�r���nrcitiurr Pagc� l8 Technical Information Report for Ridgeview Court September 26, 2005 Developed Conditions: Total Area to be detained = 2.91 Acres Offsite Area(Bremerton) = 0.31 Acres Offsite Area(Contributing) =0.20 Acres i On-site Area=2.40 Acres Impervious Surface: On-site Roads/Structures/Driveway = 1.73 acres Off-site Roads Bremerton ROW = 0.21 acres Total Impervious = 1.94 acres Pervious Surface: On-site Till Grass = 0.67 acres Off-site Pasture Bremerton ROW = 0.10 acres Offsite Forest (Contributin�) = 0.20 acres Total Pervious = 0.97 acres ***see Appendix D for a detailed breakdown of Areas on site _ Developed Area Output for site Flow Frequency Analysis Time Series File:dev.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- -----Flow Frequency Analysis------- Flow Rate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) Period 0.543 6 2/09/O1 2:00 1.08 1 100.00 0.990 0.451 8 1/05/02 16:00 0.722 2 25.00 0.960 0.649 3 2/27/03 7:00 0.649 3 10.00 0.900 0.496 7 8/26/04 2:00 0.595 4 5.00 0 .800 0.595 4 10/28/04 16:00 0.579 5 3 .00 0 .667 0.579 5 1/18/06 16:00 0.543 6 2.00 0.500 0.722 2 10/26/06 0:0a 0.496 7 1.30 0.231 1.08 1 1/09/08 6:00 0.451 8 1.10 0.091 Computed Peaks 0.962 50.00 0.980 Retention/Detention Facility Type of Facility: Detention Vault Facility Length: 110.17 ft Facility Width: 48.00 ft Facility Area: 5288. sq. ft Effective Storage Depth: 6.25 ft . Stage 0 Elevation: 396.00 ft Storage Volume: 33050. cu. ft Riser Head: 6.25 ft Riser Diameter: 12.Q0 inches Number of orifices: 2 Full Head Pipe Orifice # Height Diameter Discharge Diameter (ft) (in) (CFS) (in) 1 0.00 1 .10 0.082 2 2 . 90 1.10 0 .060 4. 0 Top Notch Weir: None Outflow Rating Curve: None -lmericnn En�ineering Col�oration Page 19 Technical Inforrnation Report for Ridgeview Court September 26, 2005 __ Stage Elevation Storage Discharge Percolation (ft) (ft) (cu. ft) (ac-ft) (cfs) (cfs) 0.00 396.00 0. 0.000 0.000 0.00 0.01 396.01 53. 0.001 0.004 0.00 0.02 396.02 106. 0.002 0.005 0 .00 0.03 396.03 159. 0 .004 0.006 0.00 0.05 396 .05 264. 0.006 0 .007 0.00 0.06 396.06 317. 0.007 0.008 0.00 0.07 396.07 370. 0 .008 0.009 0 .00 0.08 396.06 423. 0.010 0.009 0.00 0.09 396.09 476. 0.011 0.010 0.00 0.20 396.20 1058. 0.024 0.015 0 .00 0.30 396.30 1586. 0.036 0.018 0.00 0.41 396.41 2168. 0.050 0 .021 0.00 0.52 396.52 2750. 0.063 0.024 0.00 0.62 396.62 3279. 0.075 0.026 0.00 0.73 396.73 3860. 0.069 0.028 0.00 0.83 396.83 4389. 0.101 0.030 0.00 0. 94 396.94 4971. 0.114 0.032 0.00 1.05 397 .05 5552. 0.127 0.034 0.00 _ 1.15 397.15 6081. 0.140 0.035 0.00 1.26 397.26 6663. 0.153 0.037 0.00 1.36 397.36 7192. 0.165 0.038 0.00 1.47 397.47 7773. 0.178 0.040 0.00 1.57 397.57 8302 . 0.191 0.041 0.00 1.68 397.68 8884. 0.204 0.043 0.00 1.79 397 .79 9466. 0.217 0.044 0.00 1.89 397.89 9994 . 0.229 0.045 0.00 2.00 398.00 10576. 0.243 0.046 0.00 2 .10 398.10 11105. 0.255 0.048 0.00 2 .21 398.21 11687. 0.268 0. 049 0.00 I 2.32 398.32 12268. 0.282 0.050 0.00 ' 2 .42 398.42 12797. 0.294 0.051 0.00 2 .53 398.53 13379. 0.307 0. 052 0.00 2 .63 398.63 13907. 0.319 0.053 0.00 2 .74 398.74 14489. 0.333 0.054 0. 00 � 2 .85 398.85 15071. 0.346 0. 055 0.00 2 .90 398.90 15335. 0.352 0.056 0.00 2.91 398.91 15388. 0.353 0.056 0.00 2.92 398. 92 15441. 0.354 0.057 0.00 2 .93 398.93 15494. 0.356 0.058 0.00 2 .95 398.95 15640. 0.358 0.060 0 .00 2 .96 398.96 15653 . 0.359 0.063 0 .00 2.97 398. 97 15705. 0.361 0.a65 0.00 2.98 398. 98 15758. 0.362 0.066 0.00 2 .99 398 .99 15811. 0.363 0 .067 0.00 3 .10 399.10 16393. 0.376 0 .072 0.00 3 .20 399.20 16922. 0.388 0.077 0.00 3 .31 399.31 17503 . 0.402 0.081 0.00 3 .42 399.42 18085. 0.415 0 .084 0.00 3 .52 399.52 18614. 0.427 0.087 0.00 3 .63 399.63 19196. 0 .441 0.090 0.00 3 .73 399.73 19724 . 0.453 0.093 0.00 3 . 84 399.84 20306. 0 .466 0.096 0. 00 3 . 95 399.95 20888. 0 .480 0.099 0.00 4 .05 400 .05 21416. 0.492 0.101 0.00 4 . 16 400. 16 21998. 0.505 0. 104 0.00 4 .26 400.26 22527. 0.517 0. 106 0. 00 4 .37 400.37 23109. 0 .531 0. 108 0 .00 4 .47 400.47 23637. 0. 543 0.111 0 .00 4 .58 400.58 24219. 0.556 0.113 0.00 :9mericnn Engineering Corporation Page 10 Technical Information Report for Ridgeview Court September 26, 2005 4 .69 400.69 24801. 0.569 0.115 0.00 4.79 400.79 25330. 0.581 0.117 0.00 4 .90 400.90 25911. 0.595 0.119 0.00 5.00 401.00 26440. 0.607 0.121 0.00 5 .11 401.11 27022. 0.620 0.123 0.00 5.22 401.22 27603. 0.634 a.125 0.00 5.32 401.32 28132. 0.646 0.127 0.00 5 .43 401.43 28714. 0.659 0.129 0.00 5.53 401.53 29243. 0.671 0.130 0.00 5.64 401.64 29824. 0.685 0.132 0.00 5.75 401.75 30406. 0.698 0.134 0.00 5.85 401.85 30935. 0.710 0.136 0.00 5.96 401.96 31517. 0.724 0.138 0.00 6.06 402.06 32045. 0.736 0.139 0.00 6.17 402 .17 32627. 0.749 0.141 0.00 6.25 402 .25 33050. 0.759 0. 142 0.00 Hyd Inflow Outflow Peak Storage Target Calc Stage Elev (Cu-Ft) (Ac-Ft) 1 1.08 a.35 0.32 6.31 402.31 33354. 0.766 2 0.72 ******* 0.08 3 .20 399.20 16915. 0.388 3 0.65 ******* 0. 11 4.26 400.28 22634 . 0.520 4 0.59 ******* 0.04 1.70 397.70 8992 . 0.206 5 0.58 ******* 0.11 4.31 400.31 22795 . 0.523 6 0.54 ******* 0.14 5.87 401.87 31040 . 0.713 7 0.50 ******* 0.05 2 .16 398 .16 11403 . 0.262 8 0.45 ******* 0.05 2 .58 398 .58 13626. 0.313 i Route Time Series through Facility Inflow Time Series File:dev.tsf Outflow Time Series File:rdout � i Inflow/Outflow Analysis � Peak Inflow Discharge: 1.08 CFS at 6 :00 on Jan 9 in Year 8 Peak Outflow Discharge: 0.320 CFS at 11 :00 on Jan 9 in Year 8 � �, Peak Reservoir Stage: 6.31 Ft Peak Reservoir Elev: 402.31 Ft Peak Reservoir Storage: 33354. Cu-Ft . 0.766 Ac-Ft � �__ � ! i z i An:erican Engineering Corporation Page 21 Technical Information Report for Ridgeview CouK September 26, 2005 __ Flow Duration from Time Series File:rdout.tsf Cutoff Count Frequency CDF Exceedence_Probability CFS � � � ' 0.002 36187 59.013 59.013 40.987 0.410E+00 ' 0.006 2646 4.315 63 .328 36.672 0.367E+00 0.010 3628 5.917 69.245 30.755 0.308E+00 0.013 3135 5.113 74 .357 25.643 0.256E+00 0.017 2986 4 .870 79.227 20.773 0.208E+00 0.021 2635 4 .297 83.524 16.476 0.165E+00 0.025 2218 3 .617 87.141 12 .859 0.129E+00 0.029 2103 3 .430 90.571 9.429 0.943E-01 0.032 1387 2 .262 92.833 7.167 0.717E-01 0.036 1187 1.936 94.768 5.232 0.523E-01 I 0. 040 734 1.197 95.965 4 .035 0.403E-01 I' 0.044 727 1.186 97.151 2.849 0.285E-01 0.048 470 0.766 97.917 2 .083 0.208E-01 0.051 476 0.776 98.694 1.306 0.131E-01 0.055 309 0.504 99.198 0.802 0.802E-02 0.059 63 0.103 99.300 0.700 0.700E-02 0.063 15 0.024 99.325 0.675 0.675E-02 0.067 16 0.026 99.351 0.649 0.649E-02 0.071 54 0.088 99.439 0.561 0.561E-02 0.074 52 0.085 99.524 0.476 0.476E-02 0.078 39 0.064 99.587 0.413 0.413E-02 0.082 23 0.038 99.625 0.375 0.375E-02 0. 086 19 0.031 99.656 0.344 0.344E-02 0 .090 22 0.036 99.692 0.308 0.308E-02 0. 093 17 0.028 99.720 0.280 0.280E-02 � 0.097 21 0_034 99.754 0.246 0.246E-02 0.101 32 0.052 99.806 0. 194 0.194E-02 0. 105 28 0.046 99.852 0.148 0.148E-02 0 . 109 21 0.034 99.886 0.114 0.114E-02 0.112 7 0.011 99.697 0.103 0.103E-02 0 . 116 13 0.021 99.918 0.082 0.815E-03 0 . 120 13 0. 021 99.940 0.060 0 .603E-03 0. 124 7 0.011 99.951 0.049 0 .489E-03 0 .128 13 0.021 99.972 0.028 0.277E-03 0.132 7 0.011 99.984 0. 016 0.163E-03 0. 135 6 0 .010 99. 993 0.007 0 .652E-04 Duration Comparison P�aylsis Base File: predev.tsf New File: rdout.tsf Cutoff Units: Discharge in CFS -----Fraction of Time----- ---------Check of Tolerance------- Cutoff Base New �Change Probability Base New $Change 0.058 � 0.71E-02 0.71E-02 -0.2 � 0.71E-02 0.058 0.058 -0.2 0.070 � 0.53E-02 0.58E-02 8.6 � 0 .53E-02 0. 070 0.072 2 .8 0 .082 I 0 .41E-02 0.38E-02 -9_4 I 0.41E-02 0.082 0 .078 -4 .7 0 .093 � 0.30E-02 0.28E-02 -6.5 ( 0.3�E-02 0. 093 0 .091 -3. 1 O . 1Q5 I 0 .23E-02 0.15E-02 -34 .8 � 0.23E-02 0.105 0.099 -5.8 0 . 117 I 0.16E-02 0.78E-03 -52 .0 � 0.16E-02 0.117 0.104 -11.5 0.129 � 0.12E-02 0 .24E-03 -78.9 � 0. 12E-02 0.129 0.108 -16.0 0.141 I 0.86E-03 O.00E+QO -100.0 � 0 .86E-03 0.141 0.115 -18.1 0.152 � 0.62E-03 O.00E+00 -100.0 � 0.62E-03 0.152 0 .120 -21.3 0.164 � 0.46E-03 O.00E+00 -100.0 � 0.46E-03 0.164 0. 124 -24 .4 0.176 � 0.23E-03 O.00E+00 -100.0 � 0.23E-03 0.176 0.130 -26.4 0 .188 � 0.15E-03 O.00E+00 -100.0 � 0.15E-03 0. 188 0.132 -29.6 0 .199 � 0.65E-04 O.00E+00 -100.0 � 0.65E-04 0 .199 0.135 -32 .1 -imrrrcan En,�>iiteerin�� C�orpnrrrtion Page 22 Technical Information Report jor Ridgeview Court September 26, 2005- Maximum positive excursion = 0.005 cfs ( 8.8$) occuring at 0.061 cfs on the Base Data:predev.tsf and at 0.067 cfs on the New Data:rdout.tsf Maximum negative excursion = 0.074 cfs (-35.1�) occuring at 0.210 cfs on the Base Data:predev.tsf and at 0.136 cfs on the New Data:rdout.tsf See below for image rdout and target. Note that rdout is within the 10%allowance per the target. Therefore, the release rate out of the detention vault is per requirements set forth in the 1998 KCSWDM per City of Renton Standards. � '� N ' o rdout.dur O ao - � � target.dur ♦ � � � � U N I .._. � v� � � L � � � � 0 � � � � ❑ M � � V � 10 -5 10 -4 10 -3 10 -2 10 �� 10° Probability Exceedence ,-�»ie�riccn► F.r:gir:ee�-i�tg Corpurutiori - - Page?3 Technical lnformation Report for Ridgeview Court September 26, 2005� Detention Vault Outfall DesiPn Methodolo�y—Rip Rap Pad: Once runoff has been treated and detained in the proposed detention vault on the northwestern portion of the property, it leaves the vault via a 12"pipe and discharges onto a rock pad for dispersal purposes before flowing into the broad swale on the adjacent parcel. The rip rap pad as designed is sufficient to disperse runoff leaving the vault. The flow out of the vault during the 100-year(detained) event is only 0.14 cfs per the KCRTS Output above. The 12"outfall pipe is sloped at 1.25%. Therefore, the velocity of the runoff through this pipe is 2.4 f�/sec. Therefore, the rip rap has been designed to meet the above discharge standards. Furthermore, a level spreader dispersal trench will not work in this scenario because the discharge from the vault is to a channei type of feature. With that said, it would be difficult to impossible to design the level spreader to sit parallel with the contour elevations. The rip rap pad has been sized in accordance with Table 4.2.2.A of the 1998 KCSWDM. Since the exit velocity is 2.4 ft/sec (between 0 and 5 f�lsec), the rip rap pad as shown in the engineering - plans is designed at 8 feet long by 6 feet wide by 1-foot deep consisting of quarry spalls with the following properties: • Passing 8-inch sieve= 100% • Passing 3-inch sieve= 40%to 60%max. • Passing'/4-inch sieve= 0%to 10%max. Wetpool Sizing: V�[0.9A;+0.25Atg+0.25AP+0.OlAa](R) Where: _ [Q.9(76,230)+ 0.25(37,462) + Vr =Runoff Volume from Mean Annual Storm 0.25(4,356)] (0.039) ��� � A; =Area of Impervious Surface(s� ' =3,083 cf A��=Area of Till Grass(s fl AP=Area of Till Pasture (s� Ao=Area of Outwash Soils(s� N( /A) Vb—fV� Vb =Required Wetpool Volume(c� f = Volume Factor(3.0 for basic ponds) =3A (3,083) =9,249 cubic feet R =Rainfall from Mean Annual Storm(ft) required (from KCSWDM Figure 6.4.1.A) =0.039 Total Volume Provided in the Wet-Vault= 15,840 CF( 110' x 48' x 3' ) American Engineering Corporation Page 24 Technical I�Tfnirnation Report ror Ridgevietiv Court September 26, 2005 SECTION 5 CONVEYANCE SYSTEM ANALYSIS AND DESIGN Detention Vault Outlet Riser The outlet riser for the combined detention / ��vet - vault facility has been sized per Section 5.3.4 of the 1998 KCSWDM. A 12-inch diameter riser, with 0.50 feet of head can convey 2.67 CFS. The 100-Year Developed peak flow is 1.02 CFS, therefore a 12-inch riser�vill be adequate. Qo�F�cE= 3.782��� )�H �") Where D =diameter(ft)— 1.00' H =head (ft) —0.50' Qo�FicE= 3.782(1.002)(0.50''Z) = 2.67 CFS See Figure 5.3.4H Riser Inflow Curves in Appendix D. On Site Conveyance Calculations The flo�;�s on site were found by using the rational method for checking the backwater of the conveyance system, an acceptable method per the 1998 KCSWDM. Once the flows were obtained, the King County Back Water Program was used to run the backwater analysis and tl pipes were sized to ensure no overtopping would occur. The storm drainage conveyance systclii was sized to ensure that during the 25-Year 24-Hour storm event the conveyance system is able to convey the flows without overtopping occurring. Furthermore, the conveyance system was also checked to ensure that during the 100-Year 24-Hour storm events the system would function ' adequately and no overtopping would occur at any of the structures. It was found that the system does indeed function per the requirements set forth in 1.2.4 of the 1998 KCSWC�� " , Rcfcr <<� 'fahle �"I.:� - HCI. ��s. Rim an�i alsn i��F�ut� ancl outE�ut� i�� ;�����enclix I�'� � '__. Americnrt Engineering Corporation Page 25 Technical Inro�mation Report for Rirlgeview Court September 26, 2005 Rim Elev vs. HGL Elev Table Table VI.A- HGL vs. Rim System CB NO. RIM ELEV. 100-YR HGL ELEV FREEBOARD (F'I') No. 1 2 403.74 402.29 1.45 1 3 404.00 403.31 0.69 1 4 404.42 403.82 0.60 1 5 405.23 403.89 1.34 1 6 407.09 403.91 3.18 1 7 409.50 404.54 4.96 1 8 406.76 405.19 1.57 2 9 404.42 403.90 0.52 2 10 405.41 403.97 1.44 2 11 405.55 404.03 1.52 2 12 405.55 403.03 2.52 3 14 403.33 402.30 1.03 4 1 404.18 402.25 1.93 5 15 404.31 403.34 0.97 6 16 404.25 403.32 0.93 7 13 405.02 403.92 1.10 8 17 405.02 403.90 1.12 I ; � - � , i American Engineering Corporation Page 26 Technical Information Report jor Ridgeview Court September 26, 2005 SECTION 6 SPECIAL REPORTS AND STUDIES A wetlands study has been prepared by Alder NW dated March 13, 2003. Also, a geotechnical report has been completed by GeoGroup Northwest dated October 4, 2004. No other reports or studies pertaining to this project are known at this time. 4ntcric�ctii F.nginterrri�� C'or•pnrutir>n Prrge?i Technical Information Report for Ridgeview Court September 26, 2005 __ SECTION 7 OTHER PERMITS A separate building permit will be required for the detention vault and rockeries greater than 4 feet. Furthermore, a demolition permit will be required for removal of all existing buildings on site. No other permits are anticipated as part of this project at this time. � I :I ', ', � { t _' , � American Engineering Corporation Page 28 Technical Information Report for Ridgeview Court Septernber 26, 2005 _ SECTION 8 ESC ANALYSIS AND DESIGN Several standard erosion control procedures will be utilized by the contractor to minimize the amount of erosion and sedimentation perpetuated by the construction of the site. Some of the measures include a rock-lined construction entrance, filter fabric f ence, a t emporary s ediment trap and standard ground cover practices. A construction sequence will also be used to minimize the impacts of erosion due to construction. These items will be discussed in further detail when the construction / final engineering plans and final TIlZ are submitted to the City of Renton for review. Clearing Limits: T he c learing 1 imits h ave b een c learly m arked a nd w ill s how the contractor where site disturbances should occur. Construction Entrance: A rock lined construction entrance will reduce the amount of sediment transported off the site by construction vehicles. Detain Flows: The permanent vault and or temporary sediment pond will be used to remove sediment from the runoff generated by the disturbed areas during construction. The vault has I been sized per 1998 KCSWDM requirements. Refer to Section N for more information. Sediment Controls: Filter fabric fence will be used as perimeter protection to reduce the amount of sediment transported off the site. Soil Stabilization: Notes have been added to the engineering plans, describing how denuded areas will be treated if left un-worked for longer than 7 days. Slope Protection: Slopes will be protected once final grade has been achieved or left un-worked for longer than 7 days. Drain Inlet Protection: Catch Basin Inserts will be installed once the final storm system is installed. Furthermore, inserts will be installed on all catch basins adjacent to the site on Forbes { Creek Drive as shown on the Engineering Plans. Stabilized Channel Inlets and Outlets: If necessary, temporary and permanent BMP's may be required for pipe outlets and inlets. These BMP's may include but are not limited to filter fabric fence, straw bales, or filter bags at pipe ends. Pollutant Control: With the BMP's mentioned above, the pollutants should be kept to a minimum during the construction process. De-Watering Control: A temporary riser in the sediment pond or the permanent riser in the vault will be used for the de-watering control. Refer to "Detain Flows"above for more information. i_ American Engineering Corpor�tion Page 29 Technica!Information Report for Ridgeview Court September 26, 2005 BAIP's Maintenance: Temporary and permanent BMP's shall be maintained per the proper maintenance standards. Construction Sequence: A construction sequence has been shown on the final construction plans to aid the contractor in applying the different erosion control measures at the appropriate stages during construction. Sediment Trap Stzing: SA = 2 x Qlo-year/ 0.00096 where SA=required surface area at top of riser Q�o-year= 0.607 C fs SA= (2 x 0.607)/0.00096 = 1,265 sf As proposed the temporary sediment trap contains 1,655 SF at the maximum water surface (@ elev. 403). Therefore, sufficient surface area has been provided. Emergency Overflow Spillway Sizing: L= �Q(�oovR�/ ( (3.21)(H3rz) )) —�2.4) �H) L= Length of spilh��ay(6 foot min. allo���ed) - see belo��� Q��oovR>= 100 year developed flow— 1.02 cfs H = Height above head - 0.2 ft L= [1.02 l( (3.21)(0.2�'�) ) ] —(2.4)(0.2)= 3.1 feet Since the developed site produces such small flows, the required length of the spillway structure is below the minimum length (6-feet). Therefore the proposed spillway as designed has a length of 6 feet. ; � . I ' I ' American Engineerirrg Corporation Page 30 Technical Information Report for Ridgeview Court September 26, 2005 SECTION 9 BONDS, SUMMARIES AND COVENANTS A bond quantity worksheet will be provided to the City of Renton if requested. A facility summary information sheet has been provided in the next three pages. I American Engineeriirg Corpor�tion Page 31 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL STORMWATER FACILITY SUMMARY SHEET Ridgeview Court—Renton File No. B04CO217 Development: Rid�eview Court Date: 09/14/OS Location 327 Bremerton Avenue NE, Renton, Wa. ENGINEER DEVELOPER Name: Einar Gundersen, P.E. Name: Cliff Williams Firm : American En ineerin Co oration Firm: Rid eview Court LLC Address: 4032 148` Avenue NE Address: P.O. Box 2401 Redmond, Wa. 98052 Kirkland WA, 98083-2401 Phone: 425)881-7430 Phone: (206) 714 - 7161 Developed Site: 2.91 Acres Number of lots: 20 Number of detention facilities on site: Number of infiltration facilities on site: - 0 ponds 0 ponds 1 vaults 0 vaults 0 tanks 0 tanks Flow control provided in regional facility(give location): N/A No flow control required Level II Exemption number N/A Downstream Draina e Basins Immediate Ma'or Basin i Basin A Lower Cedar River Lake Washin ton / Cedar River Basin B N/A N/A Number& type of water quality facilities on site: 0 biofiltration swale (regular/wet/ 0 sand filter(basic or large?) or continuous inflow?) 0 sand filter, linear(basic or large?) 0 combined detention/WQ pond 0 sand filter vault (basic or large?) (WQ portion basic or large?) 1 combined detention/wetvault 0 stormwater wetland 0 compost filter 0 wetpond (basic or large?) 0 filter strip 0 wetvault 0 flow dispersion 0 farm management plan 0 landscape management plan 0 pre-settling pond 0 flow-splitter catch basin 0 oil/water separator (baffle or coalescing plate?) 0 oil/water separator(baffle or coalescing plate?) 