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03042 - Technical Information Report - Drainage
,a a �-_ � „d f,. �S� f � 1 . , � s �`� E ,� � x�� � ��---•- -� . ' . , ,_,y; _ ;�_ ..a_„c,.T_z- - - '-- "-- -- ��� _ � . . . . � . � � . . i ;�`r3:.�.,l,.. y � '_� , �r,.., '' , �i.;t f��:',-� L: � s .`.�., .7 . t . �L .. . ( . . . ' . . _ ' ' . . " . , . ' , . ... . . . . . . '� . .. � , . .�����. ... ' .. ' STORM DRAINAGE REPORT . . - - . . ' � � ' � , .�... . . , . _ , : � . : OF . �. . - - � ; , . . . _ , � .r ' . � . . . - .A_ . . . . .... , . ... . .♦. . . . _ . . -.. - ._ ,� .. .i � ,. ... . _ � . ' ... � . � - . � . . . .. .' . 'L.'"�� � -. ... ... � .. . .. . . . . . HIGH AVE SHORT PLAT - . _ � - " BENSON RD & SE 29T" ST - - � RENTON, WA . � . � . , - � - . . ' .ri • . . . . . . - . . � . � . . �t, � -• � � . . 'x . . . - � - � ' . . �� =.� ' . . FOR > _ _� �.- - � ���,��'�� � � -�_`�t�Frs �•�� � � - ., - 1 - . _ ._ . �-��d r� Z y . 4 - .. �� r4� �� - '� :: � >: � . - DAVE SKAGEN- - , . �����'�� � -� ��: t, � 20610 19&�' AVE SE _ . � .�:� � �' N � WA 98058 . � � "'� �� � RENTO , � �=�.���� _��.� -U7.- � ' _ ' "�s' ��: ������ ' �: ; '. ,� _ _ ��--�� � �.; : � . . �-�`'=� i��___� - _ _ - ..� � - : ' �� March 25, 2002 , - ._ C.N.I. JOB NO. 2000-204 , . � : Prepared by Larry S. Krueger, P.E. � . ; � � - � - .. ..�_ ..._ . -- . . . . . -'-—'-- ------�'--- r ['._^1v..n� {�'J �.�� i�Sr'i .. '� , ... ' .i.`� . �' �.( ��r�,y�) 1 i _J . r.� ��r t-� yf'� . ' . . j t '!i �r c. . c J�� � ):�r -•- •- ` . . �� ."r'_-'.� J.�si�. � frU� � . . . � ' � .. / •/• - . . ` ,� � , r�►`� 1 t�=' fC�-r��t� � ,� "��..,_.-' ''"�? f ,. ��•, ��i�ll ', r', f �. r.. _ �t-�-c -'` i � ' f^� � I .�'.� 1''� j `' . r�i�-�) T���ty"� �+._C -,I � ly�}-s�� ti���r� �l��} i�l� t�t{^-� �S .(i l�1,4�'..:.j .11:il/.�`!,<<�:�1 t� l ,11l.t ...t. , . . .. �`�l���1)�f-'i�,t�._ '...J� ..:t�1\I i '� �./ �i �: �vJ v� � i ./ � .r E�j� . . ' -..�.��y _ . . . . � � ..� . � . � . � � . ' . . - ' . , �� 30s�2 r � TABLE OF CONTENTS � I. PROJECT OVERVIEW 11. CONDITIONS AND REQUIREMENTS SUMMARY III. OFFSITE ANALYSIS IV. RETENTIONIDETENTION ANALYSiS AND DESIGN V. CONVEYANCE SYSTEM ANALYSIS AND DESIGN VI. SPECIAL REPORTS AND STUDIES VII. BASIN AND COMMUNITY PLANS VIII. OTHER PERMITS IX. EROSION/SEDIMENTATION CONTROL DESIGN X. BOND QUANTITIES, FACILITY SUMMARIES AND DECLARATION OF COVENANT XI. OPERATIONS AND MAINTENANCE MANUAL APPENDIX A OFFSITE AN�RLYSiS REPORT APPENDIX B CONVEYANCE SYSTEM CALCULATIONS APPENDIX C RUNOFF CALCULATIONS APPENDIX D WATER QUALITY CALCULATIONS APPENDIX E MAINTENANCE � OPERATIONS MANUAL . , • I. PROJECT OVERVlEW Existing Conditions: This project is located at the intersection of Benson Road and SE 29th Street in the City of Renton. It lies along the north side of SE 29th Street, and along the east side of Benson Road. The site is approximately 0.59 acres. The site consists of mostly tall grass with some berry vines and a few deciduous trees. The existing drainage tends to sheet flow from the north to the south toward SE 29�" Street. The runoff enters a public storm system located along the north side of SE 29�' Street and is conveyed west to a public storm system located in Benson Road. The site's soil is an Alderwood Gravelly Sandy Loam (AgC) and is considered a Type C soil. Proposed Conditions: The project proposes to subdivide the site into four residential lots. Access to the lots will be provided via a private street off of SE 29th Street at the southeast corner of the site. Roof runoff will be conveyed through perforated stubouts prior to a ditch that runs along the private access road. Road runoff from the private street will sheet flow to the ditch. The ditch will then convey the runoff to a biofiltration swale. The runoff is then conveyed to the existing storm system along the north side of SE 29"' Street. All drainage facilities have been designed per the 1990 King County Surface Water Design Manual as adopted by the City of Renton. II. CONDITIONS AND REQUIREMENTS SUMMARY Preliminary conditions hav� been provided. The core requirements of the King County Surface Water Design Manual (KCSWDM) will be provided as follows: Core Requirement#1, Discharge at the Natural Location: The natural discharge location for this site is along the southern property line where it enters the public storm system located in SE 29th Street. RunofFwill be detained and treated along the south propetty line before being released to the public storm system Iocated in SE 29th Street. Core Requirement#2, Offsite Anatysis: An offsite analysis is provided in Appendix A. Core Requirement#3, Runoff Control: Flow control is not required for this site because it does not increase the existing runoff by 0.5 cfs or greater. Per Section 1.2.3 of the KCSWDM this project is exempt from runoff control. Please see Appendix C for runoff calculations. Core Requirement#4, Conveyance System: The conveyance system will consist of storm pipes and ditches. Roof runoff will be conveyed through perforated stubouts prior to a ditch that runs along the private access road. Road runoff from the private street will sheet flow to the ditch. The ditch will then convey the runoff to a biofiltration swale. The runoff is then conveyed to the existing storm system along the north side of SE 29"' Street. Calculations are provided in Appendix B. Core Requirement#5, Erosion/Sedimentation Control: An erosion and sedimentation control plan has been provided. Some of the elements that have been provided are a construction entrance, silt fence, inlet protection, sediment trap, and soil stabilization. Core Requirement#6, Maintenance and Operations: A maintenance and operations manual has been provided in Appendix E. Core Requirement#7, Financial Guarantees and Liability: The owner will provide this information prior to permit issuance. III. OFFSITE ANALYSIS A Level 1 Offsite Drainage Analysis has been provided in Appendix A. N. RETENTION/DETENTION ANALYSIS AND DESIGN No retention/detention system is required. Per Section 1.2.3 of the KCSWDM this project is exempt from runoff control. Please see Appendix C for runoff calculations. V. CONVEYANCE SYSTEM ANALYSIS AND DESIGN The conveyance system will consist of storm pipes and ditches. Roof runoff will i, be conveyed through perforated stubouts prior to a ditch that runs along the I private access road. Road runoff from the private street will sheet flow to the �, ditch. The ditch will then convey the runoff to a biofiltration swale. The runoff is then conveyed to the existing storm system along the north side of SE 29th ', Street. Calculations are provided in Appendix B. VI. SPECIAL REPORTS AND STUDIES No special reports or studies are known to exist for this project. VII. BASIN AND COMMUNITY PLANS No basin or community plans are known to exist. VIII. OTHER PERMITS No other permits are known to be required at this time. IX. EROSION/SEDIMENTATION CONTROL DESIGN An erosion and sedimentation control plan has been provided. Some of the elements that have been provided are a construction entrance, silt fence, inlet protection, sediment trap, and soil stabilization. Sediment Trap Calcs: Surface required = 2 x Q2/0.00096 = 2 x 0.21/0.00096 = 437.5 sf Surface area provided = 23' x 23' = 529 sf X. BOND QUANTITIES, FACILITY SUMMARfES AND DECLARATION OF COVENANT This information will be provided prior to permit issuance if requested. XI. MAINTENANCE AND OPERATIONS MANUAL A maintenance and operations manual has been provided in Appendix E. I APPENDIX A OFFSITE ANALYSIS REPORT , , I I � � I i � � � ` ;1 S d ......{ . �. "`r r j.�,,,; }+� ��t.:�.i `� ,.;1 � � �'�._ a.�.. � � � . � � � .: �� ` _.�_f ,� " �.. ���.f :[}�t� -..J[� 1�;�;i:.� , : _ , . �; , ' . , , ti� _ . � , ; � � LEVEL 1 DRAINAGE �4NALYSIS , - . ' . _ � . , � . . , . , . : z: , . _ � ; , - � OF - . , _ . � HIGH AVE SHORT-PLAT, .. �. BENSON RQ & SE 29T" ST. : - � _ - � RENTON, VIfASHINGTON �_ �� � _ _ , . , _ . _ ` , _ _ . . _ _ . . , . .. . . . , ... � .- . ... _� _ ,. . , . ,. ,. . :, . _ . . .. , . .. , . ., . . _ ._ : _ : � , . ,: - <:, . •� FOR . .- _ _ - � = - - . . . :r _ ., . _ ,. - - ._ _ _ _ - - ,-t. � _ - . . . � , �r:_ . . �. -. : .. ... ... . . .. : ; . - . _ . . . .. .. . . . .. -. ..... _ . ..-., ,.... . . ,. .. .� . - . � �. � . - - - . ,. - ;5 �* ` DAVE$KAGEN : . .: - _ 20610. 196T" AVE 5E : - :, � - _ , . . . _ RENTON, WASHINGTON�98058 : , � ' � : . . � . .. . . , ,. .. . � . _ , . - . ; ,: . ; , . _ . . . - : : . . > ,�. . - . . . , . , ., . . . . . . , _ . - - � ';" : _ > - _ .. . ,, ., _ March 26,,2002 , , , . . , _ _ _ .. : ,. . . . . . .. . . . . . - - ._ '' r . � . . � , � . :. �.. . . -.- , . . .. .. . . . ._' , . � . . a . . � ,._ .._,. C.N.I. JOB N0. 2000-204 � . ~. _ � . - . -� - . . _ ; ,. , Prepared by La�ry S. Krueger, P.E. ;�, . -. .�. _�,. � —� — . �.�. � . .-. ."_—,.� . . II (' . [�^-� n �{ � �,t. . - . . . _� _ .�. ' . J^�'�` '.1 ' . . :"i� I r:: 1�i� . � .� . . � ' 1 E� i f v.�'�J��./_��.Y:�.�?-�C.r � -. � - . � `- 3 J'��� � . ,� ' ��G'ii <i"y!� . . . � .. �.. � �- lttlr Gn.'�x � C?�'7 !.}. ��G-1'l�sr.!! ''� !�. �,tJ�{?� �(�� 1 �., IC: U : l��`��i'-r�1 ���� �;`'} �,+`llfii'/'.''.'�.`�! �ri ;�'�t� ':l',.I��i�.t,�'S f�i!l�„r 'r�ljV`•i��l.t:�i�!�l;ti,,s �., i:ti r o<'S j�ut, N�� .:f , � � �� ' . , :.. , _ _ TABLE OF CONTENTS I. TASK1 STUDY AREA DEF9lNITION AIVD NlAPS II. TASK 2 RESOURCE REOOIEV'V IIi. TASK 3 FIELD INSPECTION N. TASK 4 DRAINAGE SYSTEM DESCRIPTION AND PROBLEM DESCRIPTIONS V. TASK 5 MITIGATION OF EXISTIIVG OR POTENTIAL PROBLEMS � TASK1 STUDY AREA DEFINITION AND MAPS TASK 1 STUDY AREA DEFINITION This project is located at the intersection of Benson Road and SE 29th Street in the City of Renton. It lies along the north side of SE 29'h Street, and along the east side of Benson Road. The site is approximately 0.59 acres. The site consists of mostly tall grass with some berry vines and a few deciduous trees. The existing drainage tends to sheet flow from the north to the south toward SE 29tn Street. The runoff enters a public storm system located along the north side of SE 29"' Street and is conveyed west to a public storm system located in Benson Road. MAPS A vicinity map, sensitive areas map, and offsite drainage map can be found in the proceeding pages. � S �h S Q� c e°"a� �i'io, ROY Hills Dr SE `OO ,� � I- S 4 S T s�a yln�kA eSF U S 5t S �°'hd � S ay E �7 d � �� � ��� �� �� SE 16th PI °'s � S 1 St �' E 157t St S SF T 8th`Sf �9gth St " - II� P �t r � � � I le ary ch � '� Talb Hili l eritary School h S 23rd St � cn ��2 � v � � ' asf > 0 � SICAGEN'SHORT:?LAT�=• � SE 163rd St � � � S 2�St&Benson Rd S `- SE 164t St , Renton,WA 98055 h � � J SE 165th St ' � N SE 16 Q' � s � S3 sfg 5�5 � � m � uWi � � SE 158th St ' S m � �s9 , Q L '\ � � � � � o � SE 17dEh St �` � Q Q �li W v� v -o 167 � � N M I SE 172nd St � > �'' N I � SE 17 rd St ' Q' S 174 , d SE 176t '��SE P Ga��w, `� � � ; N � a ' r � � ���n st o � L s w � � � 43rd St ' t � SE 18oth � o T 18i tSt' o="o S 182nd t ! v �I � ¢ S li � I I�� SE 186th St , �� i i I 0 mi 0.2 0.4 D.6 0.8 II w,Q..�.r. � '�, Streets98 !, Cooyright�1988-1997,Microsoft Corporation andlor;ts suppliers.Ali nghts reserved. 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I � �' � ; 1 ,�r�� < IJ �' 1,1., .�,. ; � , � � <<'.,1.._ 1 _ ' q �� I I 'i I �` t 1 >. � y �� i t-� k� � � - �� ``' \ "1 �j /� - r , '� �� t 1 � i �� � , 'i ��� � i � 1, � S � ` t� `� �� V � .,.�,; r_ --',�_ }(�'`' ��(_�s:, l- ' ��' �i� *`� ��i i� .'� _ - � _4�-! .� j�, ' , i , '�;', -_ � , �.�>I� - 4 � ��3 _ i � t� � � �_ --J i -� :�_- ;�-l� � - ~�� 'i � -�.�� ' },, ; C � '.� ',�•�'�� l i __ ��'� s � , �`��_ C- ���=�-,) I t _I�; ., '> - --,-� ,� 1_ � __ i �, '�'` �,, ;; ; - � � ��� . .� �- 1�--- � - - - < ,. _ _ �_ � .11� - �, r �\ � � '; t �. -��Y� ,____T._ -> � ?, __..r--- --T � '(I' •%� �� � � a _+ ,;�_��. ' � . ( . , � ' -. .r� �x i� � � � �\ J - '� �. i. ,_ ` � ? ;�;r� � � P . J , , ' i i �� �{ � - - � � �i� _ __r < --- " �-- J -/�� - � � , � �' i � , i_ \ � � . �� �� �� ��_� j �-� ��� ��1 �' �.' . �, _- /, ' /;' � Z _ __� �+ � l ` � 'K �x� ��� �� � � 'P:� � �� f �;; // j �� f � ,I �e /� � . � . _ � � ' 'i` ` � :' � � _._ �,.[� t � _, , , r .( � , � � �,.;'L , � .__t , � , , , _ ____ --..� _ L�, , v ; � .:�� .... • � _ __ --- ,' / , I ' l -� i� � , � � .. _ . �. _. � �.f-.��� . .�� .� �,,�1, � , . _ � -�-i- , ,�� .. ..� � � � , �,� ...