0 Catch basin inserts: Manufacturer: 0 pre-settling structure: Manufacturer 1998 Surface 4Vater Design 1�4anual 9/1;98 1 K[NG COUNT�', �'�'ASHINGTON, SURFACE WATER DESIGN MANUAL DESIGN INFORMATION A B C Water Quality design flow 0.309 cfs ( 60% develo ed 2 year(0.515 cfs) ) (0.515*0.6) Water Quality treated volume or 9,249 cu. ft. wetvault Vr DESIGN TOTAL INFORMATION, cont'd II Drainage basin(s) A B C Onsite area 2.40 ac Offsite area 0.51 ac T e of Storage Facilit Vault I� Live Storage Volume 33,000 cu. ft. Predevelo ed Runoff Rate 2-year 0.115 cfs I 10-year 0.200 cfs 100-year 0.360 cfs Develo ed runoff rate 2-year 0.515 cfs 10-year 0.616 cfs 100-year 1.04 cfs Type of restrictor 2 Orifices Size of orifice/restriction No. 1 1.10 in No. 2 2.75 in No. 3 N/A No. 4 N/A ; ', � i Ii� � � ; - i )/►i)8 1998 Surface 1�'ater Design Manual � � SECTION 15,TOWNSHIP 23 NORTH,RANGE 5 EAST,W.M. E%7FND VAULT WALL MIN 6"ABOVE FlNISHED GRADE � WRB. ADD 4 HIp1 VINYL CHAMlUNK iENCE ON TOP OF CURB I : RIM ELEV- 4'HIGH VINYL COA7EO CHAINUNK FEYCE 6�PVC WT (', � 405.03 'N71N VAULi WALL E7(7ENDED MIN. 6' 70 WTI.ET �� 392.00 , -.- �ABOVE FlNISH CRADE. 392.00- PoY ELEV= B� � � ' _-_--______- 405.&T ' '�- _-__- 39200 -__-_---ZY--- - -------- ----- 393.00 i - ' -'-'- -`- : EXIEND VAULT WALI II 4'x4'MT PAD 3�� 6'MIN.ABOVE FWI4i li �z.00 ena.a.�i.io /� en=�z. R �I \ � J92.00 /f \ � / 11 � IE=395.00�!� GRADE. � E%7RlAED / �� � FlNISHED CRADE I 11 ASPHALT CURB � II II \ C AT ROAO END / / ? I ��--FOOi1NC URNN. II � 2s2(1� � �� � 11 6'PERF. PVC 10' II � DINpNG/LOAD BEAPoNC n•� \ � II WD AT Ox �OF LID a II WALL IX7ENqNG FRpA 6.� � II t403.B5 � A II \ / TOP i0 B077p1 OPENING(T7P) � / II A .� � I \ z z a " � ��I - � � � 11 2� \ TOP=J93.00 I � M.W.S E1.��0235 - - Y 39J.00 � t. }92.00 - II \ 71A-392.00 \� II � -' TOP OF BAiFLE WAII II � � 39t. 11 6'-►xN. ,. : II �,/ }9.50 392.50 7rT TOP OF WALLN� 9AFFLE WALL ,\ II . OIVIUING WALL' I r I II i ���D�� \ II ' . - II j I �1 (zo^a.c.Min.) i i eorrou ro u.ws. �� , � �, z �II�: II � � KI� 2'vn0E.a5'tl�c,li �� � , t . II � �v \ \ � � II � � _ . I II �2'e vENnunoN " � 5X10 GRATED �� 100'-2 TOP�93. � ♦ 7(ISTINC _ PR�ONOEO�ELS�� 3Z• � 0 . ZZ• � PIPE(T1P) 9�'� ' 1B' j �� GROUND i,"', i m2505F II _ II fi'SUCA .. , n� ��1_� a �. - �F I � =-c===c=----c= - --- ----------c---cc- --- __ _-_-- c -c 6'IE�396.50 "� � . �a RIM 0.EV= MM=MATCH FlNISH 6 �� q �c . 393.00 CRADE 7YP. 'OFErMNG,. . - 406.00 B� � � . ADJJSTABIE-+ .,,E , 1 �z� - � _ _ �� W 9 6'FRON RIA1 ElEV- 18�FR04 CB j2 -0.�� .=596.00 -`p$a' E�T395.50 �5.02 IE=39t.50 � � p � . I � VAULT PLAN VIEW � g � �, o,c ' L � SCALE 1'=lO' �n /� C�a. o �,�� mm, . ,o i�"� p� �. O rCURBING 6' ' ^.ii l� \�l 0� G - - -- -- 1 HIGH ABOVE FRAME, GRA7E ANO ROUND � . . L.=393.00 �C O � � FlNISH qiADE $pUD CAVER MARKED Q W U � - - - FlNISHm GRADE �RAIN�W�LOCKING BOl7S NQTES - '-- -- __ RIIA ELEVATIqi PER VAVLT - - PLAN VIEW,iHlS SHEE7. 1. SHEAR CATE SHALL BE: ��'� SECTION B-B A CAST IRON 80DY AND GATE,OIYIAPIC fDY,S1D., OFi EWAL. ?o� �8yi� �,,I SCALE 1'=10'HORI2. B. ALUMINU41, DRAINAGE SPEpALTIES(SAVANNA, GA)$7D, m TOP OF UD i"=2'4ERT. OR EWAL. �� �. (r�.�}b3.�` 12"VENT PIPE ����o a� --__ - I I . IN CORNER 2.CATE SHALL BE B'DIAMETER UNLESS OIHERYASE SPECIFlED. °� ♦em � �'(7yp,� y UD/WALL THICKNESS YAY YARY. 3.GAIE SHALL BE JOINED 70 7EE SEC710N BY BOLTNG 8rj� pi�� � - SEE VAULT SIRUCNRAL PLANS (TMRWGH FLANGE), MELDING,OR OTHER SECURE MEANS. - ` - M.W.S.EL=102.35 Q - -.. ' �� BY O7HER5 FOR MORE r. . .-.. ..- . .. - . . - .- . -.. - - .. -.. .- - -' -.'- INFOftMAT10N. �. JFT ROD: AS SPEqFlEO BY MANUFACNRER N17H HANDLE !�+ � - _ . - EX7ENDE�TO YATNIN ONE FOOT OF COVER AND ADJUSTABLE � 6�YIN_ . u , . . t'�4'HINDCED CRAiE HOOK LOCK FAS7ENm TO FRAME OR 11PPER HANDHOLD. BAFfLE WALL � �� y ACCE55 M CORNEA � 12��RISER/FLOW - � � w . -� RE57PoCTOR PER �_ � � . _ �i . ��.i . . . . I SE�CETpd C-C.TIIS ` .., � � � . . y . . i . W 4 � TOP OF pPp1ING N � STANDARD SiEPS OR UDUER r1! p - ��-���f ' � . � � PIPE SUPPORT� J�x0.90 GA. BOITFD �r+-�� . � - � � . RE40YABLE WATERTIGHT 1••� � OR IMBEDOED 2�IN WALL ALUMINULI UFf R00,SECURE TO S1EP n � �'' CWPLING OR M£LD TO i .. 2�, . . '�� � .. ,Q AT MA%. 3'SPApNG STANOPIPE F•y H i OPENING .. �y '� , � . M.W.S.EL.�102.35 � _ _ TOP OF RISER W w � i - . . - = E1=40235 LE. (SEE RESTRICTOR a �'� .. � - _ . EL=396.00.Q_ . . .;.,. 6"PERF. PVC DETAIL) z O � ��. EL.=198.90 6'MIN. 6 6� F . .-. . -.. - . � . . - . . - . . _. � • , . - . . -. . -. - . - . . (TYPJ QEANWT/B'SHEAR GAiE � 0 6"IE J96.50 ORIFlCE DIA. 1.10� MAl(. N � �.,, < u � �- BTM L1VE STORACE � I OU7FALL PER DETAIL SHT 11 MQ.L1 ELBOM'M77F� W ��'''� � ,. _ �^ EI.=J%.00 - N 1�2�G�E�I�DiE F„� � '' � 392.00 ��12 CA. BOTTOAI PLA7E N1TH I.10'0 �� .� '" . w :. �,.. BTIA DEAD STORAGE p ORiFlCE. SFiARP EDGE. 510P DPoLLED � �..J . � ' ' - IN PUTE. EL. 39t.00 '" 397.00 0..=393.00 = � 393.00 .. _ZX M1-�- .. - . -2S M`_N.(��n. �-��-�.v- . ..-.-- . - . - . . 392.00 ELBOW DE�AIL W'1a 392.00 �� v � Q � 392. �__� 392.SQ Zx 41N.(7)p) 1--1 �y 392.� SECTION GC c� a J91.50 391.50 SCALE 1'=10'MORiZ. 1•.y r=s veRr. U SECTION A-A � sc.+� r=w' Na+¢. NOTE: � 1"=2'VERT. C1VE STORAGE/ DETENTION VOLUME REWIREO = 33,354 C.F. VOLUME PROVIOED = (6.25)(48)�710'-2') = 33,579 C.F. NOTE: �� VAULT SHAALL BE DESIGNA�ED FOR H-20 VEMICLE 0312 LOADING.. s�EEr N/A Technical Information Report jor Ridgeview Court September 26, 2005 SECTION 10 OPERATIONS AND MAINTENANCE MANUAL The storm drainage elements requiring maintenance attention inciude: detention vault, wetvault, Type 1 and 2 catch basins, and all storm conveyance lines. The detention /wetvault facility located within the separate public Tract shall be maintained by the City of Renton. The operation and maintenance guidelines can be found in Appendix E. , � ' 1»i��rica�r Engineering Cor/�orutlon Page 35 � � � A � W � a � � � c Q ' W � � Q g . ; _ � � :� � , � Z � � . ; ��_~ H�y I( t \, �- � Z � n 5 � '� 1.1l,l� �� . ;,`�"x'Y p"'� � Z � 2 � —� e �I �^ �,�`� � � l, � — --=� =�����,,�;�:�� �_-� � � g �� � f I ` 9 �' � � f � i � � I ,.�._ �pli �'n� �✓ /� � q� �R a Y � •- 1 - - , ; .. �-�) 11 , �, •.�.�,_.i f� Z � N � �� 1�� o:i� . < ,i�O-.1 �� MM � �� ` �;�'�, '��?; ��� Y —' " � ,1 a � '1. !1''� „ r� r' I; ',` Z � ��' " 1 ; � ��, R ._ � I � -�1..-,� �� � � I I � , � ,L-y'J -��'�, ,I �' jt'- i �J � f �! ���+� �� � d� � l ;, � „ �' � 1` 0 -- � � 1' 1---�,� -, � ! �'�°�' � i�:, _. .� _�'� ' �`��;�� '� t r_ _ I -i.,:� �� `�_���n.c .�:�,�� V �.. j ���' �� J�'� -- ,..\ �' ^�?.` W�' � t ' " 1 � � " �n i �:L�'� �� < �i f� s; ���! l� � � � 1 �/ !f � \ �qr � � � �� Ja� � +A ��� �� � � � �< ����� � ,d��`���-�� i'�� �� � 1T'� �? ..,�� �� �i� .f� �. ,' � . � �; �, � ,d! f, � � � 1 j'�.- �' :\ . �. ` � �`--r o -�>,.�._ / /.' �� �� ►f � � ! �j`��---, 1 � 1\ `�7 (��`� �'\ _:�. .�.;,Y' . -�� �j ",� Q� `�� �! � �• i c� �/ __ � jf� ''�\ 1� `'�� s`r f � � ��i � �- j �_ / i� -/ � i 1 1 �� _�3••...., � � !,� 1,, �; � \ , "'r � � � � �� , i �, ,, 0 , � �-2 , �� ��-., -%�' a' ':, � / �' , '��i � }��" �t_- � �/ I • ��� v� ,, T l �i � � Jr + � �, !, '' �,�°� ` „ �� �� , ,► �� ,,�,� �,, c ` ` ,- -'�a . � fy` ��,-�.-._- l, ', 1 � �`) „ ,� ' ( � � '�+ � �,-, �,-� �� 1 � _..� � � �,� ,� � r, 5— .� � , } ,�, �,, - ,, - , � � ' � ' , , �, . �., .a� � � ►— i , � �, , � ,� fr :� % � � t: '� Z �� , 1 _ _ '� ,�'` ' � '� ' I � � � ,, � i 1._,_r !� ��� `�., 1� w �Cf��•-�:.G i I� � tl� � �� �, � , � ! � � � 1 � J �� �l _ v �} I' 4 �"'` 1 1 � �,�-_ � �' ' f� \ f�` " ( � r": . -,' j� � � : 1 r`��--� � �� - 1 I f � � � !I _ � `� 1 �� � _�a_e_',-� .�1 � y� d1 �� �� � !' \_' � �I , i �/ .o,�: �' ,,. ��> ti 1 , � �, � � - � � � :� �-- T J !� . -'�7 (�.. . a ��� i r,� � 1 , t� +..'l �' -�,�' f J a } -'�y__ �I,� � /r�� 11 � l � � � _ _„f' �� � {� � �. 1 � .'i�) c'��� �+ a� �`'� � I //. , � � , , � , � s= .1 3p .i � �'' � d' �;k �/ 1� �;'� r- �i �1 ''��� �� � ` �� ( � _ �' ' � � � I � k,, � � •t i� �� 11 �- � �.,' � � � �,��Ir- i ���j `� ��� f'/ `' f� � � ;- a ,� � � ,, i� � r ���� � - � � 1 < < .a ` � /� '�' _ � l- � ' s� � � i �'�� ,, ,o ' - �_i.�_�y�l._ „' f, !b .1�l�l .. '�_.- , I I� � ° � �� r� �� !. �� ''� J I I � r- • , I �\ � W ''�.r'��1 � � �i ,11 � � !, j ! ��. � � � �- 1 � � ? , � ' - -I�_ !'' 1i o � »� +'' „`�1 J( ., !! �� -g � . I � � '�-^� v 5' � ' ��.� � , s � i ` U�L �'• _ -' , � - - r�� - I� )\ � y'"��'�:,:� � „ . o R- � � � � � � �� \� � � � � �� �� � '� �1 J ��� + � v �,� t'r `�` � \ � I �/ ( ti V \ .'7. �I '�! �\` ��'.\`"(� � , � � `''�' �• + ~��� 11 � K, f.. ✓� 4' �1 � _1 � � � ; /. i� ��� ����-, � �' �.. . ��' ,�� 'J � � �� � � ��l � � � � ���_—/�.o � �`� ( � �-._��� '���- ����� I 1 � e , 11 -r:.-,:C � �l � � l- � ��T' `, '_.�-"'� � ` �'S � � , �, � r,� i� l � �� ,, }-� , , � � ' - . � e i� �`' f! ,��.^'.'_� � � `1 � �� i�� � �� Q � t: ' ' o° 'l, I -'� . I �%`�,�✓ j ,`` -, -_ ' '� .�,,_ g w _ � - — , " , �, — �I, �: ,� ,�� _� _ . �,r ; , � i � _ � �i . � u �1 ' �" � � �� � , � �`�li 1 - � � Q W� �i t, � � � � •�� � I i v� � �0. � ..,;1 > � � � - C' i i l,f r, -: � ' ,, � � ' � -� � � � N i % 1� � � ` I � � �:.- r � r'.,'.� - �.., :l+ ,�._. _� I� ��� . Q f� #' �� ��-T-.._ t) -— _ � Y - /� � i . / �' -'�'i. I1 ,s_ + �' � o[ W J � .r--`� h"-� �+i ' �,y�,F C`_.a(�� � 'l� � ,� .. �'I �-�� `':: �t•fi � 7� \ ,l � w OC �"� . _f j� / �� � "' �t - s�-_� w _ ��,, �' i --�=ti�al c.� ��,�" �� ��� i"y�����1, .� r3�� � �� tl. '� � 1 k�, � c � . � 'L i f v r r _ � ' � J � �.��. � � � � Iq �� ` � � � �� ju��� �, s� � � � ,� �Z,! � � ' (,r- I .� �,;�,1�, �' � � � /�' 1`'`-,�' '�,_ � .% � ' - ��1 � ,�� ,,. � � �S Y t �1 ��'1 �s � � ��,f�t� I I /„ \ / °�.: ' / ��� �' �' �� f � :� �,-/-1~ �a 1� , � � � 1 � r .,� r'1r..__ _ '_ �� �J, � i,_ l s '� _/ .-.� / ' '"!` � �_L�. j'�' _ ,��� . iN �./ . _._� j .,� r �_ e t-�- i �� l. �'' - -- �i-f.. - � �.-J r, ��l ' �: ' '�.� 1 i=` ., i.! I .� ,� ! ��,'��;� .� i : - - �; �J � , . � ; ___ � � �, ' � - „y� � '� T, ��� �'���; �, i _ _ ( ,� - �� �� ���� ._ _ z � ; . . . _. _ .._ . � � � L. ._ � ,.•'�=r-" '� - � -- - ��x � ,.. i l �� '�� � � ''�� — 1{ � 'j� \�� ,,1 ;�_ 1 -.' ;?n, � � ,� .�L A - '" � � ,1�� �. �,. �:,; ' ';� � u � �F , � � �' j � ,r' �,.. � ��� y� � ?� :i � i .� , ���� i� � ,°° ; ��j;� �;F � ��� 'U�' ;s ! -- -�- � I ,� Y„ � � ., �� : � - - � � � • � , � �"- _ , _ ►! ' __ `�,,,���� i:reFr , ;'44 � �� � �-'- , . � , � �Y-_L� � o,� Z `�_. - -- -- - , ,.��,,�, _._. . , , _1� ;, �, �; � � �, .. �— — � ��--� � �_l� � � - � .� . --. � �-� . � �� n� 'r, ' �� " 1 � � 0 � � � - �\ %�� � , / �„ 1 / ' __ � J � r" II '� �1 ��_•..—.—�.._--__ � I �'� t � �- '� . �� � � � � _ �_ _ _ ; � J� 'r � � ,I � �t? �._ �l ' � �`--- _ �' ! ��� - � `1 _ C\ --� 2 � �__r,� , , . �. � ,,,i::___ _J�� �� •. �. �, -� , t+ �--, /�� � �i , 1 , `. _ � \�� ,� � : . - - - -_ - - - - -�• � � � r. .�-� - „�e;:.� ._ � _. t -�= ---- ---- ��- . �. -�� _ - - - - - � -- ,- ;- - -� -- - =._. ..... . ,\l. '� ,C- _, ,�„- . , ` � - ' '�. - `- � ^° ; _ - ,, ,� ��- � '—`„-.! �t n ,-�y���_c,,� , �' - _ - - — - _. � — �~ ,3� \�.�,� �i � J' ,o,'a.�-- -- - ' _` _ , ` ?_ , , J� .t �p�. `,� � �` . - � __�K ISH � l ' ' ` � J��1. �c.r �' I. ��,• , _ l"�, ,� _ _ ; 1 _ : _. .... _ r ,: � �. ---K� - � �.�� -V� , � t, � - �-� ."'"' ""' -_=� — � - _, � � � � � �� - --�' ( �-r � — - b�oo . , _ � - ?'� - .� 1'` ` r�`� '\\ - �� / ,. ' ..r�"� � .. ` _ _ .-■a' � Y!'} .. `. _ - . r,., c . ��.... �, �,��: ���� - -� ,�- - ;� ��. �� � ,�'SN ����QU _=�— �� �:, _ - _ _ �� , , ;y� � �-,�����s.�_. � - � � ;` .��,� . � _ MIE�`��, -_:.- -�� � -:��_ _ - . .����. - . _ - �, _\ : � ± � � i _ ;. _ . ' . - r.°"'i � '� � 41,• ra��c.... - - , . _• ,-- � ' :. '�` ,j � _- ' y„a,r,�M w,�, � . ' E . _ ' . ` '�_` �.I � on�.,u.r _ x ` - `RC f1�7��� `'o l� � - < _ �J + E�,...'�...�....,�i ` - �' -- — _ , �`y , - ,� ; � , - ��, �,� ,� , _ ,,,..,�, , �. \ � - Rf VE R . _ .. . ; _ ,�; , : e - � � _ _ . �� - . u .�_..:i r.�c.t. - � �_ ne«�^� 1 - ._.. - _ .. _ = i Ia1anA�, y�,;,�,_ - u.. ' . -- �. � _ � .. � �. �. � - " , r 1r� ..�.o.+ � P l.lGi ET ,, � .�� „�,.�G - �� _ -- - _ _ - I_.�, � - Pi.w _ . _ , __ - ;� �; � �- '��.- : - �:-. -�' _ � -�AS[N � __ � _ _. - _,� - '_._. `- \ '`` •;,, .Z_ j -_ _ - �. __i� - `" �� r ..' _ _ `� i. •"'' ' \ � ,.i_' ' . �w1a04 Fon �• "'.' . . . -. - c • t " I 5 �- • - '� - 's�w�wm�.n�,« "� -.__ I _ ` �_C _' 1 ._ � — � � -- .__'. .... ���N�� r .. � . �. .� .��� -.'�. - � -b..l . /; _ ` Q7Q -y +� '1FLOW^.'.�.I ,�- _ ` _— �. f �a�o� � t _y��� i...�`-L,_,��� .. . `� . � �_ � _ �� f'�e — �i�V I�\�� 7�1, � " � �. __ :; •—, �_ � `.. � � ..-- � _ ' ^ b��Ir� r I � � , 1 J _ t`�— ^ _ - — ^-`� ��� _ - `� 1 ' 1 - �`__ .' _ "� _ -_. __ _ _ _ ,`'''�1�:.a, ...� _. - - � � ro -- � r :r� _ --- -_ .,�'� -% . -_ °""°"" � . I --- - , - 1 �rt--:..�aa- .• _ � .•/� ' -� .^ - so,,:nc,,. ,'� �� +..+� -y� L'_-� � .ti 1�, ., _ _ �.., ;-4� _� ........_ - . ��%_ � Figure Z - �- --i � - - � __ . ,- �_ a... i" , u,v. - _ �,,.w�.ti.. _ . .. �' :'S� - .,o�v.. � � � ' �� v x _, _ � . - J:_ - � _. � ��. � � �� _.. � . . , '`=°.. _ ,o., - �F DRAINAGE �ASINS ..� ; ... ; . ; ` , •- ��,.... - � ' � ' ` w.. `-, Kin Count - — --DRAINAGE�' ._ . ` ` � _ - _ , _ , i cmo.st�n�rw�Tc�sNeo - 19BS Y ,•, �,ti� � k ��...,r _ -'. . -- , _ �J_.. fl c.�.,.p�a o.�';^ 1` ; 'c ' � � : . L__.i_ �- �`A.-=~ 1 . r{�Gic_ ��j�^ - " '� �� _ � "" _ + y - _ � - � �.� - .-_ - .� �� L � :� ; �--,- ` _ --- - � -_� .���'. �' � ,1� .:=` �■ Major Basin Boundary �- _ r�cau _ - _�, %;;-- � — ;�- �M ^ i . _ ,� �- � - ' �� �oc. -ni�..� `n.t _ '�� ._ -.. • _ . � � n• - �" _ _ �.y� , _ �L� �. _ . _ �" , ��� , � �. _____ �.-�• ti Sub-Basin Boundary . _ `\ '�� - �- -- — ^�-' � . �' � � ' � Source: King County Sensitive Aress ��)�j���,_ �_ . �~ _ �v — � �— + ` Map Folio,Wetlands Supplement 1/11 T 1! . ^^� '• -� _ __ � \ --. .- � , . Cm O�T�COr���TFIItMED _ _ _ . . ' . -�_ �'•�'• �} . . � J ..- . - `C.._ _ ' t -- '��f w�n.Rn� o.r.• '.! . . � � � �� � �. ' � . . �� - _� � BAsr�v . - , _ .� . _���,-�:,- `,--_ -.-� , �,�_ ,,��; ._ ._ . � ,; , _—_ ,�� .�,,� � _. .�,,., ` �, � 0 1 2 3 t 5 0 7 8 Mlles i�' '�� �_ - -- , ` . ' 1: 300,000 1/[lA � • i-�+ 3.2.? KCRTS/RUNOFF FILES ME7'HOD—G �I ENERATI. G TI:b1E SERIES T.�BLE 3_2�.B EQUIVALENCE BETWEEN SCS SOIL"fYPES AND KCRTS S�IL 1'YPES SCS Soil Type SCS KCRTS Soil Notes Hydrologic Group Soil Group —� Alderwood (AgB, AgC, AgD) C Till Arents, Alderwood Material (Am6, AmC) C Till Arents, Everett Materiaf (An) B Outwash 1 Beausite (BeC, BeD, BeF) C Till 2 Bellingham (Bh) D Till 3 Briscot (Br) D Till 3 Buckley {Bu) D Till 4 Earlmont (Ea) D Till 3 Edgewick (Ed) C Till 3 Everett (EvB, EvC, EvD, EwC) A/B Outwash 1 Indianola (InC, InA, InD) A Outwash 1 Kitsap (Kp6, KpC, KpD) C Till Klaus (KsC) C Outwash 1 Neilton (NeC) A Outwash 1 Newberg (Ng) B Till 3 Nooksack (Nk) C Till 3 Norma (No) D Ti(I 3 Orcas (Or) D Wetland Oridia (Os) D Till 3 Ovall (OvC, OvD, OvF) C Till 2 Pilchuck (Pc) C Till 3 � Puget (Pu) D Till 3 Puyallup (Py) B Till 3 Ragnar(RaC, RaD, RaC, RaE) B Outwash 1 Renton (Re) D Till 3 Salal (Sa) C Till 3 Sammamish (Sh) D Till 3 Seattle (Sk) D Wetland Shalcar(Sm} D Till 3 Si (Sn) C Till 3 Snohomish (So, Sr) D Till 3 Suftan (Su) C Till 3 Tukwila (Tu) D Till 3 Woodinville (Wo) D Till 3 Notes: 1. Where outwash soils are saturated or underlain at shallow depth (<5 feet) by glacial till, they should be treated as tiU soils. 2. These are bedrock soils, but cafibration of HSPF by King County DNR shows bedrock soils to have similar hydrologic response to tifl soils. 3. These are alluvial soils,some of which are underlain by glacial till or have a seasonally high water table. In the absence of detaifed study, these soils should be treated as till soils. 4. Buckley soils are formed on the{ow-permeability Osceola mudflow. Hydrologic response is assumed to be similar to that of till soifs. 1998 Surfa;:e�Vater Desi�n hlar.ual 911/98 � 3-2� JU1..21.2004 4�25PM KC WLRU NO,941 P.1 i� -- -- -- C�12-- . � 7�z, �c4 � King County Water and Land Resources (��'LR) Di��ision � 201 S Jacksou St, Suite 600 Seattle, WA 98104-3855 � Date: (J � � Number of pages includi�a cover sheet: 1-�, To: �,�Qr-��t�ir,CJ From: Cindj�Torkelson ��: ��- � � � yVLR Stormwater Senices Section Phone: 206-296-1900 Phone: — Fax I�Tumber: 20G-296-0192 ' i ' .� �MPORTANT LGVEL I ANAL'YSIS I�'OTE: «�e do not send copies o�certain complaint t�rpes that are not relevant such as BCW, FI, FIR, FTH and WQA, and we do not send CL and LS types. See key below. Type S 1, 52 and S3 wil] not be faxed�due to size constraints. i The following is a list of complaint t�pes recei�ed b�t��c 1'��ater and Land Resources Division Drainage Services Section, Complaint nwnbers beGinning prior to 1990-�:XXX have been archived and are no longer in our possession. They can sti11 be retrieved, if necessary. but will take additional tune and may not be beneficial to your research due to their age, development whicll has occurred, etc. If you are interested in reviewing the actual complaints, they can be pulled(time permitting) for your review. Copies can be obtained for$ .15 per page, and$2.00 per page for plans. Keys: �ae of TnvestiEatien Tvpe oP Problem C Action Requecc ACA Dcvelopn-cnvConstr„cnor. BC�V Busmeas'for Ctean Water DDtii Drninage-Misccllsneous CCF Reeponse to Inquiry DES Dnmagc—Eros�on/Scd�me�totion •CL Claim DLE Thainage—Landstider'Earth hfev�nrnt EH Enfarcement on Hvld DTA Drainage Techr.icat Assisrenco EIi Bnforcemrnt Reviev� L�Q Drainaoe—Gencrai Ir.quiry FCC,FCR.FCS Fac�lity Complaints M�IA Maenrc�ance•Aes�henes FI S�Vtii Fee:nquiry y1MF Mainrmancc-Flcoding F(TZ SWhl Fee Revicw MMG �:sintenance-Qe;+cral Flli S WM Pcc on Hcld :�1�Iv1 M+�inoensncc.Mowing •IS I,ausui� MNR4 Maintenance—Needs Mair.tensnce RR Facilip�Bngineering Revie�*- MAhN !�1a:nlcner.ca�Noxious�'Uceds NDA Neishborhood Dr�inagc Asdctance SV�'F 5WM Fx Quest�ons WQ� 1VRid�Qy811ty COi11p1Lint wQB �'eoer Qualip�—Best:�4an�qemc�t Pracneee WQ�. Watrr Quality Enforccment W'QD �Vottr Quali.y—Dumping WQR WStn Quelity�ngir.eerinq Rt��icw WQI R'ater QLaliry—Illicit Cmnc�.tion WQA Water Quality Audi� RE:�1 S�VM Fee•Remcasuremcni WQO WaterQuallry—Othcr GRT SWMFerGra�t St,52.SN3 Eng�neering Studics Nu'D SWM Fce-Neu•Discount "Subjec(io Pub11C Dffc:oSurt rcqwmncr.[s 1.Recript of urittcn r.qucs�for dvcumcnts 2.Rcview and approt7l by Prosecuhng Attoney's o�ce JUL.21.2004 4=25FM KC WLRL NG.941 P•Zi� ' KII�Ca�ty Water and Lantl Reao�rcBe Dl�slon-Dralnape Serulces SectlOn Complattit Search Printad: 7;�1l2004 Z:3C:44 PM Complalrrt TYAe Ty�of Prohlem qddresa of Prohlem Cemmente Nurt��er Cotle ��� •-49�6-9�35--C FLQG 13821 SE 138TH PL Sl/VA�Ap/SE 138TH PUw!DE�iVAY MTS 656J2 �aA�.n�A� r DRNG 13832 SE 131ST ST BLKED 656J2 FLDG 14005 SE'133RD 5T 656J2 DRNG 12808 f 38TH AV�SE � FLDG 656J2 .�98Z�49�-� FLDG ',4008 SE '28TH 5T MAPLE�VOOD HTS 656J2 'tAA2-f}575 r OVR 16935 i 16TH AVE SE g� SE 132ND/144YH AV� SE 656J2 FLDG 13224 14G7W AVE 8E- !!, ' ' � G56J2 - DVR 140XX SE 132ND�ST' � �i',• . .. . �• FLDG 656J2 1°RS=',,.,.,",^,'.�� DRNG 14100 SE 132ND ST ;; S�E 841005�T0 ROADS 656J2 �9$6-94�-C- DRNG 14011 SE 7�2ND S7 . _ ... _ SURFACE WATER 656J2 ��g�_m,� 656J2 -a-�dG-�2ri5-F . . . ._ . . 656J2 r386-A25G-S1 � � COVti11TTEC DATE:15T Q7R 1988. 656J2 -�86-93f�4-t DRNG 138TH AV� � 5E SYST�M SILTEO 656J2 49bb-03A�� PROB CRTD. o56J2 -tg86�9739-Fs FLDG 13323 14�TH AVE SE WATEFt FROM SCHOOL 656J2 te8'T�s3' C FLDG 14639 SE 132ND ST STANDING WATER&�:�UD 656J2 19�9-C DRNG 13323 146TH AVE SE CO DIVERTED DRNG ONTO PROPERTY 656.l2 499�-6495r-e- FLDG �3025 1387H AVE ' SE SEE 87-4463 OVCR STREFT 656J2 1987-0�45 C FLDG 13637 SE 128TM�T � • FILLING OF�OT 658J2 .1987-0445 ER FLDG 13837 SE 128TM 5T SEE 86-03A4 P'cNTON. 87-0707 656J2 -�99�-6�8-�3F F�DG 13025 1367N AVE SE ON '38TH AVE SE 656J2 �889-4�$A-�'r ORNG 14106 SE 135TH 5T STRORIl4 DRAIN FAILURE 656J2 t$8��--993�� DGBRIS 14003 SE 132ND S7 DEBR{ ON RD TO DET POND 656J2 1889-9#�3,C DRNG 13852 S� 128TH AVE QRAINAGE OF NEIGH60RS FILUROAD C0. 856J2 -'F989-@�8A-� SETTLING 13120 138TH AVE $� SIt�K HOLE IN YARQ 656J2 -49�5-948�-52 F�DG/DVR 14011 SE 132ND S7 SE�:86-0256 YAHN PH I 656J2 't888�-�� INQUIRY 14145 5E 133RC ST S7ATUS O� STUDY(YAHN STUDYj 656J2 �989�9SSS-X DRNG 14103 SE 132ND S7 YAHN STUpY COMPLAINTS 656J2 `iS9��26�-6� FLDG 14639 SE 132ND ST p17CW OVERFLOW/S70R'�A E�dENT 655J2 't�9=9SE8"�C DRNG 14105 SE 133RD ST • i, �LOODING IN NBRHD 658J2 i 990-0512 C DRNG 13604 138TH AVE ` SE CROSS PIPE ERODING RAVIN� 856J2 1999-6568-� DRNG '3323 946THAVE SE DITCH ENDS/DlV�RTED WATER 656J2 499A-@558-fR DRNG 13323 148TH AV� S� XPIPE AND POND1DiTCH ENDS 656J2 FLOG 1�t105 SE 133R�ST COhAPLEYION OF STUDY 656J2 - F�DG 14105 SE 133RD ST , CAPACITY OF PLAT DRNG 856J2 DRNG 14105 S 133RD ST PUGET COLONY NOP,�ES 65FiJ2 Page 7 of 3 ' j: JLIL.C i.cE1C�14 4=C6FM hl. L!'