���. . � � � i� ,�';� . , �_ ,�'�:i i � '' � � I � ' � � � _ _' ��� �' , 1 ; ' �, , j ; �_� , , ,; � f f r. ���. .� � � , , _ , , ,� % , , i 1 1 , , . , , � , � � , ,_ << � W � W � W U � � O u� w � N � � H TASK 2 RESOURCE REVIEW Adopted Basin Plans and Finalized Drainage Studies: The site is not located inside any basin plan areas. Basin Reconnaissance Summary Reports: No known reports are known to exist. Critical Drainage Area Maps: The site is not known to be located in any critical drainage areas. (FEMA) Maps: The site is located outside the 100 year flood plain. Other Offsite Analysis Reports: None were available Sensitive Areas Folio: None of the site is located in or near any sensitive area (see sensitive areas map under Task 1). DNR Drainage Problems Maps: Not applicable. Road Drainage Problerns: Not applicable. King County Soils Survey: The site's soil is an Alderwood Gravelly Sandy Loam (AgC) and is considered a Type C soil. Wetlands Inventory Maps: There are no wetlands located on or near the site. IVligrating River Studies: Not applicable. Drainage Complaints: According to the list of drainage complaints provided by King County, there were no complaints near the downstream analysis limits of this project that are a result of runoff from this property. Z O H U W � � Z � J W LL M � � V� � TASK 3 FIELD INSPECTION A field inspection was conducted on March 20`", 2001 to inspect the onsite drainage system of the site. Offsite drainage systems were also inspected downstream approximately 1/4 mile(s) from the discharge point of the site. The inspection involved investigation of the ten specific items of a Level 1 Inspection per the King County Surface Water Design Manual, 1990. The � inspection yielded the following findings: 1. Other than the catch basin at the south property line being partly full of sediment, there were no existing or potential problems observed. 2. The existing drainage system capacity was adequate. 3. There were no existing or potential flooding problems. - 4. The catch basin at the south property line was partiy fuil of sedimer�t, �ut there were no scouring or bank sloughing problems. 5. No significant destruction of aquatic habitat or organisms was notice� 6. Qualitative data such as land use, impervious surFaces, topography, and soil types was noted and can be found in Task 4 information. 7. Information was collected on pipes, ditches, and structures. This information is also included in the Task 4 information. 8. Tributary basins delineated in Task 1 were verified. 9. No neighbors were contacted. 10. The weather conditions at the time of the inspection were cool and rainy. TASK 4 DRAINAGE SYSTEM DESCRIPTION AND PROBLEM DESCRIPTIONS TASK 4 DRAINAGE SYSTEM DESCRIPTION AND PROBLElIA DESCRIPTIONS Site Drainaqe This project is located at the intersection of Benson Road and SE 29�' Street in the City of Renton. It lies along the north side of SE 29t" Street, and along the east side of Benson Road. The site is approximately 0.59 acres. The site consists of mostly tall grass with some berry vines and a few deciduous trees. The existing drainage tends to sheet flow from the north to the south toward SE 29"' Street. The runoff enters a public storm system located along the north side of SE 29"' Street and is conveyed west to a public storm system located in Benson Road. An insignificant amount of upstream flows enter the site. Offsite Drainaqe An Off-Site Analysis Drainage System Table is provided on the next page that � describes in detail the offsite drainage components at least '/ mile downstream from the project discharge location. Please refer to the offsite drainage map in Task 1 because the map symbols listed in the table correspond to drainage component symbols on the offsite drainage maps. �, �, � I OFF-SITE ANALYSIS DRAINAGE SYSTEM TABLE Surface Water Deslgn Manual, Core Requirement#2 � Subbasin Name• Subbasin fVumber: Basin �a G� � ��.J��� < �� ' :> Cs�istin f�aten�o�;��� Qbservat�or�s a�fioici inspe�tor S iiibol . �1r�ir���t� i ' fJr�'e.�ta�� �oc�p�ar►�r�t ,�lap� d�o�t�nc� � y : � ' i � : � Y��c�l�9��5 f�rt�bl�m� ��s�ur�� revi�wer; �r r�sident I �.e��pnnent'�y��, , ' >. , t?