�RL� N0.941 P.3i4 Complafnt TYpe T�ot Problem 14dtlrees oi Prn6lem Comme�ts Number Code lbrros Pape 199a-0�-X DRNG 14105 S 133RD ST CCF#�89-32/Y.4HN STUDY/FLOODED YAR 656J2 tJ9�-669�-SR �I�NG 14105 SE 133RD ST C.CF#SWM0124 PUGET COLONY HOMES 656J2 =8�-999��X DRNG 14105 SE 133RD ST CCFttSV1rM0�24/DEVEL.OPEPJIENT fi56J2 DRNG 14013 SE 133Rd 5T PLUGGED 656J2 '1JJt=@�+15--�f� DRNG 14013 SE 133RD ST PLUGGED PUGE7 COLOVY HOMES 656J2 ' t9�'1=@?'t�-C' FLDG t4011 SE 132ND pIVERSIONlCULVERT OVERFLOVI� 656J2 1991-0619 NDA DRAINAG� 104�73 1477H AVE 5E STORP�I EVEN�- DIIN FLOO�ING 656J2 �q98i-663fThFDA FLDG 14105 SE 133RD ST CCF#49'1-32 NOT NDA PUGET COLOfVY H 856J2 -�t�1=@fr3�--�E FLDG 14105 SE 13yRD ST CCF�t491-32/PLAT DRA!NAG� 656J2 �994-865�-i�-0A QRNG 14105 SE '133RD ST CCF#591-2 NOT NDA PUG�7 COLONY HO 856J2 T89�=B8�'7C DRNG 14705 SE 133RD ST CCF#591-2 SAME OLD PR08 656J2 FLDG 14105 SE '133RD ST � _ " _ _CCF#591-2 DUE JULY 656J2 - DRNG 14103 SE 132ND ST CCF#5WM fl520 NOT NpA PUBE7 COLON 855J2 �4�-X DRNG 14103 SE 132ND ST CCF#S�NA�Q520 MAM'CONIP 656J2 •1�� DRAINAG� 14'f05 SE 133R0 ST NEIGHBORHOOD FLOODING 856J2 t9ST�07'T'"SR CRAlNAGE 14105 5E 133RD ST PUG�T COLQNY HOMES 656J2 � DRAINAGE 14105 SE 133RD ST CCF#591-37 PUGET COLONY HOMES 655J2 � DRA.INAG� ;4105 SE 133RD ST CCFt�591-37 a56J2 �i��9�'F-A�3�--E DRAINAGG 14024 SE 133RD S7 /L4MB (CL/',I�JI) 656J2 � n��� SR DRAINAG� 14024 5E 133F2D ST /LAMB (CLAIM) NO7 NDAP 858J2 -�_ 1La3..QZ.�SR (}RNGIFI.D 14103 SE 132N�ST CCF#SVVhA-0610 NOT NDAP 356J2 1 ' FLOOCING �4103 SE 13ZND ST CCF#591-38 N07 NDA PUGET COLONY 656J2 1�664-9�-�C FLOODING 14103 SE 132ND ST CCFlf 59i-39 656J2 1�8$�-68��--� DRAINAGE 14639 SE 132ND ST 6�g�� 199+�686�-5R DRAINAGE 14010 SE 134TH ST CCF#SWM0279 NOT NI7AP 656J2 19�1'C8S�"�E DRAIN�,GE 14010 SE 134TH ST GCF#5�NA40279lPUGET CCLONI' 656J� 1�994�88$5�C FLOODING 13405 142ND AVE SE CCF�SWf�1-0854/DRAI�IAGE IMPROVcN1� 856J2 �Jt='088$-3R FLOOdING 13800 SE i28TM ST. CCF#SWNI-0852-NOT NDA.PUGET COLON 656J2 �$g4•@6�$-'X- F�pODING 13800 SE 12BTH ST CCF#SWM-08524'VETLANQ PR06LEMS 656J2 �994-994G--�C DRAINAGE 14105 S� 133RD ST CCFtt: 91-0622/GRANT1t�G EASEMENTS 656J2 188�-9-2�X DRAINAGE 14105 S� 133RD GCF#SWM t217lPROJECT SCH�DULE 656J2 4993=Bt�J-C DIVERSON 137XX 144TH AVE SE POSS CL�ARING VIOLATION 656J2 �t�JS9•6�� PONDING 12217 7A8TH AV SE POSSIBL� SA�VIOLATICN/DITCH �NCRO 656J1 4�� INQUIRY 14105 SE 133Rp ST INFO 0�'LY 656h12 1�85-�064--C- FLDG �44Q0 SE 136TH 5T GROUND i/�!ATER UNDER ROADWAY 656J2 188'91�"-E DRNG 146C0 SE 132ND ST CMKSTATBYCMDT 656J2 9-993-�68�--�R DRNG i4600 SE 132ND S- 656J2 1986-�63�-C- VACATi�N 14�10 SE 734TH S7 DRAINAGE IPAPACT FROM VACATION REQ 656H2 DISCHARG 14328 SE 126TM ST COMPLAINT REQU NO INV�THIS TIME 856J1 4886-899�h-4VQC DUMPING 12516 142N1?AVE S� APPAREN7 PROPERTY DISPUTE 656J1 Psge 2 of 3 r�C�.q.�1 F.4�a .J�)�.C 1-C2�t^ ::� F'M �L- �-�I_Fi� 6�mptafnt h�pe Type of ProDlem Ad�es�s of P�oblem Comments NIRIli18P COtl9 TOP08 P8� �'89�9884-�vQC EROSION ia328 SE 128TH 57 656J1 CfP 140TH SE �32N�-135TH SE R�QUEST TO DO ASS�SSA+iENT OF CONV 656W2 ��9t-� MP�11�ldTRB 128TH SE &149TH AVE SE D011VNS7REAM IMpACT TO�OkD CROSS 656H i �'�C FLDG S� 1287W 8 1�#2ND A SE MAiN7ENANCF OF EXISTING CHANNNEI 656J1 �'t99fi@@�-C FLDG 14105 SG 133RD ST PUGET GOLONY MOrti1�S 658J2 199Z�D:�a--NDA FLDG 14105 SE 133RD S7 PUGET COLONY FIOMES 656J2 �J9�•B8�'S'� FLDG 14105 SE 133Rp S7 PUGET COLOM'WOMES 656J2 ,�o�_n715 FCR Ri0 FENC 13845 SE 131ST ST TREE DAMP.GED FEhC� ROADS FACILITY 656H2 t8�T�737�� DRAINAGE i4044 SE 133RD SY �OCALIZED OEPt'��5510N PUGC-T COLON 65bH� DRAINAG� 14004 SE 13SRD ST LOCA�IZED D�PRESSION PUGET COLON 656H2 - DRAiNAGE 1a005 S� �33RD ST LOCALfZED CEPRESSION PUG�T COLON 656H2 DRAINAGE 132XX 140TM AVE S� OFFSITE CONVEYANGE DRAIN QUES7 CH 656H2 1�A7.1n?5 1A�QA 8MP'S 14413 SE 128TWSi 656J1 -1898�366�C DRAINAGE 14454 5E 132ND ST qPPEARS PRE GRADING ACTIVITY NO PE 656J2 �S�r33"WQC VVASHWAT 13z24 144TH AVE 5E APPARENT GREY WATER DISCHARGE 656J2 T9Sfi�3�WQR WQf 13224 144TH AVE SE APPARENT GREY WATER bISCHARGE 658J2 �-q�9-0015_ R DRAINAGE 14C13 SE 133RD ST 656N2 49Sg-42�C� DRAINAG� �4004 S� 133RD ST RECORQ OF INQUIRY ONLY-NO CLAIM 656H2 T969-0608--� CONSTRUC 1a6C6 SE �36TM ST CONCERNS R� NEW D�VELP CITY OF RE 656J2 �t"9!�9-66�§-� STND W20 13741 1487W FL S� SOGGY BACKYARD SOURC� Oi- WATER 656J2 20 C DCR 14100 SE 132ND ST' NO FIELD INV NECGSSARY. REF'D TO 51N 656M2 ..�A$9=$�6S' FCR MNM 14004 5E 933RD ST DAMAGED FENC�GA7E AT UNOPENED R! 656Hz .ZQQ�69�-�C DDM 13309 146TM AVE SE 656J: �D0�2�-CL INQ 140t2 SE 133RD ST FENC�DAMAGED BY TREE FALL. TREE G 656r+� ?rpa4.�044�--I DTA 14QTH A 8 SE 132ND ST 656,12 20049�tB'�1 DDtJI 14012 SE 133RD ST 656H2 Pege 3 0!3 � � � A � W a � � `� ��� � o:� c � . . � ...�., AlderNW March 13,2003 Project No. 21803 Mr. Robert Wenzl P. O. Box 2401 Kirkland,Washington 98083-2401 Subject: Site Observations Property at 12905 136th Avenue SE Renton,Washingtou Tax Pazcel No. 5 1 82 1 00042 Dear Mr.Wenzl: As requ� we have conductad a wetland evaluation study for the property located at 12905 136th Avenue SE, in the City of ReIIton,Washington. The purpose of this work was to complete a site evaluation to make a determination , if wetland conditions aze present on or immediately adjacent to the property. , Our scope of work included a site visit on '.�ebruary 19, 2003, at which time we completad our site evaluation. In conducting our site evaluation, we followed the general procedures for the routine on-site methodology as outlined in the March 1997 Washingtorr State Wetlands Identification and Delineation Ma»ual. This procedure involves analysis of vegetation patterns, soil conditions,and near-surface hydrology in malang a deterntinabon of wetland conditions. PROCEDURES For the purpose of tlus sludy, we used the wedand definition adopted by the Environmental Protection Agency(EPA) and the Army Corps of Engineers (COE) for administering Section 404 of the Clean Water Act. According to this definition,we�tlands are: "'Those areas that are inundated or saturated by surFace water or groun�water at a frequency and dwation sufficient to suPPort, and that under norn�al ciu•cumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands generally include swamps,marsbes,bogs,and similar areas." (33 CFR 323) I In Washington State, the Shoreline Management Act and Grow[h Managemern Act have amended this definition to exclude s�ne wetland sit�ations by adding the following sentences to the wdland definition: 518 North 59� Street, Seattle, Washington 98103• Phone (206)783-1036 email aldernw�aol.com � Mr.Robert Wenzl March 13, 2003 Wetlands do not include those artificial wetlands intentionally creatsd from non-wetland sites, including but not limited to, imgation and drainage ditches, grass-lined swales, canals, deteIItion facilities, wastewater trea�r►ent facilities, farm ponds, and landscape amenities, or those wetlands created after July I, 1990, that were intentiona.11y created as a resuh of the constructian of a road, street or Highway. Wetlands may include those artificial wetlands intentionally created from non- wetland areas to mitigate the conversion of wetlands_ Delineation procedures are based on diagnostic environmental indicators of wetland vegetation, wetland soils, and wetland hydrology. These procedures, outlined in the Washington State Wetlands Identification cmd Delineation Mam�al (March 1997) are commonly lrnown as a Triple Parameter Method. By definition, an area is designated as wetland when there aze positive indicators for all three parameters. A listiag of plant species has been developed for use in the methodology for delineating wetland areas. This listing assigns plant species to one of five indicator status caiegories ranging from Obligate wedand species, which almost always occur in wetlands, to ilpland species, which rarely occur in wetlands. Under norn�al conditions,hydroph}tic vegetation is determined to be present if more than 50 percent of the dominant species are in the Obligate (OBL), Facuhative Wetland(FACV�,or Facultazive(FAC) indicator categories. Diagnostic indicators of hydric soils are related to soil saturation, which Ieads to anaerobic conditions in the soil. Under these conditions, decomposition of organic material is inhibited and soil minerals are reduced, creating characteristic soil colors that can be quantified by comparison with Munsell Soil Color Charts. A chroma of one or less in unmottled soils or a chroma of two or less in mottled soils generally indicates a hydric soil. In addition, soils that aze saturated during the growing seasan satisfy a criterion for hydric soils. We used a hand auger to excavate shallow test pits to observe soil conditions to depths of 24 to 28 inches. We�land hydr•ology is defined as inundated or saturated soil canditions for at least 14 consecutive days during the growing season. If no water is present at the time of evaluation, other indicators may include topographic low pourts �. or channels, flood debris,complete absence of vegetation,or presence of hydric soils. Standardized data forms are available to record observations on each wetland parameter. For this projact, we co�ipletad data forms for the Rnutine On-Site Determination Method ai two representative locations on the site. Copies of these data forms are included with this report. The fonnat of the data forms is based on the forms for the Routine Wetland Detenninatian from tbe Washington State WetIand Delineation Manual and the 1987 Corps Wetland Delineation Manual_ Additional observations of soils, vegetation and hydrology, beyond those reported on the data forms were used in completing the site evatuation.� SITE CONDITIONS The subject property is a rectangular shaped property of approximately 2.3 acres. It is located ai 12905 — 136th Avenue SE in the City of Renton. There is an existing single family residence on the property alang with several outbuildings. Project No. 21803 Page No. 2 Mr.Robert Wenzl March 13,2003 The adjacent property to the south is occupied by a constiuction company and is in use as equipment a.nd material storage yard. Adjacent properties to the north and east are occupied by single-family residences. The property off the northwest comer is operated as a U.S. Postal Service facility and the property offthe southwest properiy comer is undevelaped. Soils on the property and over much of the surrounding area are mapped as Alderwood gravelly sandy Ioam on the (Soil Survey of King County, Washington, U.S. Soil Conservation Service, 1973). Alderwood soil types aze included on the National Technical Committee on Hydric Soils listing of hydric soils. O�r observations of soiI conditions across undisturbed sactions of the praperty are generally consistent with the descriptions of the Alderwood soil types. There has been grading and filling on the southem portion of the properiy and on the area surrounding the existing residence. Based on the growth of trces on the properry it appears thai the fill on the property was pIaced more than 15 years ago. Topographically,the property is generally slopes down from the south and north to a broad swale crossing the middle sedion of the site. � � Vegetation on the site reflacts the use of the property. The southern half of the property is grown up in a stand of black cattonwood (Populus balsamifera) trces with an understory of Himalayan blackberry (Rubus discolor), hardhack spirea (Spiraea douglasii), with scatiered Douglas fir (Pseudotsuga menziesii), and westem red cedar (Thuja plicata)trces pre.sent. The central low section of tbe property is occugied by dense Hiinalayan Blackberry. A system of graded driveways presently vegetated in short grasses loop around the property. There aze scattered standing Douglas fir,big leaf maple(Acer rr.acrophyllum)on the site. The attached Data Forms ide.ntify conditions on the southern section of the site. These locations were selected as Iow azeas on the site wbere vegetalion was indicative of somewhai wetter conditions. As noted an the data forms soil conditions were not indicative of long term saturation and there was no water table within the upper 18". Conditions notsd on ihe daia forms are representative of other azeas across the southem and lower sactions of the property. Ba.sed on our site observatians and the application of the wedand deterniination methodoIogy, it is our irnerpretation thai there are no wekland areas or streams on ihe site or in tt�inunediate vicinity. We trust the information presented is sufficient for your cument needs. If you have any questions or require additional informatiaq please call. Sincerely yours, , ALDER NW � r^--� " " , Gazet P. Munger Pro}ec[Scientist Encl.: Wicinity Map Data Forms (3) Project No. 21803 Page No. 3 DATA FORM ROUTINE ON-SITE WETLAND DETERMINATION Describe General Site Property has been graded in the past and is Data Point No.: DP-1 Conditions: grown up in blackberry and young alder and cottomvood. Site Disturbance? L,ocation: Southern section of ro e in low area VEGETATION o � o � Dominant Plam Species.._ ? � � Dominant Plant Species � � � .. a �' v�, � �' � 1 Spiraea douglasii FacW S $ 2 Phalaris arundinacea FacW H 9 3 Graminae H 10 4 Populus balsamifera Fac T j] 5 12 6 13 7 14 Percent of dominant spacies that are OBL,FACW,and/or FAC: 1 Do Is the hydrophytic vegetation criterion met? Yes Rationale: More than SO'�species hydrophytic SOIL Soil Type: Alderwood (old fill?) Hydric Soils List: No Histic Epipedon? no Mottles? No Gleyed? No Matrix Color: IOYR4/4 Mottle Colors: - Depth: IZ" Other hydric soil indicators: No Is the hydric soil criterion met? No Rationale: Chroma greater than 2 HYDROLOGY Is the ground surface inundated? no Surface water depth: - Is the soil saturated? No Depih to free-standing water in probe hole_ No Other field evidence hydrology: No Is ihe wetland hydrology criterion me[? no Rationale: Non hydric soils WETLAND DETERNIINATION Are wetland criteria me[? no Ra2ionale for wetland decision: Non hydric soils;no evidence oJlong term soi!saturation on disturbed site Project Name: K'e�►z!Renton Property p]�� Field Investigator(s): G.Munger S 18 North 59th Street Projed No.: 021703 Date: 2/19/03 Seattle,Washington 98103 DATA FORM ROUTINE ON-SITE WETLAND DETERMINATION Descnbe General Site Property has been graded in the past and is Data Point No.: DP-2 Conditions: grown up in blackberry and young alder and cottomvood. Site Disturbance? Locarion_ VEGETATION � � w � v, o � Dominant Plant Species � � � Dominant Plant Species � � � � •� �. � v' � c`n v� 1 Populus balsamifera Fac T $ 2 Phalaris balsamifera FacW H 9 3 10 4 11 5 12 6 13 7 14 Percent of dominant species that are OBL, FACW, and/or FAC: 100 Is the hydrophytic vegetation criterion met? yes Rabonaie: Greater than SO'�species irydrophytic SOIL Soil Type: Alderwood (old fr/1?) Hydric Soils Lis[: no Histic Epipedon? no Mottles? No Gleyed? �o Matrix Color: IOYR4/3 Mottle Colors: - Depth: Other hydric soil indicators: No soil is disturbed with some fill placed. Is the hydric soil criterion met? No �p�]g; Chromo greater rhan 2 HYDROLOGY Is the ground surface inundated? no Surface water depth: - Is the soil satwated? No Depth to free-standing water in probe hole: Nor in upper 18" Other field evidence hydrology: No Is the wetland hydrology criterion met? no Rationale: No water in upper 1Z", no evidence ojsaturation WETLAND DETERMINATION I, Are wetland criteria met? No I Rationale for wetland decision: Non hydric soils;no evidence ojlong term soil saturation on disturbed site Project Name= Wenzl Renton Property p]derNW Field Investigator(s): G.Munger 518 North 59th Stre�t Project No.: 021703 ��: 2/19/03 Seattle,Washington 98103 DATA FORM ROUTINE ON-SITE WETLAND DETERMINATION Describe General Site Prosperiry has been graded in the past and is Data Point No.: DP-3 Conditions: grown up in blackberry and young alder and conomvood. Site Disturbance? Locarion: Low point of swale - alon east side o ro . VEGETATION o �, � o �, � Dominant Plant Species � � � Domin�wt Plant Species � � � � � � �� � 1 Rubus discolor Upl S $ 2 9 3 10 4 11 I S I2 'i 6 13 7 14 Percent of dominant species that are OBL,FACW,andlor FAC: Is the hydrophytic vegetation criterion met? Rationale: SOIL Soil Type: Alderwood(old fill) HydriC Soils List: no Histic Epipedon? rro Mott]es? No Gleyed? No Matrix Color: IOYR4/3 Mottle Colors: - Depth: Other hydric soil indicators: No Is the hydric soil criterion met? No Rationale: Chroma greater than 2 HYDROLOGY Is the ground surfa�ce inundated? no Sutface water depth: - Is the sail saturated? No Depth to fr�ee-standing waier in probe hoIe: Not in upper 18" Other field evidence hydrology: no Is the wetland hydrology criterion met? no Rationaie: No water table present in upper 12" WETLAND DETERNIINATION Are wetland criteria met? no Ratio�ale for wetland decision: Non hydric soils;no evidence of long term soi!saturation on disturbed site ProjeCt Nanle: Wenzl Renton Property AlderNW Field Investigator(s): G.Munger 518 North 59th Street Proje�t No.: 021703 Date: 2/19/03 Seattle,Washington 98103 - �� ' 52E� 0p55'�3 -�r�,5 K� o� a_.. �1�; rl:.� ^23t �' c,s.} _ ;T? o_ K ��'` - --i�- 06C�S_- ��zr�6S' c35 —��6tt!- rJ7_^ Q� -- -'�-o -- -4�65 Oc:SE�/1S G�56 -_ � 1--- - GS�i ' 0;2? u� r�„ C`54i , y� • ��`-� - �C� �t _-- -- NE 6TN 51 - - - - - --- - +� ; �u- rn .- - - - --- 9Cjtr __ �NE6T,�i,sT=__. �12A'f�5T_ z ,r 9t89 9tia 92:6 a.-- -- � � � A � W a a � GEOTECHNICAL ENGINEERING STUDY PROPOSED RESIDENTIAL DEVELOPMENT 12905 136"' AVENUE SE RENTON,WASHINGTON G-1846 Prepared for Mr. Robert Wenzl Vineyards Construction, LLC P.O. Box 2401 Kirkland, WA 98083-2401 October 4, 2004 GEO GROUP NORTHWEST,INC. 13240 NE 20`h Street, Suite 10 Bellevue, Washington 98005 Phone: (425) 649-8757 Email: info@geogroupnw.com � . � � � Geotechnical Engineers,Geologists � G r o u p N o r t h w e s t, I n c• 8 Environmental Scientists _.__� � � � October 4, 2004 G-1846 Mr. Robert Wenzl Vineyards Construction, LLC P.O. Box 2401 Kirkland, WA 98083-2401 SUBJECT: GEOTECHNICAL ENGINEERING STUDY PROPOSED RESIDENTIAL DEVELOPMENT 12905 136T"AVENUE SE RENTON, WASHINGTON Dear Mr. Wenzl: Geo Group Northwest, Inc. has completed an investigation of subsurface soils at the above referenced site in Renton, Washington. This work was performed in accordance with our proposal to you dated June 22, 2004. Geo Group Northwest, Inc., explored subsurface soil conditions at the site by excavating eight exploratory test pits on July 7, 2004. Soils encountered in the test pits on the southern half of the site and near the existing residence consisted of loose to medium dense cobbly and gravelly silty SAND fills with occasional debris overlying dense to very dense fine SAND or gravelly silty SAND (till). The fills had thicknesses ranging from 1.5 feet to 10 feet at the test pit locations. Soils encountered in the test pits located near the north property line and at the northwest corner of the site consisted of loose to medium dense fine SAND and gravelly/cobbly fine SAND overlying dense gravelly silty SAND (till) at a depth of between one and three feet below the I ground surface. Based on the results of our study, it is our professional opinion that the site is geotechnically suitable for the proposed development. The proposed buiidings can be supported on canventional spread footings bearing on the dense native site soils or on compacted structural fill placed on top of the dense native soils. The loose site soils and fills are not suitable to support foundations due to their loose and variable condition. Based on the findings from our soil investigation at the site, we anticipate that the dense soil under the building areas is present between 1.5 feet and 10 feet below ground surface (bgs). For the proposed residential development we recommend that tl�e site be developed in accordance with one of the following options: 13240 NE 20th Street, Suite 12 • Bellevue, Washington 98005 Phone 425f649-8757 • FAX 425/649-8758 October 4, 2004 G-1846 Proposed Residential Development - 12905 136`�Ave. SE, Renton, Washington Page ii 1. The fills and loose site soils on the southern portion of the site and near the existing house should be over-excavated and replaced with compacted structural fills. The proposed homes may be constructed to bear on compacted structural fill placed on top of the dense site soils. This option would require a large amount of excavation and fill placement across the entire southern and northeastern portions of the site. Because of the high-density of the proposed buildings and the predictable behavior of structural fill it is our opinion that this option, over-excavation and structural fill replacement, is the preferable option. 