�s�rip�eon ; �rorro sit �1am��;an� „� < dis�l��r � > ; ..� �� ;: �.shea4 i{aW:'SVvwa�� '! '' ': ;: ;: :.:': ,�a�n b�ftd,tlnc3 p��y��4 din�, c�+od oP er� Type� .__ �, , , ;: �trlo�f �r�a h . , ': ° . auc�i cc�ve->; 9�: 1L4 tnl �;3�0 ft evert�pp. <atrea ':c a I;'"I ;,i dr�inaga t��in�.veg�f , �.r,;, 9� ; >;. � _� ablt�4r nrgqnl�t� tribut�►y�r��,11k21ilo d �r�t�s se�map n�,,, n nn�,:.P,pa� � In �floddln �� .. , �i:setie�tivs'a�e� vnlurr�e ; , nd�:5fz� tllsttieter, ;;depth,type „d�st�ctlon,ecouHn �bank aloughing, �vertlow'pathwrrys�Potp�t I Imp , i� Pa � _ � _ ;: i ;s�dgmenfation;:lncl$lon oth�rerosion , aurface aree:: > > i „ . " �i. ��;',i�f:i� T; �•���i,i�,';;;, .�_�'� �- � _e, ♦ ��n.���' �Ehd�' ��r.r��r1.�d� C�p,_�„t �.� � a , f a ; � d ' �.+.,e'°,13�i .:.y �l p � ��,p, t ` � � T /� h �� pt �`''y�� <-"� `� e� �r"S��t�s�' ���e1.�,ev�C¢ �4��lstii��t! i� J+�+ty c�?,.x.�k.f:�',�+ :i 8� � l�7G�+:Y1 � � �!� B.fG,.It?ri c�1" C�- aCiT' J( �y �a�� ���t';�„5� Pr�P� �p� L/v/_� q!� � ��'d's�,- �1 CJ��. ��(9��'`�r�.� f�� •.+.e�e�r a��'� � C}I��� ( Y 6 �lil /`+�,r �Sdift ..:� tr�, r'}�"�1 � �ua��l, � 1 L� �,r��,�°kn �,�r ,��i."�C~�' C ;�l9 ,�^ )�{� ��dtLF.'`s '�1.i°��..�, e�S� � �� /�� /[C/—� � " r d . ' ..� 4��3.,� P^' ? i ` �"m i�'# d f �V ! V✓ .� f`.�i;l i�' ��� :o'd`T � "�"P"f ' �� ,eV` ��tl,x �" ���[' ,e gj }� ciuJr,,,�� �- ra.5� lav.,15 N c� �"�t��r�'r r � r ( � ..� ( j y',�r� �_r� , ��i i�. wk - �� ���`�' �'t7� tiV c �I � � �O/� J�` ,r j / 7��'�. � ( "rr�.2 " ..d �.L»j��.��1 � � a��c?tcl /.' r�c(�,Yr't� Q ti€�� t,vr�..� •�r),�+ s � a ; � , � d �.,��c��', rk.� �;. I_ _�' o �' � / � I �/'/\ '°' ,�J�'{,�e. �'� � �� CJ �r� Q -;- s r ��� , , � �`� �G rV'\ �.��r�,��t�? �� &^°�t�c.'.�� � �� !2� Y�<�� C�.1�p' •s.:..y,. >�•ti a� .R-.� � y d d,; (,� u� r��euz� :"t.�t.'� �.'�,+';�,�y ��rr�w �`�'?'"�' Jt��' p ' 1 c I��rl- � ?���� �'" ����r� ra�,�:�� o,) $� -�'n;e� L1Table.doc 11l2l92 TASK 5 MITIGATION OF EXISTING OR POTENTIAL PROBLEMS TASK 5 MITIGATION OF EXISTING OR POTENTIAL PROBLEMS Aiter a thorough field inspection and a detailed resource review there were no major or existing problems identified. The proposed improvements will not produce a significant impact to the existing drainage pattems once the site has been stabilized and the runoff has been controlled via perforated stubouts and a new conveyance system. The catch basin at the southern property and the three pipes entering it shall be cleaned free of sediment. A temporary erosion and sedimentation control has been created to minimize the transport of sediment laden runoff to the downstream conveyance system. � APPENDIX B CONVEYAfVCE SYSTEM CALCULATIONS Project Summary Report Project Description Worksh�t ditch @0.3% Flow Element Triangular Channel Method Manning's Formula Solve For Discharge Input Data Mannings Coefficient 0.030 Slope 0.0030 fUft Depth 1.00 ft Left Side Slope 2.00 H:V Right Side Slope 2.00 H:V Results Discharge 3.17 cfs Flow Area 2.0 ft2 Wetted Perimeter 4.47 ft Top Width 4.00 ft Critical Depth 0.69 ft Critical Siope 0.0217 fUft . Velocity 1.59 ft/s ' Velocity Head O.o4 ft Specific Energy 1.04 ft Froude Number 0.40 Flow Type Subcritical Project Engineer:larry krueger c:lhaestadlfmw12000-204.fm2 cramer northwest FlowMaster v6.0[6'14e] 03/25l02 04:53:16 PM �Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 USA (203}755-1666 Page 5 of 5 Project 5ummary t�eporc Project Description Worksheet ditch�0.71°.6 Flow Element Triangular Channel Method Manning's Formula Solve For Discharge Input Data Mannings Coe�cient 0.030 Siope 0.0071 fUR Depth 1.00 ft Left Side Slope 2.00 H:Y Right Side Slope 2.00 H:V Results Discharge 4.88 cfs Flow Area 2.0 ft� Wetted Perimeter 4.47 ft Top Width 4.00 ft Critical Depth 0.82 ft Critical Sbpe 0.0205 fUft Velocit�r 2.44 ft/s Velocity Head 0.09 ft Specific Energy 1.09 ft Froude Number 0.61 Flow Type Subcritical I Project Engineer.larry krueger c:lhaestadlfmw�2000.204.fm2 cramer northwest FlowMaster v6.0[614e] 03l25/02 04:53:16 PM �Haestad Methods,Inc. 37 Brodcside Road Waterbury,CT 06708 USA (203)755-16fi6 Page 4 of 5 Project Summary Report Project Description Worksheet ditCh @ 0.48°k Flow Element Triangular Channel Method Manning's Fortnula Solve For Discharge Input Data Mannings Ccefficient 0.030 Sbpe 0.0048 ftfft . Depth 0.50 ft Left Side Slope 2.00 H:V Right Sfde Slope 2.00 H:V ', I Results I I Discharge 0.63 cfs � Flow Area 0.5 ft' � Wetted Perimeter 2.24 ft ' Top Width 2.00 ft Critical Depth 0.36 ft Critical Slope 0.0269 fVft Velocity 1.26 ftls Velocity Head 0.02 ft SpeciFc Energy 0.52 ft Froude Number 0.45 Flow Type Subcritical Project Engineer:larry krueger c:lhaestad\frnw12000-204.fm2 cramer noRhwest FlowMaster v6.0[614e] 03/25/02 04:53:�6 PM OO Haestad MethaJs,Inc. 37 Brookside Road Waterbury,CT 06708 USA (203}755-1666 Page 3 of 5 Project Sumrnary Report Project Description Worksheet 8"PVC�7.95% Flow Element Circular Channel Method Manning's Formula Solve For Discharge Input Data Mannings Coefficient 0.010 Slope 0.0795 fVft Depth 0.67 ft Diameter 0.67 ft Results Discharge 4.49 cfs Flow Area 0.4 ft� Wetted Perimeter 2.10 ft Top Width 0.00 ft Critical Depth 0.67 ft Percent Full 100.0 °k Critical Slope 0.0761 fUft Velocity 12.73 ft/s Velocity Head 2.52 ft Specific Energy 3.19 ft Froude Number 0.00 Maximum Discharc 4.83 cfs Discharge Full 4.49 cfs Slope Full 0.0795 Wft Flow Type N/A II �I ,I , Project Engi�eer.larry krueger c:lhaestadVmw�2000-204.fm2 cramer northwest FlvwMaster v6A[6'14e] 03/25/02 04:53:�6 PM �Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 USA (203)755-1666 Page 2 of 5 IL _ rro�ect�ummary rcepor� Project Description Wofksheet 8"DI�496 Flow Element CircularChannel Method Manning's Formula Solve For Discharge Input Data Mannings Ccefficient 0.013 Siope 0.0400 fUft Depth 0.67 ft I Diameter 0.67 ft Results Discharge 2.43 cfs Flow Area 0.3 ft� ' Wetted Perimeter 2.08 ft � Top Width 0.01 ft Critical Depth 0.65 ft Percent Full 100.0 °k ' Critical Slope 0.0355 fUft Velocity 6.95 ft/s Velocity Head 0.75 ft Specific Energy 1.42 ft Froude Nurnber 0.24 Maximum Discharc 2.60 cfs Discharge Full v 2.42 cfs Slope Full 0.0403 ft/ft Flow Type Subcritical Project Engineer: larry krueger c:\haestadlfmw12000-204.fm2 cramer northwest FlowMaster v6.0[614e] 03/25/D2 04:53:16 PM OO Haestad Methods, Inc. 37 Brookside Road Waterbury,CT 06708 USA (203)755-1666 Page'I of 5 APPENDIX C RUNOFF CALCULATIONS RUNOFF CALCULATIONS (per 1990 KCSWDM with StormShed from Engenious Systems) Proiect Precips [2 yr] 2.00 in [10 yr] 2.90 in i [25 yr] 3.40 in [100 yr] 3.90 in Detailed Basin Descr�ations Drainage Area: predev Hyd Method: SBUH Hyd Loss Method: SCS CN Number Peak Factor. 484.00 SCS Abs: 0.20 . , Storm Dur 24.00 hrs Area CN TC Pervious 0.7800 ac 85.00 0.64 hrs Impervious 0.0000 ac 0.00 0.00 hrs Total 0.7800 ac Supporting Data: Pervious CN Data: dense grass, vines, low brush, trees 85.00 0.7800 ac � Pervious TC Data: I� Flow type: Description: Length: Slope: Cceff: Travel Time Sheet grass, vines, low brush, trees 180.00 ft 1.00% 0.2400 38.12 min Drainage Area: postdev I Myd Method: SBUH Hyd Loss Method: SCS CN Number Peak Factor. 484.00 SCS Abs: 0.20 Storm Dur 24.00 hrs Area CN TC � - Pervious 0.4200 ac 86.00 0.44 hrs Impervious 0.3600 ac 93.00 0.00 hrs Total �.7800 ac Supporling Data: Pervious CN Data: lawn, grass 86.00 0.4200 ac �` Impervious CN Data: � ` paving & roofs 98.00 0.3600 ac Pervious TC Data: Flow type: Description: Length: Slope: Cceff: Travel Time Sheet lawn 180.00 ft 1.00% 0.1500 26.17 min Imperviaus TC Data: Flow type: Description: Length: Slope: Cceff: Travel Time Sheet dummy 1.00 ft 100.00% 0.0050 0.00 min Basin Flows BasinlD Peak Q Peak T Peak Vol Area Method Raintype Event -- (cfs) (hrs) (ac-ft) ac ILoss predev 0.0743 8.17 0.0517 0.78 SBUH/SCS TYPEIA 2 yr predev 0.1663 8.17 0.0978 0.78 SBUH/SCS TYPEIA 10 yr predev 0.2229 8.17 0.1254 0.78 SBUH/SCS TYPEIA 25yr predev 0.2817_ 8.17 0.1539 0.78 SBUH/SCS TYPEIA 100 yr postdev 0.2083 8.00 0.0829 0.78 SBUH/SCS TYPE1A 2 yr postdev 0.3420 8.00 0.1352 �.78 SBUH/SCS TYPEIA 10yr postdev 0.4190 8.00 0.1653 0.78 SBUH/SCS TYPEIA 25 yr postdev 0.4972 8.00 0.1959 0.78 SBUH/SCS TYPEIA 100 yr I APPENDIX D ' WATER QUALITY CALCULATIONS Project Summary Report r� , �t � � �t; t'�i��tc�"�G'{�1 Project Description Worlcsheet bioswaie Flow Element Trapezoidal Channel Method Manning's Formula Solve For Bottom Width Input Data ! � ManningsCcefficient 0.35 ts�o����1�xx`t�pd� i►�Ct���'1 Slope 0.01 fUFt �� � A Depth 0.33 ft �.ct,i c�� �lsr"{a�t,�d a,� ,�+?''