2. Alternatively, all homes located in the southern and northeastern fill areas may be supported by small diameter pipe piles driven into the dense site soils. Both the building foundations and the proposed concrete floors should be structurally supported on pipe piles for the buildings located in the anticipated fill area. The homes to be located outside of the anticipated fill areas, at the north and northwestern portions of the site, may be constructed to bear on the dense native site soils or on compacted structural fill placed on top of the native dense site soils. We anticipate that the dense soils ar�� ' present at depths ranging from 1 to 3 feet below the ground surface. Ple�. � � report for more specific recommendations regarding the site devel,�;�:���;.� We appreciate this opportunity to have been of service to you on t:������ ,,:��� ��� ��`�• �. ,����:� ������.��::�; • to working with you as this project progresses. Should you ha��� un�� �luc�ti��u; r���ar��in� �hi, rel���rt or ��eed aclditic�ilal consult�ition, plea5e feel ti�ee to eall us. Siilc�r�lv. Geo Group Northwest, Inc. ti�AM c�► . ,�~�°�,W'�t�'c,�'' �� � �� .., 4 William Chang, P.E. �� '��°t�� � Principal �oNAL. � EXPIRES: 2119/ Geo Group Northwest, Inc. TABLE OF CONTENTS JOB NO. G-1846 Page 1.0 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1 Project Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2 Scope of Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2.0 SITE CONDITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2.1 Site Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2.2 Geologic Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.3 Field Investigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.4 Soil Conditians . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.5 Groundwater Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3.0 CONCLUSIONS AND RECOMMENDATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3.2 Site Preparation and Generai Earthwork . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3.2.1 Temporary Excavation and Slopes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 3.2.2 Structural Fill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 3.3 Spread Footing Foundations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 3.4 Pipe Pile Foundations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 3.5 Slab-on-Grade Floors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 3.6 Footing Drains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 3.7 Pavements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 4.0 LIMITATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 5.0 ADDITIONAL SERVICES . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 ILLUSTRATIONS Plate 1 - Site Vicinity Plate 2 - Existing Site Plan Plate 3 -Proposed Site Plan Plate 4 -Typical Footing Drain APPENDIX A: TEST PIT LOGS Geo Group Northwest, Inc. GEOTECHNICAL ENGINEERING STUDY PROPOSED RESIDENTIAL DEVELOPMENT 12905136TH AVENUE SE RENTON, WASHINGTON G-1846 � lA INTRODUCTION 1.1 Project Description The project site is located at 12905 136�' Avenue SE in Renton, Washington, as shown on Piate 1 -Vicinity Map. 136`�Avenue SE is also refened to as Bremerton Avenue NE. The project parcel consists of an approximately 2.4 acre lot located on the western side of 136'�Avenue SE. We understand that the proposed development will be called Ridgeview Court. We have been provided with a preliminary site plan for the proposed site development by Nash, Jones, Anderson Architects. According to the site plan the development will consist of 20 new single family residences, as shown on Plate 3 - Proposed Site Plan. We understand that the existing residence and outbuildings at the site will be demolished. An access road and cul-de-sac turnaround is planned for the center of the lot. Finish floor elevations for the new buildings were not provided. Based upon our discussions with Mr. Mike Johnson of Nash Jones Anderson we understand that structural fills may be placed over the southern portion of the site to create a more level site. Consequently, we understand that the main floors for the proposed buildings are planned to be at or above the present grade. We understand that a stormwater facility such as a detention vault is planned for the westem side of the site with excavations on tbe order of eight feet below existing grade. 1.2 Scope of Services The tasks we completed for this study were conducted in general accordance with the scope of work presented in our proposat dated June 22, 2004. The scope of work included the following: 1. Field exploration with six to eight test pits; 2. Prepazation of test pit logs containing subsurface soil and groundwater observations; 3. Preparation of a written geotechnical report with the following recommendations: Geo Group tiorthwest, Inc. October 4, 2004 G-1846 Proposed Residential Development- 12905 136�' Ave. SE, Renton, Washington Page 2 • Allowable soil bearing capacity and foundation design criteria; • Slab-on-grade floors and capillary break; • Excavations, including temporary cut slope recommendations; • Grading and earthwork; • Drainage recommendations. The results of our subsurface investigation and our recommendations regarding the proposed development are summarized in the following report. 2.0 SITE CONDITIONS 2.l Site Description We have been provided with a topographic survey for the project site by American Engineering, Inc.. According to the survey, a single story residence is located near the northeast corner of the site, as shown on Plate 2 -Existing Site Plan. Based upon our discussions with the current resident at the site, we understand that the residence has a basement, although it is not apparent from the exterior of the house. A concrete rubble rockery is located just east of the existing residence. According to the topographic plan the rockery has a maximum height of 5.5 feet. A shed and shop building are located near the western property line. A gravel and dirt driveway runs roughly parallel and in close proximity to the north property line. The remainder of the site is undeveloped and highly vegetated by blackberry bushes and small deciduous trees. Some larger evergreen trees are located on the northern portion of the property. The site has a vertical relief of approximately 20 feet with an elevation of 416 at the north ' property line and 396 near the southwest corner of the site. In general the topography on the northern half of the site consists of a flat to gentle south-facing slope. A nearly level area is located at the base of the gentle slopes and extends over the majority of the southern portion of the site. The level area is bordered on the east by a small west-facing slope, the embankment for 136`� Avenue SE. On the south the level area is bordered by a berm which parallels the southern property line. At the western edge of the property the level area drops off to another level area on the adjacent western property, approximately eight feet lower. Geo Group Northwest,Inc. October 4, 2004 G-1846 Proposed Residential Development - 12905 136`�Ave. SE, Renton, Washington Page 3 Based upon discussions with the current site resident and Mr Cliff Williams of Vineyards Construction, LLC we understand that fills are known to have been placed at the southern berm location and just to the east of the existing house,behind the existing rockery. 2.2 Geologic Overview According to the Geolo i�c Map of the Renton Quadran lg e, King County, Washington, by Mullineaux, dated 1965, the surficial geology in the site vicinity is mapped as Ground Moraine Deposits (Qgt). The ground moraine deposits consist of glacial till soils which are generally described as an over-consolidated mixture of sand, silt and gravel which was deposited during the Pleistocene Fraser Glaciation period about 14,000 years ago. 2.3 Field Investigation Geo Group Northwest, lnc., explored subsurface soil conditions at the site by excavating and logging eight exploratory test pits TP-1 through TP-8 on July 7, 2004. The test pits were spaced relatively equidistant across the site, as shown on Plate 2 - Site Plan. The test pits were excavated to depths ranging between 4 and 10.5 feet below ground surface (bgs). Soil samples at varying depths were coIlected, classified and returned to our laboratory for moisture testing. The test pits were then backfilled with the excavated site soils and tamped into place by the backhoe bucket. 2.4 Soil Conditions Soils encountered in the test pits on the southern half of the site and near the existing residence consisted of loose to medium dense cobbly and gravelly silty SAND fills with occasional debris overlying dense to very dense fine SAND or gravelly silty SAND (till). The fills had thicknesses ranging from 1.5 feet to 10 feet at the test pit locations. Soils encountered in the test pits ]ocated near the north property line and at the northwest corner of the site consisted of loose to medium dense fine SAND and gravelly/cobbly fine SAND overlying dense gravelly silty SAND (till) at a depth of between one and three feet below the ground surface. We interpret the gravelly silty SAND soils to be the glacial till soils discussed in the geologic literature. The following table summarizes the depth to dense site soils at each test pit location: Geo Group Northwest, Inc. October 4, 2004 G-1846 Proposed Residential Development- 12905 136`� Ave. SE, Renton, Washington Page 4 Test Pit Number Project Area Depth to dense native soil ft TP-1 Southeast 8 TP-2 East 3.5 � TP-3 South 7 TP-4 Southwest 10 TP-5 West 4 TP-6 Northwest 3 TP-7 North 1 TP-8 Northeast 7 � Copies of the Test Pit Logs are presented in Appendix A: Test Pit Logs. 2.5 Groundwater Conditions No groundwater seepage was encountered in the test pits. It should be noted that groundwater conditions may fluctuate seasonally, depending on rainfall, surface runoff and other factors. 3.0 CONCLUSIONS AND RECOMMENDATIONS 3.1 General Based upon the results of our study, it is our professional opinion that the site is geotechnically suitable for the proposed development. The proposed buildings may be supported on conventional spread footings bearing on the dense native site soils or on compacted structural fill placed on top of the dense native site soils. The overlying loose to medium dense site soils and fills are not suitable to support foundations. Because the existing fills are non-uniform in density and consistency their settlement cannot be accurately predicted. For this reason we recommend that either the fill soils be over-excavated or the buildings be supported on pile foundations. The anticipated extent of the existing fills consists of the entire southern half and a portion of the Geo Group Northwest, Inc. ; I . October 4, 2004 G-1846 � Proposed Residential Development- 12905 136`''Ave. SE, Renton, Washington Page 5 northeastern corner of the property as shown on Plate 2 - Site Plan. Based upon our subsurface ` exploration the fills and loose soils in the southern and northeastern portion of the site overlie the dense site soils at depths ranging from 1.5 to 10 feet below the ground surface. For the proposed residential development we recommend that the site be developed in accordance with one of the following options: 1. The fills and loose site soils on the southern portion of the site and near the existing house should be over-excavated and replaced with compacted structural fills. The proposed homes may be constructed to hear on compacted structural fill placed on top of the dense site soils. This option would require a large amount of excavation and fill placement across the entire southern and northeastern portions of the site. Because of the high-density of the propased buildings and the predictable behavior of structural fill it is our opinion that this option, over-excavation and structural fill replacement, is the preferable option. 2. Alternatively, all homes located in the southern and northeastern fill areas may be supported by small diameter pipe piles driven into the dense site soils. Both the building foundations and the proposed concrete floors should be structurally supported on pipe piles for the buildings located in the anticipated fill area. The homes to be located outside of the anticipated fill areas, at the north and northwestern portions of the site, may be constructed to bear on the dense native site soils or on compacted structural fill placed on top of the native dense site soils. We anticipate that the dense soits are present at depths ranging from 1 to 3 feet below the ground surface. 3.2 Site Preparation and General Earthwork The building pad areas should be stripped and cleared of surface vegetation and forest duff soils. Silt fences should be installed around areas disturbed by construction activity to prevent sediment-laden surface runoff from being discharged off-site. Exposed soils that are subject to erasion should be compacted and covered with piastic sheeting. Under option #1, the entire southern half of the site and a portion of the northeastern corner of the site should be over-excavated to the dense native site soils. The overiying loose fills may be Geo Group Northwest, Inc. October 4, 2004 G-1846 Proposed Residential Development - 12905 136�' Ave. SE, Renton, Washington Page 6 stockpiled at the site for use as structural fill provided that the anticipated debris is removed. We recommend that Geo Group Northwest, Inc. be retained to verify that the over-excavation has extended to the appropriate depth to remove all loose soils and fills. Under option#2, the building pads would be excavated to the design elevations in preparation for pipe pile installation. 3.2.1 Temporary Excavation and Slopes Under no circumstances should temporary excavation slopes be greater than the limits specified in local, state and national government safety regulations. Temporary cuts greater than four feet in height should be sloped at an inclination no steeper than 1 H:1 V (Horizontal:Vertical) in the loose site soils. Temporary cuts in the dense site soils may be excavated no steeper than IH:2V provided that no seepage is encountered. Permanent cut and fill slopes at the site should be inclined no steeper than 2H:1 V. Surface runoff should not be allowed to flow uncontrolled over the top of slopes into the excavated area. During wet weather exposed cut slopes should be covered with plastic sheeting during construction to minimize erosion. If groundwater seepage is encountered during construction, excavation of cut slopes should be halted and the cut slopes should be re-evaluated by Geo Group Northwest, Inc. 3.2.2 Structural Fill All fill material used to achieve design site elevations below the building areas and below non- structurally supported slabs,parking Iots, sidewalks, driveways, and patios, should meet the requirements for structural fill. During wet weather conditions, material to be used as structural fill should have the following specifications: 1. Be free draining, granular material containing na more than five (5}percent fines (silt and ciay-size particles passing the No. 200 mesh sieve); 2. Be free of organic material and other deleterious substances, such as construction debris and garbage; 3. Have a maximum size of three (3} inches in diameter. Geo Group Northwest, Inc. October 4, 2004 G-1846 �� Proposed Residential Development - 12905 l 36`h Ave. SE, Renton, Washington Page 7 I All fill material should be placed at or near the optimum moisture content. The optimum moisture content is the water content in soil that enables the soil to be compacted to the highest dry density for a given compaction effort. The majority of the surficial site soils will be moisture-sensitive because they consist of fine SAND with some silt soils. The site soils should be suitable for use as structural fill as long as they are placed near their optimum moisture content. If these soils are too wet they will be very difficult to compact because of their silt content. Alternatively, an imported granular fill material may provide more uniformity and be easier to compact to the required structural fill specification. If the on-site soils are to be used as engineered structural fill, it will be necessary to segregate the topsoil and any other organic- or debris-containing soil, because such soils would be unsuitable for use as structural fill. Excavated on-site material that is stockpiled for later use as structural fiil should be protected from rainfall or contamination with unsuitable materials by covering it with plastic sheeting until it is used. Structural fill should be placed in thin horizontal lifts not exceeding ten inches in loose thickness. Structural fill under building areas (including foundation and slab areas), should be compacted to at least 95 percent of the maximum dry density, as determined by ASTM Test Designation D-1557-91 (Modified Proctor). Structural filI under parking lots and sidewalks should be compacted to at least 90 percent maximum dry density, as determined by ASTM Test Designation D-1557-91 (Modified Proctor). Fill placed within 12-inches of finish grade should meet the 95% requirement. We recommend that Geo Group Northwest, Inc., be retained to evaluate the suitability of structural fil] material and to monitor the compaction work during construction for quality assurance of the earthwork. 3.3 Spread Footing Foundations Geo Group Northwest, Inc. October 4, 2004 G-1846 Proposed Residential Development- 12905 136`''Ave. SE, Renton, Washington Page 8 The proposed buildings can be supported on conventional spread footings bearing on the dense native site soils or on compacted structural fill placed on top of the dense native site soils. Based on the findings from our soil investigation at the site, we anticipate that the dense soils are present between 1.5 feet and 10 feet below ground surface at the building locations. We recommend that over-excavation and re-placement with structural fill occur at the southern half of the site and northeastern corner of the site, as discussed in the site preparation section of this report. Individual spread footings may be used for supporting columns and strip footings for bearing walls. Our recommended minimum design criteria for foundations bearing on the dense site soils or on compacted structural fill are as follows: - Allowable bearing pressure, including all dead and live loads Dense native soil = 2,500 psf Compacted structural fill = 2,500 psf - Minimum depth to bottom of perimeter footing below adjacent final exterior grade= 18 inches - Minimum depth to bottom of interior footings below top of floor slab = 18 inches - Minimum width of wall footings= l 6 inches - Minimum lateral dimension of column footings= 24 inches - Estimated post-construction settlement= 1/4 inch - Estimated post-construction differential settlement; across building width= 1/4 inch A one-third increase in the above atlowable bearing pressures can be used when considering short-term transitory wind or seismic loads. Lateral loads can also be resisted by friction between the foundation and the supporting compacted fiil subgrade or by passive eartH pressure acting on the buried portions of the foundations. For the latter, the foundations must be poured "neat" against the existing Geo Group Northwest, Inc. October 4, 2004 G-1846 Proposed Residential Development- 12905 136`'' Ave. SE, Renton, Washington Page 9 undisturbed soil or be backfilled with a compacted fill meeting the requirements for structural fill. Our recommended parameters are as follows: - Passive Pressure (Lateral Resistance) � • 350 pcf e4uivalent fluid weight for compacted structural fill • 350 pcf equivalent fluid weight for native dense soil. - Coefficient of Friction (Friction Factor) • 0.35 for compacted structural fill • 0.35 for native dense soil We recommend that footing drains be placed around all perimeter footings. More specific I details of perimeter foundation drains are provided below in Section 3.6-Footing Drains. 