�5� Left Side Slope 3.00 H:V Right Side Slope 3.00 H:V Discharge 0.21 cfs � +y� �;�.�s�,�e;�.�� Results Bottom Width 2.05 ft Flow Area 1.0 ft� Wetted Perimeter 4.14 ft Top Width 4.03 ft CriGcal Depth 0.07 ft Critical Slope 4.48 fUft Velocity 0.20 ff/s Veloc�ty Head 6.5e-4 ft Specific Energy 0.33 ft Froude Number 0.07 Flow Type Subcriticai -�^ �y , � If `.'sy'a�� )C �f'Gr? {�t,?5��� _ ��a._ t r'Y `�fa.� � O�'�..7`T �"' +..`:J �'rP,�i1,,�F,t� v.0�0.C� �'E0. �^' i . � ,,t{,� _ ���+ ,� +� °�'� -` �``t0 �' �e1'" (f� ���.�w� �C ����a<� t F�� h���- = L, . � I r j r _ 1 , ' � �� � �d� ����� .� �c�cw� �.�:a��.j ����f ���� �'s:.•�� 5f�� Project Enginee�-iarry krueger c:\haestadVmw12000-204.fm2 cramer northwest FlowMaster v6.0[6�4e] 03/25/02 09:57:00 AM m Haestad Methods,Inc. 37 Brodcside Road Waterbury,CT 06708 USA (203)755-1666 Page'I of 3 Project Summary Report Z� �/ea-�' c.-��G-�* Project Description Worksheet bioswale 25yr Fiow Eiement Trapezoidal Channei Method Manning's Formula SoNe For Channel Depth Input Data Mannings Ccefficient 0.03 Slope 0.01 ft/ft Left Side Slope 3.00 H:V Right Side Slope 3.00 H:V Bottom Width 5.�0 ft Discharge 0.42 cfs Results Depth 0.09 ft Flow Area 0.5 Tt� Wetted Perimeter 5.54 ft Top Width 5.52 ft Critical Depth 0.06 ft Critical Slope 0.03 ftlft Vefocity 0.93 tUs Velocity Head 0.01 ft Specific Energy 0.10 ft Froude Number 0.57 Flow Type Subcritical Project Engineer.larry krueger c:Uiaestadlfmw�2000-204.fm2 cramer northwest FlowMaster v6.0[614e] 03/25/02 09:57:00 AM �Haestad Methods,Inc. 37 Brodcside Road Waterbury,CT 06708 USA (203)755-1666 Page 3 of 3 Project Summary Report �dQ�e� �,,(,�e G� Project Description Worksheet bioswale 100yr Flow Element Trapezoidal Channel Method Manning's Formula SoNe For Channel Depth Input Data Mannings Ccefficient 0.03 Slope 0.01 ffik Left Side Slope 3.00 H:V Right Side Slope 3.00 H:V Bottom Width S.OD ft Discharge 0.50 cfs Resufts Depth 0.10 ft Flow Area 0.5 ft2 Wetted Perimeter 5.60 ft Top Width 5.57 ft Criticai Depth 0.07 ft Critical Slope 0.03 fUft Velocity 0.99 ft/s Velocity Head 0.02 ft Specific Energy 0.11 ft Froude Number 0.58 Flow Type Subcritical � Project Engineer:larry krueger c:lhaestadlfmw�2000-204.fm2 cramer northwest FlowMaster v6.0[6'14e] 03/25/02 09:57:00 AM �Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 USA (203)755-1666 Page 2 of 3 APPENDIX E MAINTENANCE AND OPERATIONS MANUAL i �i i ; � � KING COUNTY, WASHINGT �N, SURFACE WATER DESTGN MANUAL � NO. 5 - CATCH BASiNS Maintenance Conditions When Mafntenance Results Expected Component Defect is Needed When Maintenance is Perfwmed General Trash&Debris Trash or debris of more than 1/2 cubic No�rastf or debris located immediately in (lncludes ioot which is located immediatefy in front froni of catch basin opening. Sediment) oi the catch basin opening or is btocking capacity of basin by more than 10%. Trash or debris (in the basin)that No trash or dabris in the catch basin. exceeds 1/3 the depth irom the bottom of basin to invert of the lowest pipe into or out of the basin. Trash or debris in any inlet or outlet pipe lnlet and outiet pipes free of trash or blocking more than 1/3 of its height. de6ris. Dead animals or vegetation that cauld No dead animals or vegetation present generate odocs that would cause w'sthin the catch basin. compiaints or dangerous gases (e.g., methane). Deposits of garbaga exceeding 1 cubic f�fo condition present which would attract I foot in volume. or support!he breedfng of insects or rodents. Sttuctural Damage Comer of frame extends more than 3/4 Freme is even vrith curb. to Frame and/or inch past curb faoe into the street(if I Top Sfab applicablej. Top siab has holes larger ihari 2 square Top slab is free of holes and cracks. inches or cracks wider than 1/4 inch (intent is to make sure alt material Is t�` running into the basin). Frame not