3.4 Pipe Pile Foundations As an alternative to the mass over-excavation and structural fill scheme, each of the new homes may be supported on small diameter pipe piles, commonly referred to as pin piles. The pipe piles should be used to support the new buildings as well as all building slabs, such as those for the �arage floors. Small-diameter pipe piles typically consist of 2 to 6 inch diameter steel pipe driven to the appropriate refusal criteria into the dense site soils. We estimate that dense, native soils may be present at 3.5 to 10 feet below the existing grade in the anticipated fill areas. Pin piles can consist of two-inch diameter, Schedule 80 steel pipe. The aIlowable capacity of these piles is three tons per pile when the piles are driven to refusal by using a 90-pound jackhammer. The refusal criterion is defined to be less than one inch of pile penetration per minute of continuous driving for a period of three consecutive minutes. Alternatively, 3-inch or 4-inch diameter, Schedule 40, galvanized steel pipe can be used for supporting the proposed structure. The refusal criteria for these larger pile sizes are substantially different from that for 2-inch piles. Also, the equipment needed to drive these larger piles is more powerful, as these piles require more effort to drive and can attain higher bearing capacities. Table 1 below presents a selection of available pile hammers,pipe sizes, allowable bearing capacities,and installation refusal criteria recommended for supporting the residence foundations. Table 1 - Pipe Pile Design Criteria Geo Group Northwest, Inc. October 4, 2004 G-1846 Proposed Residential Development- 12905 136`h Ave. SE, Renton, Washington Page 10 Pipe Pipe Hammer Hammer Refusal Allowable Diameter S ecification Wei ht T e Criterion Ca acit ; 2 inch Schedule 80 90 pound Jackhammer 60 sec/inch 3 tons 2 inch Schedule 80 135 pound TB100* 40 sec/inch 3 tons 3 inch Schedule 40 650 pound TB225* 16 sec/inch 6 tons 4 inch Schedule 40 850 pound TB325* 16 sec/inch 9 tons 6 inch Schedule 40 1500 ound TB625* 16 sec/inch 12 tons * = TeledyneT;�t pneumatic hammer model number; criterion can be used for other equivalent strength hammer The pipe piles are usually tied into the foundation by one of the following configurations: A. Installing a steel plate on top of the pile which is located within the continuous or column footings. B. Placing bent rebar into end of piles and tying to the continuous reinforcement in the continuous or column footings. Our recommended parameters for passive pressure and coefficient of friction are the same as those noted in Section 3.3 - Spread Footing Foundations. 3.5 Slab-on-Grade Floors Loose forest duff should be excavated from all slab subgrade areas. Slab-on-grade floors may be constructed on top of the medium dense to dense native site soils or on top of compacted structural filI placed on top of the competent site soils. The slab-on-grade floors should not be constructed on top of the loose fills at the site. If the loose site soils and fills are not over- excavated as discussed in scheme #l, then we recommend that the building concrete floors be structurally supported by pipe piles. To avoid moisture build-up on the subgrade, slab-on-grade floors should be placed on a capillary break, which is in turn placed on the prepared subgrade. The capillary break should consist of a Geo Group Northwest, Inc. October 4, 2004 G-1846 Proposed Residential Development- 12905 136`�Ave. SE, Renton, Washington Page 11 minimum of a six (6) inch thick layer of free-draining crushed rock or gravel containing no more than five (5)percent finer than the No.4 sieve. A vapor banier, such as a 6-mil plastic membrane, is recommended to be placed over the capillary break beneath the slab to reduce water vapor transmission through the slab. Two to four inches of sand may be placed over the barrier membrane for protection during construction. 3.6 Footing Drains We recommend that drains be installed around the perimeter of the foundation footings. The drains should consist of a four(4) inch minimum diameter, perforated or slotted, rigid drain pipe laid at or near the bottom of the footing with a gradient sufficient to generate flow, as schematically illustrated in Plate 4 -Typical Footing Drain Detail. The drain line should be bedded on, surrounded by, and covered with a free-draining rock, pea gravel, or other free- draining granular material. The drain rock and drain line should be completely surrounded by a geotextile filter fabric, Mirafi 140N or equivalent. Once the drains are installed, the excavation should be backfilled with a compacted fill material. The footing drains should be tightlined to discharge into the storm water collection system. Under no circumstances should roof downspout drain lines be connected to the footing drainage system. All roof downspouts must be separately tightlined to discharge into the storm water collection system. We recommend that sufficient cleanouts be installed at strategic locations to allow for periodic maintenance of the footing drains and downspout tightline systems. 3.7 Pavements The adequacy of pavements is strictly related to the condition of the underlying subgrade. We recommend that all pavement subgrades be compacted by several passes of a large vibratory drum roller prior to placement of the crushed rock base. Before paving, we recommend that the subgrade be proof-rolled under the supervision of the geotechnical engineer to verify that the subgrade is firm and unyielding at the time of paving. The proof-roll may be performed by driving a fully loaded dump truck over the subgrade areas. If loose or yielding soils are encountered it may be necessary to over-excavate and replace with compacted structural fill in some areas. For firm and unyielding native subgrade soils we recommend the following minimum pavement sections for driveways: Geo Group Northwest, Inc. � October 4, 2004 G-1846 Proposed Residential Development - 12905 136�'Ave. SE, Renton, Washington Page 12 Class"B" Asphalt Concrete (AC) 3 inches Crushed Rock Base (3/4-inch minus) 6 inches Or Concrete Pavement 6 inches Crushed Rock Base (3/4-inch minus) 4 inches In accordance with the Washington State Department of Transportation Construction Manual, transverse cracks will develop in concrete slabs at about 15 foot intervals along the length of slabs and a slab wider than 15 feet may crack longitudinally. To control cracking of the concrete, contraction joints should be installed. Contraction joints are weakened planes which collect the cracking into a controlled joint, creating a maintainable joint in the slab, and preventing random ragged cracks which spread and require expensive maintenance. We recommend that contraction and construction joints be connected with#5 dowel bars, 30 inches long, 18 inches on center. The contraction joints should be placed at maximum 14 foot intervals. ' 4.0 LIMITATIONS This report has been prepared for the specific application to this site for the exclusive use of Mr. Robert Wenzl of Vineyards Construction, LLC and his authorized representatives. We recommend that this report be included in its entirety in the project contract documents for use by the contractor. Our findings and recommendations stated herein are based on field observations, our experience and judgement. The recommendations are aur professional opinion derived in a manner consistent with the level of care and skill ordinarily exercised by other members of the profession currently practicing under similar conditions in this area and within the budget constraint. No warranty is expressed or implied. In the event the soil conditions are found to vary during site excavation, Geo Group Narthwest, Inc. should be notified and the above recommendation should be re-evaluated. 5.0 ADDITIONAL SERVICES Geo Group Northwest, Inc. October 4, 2004 G-1846 Proposed Residential Development - 12905 136`t'Ave. SE, Renton, Washington Page 13 We recommend that Geo Group Northwest Inc. be retained to perform a general review of the final design and specificatians of the proposed development to verify that the earthwork and foundation recommendations have been properly interpreted and implemented in the design and in the construction documents. We also recommend that Geo Group Northwest Inc. be retained to provide monitoring and testing services for geotechnically-related work during construction. 1'his is to observe compliance with the design concepts, specifications or recommendations and to allow design changes in the event substance conditions differ from those anticipated prior to the start of construction. We anticipate the following construction monitoring inspections may be necessary: l. Site clearing and grubbing; 2. Over-excavation and structural fill placement in the southern half and northeastern corner of the site; I 3. Verification of bearing soil conditions for foundations; 4. Structural fill placement and compaction; I 5. Slab-on-grade preparation; 6. Pipe pile installation(if required); � 7. Subsurface drainage installation; 8. Proof-rolling of pavement subgrade areas. �' We appreciate this opportunity to have been of service to you on this project. We look forward to working with you as this project progresses. Should you have any questions regarding this report or need additional consultation,please feel free to call us. I Geo Group Northwest, Inc. October 4, 2004 G-1846 Proposed Residential Development - 12905 136`h Ave. SE, Renton, Washington Page 14 Sincerely, Geo Group North�vest, Inc. � I,(.n'� � y`1 " " Adam Gaston Staff Engineer tit�'M �� . a�~�'�� W���c . �� �_� �z Z0114 William Chang, P.E. ������ Principal ��NA4. EXPIRE : 2J19! � � i i' � Geo Group Northwest, Inc. ILLUSTRATIONS G-1846 Geo Group Northwest, Inc. � � , � . �Ir� . w rr�y��i`ii°�,,,.n�+,,:r�w!u'i4Y'�Y'liLf;,.t',��"�i'�r�x 3s,te " — .�., � ,: � .. � . ��'��J Y 3N � '� „ �� � � �,.,,,- � �� 1H, " hd � �ft,��,��,,�� AV� SNOAl�i��l� �N19rf �������� 35 i���� �� ���i�fr,�ia�'��yy���5�;r u��� ��� ��� �.. � � r ` * � r 3 rd+f ,,. ��I I" .1�� U�DIN�f� n07f[ {-� f���. j��.'c� A N19�4 '�� c�.:cZ" '�x 9� � � iA -� �( F I-�.� �. 561. I� �„�35 AY fllSjf g �o r ���''�� ,�,..1 axu.� ��L4 �Si m`nr� T �^i�� I�N� � .35 AV .Hlb6i i �n ��.e'^a d ' i �n' f ,$E 1� � 1�' �, �^ 1 �� ' �'� 'I.��" {^ 3�, /IV I � ���d �~ir� � 'l� � � � j4A ��, � � ,P�r � . __ � "AV��'L� )�GA7�E�� � `i�w �'�' � a�i�fMfb[ � � �� � H166I��ac i �� t r 4Mn+stt.� `"�K � m I �n � �� i7�, i , 3N i� � fl(lx/�i �' I _ '.i i 4 n � tM i N.9 � F �� �e� � �i� ��� "��'fna�� ;, � � r� ~IG �n�'J„ �� I 3S�a �Y ON'£61� �S>n I � � ,,,�. 6G ^ i' +fl W 00 � 1 - M . _� +..•,,.�-P !AV P 1 �I . .�r� �'^"'h-` �'w^--..."' .��.. _.35".. ...... 3S AV lt i _ L�" ..'�,� : I A �j' .� _ 1:; �+ til - � ~�,.. 1 iStYt'�ZIAZ6C n �� -`'< ��—. -. �g""'.� s. "..�.� [� � P a.�i� �," Sf r \ - �- .ti � �s�' � M�i � "�j r;l�" �, i , '� ��orH.P „fia � �.,SE ai � � � _� ',`' � �0>r � h+r�r " I � ..�4— .. ��� ~� �tiS1. ~' b :� I, !l �I` N N�r �`.. � �J � �I . ��3r � CZ. . � N w �.� ',�': � �' �, �.I�s I 3S [ x ��s � � �' � �`� � �N /ld �"�1;1.1�/1(�(� ' '.�� '+;�� �. ni i 5 . �, . s,.,,,, , x , r,� �, '�L' � -' C : ��}� � ^y N�,11�9 ny"�."� a��f�i rt � � �W�- H�,�,�'� "I I ,�. � .. J� e �s. 4 _ � �� I Av yn��AhnU � ' y '},..u1BEL � n �f �^ �� �d5 ii�ll,g� tk)F 1 ~ W � F �,�� ��I� �L'� ` ;k, , wv+j �,,�'�>v; { /( ti / � � � /� y ,""�� ,,.�.i,_ .�aN nV ,Noi}rawaad� "„ � � � �,� � y�� :. 1\ ,i i° t a y�mr, 1..�..i Fl � Fti � 4 E I .. �" ,n�.a,�.� �5 �,�.. �..�h i� �4`r � �� � ,�,'O � {�� � �I O 0 t s� �' � �I� 1�96T � a� � �'� � �� ^ , �. /� C....� � � z �- � �� � � �� l,n , ' �`�'���,F�'�"r`, � ��� I I� . , ,, : � � ''—� � � ��N 7�- '. ��` � � nin. �,�� : J f ai�'_ � � N �. i � '' � -. �- � �� � p� � � dt� � . '�1a�;;�,�ft�� , d �� av"�'��t �� �' A ~ " ' -��- :.� .� .. �'u�, �,�5�v r'.,,_'+r � �.�;-tt,�-- . r ._ � �`s� , - � -�----�--—�---- � I .�''' r�-_ �► `n U n� PU5 �OOV. �.��df''' �� 6VF`,�1av��"�..7` `h '�) �� `n�i r�s�g�„F,+ �x.� ��k .AStr .r',^.,(,�" �f�;S � � �tigl �r 7 ,. , U �'�nN,-' � ��Sv �'� �'.�� �����:r�..,. � $ I� � I Mc�S�o,vi��V T ra �tli. - ��" n 'nt, � v�, , ` .i..��, a4`ctl �� (�.,�.,,, � �`. � � � � � I � a / � � �� O ` Mii���1{���ia �ia�fi�� � `, �� I 4,��.4,i,4�,�,,`fa � � � �y`,r���p i�r;� � �r� is 'ie ai �� T 7e�iaii�inrs 2 .,yl� rn ;�. � .w �'� :' ��'�' �'� Y i ,.:, y� { ��v �,.��' f � 15��A 1S� QI �7�tir 4 � �? �.,� � r `�� 1r� �1'� �`r� �� � �'�, �r�•ih�� � 'Y ,,e�� s�'!�' � �� � �":�',����+��'��a�y� I=� � ?�" ;+ i! �,r � � 'i`� �� o�`'' ���i�.�E� '" rr r�x��'J� �ia Hiocr x� � �� '� � S �J ;7 � �o L..: �..1 1X�n. +-�.� � . r �}I 2� G ;I'�, N7#�47 Ch � � . ��� f„ ��, '�; � � � 1 �H � hd w �33(10�; � r�r y+�r— ' +.e_ ?��ftA+ nv sC� _ „ ' �;; �..' y�y''r. .a� �I� �� �Gl - -� � � � ,a p��C'_r'� �Tj�iS �'i � � ��� i � d ai'� ��t6^� ti� `rh��$�'��tie��f"z ��vwi��" �,� I "° ''� �j U � �� .R • � '�'�/ °��� ' � ' .. + ��u����k#,luezi �'� p��, ,� {`.� as nr ��.,,��. '�.�,—�.y,".._,..�'""�'�J �'I�Ai �;�. �}, � F W x �,����A� `'� m�J�. ' �����v...�::,.. u. ,:..��E{lCE ,V'�y �°k. ,;:(��` '' ..� � � �s,� ( � a� r {^' V . �...:. N Z11N ��F; � Ff �il � f/� ', f;� r r+Ws�iwr� - � � '?""� ar nv�o�yMV1A� sF ;��"r' ��� " w 3N �,. .. •� �i` ' :' f� I ai � �ti� �y� -�ii R'" � ' }SYldHalr} �4 �' � `�1��Y n '�uiizi � etl �d �biiN' r � p" lt� ,� �d �, � r ''�^ f�rH �G 3 � . � '�r��N�� "' d c� � ' � ' w� G +o � �fh ti �� ���! � , ne�3N d � a m/ � .��.�� �.- ,�.• � � w 3N AN ONVIHS' l,L! w E`"7 �' .�ti" ! ' '� 4i� � n ` ypNROE.S� �F� �1 y �. ��� �.�� ,� �1G ��' � � � � � ;�'" ti E��,�"s, `�"�� f���� � ti" ��,�� � �� �`«�"v�i ti � ': 4 � � . � �, ��ti .� „'�' ° `�',{�,. � . � `�,,, �,, �'� l� . V � ��'��� , ��,������N�r � , � � { , � � �, i �a� s � '' � , d�s�' �.�3s,� w ��. ��' _.r�H,� � s '� "�r � 7��r g w � �� � �` :�.,� �a�l ���"y��� ''�,y� t� �s�� ��y C �S3 � ,�� �n aN y..,.�:��' �-, � � y ���. ��,� �� ��iu�`q���#� ' i �� d�wn �Sp��h �;,%�wSsnP� �`i.i ��� ��� ./ ' � �rl � � c`p a ir y ' �N ��n� i hv�9nei Ti k��xa ,� a , � `� � � e e j� 4 ti I �p.,� -.r �r � c � � �, � j � 3s nv, � a y .-i .'3,P� �IMMI � - � Y£' � M �.� �l 1F, t S .��/ �i �' ~ E e nuiHe� �' — � � d ' isizF u 35 nG y ( iF`1' , � � �+°e ��b�y� , �� �� 'f �, `�'�r z I j �5 � r a .�i "�, (:;� � `�/,.;r . �'I '�°Ma r���1W � a j r � ' �� ��v'�' � ,� !'�h� ��.�r 3S AV i � a .e �,•v. ��� -�a �.�.._ _ Xe )o-��d,�� �'�^ 4iy 4 Qr M �.!` l, ^�l u� S� > r7y.r� irc y� i - � ..;"'��'��_,.' b � � �. �.., ..h`'�gW74� a. ��,ln'�� ',Y �_'�I��- vr� f�� Z .c 15 � ,4}j ' y� lc' � _ "�'+• �F'A � k�'N �'.ra ° I d � ' � �3' � t �' '�s > � 35AVN16' u � � � �� �l .�� ��v'n�` �, ���n3h (; � � }> �,y,l� W�1 � 1 r. ew d y. g o � , ,Y�. x ,� � f 1��4y -,.��i tvs .��. � F�" ��. � C�/3 rc�. �. �r,@.r .� _(�, l�r, Q�, `� ' � f�� , �'� �'rFN'wo�i� nV $ c.lu �,�'n ��,�� '. �,��I.y`�Q a�w� r' c� �1 � � �N �b' � ;:Y� �oHohins ,: , � � � 1 y ��,' �ye�-�. . �S��N W ' �� � �� ����' ��� } � � � �de��'�t �j ��4 �;is"nv Hlifi .�.4..I � . u ,� ��ry � �� �`�i ���:. � �3�.K� r � ��,�.�"�p�+ '3 t�� �+ ''"�,+' � � �s ye �mvuu � << . � 1��� ���'�'� �„��at �� � ��+�4� tA�� ��i��� , , �� � ,�"�� � � � tt� ���� ����� � V] ,: ,. ��'�`�'�G'Y.� •, �v�,�t� er�'�t �'nMi ;, , '�' ' ` 'n�' �.� ✓Y . Jyi c��� ^�sr �j , ..i:Mt-, . . .. .... , , , f. ,.,�� ..s� :�1 :�� . � .. �e. ...:._ ��. � .� � J`.�f �lL9 kJ' .I ...,._.I. � (I � I U h � - __ _I � _ � '` i , .'� � , i;.�, , . �;'� ,''� �✓ �,�� J ,'`, � 1• �!,1 / , 1 �� ,�• 1�� '=�� a .,' , ' ��`��d �nrn-d yn M ,ot n y�1 ;�'!� `�+, �, '�, �., o�ddv�toN a�vs��a �" � li`�t� . � � ti� ` � � 3 � 3.��,Lti.00N ,Zf'0££ io� s � �� 2b �� r i 3�N NNl7 N/VI�J �� ' a �; � •�a,e ,�► � �y�1. � tj '� x �r °bi yo� o� y 03 HS � x �- � � � �� N ^;';� ,;=• � � :;''.< x � Z � , �� _���. ,�,.`;, I � ` � i 1 `1 .e,��� 1,�� .,�;,. �— � � + ' �' `,�� 't�' I : � � . � , �r;; x� � E � �!� ��7' �• M r . � �•; o`' �„ 1^`L,' Q � �;,: x . `4c '.' �.. :`'� I �+1 ���: � �1Y �':a'.��� '4 �� ' � � �':'�' 1 x p`� �.+ � � r p�� I �� �� � ►��� r. . x � � � � J ,�,�`�• �j� �I :�•, � x � � :;�.. ,. • � ,F�,S � •,��• oarX_J.e o�f '� � X � � .;:.. .: . �-. X x z � .�o ,!�.'� W I � � £ g� �;''1;� x k � � ,",:'r' J ,� E ar�Bor-� �t�';'; 3S�OH � R x � .11/QLS 3�NIb' '.'��;� x I � / � �t�jI'�;' ��� x i i� � � ;;,. x I �� ..,'. � M• . .;i,.': x AEI3M70 ` `�1 �C '��j� 01' JNO� N3 8 "� ,.i,,,.. C���� � f� �� � •"t!:,'':. �d'DO 3 d/1CJ x f �3c �►, •� ;:.. �iY03d(1 X3 �� ,,�, I. , • � �. �"'' 01� OYd 9 ZD► � .•',^�, Y�07 � �D� � ' ''� ,,, �� 7 (�1 . �C��Q J��L�I �N /�7LYd 17Yl�dSV-�'� �M � 3:JY!1�Li1 Btf/1.7 � ' ' nnu w�o� dd �r►�► � � �J . , '� �oo� E�3lYM XOddV ror � � � �i ✓ -i0t._.._ ,� 40� o� �f (�u1J � �/3L3IY�iLYM W � �' ►� �-� � � � �, � � c � � � � � � � � � � � � � � � � � � q NOTE: SITE PLAN IS ADAPTED FROM TOPOGRAPHIC PLAN BY AMERICAN ENGINEERING � � � SITE PLAN � PROPOSED RE5IDENTIAL DEVELOPMENT � ,� Group Northwest, YI1C. 12905136TH AVENUE SE ., � O�ot�ohnb�l6�pin��rr,a.obowa,s RENTON,WASHINGTON Env Ironrtrntal SoNntlsts 8CA1,E 1" =40' DATE 7/14/04 MADE AC} CHKll WC JOH NO. G-1846 PLATE 2 � i ' I � . � , � !� , :; ` � I I : __{ � ; *, „�_'�_-- -��` ` ' o \' � °o � ��� �� �� d-+ q . ... � ( . \�,� / � o — — � � � _n�seros�rw� 323.52' __—— _1 , � ; i ; . , - - - - , -- , ' � � ,I\ � !1 � �_--- _ �=�-' _�' , l °' ��� �——�-• / -' � � � 25 � ,30,� � �� I / J � �� O ' ' .�{ I v' � �, l � 1 .' �---� ,t1� 6' I� � � .i I � \� �,' - • � .1 I ' �{ N \ I--` � J ' P � I � ��. : ` '� S`:' ,� � '._ � ��_/ � I 20' � � �� � �� � �f � �� ( � � �I _ � D I �` � �—�--� _f _�� ` 1° � � \� -• m �-. �.- ; � . �, I I � � { � ,' I z � �I I ' z I , f .) � � o � I O �� J,d'" .• � �� I � _) I i- R+yS;• / � t� i _1 �°°` /�_ — / _ _ , o J) �� S I; I _ °'J a 50+21 �;— .` � � � tt i ' �� , —— _ - _ - _ R�„An , q N _ W � I,�� ... � i" � �� � o � � I —__ _—N � _ ' 7� �iytj � ; ,�, . �� i I, � � ! r � . ti� `Z4. � � _ �' i .\ zor�' � � �` I . . `� \` �— _ � � i � -� ` j �� � �� ���� �\ � � �,i � ——— �� _ �i \ 4 ' � ��` ��` W�� �; i � ` i � � � � ( - � i , . Ob� I' I � ___ I --{ I � -�—� I I �r I I / / / 2�� ;\ \ . 1 � I y � ' � �� I: �di' i m�D I I � / _ % �N Lo.� ' ; --{ , � �; ,��� , - _,- � . I . - c.rs, i z C� . _--'�' � P'. -- `� � ��--1 �----'_ -- , -- �. ' � D _ i , � �;" _ � —'�� � � `5 .6� i I ' �.. 0 i�'L� -i�D��1L- �-�=� -=�-J �-/i , �� s , - = -- �-"��- - --- -��'� .� � .�(1� �\ ��- 964.,�'� ' . '�� � 7 " �_— —_ _'_ ��___ I I -T� 1�— _ �� I � oa' ��, $s�-a .��- - ——— ' � '� -' o `. - / o � �I� -- ' . aO�� ` � --- —' � ' �— , � - �? �o. - - - .-�•_-----_ _—=�!$8_'��3.83' - 1__ , - -- _ o ,g,� I ��. --� '. Q `� �= g � � '�. __. � ��� NOTE: SITE PLAN IS ADAPTED FROM PLAN PROVIDED BY AMERICAN ENGINEERING. INC. 10/1/04. = PROPOSED SITE PLAN [� Group Northwest, IliC. PROPOSED RESIDENTIAL DEVELOPMENT — Geotechnical Fngineers.Geobgists,8 12905 136TH AVENUE SE Env'ronrtental5cientists RENTON��'rf�SHliV�iT��1� SCALE: 1"=60' DATE: 10!4,�04 �IADE: AG CHKD: WC JOB NO: G-1846 PI.ATE 3 i i i � T � 6"to 12" �;�8:..::.:: I BACKFILL WTTH COMPACTED - - NATIVE,REI.ATIVELY - - IIv1PERMEABLE SOIL - ��� I I GEOTEXTII..E FILTER FABRIC NIIRAFI 140N OR E UIVALENT i Q , 1 FREE DRAINING BACKFII.L :�047 i NG:�::.':;::;:;�::;:.: CONSISTIIVG OF WASF�D I ROCK OR CRUSHED ROCK IvID�IIMUM 4 INCH DIAMETER I PERFORATED PVC PIPE WIT�I POSTTIVE GRADIENT TO DISCI�ARGE I I i NOT TO SCALE � NOTES: ' 1.) Do not replace rigid PVC pipe with flexible corrugated plastic pipe. 2.) Perforated or slotted PVC pipe should be tight jointed and laid with Iperforations or slots down,with positive gradient to discharge. 3.) Do not connect roof downspout drains into the footing drain lines. I I i � TYPICAL FOOTING DRAIN DETAIL (� Group Northwest, IIIC. PROPOSED RESIDENTIAL DEVELOPMENT I � Geotechnical Engnters,Geobglsts,8 12905 136TH AVENUE SE �'"°°"'"°"�'�"°"'�`S RENTON, WASHINGTON SCALE NONE DATE 7/26/O4 MADE AG CHKD WC JOB NO. G•1846 PLATF 4 , i � ! APPENDIX A: TEST PIT LOGS G-1846 Geo Group lorth��est, Inc. LEGEND OF SOIL CLASSIFICATION AND PENTRATION TEST I UNIFIED SOIL CLASSfFICATION SYSTEM (USCS) � � MAJOR DIVISION ' GROUP TyPICAL DESCRIPT�ON LABORATORY CLASSIFlCATION CRITERIA SYMBOL CLEAN GW WELL GRADED GRAVELS,GRAVELSAND Cu=(D80!D1�grsater Nan 4 MIXTURE,LfTTI_E OR NO FlNES DETERMINE �-������0•�beN+een 1 and 3 GRAVELS t � PERCENTAGES OF GRAVELS Qi@le or no � POORLY GRADm GRAVELS,AND GRAVEL- GRAVEL AND SAND (Hbra Than Half fines) r'P SAND MIXTURES LITTLE OR NO FlNES FROM GRAIN SIZE NOT MEETING ABOVE REQUIREMENTS COARSE- �arse Gnins DISTRIBUTION � GRAINED SOILS CURVE MTfERBERG LIMITS BELOW Larger Than No.4 g�� DIRTY GM SILTY GRAVEI.S,GRAVFI-SAND-SILT MIXTURES I "A`UNE. � GRAVELS ��ES w P I.LESS THAN 4 (with some GC CLAYEY GRAVELS,GRAVELSAND-CLAY IXCEEDS 12% An�BERG LIMffS ABOVE COARSE GRAINED 'A'LINE fines) I I MIXTURES SpILS ARE or P.I.MORE THAN 7 �� CLASSIFIED AS W ELL GRADED SAN0.S,GRAVELLY SANDS, FOILOWS: Cu=(D60!Dt�greatar than B SANDS CLEAN � LIfRE OR NO FWES Cc=(D30�)/(D10'D60)beiween 1 and 3 SANDS (Mwe Than HaM Coarse Grains i ��me w no POORLY GRADED SANDS,GRAVELLY SANDS, <59G Fine Grained: More Than nalf by �a) SP �RTLE OR NO FINES GW,GP,S1N,SP �T MEETING ABOVE REOUIREMEN7S WeigM Laryer �Iler Than No. Than Nu.200 4 5��� � ATTERBERG LIMfTS BELOW >129i Fine Gnined:� Sieoe p��y � SILTV SANDS,SANDSILT MIXTURES � GM,GC,SM,SC � CONTQJT OF ��"LINE SANDS with P.L LESS THAN 4 FINES ���� 5 tu 12%Fne IXC����j ATTERBERG UMITS ABOVE fi�� SC CLAYEY SAN0.S,SAND•CLAY MIXTURES Grained:use dual i "A"L1NE symbols with P.1.MORE l}IAN 7 SILTS Liquid Limit � �I INORGANIC SILTS,ROCK FLOUR,SANDY SILTS ; (Bebw A-Line on ��% OF SLIGHT PLAST1CffY bo , Plasticity ChaR PLASTICffY CHART A-Line =1NE-GRAINED ' Neglgible Liquid l�mft � INORGANIC SILTS,MICACEOUS OR i � FOR SOIL PASSING � i SOILS �Ba���) >5p% DIATOMACEOUS,FINE SANDV OR SILiY SOIL NO.40 SIEVE I a CH or OH CLAYS � Liquid limd INORGANIC CLAYS OF�04V PLASTiC(iY, W qp i CL GRAVELLV,SANDY,OR SII.TY CLAYS,CLFJW O , (Above A-Line on �� �YS Z � ' Plactiaty ChaR, } 3p Negligible Liquid LimR INORGANIC CLAYS OF HIGH PLASTIGITY,FAT , ~ Organic) >�a� � CLAYS F CL a OL �1 ' More Than Half by -- � � , Weight Sma{ler Liquid Limit ORGANIC 5llTS AND ORGANIC SILTY CLAYS OF d � MM or OH ORGANIC Sil TS 8 � OL �p ' Than No.200 c Spyb LOW PLASTICITY Sieve CLAVS _ ' 7 'OL ML � � � (Bebw A-line on, 0 --�— • I—�. I I p���,�a� i Liquid LimR OH ORGANIC CUYS OF HIGH PLASTICfTY � �—� i � >50% 0 10 ZO 30 40 S 60 70 SO 90 100 110 -- — LIQUID LIMIT(%} NIGHIY ORGANIC SOILS Pt PEAT AND OTFIER HIGHLY ORGANIC SOILS i SOIL PARTICLE SIZE OENERAL GUIDANCE OF SOIL ENOINEERlN6 PROPERTIES FROM STANDARD PENETRATION TEST(SPTJ � U.S.STANDARD SIEVE FRACTION Passing Retained SANDY SOILS SILTY 8 CLAYEY SOILS Size Size SIlVE mm SIeVe (mm Blow Relative Friction Blow Unconfined ---�- ( � � Counts Density Angb Desctiption Counts Strength p�i�� SILT I CLAY #'100 0_075 N % 0,�9�� N qu,tsf SAND i i 0-4 0-15 I Very Loose �2 <025 Very soft i FlNE I AWO 0.425 �'� #200 0 075 �-10 15-35 26-30 Loose 2-4 � D25-0.50 Sott I ME�IUM j #10 � 2 #40 0.425 10-30 I 35-65 2B-35 � Medium Dense 4-B 0.50-1.00 Medium SdH COARSE � #4 � 4J5 #'I O 2 30-50 � 85-85 35-42 � Dense 8-15 1.00-2.00 Stiff — � GRAVEL >50 85-100 38-46 Very Dense 15-30 2.00-4 00 Very Stitt FlNE t9 #4 475 I >30 � >4.00 , Fiaid I COARSE 76 19 --- --- - - ---- � C08B1E5 76 mm to 203 mm � ---- -;------ — — � Group Northwest, Inc. BOULDERS >203 mm �� _ Geotechnical Engineers,3eobgists,8 ROCK Environmentai Scientis5 >78 mm FRAGMENTS 13240 NE 2(Itl�SI 2(tl reeR Suite 12 9ellevue,WA 98005 ROCK ��, >0 76 cubic meter tn wlume Phone(42�649-9757 rax(425�64&8�58 P LAT E !1� TEST PIT NO. TP-1 LOGC'ED BY AG TEST PfT DATE: 7/7/04 GROUND ELEV. 404(+/-) DEPTH SAMPLE Water OTHER TESTS/ R. USCS SOIL DESCRIPTION No. X COMMENTS , SM Forest Duff and moss(6-inches) S1 7.4 �' ----- --------------------------------------------------- SM Brown gravelly/cobbly silty SAND,dry,medium dense(FII,L) est 10%cobbles S2 �•g plastic sheeting and alumii►um cans debns S3 7.6 �,L 5 SM dark brown,moist S4 9.7 plastic sheeting debris --- ----- ---------------------------------------------------- - SP Tan fine SAND with some silt,moist,dense SS 8•9 NATNE �� grades to some mediutn grained SAND w/gravel,very dense 9'bgs S6 g2 Total depth of test pit= 10 feet No groundwater seepage 15 TEST PIT NO. TP-2 ' LOGGED BY AG LOG DATE: 7/7/04 GROUND ELEV. 400(+/-) DEPTH SAMPLE Water OTHER TESTS/ ft. USCS SOIL DESCRIPTION No. `�G COMMENTS _ Forest Duff(8-inches) �� ----- --------------------------------------------------- SP Brown fine SAND with some silt,moist,loose S 1 12'1 Probe 12-16" --- ----- ---------------------------------------------------- S2 8.2 SP Gray fine SAND with some silt,moist,dense at 3.5 feet bgs 5 Probe 1-2" SP moist to wet S3 23.1 Total depth of test pit=7 feet No groundwater seepage � 10 15 TEST PIT LOGS _ �� PROPOSED RESIDENTIAI.DEVELOPMENT � Group Northwest, Inc. 12905136THAVENUESE — �':� Geotechn�cal Engmeers,Geobgists,8 �,N'j'OTI,WASHINGTON Env ironmental Scicnriscs JOB NO. G-1846 DATE 7/7/Od PLATE A2 i TEST PIT NO. TP-3 LOGGED BY AG TEST PIT DATE: 7/7/04 GROUND ELEV. 400(+/-) DEPTH SAMPIE Water OTHER TESTS! ft. USCS SOIL DESCRIPTION No. °� COMMENTS SM Brown gravelly/cobbly silty SAND with debris,moist,medium d�(�) S1 9.8 brick debris 5 buried log-24"diameter and brick debris S2 14.0 FILL SM Dark gray silty SAND with some gravel,moist to wet,medium dense S3 15.3 -----------------�-------�------------------- SP Brown fine SAND with some vels,mois dense 14"7 NATNE Total depth of test pit=7.5 feet I 10 No groundwater seepage 15 TEST PIT NO. TP-4. LOGGED BY AG LOG DATE: 7/7/04 GROUND ELEV. 400(-}/-) DEPTH SAMPLE Water OTHER TESTSI ft. USCS SOIL DESCRIPTION No. °�b COMMENTS SM Brown gravelly/cobbly silty SAND with plastic debris,moist, S1 g.2 medium dense(FILL) with re-bar debris with a boulder at 3'bgs S2 11.0 5 FILL SM with pipe debns S3 12.8 with signi5cant amount plastic,asphalt,bicycle and tire debris ---- ------------------------�--------------------------- " SP Brown fine St�ND with some sil moist,dense � 6 g NATTVE Total depth of test pit= 10.5 feet No groundwater seepage 15 TEST PIT LOGS _ � PROPO5ED RESIDENTIAI,DEVELOPMENT � Group Northwest, Inc. 12905136THAVENUESE �� Geotechnical Fngineers,Geobgists,S RENTON, WASHIIVGTON Env ronmental Scientists .loB No. G-1846 DATE 7/9/O�l PLATE A3 TEST P1T NO. TP-5 LOGGED BY AG TEST PIT DATE: 7/7/04 GROUfJD ELEV. 402 (+/-) �EPTH SAMPLE Water OTHER TESTS/ ft. USCS SOIL DESCRIPTION No. °h COMMENTS SM Brown silty SAND with some cobbles and gravel,dry,med.dense FILL --- ----- ------------------------------------------=--------- SP Brown gravelly fine SAND,dry,med. dense to dense S 1 4.3 NATNE dense S2 4.6 5 SP Brown medium grained gravelly SAND,dry,very dense S3 3.3 Total depth of test pit=7 feet No groundwater seepage 10 15 TEST PIT NO. TP-6 LOGGED BY AG LOG DATE: 7/7/04 GROUND ELEV. 407 (+/-) DEPTH SAMPLE Water OTHER TESTS/ R. USCS SOIL DESCRIPTION No. % COMMENTS SY� Brown fine SAND with some silt and gravel,loose to medium dense S 1 12.9 SM ---------------------------------------- S2 10.2 'SM Tan gravelly silty SAND,moiat,dense(TII�L),some cementaUon 5 Total depth of test pit=4.5 feet No groundwater seepage 10 15 TEST PIT LOGS _ �� PROPOSED RESIDENTIAL DEVELOPMENT � G rou p Northwest, Inc. 12905 136TH AVENUE SE �� Geotechnical Engmeers,Geobgists,S RENTON,WASHII�IGTON Env ironmental Sc�entists JOB NO. �'i-18�6 DATE 7/9/04 PLATE A�1 TEST PIT NO. TP-7 ' LOGGED BY AG TEST PIT DATE: 7/7/04 GROUND ELEV. 410 (+/-) DEPTH SAMPLE Water OTHER TESTS/ ft. USCS SOIL DESCRIPTION No. % COMMENTS SP/ Brown gravelly/cobbly fine SAND with some silt;dry,dense at 1' SM bgs. S1 3.9 --- ----- ---------------------------------------------------- SM Tan gravelly silty SAND,moist,cemented,very dense(TII..L) S2 7.b 5 Total depth of test pit=4 feet No groundwater seepage 10 15 TEST PIT NO. TP-8 LOGGED BY AG LOG DATE: 7/7/04 GROUND ELEV. 408 (+/-) DEPTH SAMPLE Water OTHER TESTS! ft. USCS SOIL DESCRIPTION No. °/, COMMENTS SP� Brown gravelly fine SAND with some silt,dry,loose SM S 1 3.9 probe 2' with glass and tire debris,caving,very loose FII,L 5 --- ---- ---------------------------------------------------- SM Gravelly silty SAND moist,dense at T bgs S2 �•6 NATNE Total depth of tesc pit=8 feet 10 No groundwater seepage House oc:cupant indicates 611s placed here in 1960 15 � TEST PIT LOGS PROPOSED RESIDENTIAL DEVELOPMENT D 1 Group Northwest, Inc. 12905 136THAVENLJE SE �� Geotechnical Engmeers,Geobgs�,A REIYTON, WASHIlVGTON Env�rcnmental Sc�enRsts .ros No. G-1846 DATE 7/9/04 PLATE A5 A � � A � W a � ' � ST 1.0/ ST 1.0 LA 0.8 LA 0.9 LA 1.0 LA 1.2 ST 1.1 =�o��M,s� ���vr. 1 . ��SE � _'lOTMFi� '. /VO�Di�avKL§ � KING COUNTY PEST i h .\ r . r �¢c� r _ _�j o - i F� � „_� � _: i �; -, I-.� _ , �_�r��... � .� �.• � � j .� + 41i��. i_ � � ��l ; � . iSE�AT E' 7 � � ` , _ � �r�_�, • - _ ---, � . � �- ��,- -� � , _� � s a . �o�o�� � , � , � , WM4l.1N� � \ lr �� ' � --, ' RE �OND,�.. —`1 � �� ?J� i �T—�� . � d , _ � � � =:_- �--_ � I . __�.�__--L�i � � �-_' '- - N � � 'r �"I r°�~c� �� � � t� -- V . /�� t-�-- ' { �� - ~ ., Iltdnw.T `J � 1 f � �i �� ���� ' �' � ��p � .../ , / ����� -_- �J � � ^ '_� � �.� �. ( '� 'i �.� i"'�J, . �`-� �� �� �.� �� . L :SEALTL ) Me�vri ��_.� � .c � ����Tr- �� I � � ELLEYUE � � �o� � i � . ' �,, ►� — o�_ BBJ �I�J��� E�l:x 1 +S .. �WCE " B �. �� � � � A . j i, .1 \, � cwMu1 .� MENCER L- �- �- J � \ - x.�.o r �..� I I i ' '��I �_�I � � �� � h r� � _� -� � ro� ' � � �'.'?` V '� ( ,;m� , -, � -'r-j � /� 77`,,: ���' r ,� - ' `'� / � l,,` �� I �\ ( i . : I \� ^ P11E6T0 �i SNOOl1ALYlEL�I SEATTLE �-� I � �� . �E,�. �E--, J I ��� � ;�....`:._._,.,;1��` �� ( `"1 � � �1-s.au���,r' oo�w� i� `--J i i � P__ 1 � '-_ �r,�r _.. � z j 0 - � ! v .r'1, - ' � `� � � � •� I / VR 9TnCN ( M � I i ' ` TO CM 1 � • o - � \ " � "�.'1 �. _ , __ J 1 1 � � !,� r�� �''. i_ ' �1 � , � auniea�� ��'��W�u` . '�.' � � \ � ., � ;�-,_ �ATa4 a S�.� ���: � �Rw�wov{ i � � i�: ``i � `1 � K[naisro« � �+Kn� S TAC� ,: _i_,�—_�.:.,, / � � LANDSBURG , � — � /� ��, � � ��w -f �I� (-� V cEo.a�, �'_' � r�/..'— 11._�_ I O I 'l \\ caorE v..nen U ,w.�a , j �-_ r � r-----' , _ \L� I �, q 9N01 _ nCHT '.f�/l �l� a � ` ' ,'tr ��J�-4- f _f� � ( �'a -:�—� -�- , —�-- _ _ � � �— � a �. � ;� ��� , ; � /. ,, -- �, (i Put� � ,_ � , ,� �i � ���o 1 SOtl(ItI .�.-J ! •EM� c y - - � , '_ _� , �;-'i�.--_ _ .- _ � ,i i '- .��_�-`r �� _ �,y � ;; , "�, � - , _��� �.� —---1 m � , _� ; , �. �(_. � ��,_"' ^ , . � ~ ws�nw �, . U.�—' -Bi�K . _' t � ^ - _ ouw6no —• � i' 1 ' � ��. i - I I"��_ . ST �.� eOEW�LwAY�,, � � :� ! � � _� .. .j\ � � � i /� ` L]�VI� �; '� ,� ;�_,_�._ � �,,�;. 1 PACif� �iKl`.O �OUNTY _ \ � ?IERCE COUNTY I ST 1.0 ` � ;.; ST 1.0/ � h: �����.w,�. Rainfall Regions and �a o.s �' � , ,--, Regionai Scale Factors �A 0.9 �—,� \ .� LA 1.2 ____'. Incorporated Area LA 1.0 ._.�� River/Lake -- P�lajor Road SECTION�.3 DETEVTION FACILITTES Riser Overflow The nomo;raph in Fi�ure �.�.4.H can be used to determine the head (in feet) above a riser of Qiven diameter and for a�iven flo�v I:usually the 100-year peal: flow for developed conditions}_ FIGURE 5.3.�3.H RISER INFLOW CURVES ioo __ ____-- —�— ' ' 72 54 48 ' i i I I i � ' II ' � i ; a2 ; I � ; � � � , i � ; — � ; , � ' � I ss ' a i , i ' � � 33 i i i ! I I � ! i i I i i 30 , . i ; � I i � � � I � i � 2� � � I I l � � i I I I I Z4 I L i 1 i I �� I � 2 1 i I c � ; o � � f" i � 18 W ! i d ; � � i h , i � � � j ' � ; i � , ; n � i � I i , i � �� � I 15 w • 1 d '�- I - � � i � I � � I I II � i � i � p i j ' I 12 i I � I , i I I � i � � , , i � i i I 10 � � i j I i � � , I i .G7 — ' � ' � � � � '• �. � , Z , : � , 1 � ' ' � ! � � � � ± �I "2.. � ', ( I , ' , I ; i � � i� � � � � � � � I I i i , � II I � � � � , , ; � � �i � I i i � , o.i �•s � 1 0 HEAD IN measured from crest of riser) Qw�;,=9.739 DH3iz x i!z Qo,���«=3•782 D H � in cfs, D and H in feet Slope change occurs at weir-orifice transition 9i I/9S 199� Surfac��V�ter Design�lanua! �-�0 � �_ �� �-::-�::��-�'- � i PIPE SIZING CHART, 100-YEAR CONVEYANCE DESIGN, RIDGE VIEW COURT,CITY OF RENTON AEC#0448, 9-13-05 BY: RWS PERV TRIB PEAK q qREq DWNSTR UPSTRM IMP PERV IMPERV AVG Tc ACTUAL Q V PIPE DWNSTR UPSTRM PIPE PIPE PIPE HYDRAULIC Q FULL SYSTEM DWNSTRh1 UPSTRM AREA AREATO RAINFALL DESIGN OF DWNSTR UPSTRM INVERT INVERT Q-FULL V Q AREA TO "C 'C' 'C' W! Tc Af,� Bf,�� P,� If,�, DESIGN AT DESIGN NO.PER RIM E�EV RIM ELEV LENGTN SLOPE SIZE "N" RADIUS 'R' Q NO. CB CB TOCB CB INTENSITY SYSTEM PIPE (FPS) CB CB KCBW (F7� ELEV �FT� ELEV (FT) (FTlFT) (IN) (FT) (CFS) FULL DESIGN �TIO (AC) CB(AC) �AC) TO CB TO CB TO CB VFu�� USED .,��, STRUCTURE (CFS) (SF) (FT) (FT) 1 VAULT C62 0.00 0.07 0.07 0.25 U.90 0.90 0.1 8.0 2_61 0.63 3.82 0.70 2.69 0.17 4.66 1.77 2.64 VAULT CB2 N1 403.75 394.50 403.74 399.00 57 0.0882 18.00 0.014 0.375 17.3 9.8 3.7 0.19 1 C82 CB3 0.00 0.00 0.00 0.25 0.90 0.00 0.2 7.9 2.61 0.63 3.82 0.71 2.71 O.OD 3.90 1.77 2.21 CB2 CB3 N2 403.74 399.00 404.00 399.75 51 0.0147 'I8.00 0.014 0.375 7.1 4.0 1.8 0.51 1 C63 CB4 0.00 0.04 0.04 0.25 0.90 0.90 0.3 7.7 2.61 0.63 3.82 0.72 2.76 0.10 2.58 0.79 3.29 CB3 C84 N3 404.00 400.25 404.42 401.00 54 0.0139 12.00 0.0'14 0.250 2.7 3.4 1.0 1.95 'I CB4 CBS 0.14 0.15 029 0.25 0.90 0.59 0.3 7.4 2.67 0.63 3.82 0.74 2.82 0.48 0.88 0.79 7.11 CB4 C85 N4 404.42 401.00 405.23 401.90 65 0.0138 12.00 0.014 0.250 2.7 3.4 3.0 1.21 1 CB5 CB6 0.02 0.04 0.06 0.25 0.90 0.68 0.2 7.1 2.61 0.63 3.82 0.76 2.90 O.t2 0.40 0.79 0.51 CB5 CB6 N5 405.23 401.9D 407.09 402.25 36 0.0097 12.00 0.014 0250 22 2.8 5.6 0.43 1 C86 C87 0.04 0.05 0.09 0.25 0.90 0.61 0.6 6.9 2.61 0.63 3.82 0.77 2.95 0.76 0.28 0.79 0.35 CB6 CB7 N6 407.09 402.25 409.50 404.25 130 0.0154 12.00 0.014 0.250 2.8 3.6 10.1 1.40 'I CB7 CB8 0.04 0.03 O.D7 0.25 0.90 0.53 6.3 6.3 2.61 0.63 3.82 0.82 3.13 0.12 0.12 0.35 0.33 CB7 CB8 N7 409.50 404.58 409-76 405.00 17 0.0247 S_00 0.0'i4 0.167 1.4 4.0 11.9 0.00 2 CB4 C89 0.00 0.05 0.05 0.25 0.90 0.90 02 7.2 2.61 0.63 3.82 0.75 2.87 0.13 1.08 0.79 1.38 C84 C69 N7 404.42 401.00 404.42 401.37 31 0.0100 12.00 0.014 0.250 2.3 2.9 2.'I 0.14 2 C89 CB10 0.02 0.03 0.05 0.25 0.90 0.64 0.5 7.0 2.61 0.63 3.82 0.76 2.92 0.09 0.95 0.79 1.21 CB9 CB10 N2 404.42 401.31 405.47 401.93 77 0.0081 12.00 0.014 0.250 2.0 2.6 2.1 0.11 2 CBtO C611 0.03 0.18 0 21 0.25 0.90 0.81 0.2 6.5 2.61 0.63 3.82 0.80 3.05 0.52 0.86 0.79 1-09 C610 CB11 N3 405.41 401.93 405.55 402 24 38 0.0082 12.00 0.014 0.250 2.0 2.6 2.4 1.52 2 CB1 1 C812 0.04 0.'11 0 15 0.25 0.90 0.73 6.3 6.3 2.61 0.63 3.82 0.82 3.13 0.34 0.34 0.79 0.43 C611 CB12 N4 405.55 402.24 405.55 402 55 31 0.0100 12.00 0.014 0.250 2.3 2.9 6.6 0.00 3 C62 C614 0.00 0.21 0.21 0.25 0.90 0.90 6.3 6.3 2.61 0.63 3.82 0.82 3.13 0.59 0.59 0.79 0.75 CB2 C614 Nt 403.74 399.50 403.33 400.00 24 ' 0.02(IS 72.00 0.014 Q.25Q 3.3 4.2 5.5 0.00 4 VAULT CBt 0.27 0.29 0.56 025 0.90 0.59 6.3 6.3 2.61 0.63 3.82 0.82 3.13 1.03 1.03 0.79 1.31 VAULT CB1 N1 403.75 395.00 404.18 399.28 29 , 0.1476 12.00 0.014 0.250 8.7 11.1 8.5 0.00 6 B3 16 0.14 0.18 0.32 0.25 0.90 0.62 6.3 6.3 2.61 0.63 3.82 0.82 3.13 0.62 0.62 0.79 0.78 B3 16 2 404.00 400.25 404.25 400.7 39 0.0128 12.00 0.014 0.250 2.6 3.3 4.2 0.00 7 C69 CB13 0.17 0.09 0.26 0.25 0 90 0.48 6.3 6.3 2.61 0.63 3.82 0.82 3.13 0.39 0.39 0.35 1.11 C69 CB13 N2 404.42 401.64 405.02 402.02 11 0.0345 B.00 0.014 0.167 1.6 4.7 4.2 0.00 6 ;' CB4 `-C617 O.W 0.05 0.05 0.25' 0.90' 0.90:'. 6.3; - 6.3 . -2.61T', z0:G3';: 3.82 0:82 3.13 0.14 ,0:14 �. < 0_35 :0:40 :`eB4 .-•=.-C817 Nt. ;404.42 �-AOt.3� ;?':405:Q2:.'s-902.02' ��'�i�:t, 0.062t '';B.DD_ 0.014 .:_ -0:167 2.2 6_3' .. 15.7'::'';Q:00- Pen- Im Total 1.16 1.75 1.16 1]5 291 Totat Area= 2.91 � KING COUNTY BACKWATER COMPUTER PROGRAM FOR PIPES Pipe data from file:systeml.bwp Surcharge condition at intermediate junctions Tailwater Elevation:402.2 feet Discharge Range:4 .65 to 4 .66 Step of 0.01 [cfs] Overflow Elevation:409.76 feet Weir:NONE Upstream velocity: l. feet/sec VA UL T- CB2 PIPE NO. 1: 51 LF - 18"CP '� 8.82% OUTLET: 394 . 50 INLET: 399. 00 INTYP: 5 JUNC NO. 1: OVERFLOW-EL: 403 .74 BEND: 25 DEG DIA/WIDTH: 2 .0 Q-RATIO: 0.19 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI ***************************************,r*************************************** 4 .66 3 .29 402 .29 * 0.012 0 .83 0.38 7 .70 7 .70 3 .29 3 .18 0 . 90 CB2- CB3 PIPE NO. 2 : 51 LF - 12"CP @ 1.47� OUTLET: 399.50 INLET: 400.25 INTYP: 5 JUNC NO. 2: OVERFLOW-EL: 404.00 BEND: 30 DEG DIA/WIDTH: 2 .0 Q-RATIO: 0 .51 Q(CFS) HW{FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI ******,r****+*****,r*****************,r******************************************* 3 . 92 3 . 06 403 .31 * 0 .012 0 . 85 0.70 2 .79 2 .79 2 .56 3 .06 1 .58 CB3- CB4 PIPE NO. 3 : 54 LF - 12"CP @ 1.39� OUTLET: 400.25 INLET: 401.00 INTYP: 5 JUNC NO. 3 : OVERFLOW-EL: 404.42 BEND: 0 DEG DIA/WIDTH: 2 .0 Q-RATIO: 1.95 Q(CFS} HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI ****,r************************************************************************** 2.59 2 .82 403 .82 * 0.012 0.69 0.55 3 .07 3 .07 2 .57 2.82 1.10 CB4- CBS PIPE NO. 4 : 65 LF - 12"CP @ 1.38� OUTLET: 401.00 INLET: 401 .90 INTYP: 5 JUNC NO. 4 : OVERFLOW-EL: 405.23 BEND: 45 DEG DIA/WIDTH: 2 .0 Q-RATIO: 1.21 Q(CFS) HW(FT} HW ELEV. * N-FAC DC DN TW DO DE HWO HWI ***********************************,r******************************************* 0 . 88 1. 99 403 .89 * 0. 012 0.40 0.30 2 .82 2 . 82 1 . 96 1.99 0.54 CBS- CB6 PIPE NO. 5: 36 LF - 12"CP @ 0.97$ OUTLET: 401.90 INLET: 402.25 INTYP: 5 JUNC NO. 5: OVERFLOW-EL: 407.09 BEND: 45 DEG DIA/WIDTH: 2 .0 Q-RATIO: 0.43 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI ******************************************************************************* 0 .40 1.66 403 .91 * 0.012 0.27 0.22 1.99 1. 99 1.65 1.66 0.35 �'. CB6- CB7 PIPE NO. 6: 130 LF - 12"CP @ 1.54� OUTLET: 402 .25 INLET: 404.25 INTYP: 5 JUNC NO. 6: OVERFLOW-EL: 409.50 BEND: 90 DEG DIA/WIDTH: 2.0 Q-RATIO: 1.40 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI ******************************************************************************* 0.28 0.29 404 .54 * 0.012 0.22 0.17 1.66 1.66 0.22 ***** 0.29 CB�- CB8 PIPE NO. 7: 17 LF - 8"CP Q 2.47� OUTLET: 404 .58 INLET: 405.00 INTYP: 5 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI *************************************************************,r***************** 0.12 0.19 405.19 * 0.012 0.16 0.11 0 .00 0 .11 0.16 ***** 0.19 Pipe data from file:system2.bwp Surcharge condition at intermediate junctions Tailwater Elevation:403.82 feet Discharge Range:1.07 to 1.08 Step of o. ol (cfs) Overflow Elevation:405.55 feet Weir:NONE Upstream Velocity:l. feet/sec CB4- CB9 PIPE NO. 1: 31 LF - 12"CP Q 1.00% OUTLET: 401.00 INLET: 401.31 INTYP: 5 JUNC NO. 1: OVERFLOW-EL: 404.42 BEND: 90 DEG DIA/WIDTH: 2.0 Q-RATIO: 0. 14 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI *******************************************************,r*******************,r**� 1. 08 2 .59 403 .90 * 0 .012 0.44 0.37 2 . 82 2 . 82 2 . 53 2 .59 0.63 CB9- CB10 PIPE NO. 2 : 77 LF - 12"CP @ 0.81% OUTLET: 401 . 31 INLET: 401. 93 INTYP: 5 �� JUNC NO. 2 : OVERFLOW-EL: 405.41 BEND: 45 DEG DIA/WIDTH: 2 .0 Q-RATIO: 0.11 IQ(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI **********************,r******************************************************** 0.95 2 . 04 403 .97 * 0.012 0.41 0.36 2 . 59 2 .59 2 .01 2 .04 0.56 CB1 D- CBI1 PIPE NO. 3 : 38 LF - 12"CP � 0.82% OUTLET: 401. 93 INLET: 402 .24 INTYP: 5 JiTNC NO. 3 : OVERFLOW-EL: 405.55 BEND: 45 DEG DIA/WIDTH: 2 .0 Q-RATIO: 1.52 i Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI ******************************************************************************* O. B5 1.79 404 .03 * 0.012 0 .39 0 .34 2 .04 2 .04 1.76 1.79 0 .54 CBll - CB12 PIPE NO. 4 : 31 LF - 12"CP C 1.00� OUTLET: 402.24 INLET: 402 .55 ZNTYP: 5 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI ******************,r************************************************************ 0.34 1.48 404 .03 * 0.012 0.24 0.20 1.79 1.79 1.48 1.47 0. 