sitting flush on top siab,i.e., - Frame is sitting flush on top siab. separation oi more tMan 3J4 inch of the frame#rom the top slab. Cracks in 8asin Ccncics wider than 1/2 inch and tonger Basin replaced or repaired to design Walis/Bottom than 3 feet,any evidence af soif particfea standards. entering catch besfn through cracks,or maintenance person judges that strucfure is unsound. Cracks arider than 1/2 inch and longet No cracks more ihen 1/4 inch wide at the than 1 foat at the joirrt of any inietJoutlet joini of inlet/ouUet pipe. pipe or any evidence of soil partioles entering catch basin through cracks. Settlemeni/ Basin has settled more than 1 inch or has Basin reptaced or repaired to design Misalignment ratated more than 2 inches ovt of sfaadacds. alignment. Fire Hazard Presence of chemicals such as natura! No flammable chemicais present: gas,oil,and gasoline. Vegetation Vegetation growing across and blocking No vegetation blocking opening to basin. more than 70%of the basin opening. Vegetatan gsowirvg in intetfoutlet pipe i3o vegetation or root growtFt present. joints that is more than six inches tatl and less than six inches apart. Potlutian Nonflammable chemicals of more fhan No pollution present other thart surface 1/2 cubic foot per three teet of basin film. length. a-5 1/90 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL NO. 5 - CATCH BASINS (Continued) ... Matntenance Conditlons When INafrnenance Resulb Exp�cted Component Defect la Nasded When Mairrten�nc�la Psrtarmed Catch Basin Cover Cover Not in Piace Cover is missing or ony partfatly in plsce. Catch basin cover fs dosed. Any open catch basin requires maintenanca. Locking AAechanism cannot be opened by ona Mechaniam opens with proper tools. Mechanism Not mafntenana peraon with proper boofa. Working Botte into frama have less than t/2 ir►ch of thread. Cover Difficult to One meirrtenancr person cannot removs Cover can bs removed by one Remove lid after applying 801ba.of lift;irttent is maintanancs psrson. keep cover from aea{inp off access to maintenance. Ladder Ladder Runge Ladder le unsafs due to missing rungs, Ladder meets design standards and Unsafe misalignmeM, rust,craaka,or sharp allows mainte�ance person safe acxess. edges. Metal Grates Grate wittt opening wider than 7/8 inch. C3rate openings meet design atandards. (if appiicable) Trash and Debris Treish and debris that is blocking more Grate froe of trash and debris. than 2096 ot grate surface. Damaged or Grate missirig or broken member{s).of Grate is in place and meets design Missiny the grate. standards. r./� � . . �mn KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL NO. 10 - CONVEYANCE SYSTEMS (Pipes & Ditches) � � � Maintenance Cond6tlons When Malntenanca Results Expected Component Delecl is Needed When Melntenance is Per�ormed Pipes Sediment&Debris Accumulateci sediment that exceeds 20% Pipe cleaned of aN sediment and debris. . of the diameter of the p1pe. Vegetation Vegetation that reduces free movement of All vegetation removed so water flows water through pipes. treely through pipes. Oamaged Protectfve coating is damaged;rust is Pipe repaired or replaced. causing more than 50%deterioration to any part of pipe. Any der►t that decreases the cross section Pipe repaired or repiaced. area oi pipe by more thart 20%. Open Ditches Trash 8�Debris Trash and debris exceeds 1 cubic foot Trash and debris deared from ditches. pet 1,000 square faet of ditch and slopes. Sediment A�ccumulatsd sediment that exc�eds 2096 Ditch deaned%flushed of all sediment and of the des(gn depth. debrls so that it matches deaign. � Vegetation Vegetatfon that reducee free movement of Water flowa heely U�rough ditches. water through ditches. Erosion Damage to See"Ponds"3tandard No. t See'Ponds'Standard No. 1. I�� Slopes Rodc Lining Out M Mafntenance person can see naUve adl Replace rodcs to design standard. Place or Missing (If beneath the rock tining. ApPlicable) Catch Basins Sea"Catch Basins'$tandard No.5 See'Catch Basins'Standard No.5 �� Debris Barriers See'Dabr(a Barriera"Standard No.6 See"Debr(s Barriers"Standard No. 6 • (e.g.,Trash Rack) .�, � �� 1/Qfl