30 Pipe data from file:system3.bwp Surcharge condition at intermediate junctions Tailwater Elevation:402.29 feet Discharge Range:0.58 to 0.59 Step of 0.01 [cfs] Overflow Elevation:403 .33 feet Weir:NONE Upstream Velocity:l. feet/sec CB2- CB14 PIPE NO. 1: 24 LF - 12"CP C 2 .08% OUTLET: 399.50 INLET: 400 . 00 INTYP: 5 Q{CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI ******************************************************************************* 0.59 2 .30 402.30 * 0.012 0.32 0.22 2.79 2.79 2 .30 2 .29 0.41 Pipe data from file:system4.bwp Surcharge condition at intermediate junctions Tailwater Elevation:402.2 feet Discharge Range:1.02 to 1.03 Step of 0. 01 [cfs] Overflow Elevation:404.18 feet Weir:NONE Upstream Velocity:l. feet/sec VA ULT- CBI PIPE NO. 1: 29 LF - 12"CP @ 14.76% OUTLET: 395.00 INLET: 399.28 INTYP: 5 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI ******************************************************************************* 1.03 2 .97 402 .25 * 0. 012 0.43 0 .18 7 .20 7 .20 2 .94 2 .97 0 .52 i I_ Pipe data from file:system5.bwp Surcharge condition at intermediate junctions Tailwater Elevation:403 .31 feet Discharge Range:0.69 to 0.7 Step of 0.01 [cfs] Overflow Ele�.ration:404.31 feet Weir:NONE Upstream Velocity:l. feet/sec CB3 - CBI S PIPE NO. 1: 69 LF - 12"CP C� 1.09� OUTLET: 400.25 INLET: 401.00 INTYP: 5 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI �**********************,r******************************,r************************ 0 .?0 2 .34 403 .34 * 0.012 0. 35 0 .29 3 .06 3 . 06 2 .33 2 .34 0.46 Pipe data from file:system6.bwp Surcharge condition at intermediate junctions Tailwater Elevation:403.31 feet Discharge Range:0.61 to 0.62 Step of 0.01 [cfsJ Overflow Elevation:404 .25 feet Weir:NONE Upstream Velocity:l. feet/sec CB3 - CB16 PIPE NO. 1 : 39 LF - 12"CP 4 1.28% OUTLET: 400.25 INLET: 400.75 INTYP: 5 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI *****************************************************************************,r* 0 .62 2 .57 403 . 32 * 0.012 0.33 0 .26 3 .06 3 .06 2 .57 2 .57 0 .43 Pipe data from file:system7.bwp Surcharge condition at intermediate junctions Tailwater Elevation:403.9 feet Discharge Range:0.38 to 0.39 Step of 0.01 [cfs) Overflow Elevation:405.02 feet Weir:NONE Upstream Velocity: l. feet/sec CB9- CB13 PIPE NO. l: 11 LF - 8"CP @ 3.45% OUTLET: 401.64 INLET: 402 .02 INTYP: 5 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI �**+*************************************************************************** 0 . 39 � . 90 403 . 92 * 0 . 012 0. 30 0 . 19 2 .25 2 .25 1 . 89 1 . 90 0 . 39 Pipe data from file:system8.bwp Surcharge condition at intermediate junctions Tailwater Elevation:403 .9 feet Discharge Range:0.13 to 0.14 Step of 0. 01 [cfs) Overflow Elevation:405.02 feet Weir:NONE Upstream Velocity: l. feet/sec CB4- CB17 PIPE NO. l: 11 LF - 8"CP � 6.27% OUTLET: 401.33 INLET: 402 .02 INTYP: 5 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI , ******************************************************************************* 0.14 1.88 403 . 90 * 0. 012 0 . 18 0 .10 2 . 5? 2 .57 1.88 1 .87 0.20 � i Developed Area Table On-site Im ervious ROV� Road/Walk in ROW 17,864 SF 0.41 AC On-site Pervious Area GrasslLandsca ing 29,050 SF 0.67 AC I Impervious On-site Lots Lot Size Imp Area (Roof/Drivewa s/Walks/Access) (75% or 4000 s� Lot 1 4446 3335 Lot 2 3600 2700 Lot 3 4983 3738 Lot 4 3371 2528 Lot 5 3344 2508 Lot 6 2849 2137 Lot 7 3187 2390 Lot 8 5831 4000 Lot 9 3928 2946 Lot 10 4120 3090 Lot 11 4342 3257 Lot 12 4340 3255 Lot 13 4065 3049 Lot 14 3117 2338 Lot 15 2725 2044 Lot 16 2779 2084 Lot 17 3683 2762 Lot 18 4835 3626 Lot19 3600 2700 Lot 20 4105 3079 Det. Tract NA 350 TOTALS 57566 SF 1.32 AC Off-site Contributin Area Forest (adjacent parcel) 8,880 SF 0.20 AC � Off-site Bremerton ROW Area 13,521 SF 0.31 AC Impervious Road/Walk 9,071 0.21 Pervious Pasture 4,450 0.10 � � � � A � W a � � APPEi�IDIX A MAIN7'ENANCE STANDARDS FOR PRIVATELY:�fAINTAINED DRAINAGE FACILITIES 'i NO. 3-CLOSED DETENTION SYSTEMS(PIPES�TANKS) Maintenance Defect Conditions When Maintenance is Needed Results Expected When Component Maintenance is Performed Storage Area Plugged Air Vents One-half of the cross section of a vent is blocked at Vents free of debris and any point with debris and sediment sediment Debris and Accumufated sediment depth exceeds 10%of the All sediment and debris Sediment diameter of the storage area for'fz length of storage removed from storage area. vault or any point depth exceeds 15%of diameter. Example:72-inch storage tank would require cleaning when sediment reaches depth of 7 inches for more than�h length of tank. Joints Beriveen Any crack allowing material to be transported into All joint between tank/pipe TanklPipe Section facility sections are sealed Tank Pipe Bent Any part of tank/pipe is bent out of shape more than Tank/pipe repaired or replaced Out of Shape 10%of iYs design shape to design. Manhole Cover Not in Place Cover is missing or only paRially in place.Any open Manhole is closed. manhole requires maintenance. Locking Mechanism cannot be opened by one maintenance Mechanism opens with proper Mechanism Not person with proper tools.Bolts into frame have less tools. Working than'/z inch of thread(may not apply to self-locking tids.) Cover Difficutt to One maintenance person cannot remove Iid after Cover can be removed and Remove applying 801bs of lift. Intent is to keep cover from reinstalled by one maintenance sealing off access to maintenance. person. Ladder Rungs King County Safety Office and/or maintenance person Ladder meets design standards Unsafe judges that ladder is unsafe due to missing rungs, allows maintenance person safe misalignment,rust,or cracks. access. Catch Basins See"Catch Basins"Standards No.5 See`Catch Basins"Standards No.5 1998 Su-face���ter D�si�*a�13�ua1 9;1i98 � A-3 APPENDIX A V1AIN'IENP.��ICE STA:�iDARDS FOR PRIVATELY MAINTAI'.�7ED DRAINAGE FACILITTES NO. 4- CONTROL STRUCTURE/FLOW RESTRICTOR Maintenance Defect Condition When Maintenance is Needed Resuits Expected When Component Maintenance is Pertormed General Trash and Debns Distance between debris build-up and bottom of Ali trash and debris removed. (Inctudes Sediment) orifice plate is less than 1-1/2 feet Structural Damage Structure is not securely attached to manhole wall Structure securely attached to and outlet pipe structure should support at least wall and ouUet pipe. 1,000 Ibs of up or down pressure. Structure is not in upright position(allow up to Structure in correct position. 10%from plumb). Connections to ouUet pipe are not watertight and Connections to outlet pipe are show signs of rust. water tight;suucture repaired or replaced and works as designed. Any holes—other than designed holes—in the Structure has no holes other structure. than designed holes. Cleanout Gate Damaged or Missing Cleanout gate is not watertight or is missing. Gate is watertight and works as designed. Gate cannot be moved up and down by one Gate moves up and down easily maintenance person. and is watertight. Chain Ieading to gate is missing or damaged. Chain is in place and works as designed. Gate is rusted over 50'0 of its surface area. Gate is repaired or replaced to meet design standards.. Orifice Plate Damaged or Missing Control device is not working properly due to Plate is in place and works as �) missing,out of place,or bent orifice plate. designed. i Obstructions Any Vash,debris,sediment,or vegetation Plate is tree of all obstructions blocking the plate. and worics as designed. Overflow Pipe Obstructions Any trash or debris blocking(or having the Pipe is free of all obstructions potential of blocking)the overffow pipe. and works as designed. Manhole See"Closed Detention Systems"Standards No.3 See"Closed Detention Systems' Standards No.3 Catch Basin See`Catch 8asins"Standards No.5 See'Catch Basins"Standards No.5 911/98 1993 �urface�L'ater Desi�n hlaaua! A-4 APPENDIX A MAINTENAIVCE STANDARDS FOR PRNATELY MAINTAINED DRAINAGE FACILITIES NO. 5 -CATCH BASINS Maintenance Defect Conditions When Maintenance is Needed Results Expected When Component Maintenance is performed General Trash&Debris Trash or debris of more than 1!2 cubic foot which is No Trash or debris tocated (Includes Sediment) located immediately in front of the catch basin immediately in front of catch opening or is blocking capaciry of the basin by basin opening. more than 1 U% Trash or debris(in the basin)that exceeds 1/3 the No trash or debris in the catch depth from the bottom of basin to inveR the lowest basin. pipe into or out of the basin. Trash or debris in any inlet or outlet pipe blocking Inlet and ouUet pipes free of more than 1!3 of its height trash or debris. Dead animals or vegetation that could generate No dead animals or vegetation odors that could cause complaints or dangerous present within the catch basin. gases(e.g.,methane). Deposits of garbage exceeding 1 cubic foot in No condition present which volume would attract or support the breeding of insects or rodents. Structure Damage to Comer of frame extends more than 3/4 inch past Frame is even with curb. Frame and/or Top Slab curb face into the street(If applicable). Top slab has holes larger than 2 square inches or Top slab is free of holes and cracks wide�than 1/4 inch(intent is to make sure cracks. all material is running into basin). Frame not sitting flush on top slab,i.e.,separation Frame is sitting flush on top I of more than 3/4 inch of the frame from the top slab. slab. Cracks in Basin Walls/ Cracks wider than 1!2 inch and longer than 3 feet, Basin replaced or repaired to Bottom any evidence of soil particles entering catch basin design standards. through cracks,or maintenance person judges that structure is unsound. Cracks wfder than ti2 inch and longer than 1 foot No cracks more than 1/4 inch at the joint of any inleV ouUet pipe or any evidence wide at the joint of inleVoutlet of soil particles entering catch basin through pipe. cracks. SedimenU Basin has settled more than 1 inch or has rotated Basin replaced or repaired to Misalignment more than 2 inches cut of alignment. design standards. 1998 Surface V+'ater Desi�n ivianuat y�1r9e v A � APPENDIX A htAINTENANCE ST.�NDARDS FOR PRIVATELY M�INTAINED DRAINAGE FACII.ITTES i NO.5- CATCH BASINS (CONTlNUED) Maintenance Defect Conditions When Maintenance is Needed Resuits Expected When Component Maintenance is pertormed Fire Hazard Presence of chemicals such as natural gas,al and No flammable chemicals gasoline. present. Vegetation Vegetation growing across and blocking more than No vegetation blocking opening 10%of the basin opening. to basin. Vegetation growing in inleVoutiet pipe joints that is No vegetation or root growth more than six inches tall and less than six inches present. apaR. Pollution Nonflammable chemicals of more than 1/2 cubic foot No pollution present other than per three feet of basin lenqth. surface film. Catch Basin Cover Cover Not in Place Cover is missing or only partiatly in place.Any open Catch basin cover is closed catch basin requires maintenance. Lacking Mechanism Mechanism cannot be opened by on maintenance Mechanism opens with proper Not Working person with proper tools.Bolts into frame have less tools. than 1/2 inch of thread. Cover Difficult to One maintenance person cannot remove lid after Cover can be removed by one Remove applying 80 Ibs.of lift;intent is keep cover from maintenance person. sealing off access to maintenance. Ladder Ladder Rungs Ladder is unsafe due to missing rungs,misalignment, Ladder meets design standards Unsafe rust,cracks,or sharp edges. and albws maintenance person safe access. Metal Grates Grate with opening wider than 7/8 inch. Grate opening meets design (If Applicable) standards. Trash and Debris Trash and debris that is blocking more than 20%of Grate free of trash and debris. grate surface. Damaged or Grate missing or broken member(s)of the grate. Grate is in place and meets Missing. design standards. NO. 6 DEBRIS BARRIERS (E.G.,TRASH RACKS) Maintenance Defect Condition When Maintenance is Needed Results Expected When Components Maintenance is Performed. General Trash and Debris Trash or debris that is plugging more than 20%of Barrier clear to receive capacity !he openings in the barrier. flow. Metal Damaged,`P:lissing Bars are bent out of shape more than 3 inches. Bars in place with no bends more B2rs. than 3/4 inch_ Bars are missing or entire barrier missing. Bars in place according to design. 6ars are loose and rust is causing 504o deterioration Repair or replace barrier to to any part of barrier. design standards. 9!1/9S 1998 Surface V1,'ater Desi�n Nianual A-6 APPENDIX A MAINTENANCE STANDARDS FOR PRIVATELY'v1AINT�INED DRAINAGE FACILITIES NO. 7- ENERGY DISSIPATERS Maintenance Defect Conditions When Maintenance is Needed Results Expected When Components Maintenance is Pertormed. Extemal: Rock Pad Missing or Moved Only one Iayer of rock exists above native soil in Replace rocks to design Rock area five square feet or larger,or any exposure of standards. native soil. Dispersion Trench Pipe Plugged with Accumulated sediment that exceeds 20°0 of the Pipe cleaned/flushed so that it Sediment design depth. matches design. Not Discharging Visual evidence of water discharging at Trench must be redesigned or Water Prooerly concentrated points along trench(normal condition rebuilt to standards. is a"sheet flotin/'of water along trench). Intent is to prevent erosion damage. Perforations Over 1!2 of perforations in pipe are plugged with Clean or replace perforated pipe. Plugged. debris and sediment. Water Flows Out Maintenance person observes water flowing aut Facility must be rebuilt or Top of"Distributo�' during any storm tess than the design storm or its redesigned to standards. Catch Basin. causing or appears likely to cause damage. Receiving Area Water in receiving area is causing or has potential No danger of tandslides. Over-Saturated of causing landsfide problems. IntemaL• Manhole/Chamber Wom or Damaged Structure dissipating flow deteriorates to 1i2 or Replace sVucture to design Post.Baffles,Side original size or any concentrated wom spot standards. of Chamber exceeding one square foct which would make structure unsound. Other Defects 5ee"Catch Basins"Standard No.5 See"Catch Basins"Standard No. � 5 1998 Surface Water Design b9anu.:l 9/I�98 :�-i APPENDIX A MAINTENANCE STANDARDS FOR PRIVATELY MAINTAINED DRAINAGE FACILI'ITES NO. 8- FENCING Maintenance Defect Conditions When Maintenance is Needed Results Expected When Components Maintenance is Perfo�med General Missing or Broken Any defect in the fence that permits easy entry Parts in place to provide adequate Parts to a facility. security_ Erosion Erosion more than 4 inches high and 12-i S No opening under the fence that inches wide permitting an opening under a exceeds 4 inches in height fence. Wire Fences Damaged Parts Post out of plumb more than 6 inches. Post plumb to within 1-1/2 inches. Top raiis bent more than 6 inches. Top rail free of bends greater than 1 inch. Any part of fence(including post,top rails,and Fence is aligned and meets design fabric)more than 1 foot out of design alignment. standards. Missing or loose tension wire. Tension wire in place and hoiding fabric. Missing or loose barbed wire that is sagging Barbed wire in place with less than more than 2-1/2 inches between posts. 3!4 inch sag between post. Extension arm missing,broken,or bent out of Extension arm in place with no shape more than 1 1!2 inches. bends larger than 3/4 inch. ', Deteriorated Paint or Part or parts that have a rusting or scaling Structurally adequate posts or I Protective CoaUng condition that has affected structural adequacy. parts with a uniform protective coating. Openings in Fabric Openings in fabric are such that an 8-inch- No openings in fabnc. 'i diameter ball could fit through. ,I � NO. 9-GATES !, Maintenance Defect Conditions When Maintenance is Needed Results Expected When �I Component Maintenance is Performed General Damaged or Missing Missing gate or locking devices. Gates and Locking devices in ' Members place. Broken or missing hinges such that gate cannot Hinges intact and lubed.Gate is �. be easily opened and closed by a maintenance woricing freely. person. , Gate is out of plumb more than 6 inches and Gate is aligned and vertical. more than 1 foot out of design alignment. Missing stretcher bar,stretcher bands,and ties. Stretcher bar,bands and ties in place. Openings in Fabric See"Fencing"Standard No.8 See"Fencing"Standard No.8 9/1/98 1998 Surface Wa[er Desi�n�Ianual a-s APPENDIX A 'vIAINT'ENANCE STANDARDS FOR PRNATELY MAINTAINED DRAINAGE FACII.IT'IES N0. 10-CONVEYANCE SYSTEMS(PIPES & DITCHES� Maintenance Defect Conditions When Maintenance is Needed Results Expected When Component Maintenance is Pertormed Pipes Sediment&Debris Accumutated sediment that exceeds 20%of the Pipe cleaned of all sediment diameter of the pipe. and debris. Vegetation Vegetation that reduces free movement of water Afl vegetation removed so water through pipes. flows freely through pipes. Damaged Protective coating is damaged;rust is causing Pipe repaired or replaced. more than 50%deteriora6on to any part of pipe. Any dent that decreases the cross section area of Pipe repaired or replaced. pipe by more than 20�e. Open Ditches Trash&Debris Trash and debris exceeds t cubic foot per 1,000 Trash and debris cleared from square feet of ditch and slopes. ditches. Sediment Accumulated sediment that exceeds 20%of the Ditch cleaned/flushed of all design depth. sediment and debris so that it matches design. Vegetation Vegetation that reduces free movement of water Water flows freely through through ditches. ditches. Erosion Damage to See"Ponds"Standard No. 1 See"Ponds"Siandard No.1 Slopes Rock Lining Out of Maintenance person can see native soil beneath Replace rocks to design P(ace or Missing(If the rock lining. standards. Applicable). Catch Basins See"Catch Basins:Standard No.5 See"Catch Basins"Standard No.5 � Debris Barriers See'�ebris Barriers"Standard No_6 See"Debris Barriers"Standard ' (e.g.,Trash Rack) No.6 NO. 11 -GROUNDS (LANDSCAPING) Maintenance Defect Conditions When Maintenance is Needed Results Expected When Component Maintenance is Perforrned General Weeds Weeds growing in more�an 20%of the landscaped Weeds present in less than 5% (Nonpoisonous) area(trees and shrubs only). of the landscaped area. Safety Hazard Any presence of poison ivy or other poisonous No poisonous vegetation vegetation. presentinfandscaped area. Trash or Litter Paper,cans,bottles,totaling more than 1 cubic foot Area clear of litter. within a landscaped area(trees and shrubs only)of 1,000 square feet. Trees and Shrubs Damaged Limbs er parts of trees or shrubs that are split or Trees and shrubs with less than broken which affect more than 25',0 of the total 5°'a of total foliage with split or foliage of the tree or shrub. broken limbs. Trees or shrubs that have been blown down or Tree or shrub in place free of knocked over. injury. Trees or shrubs which are not adequately supported Tree or shrub in place and ' or are leaning over,causing exposure of the roots. adequately supported;remove , any dead or diseased trees. ' 1993 Surface Vl`a[e:DesiQn�tanual 9/1'9b �� a-9 � � �PPENDIX A M,aIN'CEN�.NCE STAI�IDARDS FOR PRIVATELY MAINTAINED DRAINAGE F.ACILITIES NO. 12-ACCESS ROADS/EASEMENTS Maintenance Defect Condition When Maintenance is Needed Results Expected When Component Maintenance is Pertormed ' Generai Trash and Debns Trash and debns exceeds 1 cubic ioot per 1,000 Roadway free of debris which square feet i.e.,trash and debris wauld fiil up could damage tires. one standards size garbage can. 8locked Roadway Debris which could damage vehicle tires(glass Roadway free of debris which , or metal). could damage tires. Any obstruction which reduces Gearance above Roadway overhead Gear to 14 feet road surface to less than 14 feet high. Any obstruction restricting the access to a 10 to Obstruction removed to allow at 12 foot width for a distance of more than 12 feet least a 12 foot access. cr any point restncting access to less than a 10 foct width. Road Surtace Settlement, Potholes, When any surface defect exceeds 6 inches in Road surface uniformly smooth Mush Spots,Ruis depth and 6 square feet in area.In general,any with no evidence of settlement. surface defect which hinders or prevents potholes,mush spots,or ruts. maintenance access. Vegetation in Road Weeds growing in the road surface that are Aoad surface free of weeds taller Surface more than 6 inches tall and less than 6 inches than 2 inches. tall and less ihan 6 inches apart within a 400- square foot area. Modular Grid Build-up of sediment mildly contaminated with Removal of sediment and disposa! Pavement petroleum hydrocarbons. in keeping with Health Department recommendations for mifdly contaminated soils or catch basin sediments. Shoulders and Erasion Damage Erasicn�vithin t foof of the roadway more than 8 Shoulder free of erosion and Ditches inches wide and 6 inches deep. matching the surrounding road. V'Jeeds and Brush Weeds and brush exceed 18 inches in height or Weeds and brush cut to 2 inches hinder maintenance access. in height or cleared in such a way as to allow maintenance access_ 9/;l93 1998 Surface�vater Design`lanual A-10 APPENDIX A �IAINTENANCE STANDARDS FOR PRIVATELY MAINTAINED DRAINAGE FACILITIES N0. 13-WATER �UALITY FACILtT1ES(COMINUECJ� D.)Wetvaults � Maintenance Defect Condition When Maintenance is Needed Results Expected When Component Maintenance is Performed Wetvault Trash/Debris Trash and debris accumulated in vault,pipe or Trash and debris removed from Accumulation inleV outlet,(includes floatables and non- vault. floatables). Sediment AccumulaUon Sediment accumulation in vault bottom that Removal of sediment from vault. i�Vault exceeds the depth of the sediment zone plus 6- inches. Damaged Pipes InIeU ouUet piping damaged or broken and in Pipe repaired and/or replaced. need of repair. Access Cover Cover cannot be opened or removed,especially Pipe repaired or replaced to Oamaged/Not Working by one person. proper working specifications. Vault Structure Vault:Cracks wider than 1/2-inch and any No cracks wider than 1/4inch at Damaged evidence of soil particles entering the shucture the joint of the inleV outlet pipe. throuqh the cracks,or maintenancel inspection V3ult is determined to be personnel determines that the vault is not structurally sound. structurally sound. Baffles Baffles corroding,cracking,warping and/or Repair or replace baffles to showing signs of failure as determined by specifications. maintenance/inspection staff. Access Ladder Damage Ladder is corroded or deteriorated,not functioning Ladder replaced or repaired to properly,missing rungs,has cracks and/or specifications,and is safe to misaligned. use as determined by inspection personnel. 1998 Surface Water Desi�n Manual 9����� A-13 =111 s�vNON �vv��sorv iNc. A`�� ��o�oo ��ortioa MfSSOUAI - GEOTECHNICAL ANO ENVIRONMENTAL CON ULTANTS oRe6on WASHING-Oh May 12,2006 ���'��h� ��� C(TY�F RENTON �4�,`C 1 '� �006 Mr.Tom Foster ���UED Fourth Avenue Associates, LLC 6450 Southcenter Boulevard, Suite 106 Seattle, WA 98188 RE: EXISTING CONDTTIONS REVIEW FOR THE FOURTH AVENiJE ASSOCIATIES,LLC STTE IN RENTON,WASHINGTON,AS THEY PERTAIN TO A PROP�SED RELEASE OF STORMWATER ONTO THE SI'TE Dear Mr. Foster: At yow request, Shannon&Wilson, Inc. has prepazed this letter describing the conditions observed during our November 20, 1998,wetland and stream deIineation on the former Ribera property located within the city limits of Renton,Washington{�1E 1/4 of Section I5,Township 23 North, and Range 5 East,'4�'.M.). Since our site visit in 1998,it is our understanding that the Ribera property has been subdivided into two parcels, Parcel Nos. 518210-fl020 and 0031. Parcel No. 5182I0-0031 is a rectangular lot located in the northeast corner of Ehe former Ribera property and has since been develaped as a U.S. postal office. The remaining portion of the former Ribera property(Pazcel No. 51821 Q-0020)is an L-shaped lot,located along the south side of NE 4th Street between Uzzion Avenue NE and Bremertan Avenue NE,which is now known as the Fourth Avenue Associates, LLC Property(hereto refezxed as"the site"}. This letter describes those conditions obsezved on the site at the time of our site visit in 1998. As a result of a proposed stormwater dischazge system associated with a subdivision to the southwest of the site,you are primarily interested in our observations along the southern property boundary. BACKGROUND I On November 20, 1998, Shannon&Wilson,Inc. conducted a wetland and stream delineation on ' the former Ribera property, the fmdings of which are gresented in the Preliminary Wetland Delineation Ribera Property Report, dated December 1998. 400 NORTii 34TFi S7FEET•SUITE 100 21-1-12193-001 F.O. BOX 30Q303 SEATTLE, WASHINGTON 98103 206•632•802G FAX 206•695�6777 TDG, 7•BCO•833•6388 �ti-wv�.s`�anncnwilson.com Mr. Tom Foster SHANNON F�Vi/ILSON,INC. Fourth Avenue Associates, LLC May 12,2006 Page 2 Our wetland and stream delineation occurred during a period of heavy rainfall. According to the Western Regional Climate Center summary for SeaTac Intemarional Airport (http://www.wrcc.dri.edu/cgi-bin/cIiV1AIl�.p1?waseat),November 1998 received a monthly precipitation total (11.62 inches),which was 195 percent above the historical mean(5.97 inches}. During oux wetland and stream delineation,two wetlands{WetIands A and B}and one stream (Maplewood Creek)were identified on the site. The eastern half of the Ribera praperty was dominated by mature Douglas fir forest. The western half of the site was dominated by Scots broom, reed canarygrass, and Himalayan blackberry. Topography throughout the site generally siopes southwest,toward Maplewood Creek. Maplewood Creek entered the property in the northwest comer and flowed along the westem property line. As it reached the southern property line,Maplewood Creek flowed east-southeast before it turned south off site. The property directly southeast of the site had been filled previously,creating an abr�pt rise of approximately 15 feet along the south property line.. At the time of our site visit,there was no east-to-west surface conveyance located along the southem property Iine except the area associated with Maplewood Creek to the west. Although the topography generally sloped southwest toward Maplewood Creek,there was no defined I drainage or drainage channel observed, despite the heavy rainfall that had occurred during and preceding our site visit. It is our understanding that tlie existing neighboring development(Ridgeview Court)southeast of the site has created a stormwater pond located on its southwest corner, adjacent to the site. It is also our understanding that the Ridgefield Court development has received appzoval by the City to discharge stormwater from this pond onto your site,into an east-to-west surface conveyance, reportedly located along the southern property line and into Maplewood Creek. Based on our site observation in 1998,no channel existed in this azea that would accommodate the proposed stormwater d.ischarge. CLOSURE The findings and conclusions documented in this Ietter have been prepared for specific application to this project, and have been deveIoped in a manner consistent with the Ievel of care 21-t-12193-001-LUwpLKD 21-1-12193-001 � Mr. Tom Foster SHANNON�WILSON.INC. Fourth Avenue Associates, LLC May 12, 2006 Page 3 and skill normally exercised by members of the environmental science profession currently practicing under sirnilar conditions in the azea,and in accordance with the terms and conditions set forth in our signed proposal, The conclusions presented in this letter are professional opinions based on interpretation of information cucrently available to us, and are made within the operation scoge,budget,and schedule constraints of this project. No warranty,express or implied,is made. Shannon&Wilson has prepared the enclosed"Important Information About Your Wetland Delineation/Mitigation and/or Stream Classification Report"to assist you and others in understanding the use and limitations of our report. Sincerely, SHANNON &WILSON,L1TC. �'� � �n� Karie L.Walter, P.W.S. Associate Natural Resources Manager PCJ:KLWIpcj Enclosure: Important Informarion About Your Wetland Delineation/?Vlitigation and/or Stream Ciassification Report 2!•1-12193-001•LI/wpJLKD 21-1-12193-001 - SHANNON 8�WILSON,lNC. Attachment to and part of Report 21-1-12193-001 - Geotechnical and Environmentat Consultants Date: May 12,2006 - To; Mr.Tom Foster Fourth Avenue Associates,LI,C IMPORTANT INFORMATION ABOUT YOUR WETLAND DELINEATfONIMITIGATiON AND/OR STREAM CLASSIFiCAT10N REP�RT A WETLAND/STREAM REPORT IS SASED ON PROJECT SPECIFIC FACTORS. Wetland delineation/mitigation and strcam classiScatian rcports are based on a uniquc set of project-specific factors. These typically include the general nature of the projcct and properry involved,its size,and its configuration;historical use and practice;the locacion of the project on the site and its orientation; and the levef of additional risk the client assumed by virtue of limitations imposed upon the exploratary program. The jurisdiction of any particular wetlandistream is determined by the regulatory auihority(s)issuuig the permit(s).As a result, one or more agencies will have jurisdiction over a particnlar wetland or stream with sometimes confusing regulations. It is necessary to involve a consultant who understands v��hich agency(s}has jurisdiction over a particular wetlandlstream and what the agency(s) permittimg requirements are for that wefland/scream. To help reduce or avoid potential costly prohlems,have thc consultant determine how any factors or regulations{which can change subsequent to the report}may affect the recommendati.ons. Unless your consultant indicatcs otherwise,your report should not be used: ► If the size or configuration of the proposed project is altered. ' ► If the location or orientation of the proposcd project is modified. ► If there is a change of ownership. ► For application to an adjacent site. ► For COnstruction aE an adjacent Site or on site. ► Following floods,earthquakes,or other acts of nature. u'etlandJsueam consultants cannot accept responsibility for problems that may devclop if they are not consulted after£acto�considezed in their reports havo changed. Therefore,it is incumbent upon you to notify your consaltant of any factors that may have c6anged prior to submission of our final report. Wedand boundaries identified aud strcam classifications made by Shannon&Wilson are considered prelimiz►aryuntil vaIidated by the U.S. th 1 1' ' ictioaaI a ene . Validation b the re atin a en s rovides a eertification Arm Co s of En ineers Co s and/or e oca unsd , Y �P g � IF ) J g Y Y S� B 8 � }P usually written,that the wetland boundaries verif al are the boundaries that wili be regulated by the agency{s)untii a specified date,or unt�l the regulations are moda5eci,and that the s�eam has bcen properly classified. Only the regulating agency(s}can pro�ide this certification MOST WETLANDISTREAM"FINDINGS"ARE PROFESSIONAL ES7iMATES. Site exploration identiftes wedand/sveam conditions at only those points where samples are taken and whea they are taken,but the physical means of obtaining data precludo th�determination of precise conditions. ConsequenUy, the infor�nation obtained is intended to be sufficienfly accurate for design,but is subject to interprctation. Additionally,data derived ihrough sampling and subsequent laboratory testing are exhapolated by the consultant who theQ rcnders an opinion about overall conditions,the likely reacrion to proposed construction activity,and/or appropriate design. Even uader optimal circumstances,actual conditions may differ fzom those thought to exist because no consultant,no matter how qualified,and no eacploration program,no matter how comprehensive,can reveaI what is hidden by eazth,rock, and ticne. Nothing can be done to prevent the unanticipated,but steps can be taken to help reduee their impacts. For this reason,most experienced owners retain thcir consultancs tlirough the construction or wetland mitigation/s�eam classification stage to identify variances, to conduct additional evaivations that may be needed,and to recommend solutions to problems encountered on site. Page I of 2 1/2006 9 WETLANDIS7REAM CONDIT[ONS CAN CHANGE. Since natural systems are dynamic systems a$xted by both natural processes and human activities,changes in wetland boundaries and stream conditions may be expecced. Therefore,delineated wetland boundaries and stream classificaiions cannot remain valid for an indefcnite period of time. The Corps typicaily recognizcs the validity of wetland delineations for a period of five years after completion. Some city and county agencies recognize the validiry of wetland delineations for a period of two ysars. If a period of years have passed since the wedand/stream rtport was completed,the owner is advised to have the consultant reexamine the wetland/stream to deEermine if the classification is still accurate. Construcdon operations at or adjacent to the site and natural evenu such as floods,earthquakes,or water fluctuaaons may also affect conditions and,thus,the continuing adequary of the wetland/stream report. The consultant should be kept apprised of any such events and should be consultcd to determine if additional evaluation is necessary. THE WETLANDISTREAM REPORT fS SUBJECT TO MIStNTERPRETATION. CosTly problems can occur when plans are developed based on misinterpretation of a wetland/stream report. To help avoid these problems, tho coasultant should be retained to work with other appmpriate professionals to explain relevant wetland,stream,geological,and other findings,and to review the adequacy of plans and speci#ications relative to these issues. DATA FORMS SHOULD NOT BE SEPARAT�D FROM THE REPORT. Final data focros are developed by the consultant based on interpretation of field sheets(assembled by site personnel}and laboratory evaivation of Seld samples. Only final data forms customarily are included in a report. These data forms should not,under any circumstances,be drawn for inclusion in other drawings because drafters may commit errors or omissions in the transfer process. Although phosographic reproduction elirninates this problem,it does nothing to reduce the possibilitt�ofmisintecpreting the fomu. Whenthis occurs, delays,disputes,and unanticipated costs are frequently the result. To redace ibe likelihood of data form misinterpretation,contractors,engineers,and planners should be given ready access to the complete report. Those who do not provide such access may proceed under the mistaken impression that sunply disclaiming respoosibility for the accuracy of information always insulates them from attendant liability. Providing the best available information to contractors,engineers, and planners helps prevent cosdy problems and the adversarial attitudes that aggravate them to a disproportionate scale. READ RESPONSISILITY CLAUSES CLOSELY. Because a wetland delineation/s�eam classification is based extensiveiy on judgment and opinion,it is far less exact ihan other design disciplines. This situation has resulted in wholly unwarranted claims being lodged against consultants. To�elp prevent this problem, consultants have deveIoped a number of clauses far use in written transmittals. These are not exculpatory clauses designed to foist the consultant's liabilities onto someone else;rather,they aze de8nitive clauses that identify where the consultant's responsibilitzes begin and end. Their use helps all parties involved recognize their individual responsibilities and take appropriate aciion Somo of these definitive clauses are likely to appear in your rtport,and you are encouraged to read them closely. Your consultant will be pleased to give full and frank answers to your questions. THERE MAY BE OTHER STEPS YOU CAN TAKE TO REDUCE RISK. Your consultant wil!be pleased to discuss other techniques or designs that can be emptoyed to mitigate the risk of delays and to provide a vaziety of alterriatives that may be beneficial to your project. Contact yow consultant for fitttt�er information. Page 2 of2 I/zoo6 --- ....__ __---- -----_ ___ ___ _ __- -----.. —.__-- --- -__-------.-- Michael Dotson - Ridgeview Court - Storm Drainage Page �� From: "Cheryl Girard" <cg@american-engineering.net> To: <mdotson@ci.renton.wa.us> Date: 2/8l06 11:39:45 AM Subject: Ridgeview Court-Storm Drainage Mike, In response to the City of Renton letter to Cliff Williams dated February 7, 2006 American Engineering has reviewed our Technical Information Report and offsite analysis/investigation field notes dated July 8, 2004. The offsite analysis did not identify a closed depression or a low spot in this area. As a matter of fact, the notes make reference to a broad yet shallow ditch heading westerlyjust off of the site until entering an area that was flagged for what appears to be wetlands. Therefore American Engineering is confident that the analysis as described in Section 3, Task 4, of the TIR dated September 26, 2005 is accurate. Evidently a low spot or depression has accidentally been constructed off site -downstream of the Ridgeview Court detention vault since our original field inspection. Our recent field inspection indicates there has been clearing by others and possibly some grading by others in the vicinity of the Ridgeview Court Detention Vault outflow. Please note that the subject low area where ponding has been reported does not meet the definition of a "closed depression". Per the 1998 KCSWDM, the definition of a closed depression is as follows; an area which is low-lying and either has no surface water outlet, or has limited outlet that during storm events the area acts as a retention basin, with more than 5,000 sf of surface water area at the overflow elevation. American Engineering has evaluated this area and calculated it to consist of approximately 3,070 sf of surface area at the overflow elevation. Hence, this area does not meet the definition of a "closed depression". With that said, we maintain that no further flow control or safety factors are required for the Ridgeview Court detention system. I hope this concludes discussions regarding the off site area to which our detention system outfalls. If you have any questions feel free to call me anytime. Cheryl Girard, P.E. Project Engineer American Engineering Corporation 4032 148th Avenue NE Redmond, Wa. 98052 Phone No. (425) 881 - 7430 Fax No. (425) 881 - 7731 CC: "'Cliff"' <Cliff@belmonthomeswa.com>, "Bob Wenzl" <bwenzl@belmonthomeswa.com> I _ I �� � � p .. � .... ,:: �.r'I �!� y Y �- J � �`,�r' � ���. . . IR.t��'� � %�rN(il �.. .. ,y� � 6 � � � � , ` � `�) . .i. / qase ' �h . �' UU9� INJ� � �S . . ':�9�J.4i�. � � Iti�'>.... f,", 7� ' � r.�99A11 �-...... ........ _ ..,.. . , �. � . ........ .... � �. � � ��., IB 4d_ �' . . � ��_ � . ,. � ^�, ' - � � w '� ��� � �',, �� In�a � . � � _� 3���>_�' iR�n � � '. IyJI _ .._ :� 9n.y� . . m O � ". •. ".... . _._... ... . .....:3y>95 � ,... I I -'�7 ` �'.. . .� . � 1 N —I \, y IBIFl � . Itf4S � —_—._ ' . G9�\an .j9a"qa lyz�, ,��C��.].]s ,- z ` l , �� ✓�9].li . � ' �S � , ` �• ,. IRiS , � �'�i, �, ,��. ��yo4.l: In'�� . ' 6 — . ,. � , ., =��, � o D -� _ � �"� .:�d9�o la �' ... �� ......,. .... �.;39 n5� ' ��' ;7 ,;` �� .. . GS GS 7 � � � ...-.- . � '. .. ��� IBlti y�� .�. " _ .. ' � . ,,�,e � � .. IF.2 ' `.]��^0 iE _ . _-�— . .. "Y �� . ` .'!2.Je �' ��Ls,.a' Gc ,���.;::: .' . . _,. , _. �, GS �. . , ..... . ` IP2l : Id'1 ��)�:=" ' � 'w!8`f,Yy ...J��.I(, '1- .. . .... .GS ' fS � IN[Y i . 1r�y„4 Y..._ " ... .. . �..�_.. ' '� � IR25 �.3')4.iL �'�i... Z .. . , .. ... 18t�11 f� . ..34`i.p0 f�...... (� .. .. .... ........_. .. . ..IfS�" . ;��9ytY . �' IR�] , . � iE� n `�('l'Z. � 7 � ........ ,.. � •.... „ _� ... --rF1448U " ' . ' .. . ;-i � � ' ..._,�_,r�3eab"a_�= T[> ' 1€ -..� ��'�iuu� �.����W �w ,-" .� i � ,"� � .. �- '� . ...... ...... tE. -- t�e—=" ii S Cl(S'� � � .�,'� ; :.�� . v��� A __ —_ — — — -- — � .— _ — —. :l'�Y/ . 'Y......._. . . 7 �.... .._ —. — _.. _— . _ ..... ... _. .— — —__ _ —_ ...... . _ —�-- -- —.. — . ...._... .