Loading...
The URL can be used to link to this page
Your browser does not support the video tag.
Home
My WebLink
About
SWP272188
L1... ... � A :' .::.::.:::.:.::..:: QR .> >:::> ......1�{E�T.... ::PL T :» . C�:.;; �.< :F:.:: 48 1 EN:UE.::< .....::::. .. .: OUR JOB NO. 5150 PAP' GF? FEBRUARY 17, 1995 f WASh�,yC� Fcisrt�� �e Prepared By: EXPIRES ROBERT E. HANKINS BARGHAUSEN CONSULTING ENGINEERS, INC. 18215 72ND AVENUE SOUTH KENT, WASHINGTON 98032 (206) 251 -6222 �GHACiS 0 CIVIL ENGINEERING, LAND PLANNING, SURVEYING, ENVIRONMENTAL SERVICES r�n'G ENG�N� TABLE OF CONTENTS I. INTRODUCTION/GENERAL INFORMATION: A. General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1. TIR Work sheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2. Site Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . II. PRELIMINARY CONDITION SUMMARY III. OFF SITE ANALYSIS a. Upstream Drainage Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . b. Downstream Drainage Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IV. RETENTION/DETENTION ANALYSIS AND DESIGN a. Existing Site Hydrology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . b. Developed Site Hydrology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C. Hydraulic Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . d. Retention/Detention System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . V. CONVEYANCE SYSTEM DESIGN AND ANALYSIS VI. SPECIAL REPORT AND STUDY VII. BASIN AND COMMUNITY PLAN AREAS VIII. OTHER PERMITS IX. EROSION/SEDIMENTATION CONTROL DESIGN X. ADDITIONAL DOCUMENTS a. Bond Quantity Worksheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . b. Retention/Detention Facility Summary Sheet and Sketch . . . . . . . . . . . . . . C. Declaration of Covenant . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . XI. MAINTENANCE AND OPERATION MANUAL � { 3313.010 I. INTRODUCTION / GENERAL INFORMATION 1.0 INTRODUCTION AND GENERAL INFORMATION This proposed project is a plat to be developed on an existing 2-acre parcel located on the south side of N.E. 12th Street and approximately 400 feet west of Aberdeen Avenue N.E. This site is between the south right-of-way of N.E. 12th Street and the north property line of State Route 900. The existing use of the property is vacant. There are a few trees on it, but the majority of the site is covered with thick blackberry bushes. There is a grade of roughly 8 to 10 percent from the northeast to the southwest corner. The proposal on this site is to develop this parcel into 12 small single-family residences with one cul-de-sac connecting to N.E. 12th Street. 2.0 UPSTREAM DRAINAGE BASIN ANALYSIS As mentioned in the introduction, the site drains from the northeast to the southwest onto the state right-of-way property. N.E. 12th Street which abuts the north property line of this site drains in a westerly direction with open ditches and culverts. Therefore, this blocks any further upstream basin on the north side of N.E. 12th Street. Adjacent to the eastern property line of the site are existing large lot single-family residences. Some of this area does drain onto the site, but the majority of this area drains onto the state right-of-way located to the south. Please see the attached drainage area map which basically shows the directional flows. Depending on the details of the final construction drawing phase of this project, subsurface drain lines may need to be installed along portions of the eastern property line of this project. 3.0 ON-SITE DRAINAGE ANALYSIS As mentioned earlier, this site is covered with thick blackberry bushes and some trees. The proposal is to install one cul-de-sac into the property serving 12 new lots. A two-celled detention pond is proposed at the southeast corner of this property with a biofiltration swale along the south boundary that discharges near the southwest corner. The detention pond, biofiltration Swale, and temporary sediment trap were designed per the 1990 King County Surface Water Manual (SWM). Water from the house and footing drains along with roadway surfaces shall be collected in catch basins then conveyed via 12-inch pipes to a two-cell detention pond. The pond was sized for the 2-year existing release rate during a 2-year storm and 10-year existing release rate during a 10-year storm with a storage volume of 30 percent added. The pond was designed to control runoff with a biofiltration swale after detention. The biofiltration swale was designed per the King County SWM and was shortened to the minimum 80-foot length. The width of the swale was increased to provide the required surface area. A stability check was then run to convey the 100-year developed storm event. Storm drainage then exits the bioswale (via 12-inch storm conveyance pipe) to the off-site storm drainage system within the state right-of-way. Since this site is not an aquifer protection area, pond lining or special drainage considerations should not be needed. Refer to the road and storm drainage plans which shows how the site will drain and be controlled by the stormwater facilities. Page 1 of 2 5150.007 [REH/krl 4.0 DOWNSTREAM DRAINAGE SYSTEM DESCRIPTION AND PROBLEM SCREENING Please refer to the downstream drainage area map and the off-site analysis drainage system table for a detailed description of the downstream properties. Briefly, the drainage path from the site is in a sheetflow fashion along the cutbanks of SR 900. This sheetflow is undefined and existing channels are not apparent. Some of the runoff from the east side of our site and the properties located east of our site sheetflows down the cutbanks and is intercepted by existing catch basins located within the roadway. There is also an 8-inch diameter perforated pipe that is located at the toe of the slope which intercepts some of the surface water draining from the adjacent properties. This pipe connects into the existing 30-inch diameter corrugated metal pipe as shown on the attached downstream drainage area. Please refer to the attached maps and table for further description of the downstream system. The on-site analysis performed did not reveal any significant drainage or erosion control problems. Page 2 of 2 5150.007 [REH/krl Page 1 of 2 King County Building and Land Development Division TECHNICAL INFORMATION REPORT (TIR) WORKSHEET PROJECTPART I PROJECT OWNER AND PART 2 PROJECT LOCATION AND DESCRIPTION ProjectOwner C51. JJEVELdpMEN ' Project Name 1NfiESTVIEW 4>L8T' Address Z So 6 Flo b HiL L Aya. _ M' Location .S t e s L y 7 sw Township 2'5 N. PhoneLv�, E. Project Engineer N A 1. G R O b b Range S Section g Company 13A1ZGNA445EtiI GcruS Er. UG. 1AX. Project Size AC Z •O Address Phone 153 Z 15 7 L NP AVE So4-tltil Upstream Drainage Basin Size AC C LS(p K b 3TYPEOF PERMIT APPLICATIONOTHER PERMITS (�Subdivision DOF/G HPA 0 Shoreline Management 0 Short Subdivision COE 404 ED Rockery ( K Grading 0 DOE Dam Safety Structural Vaults F--1 Commercial FEMA Floodplain Other Other 0 COE Wetlands [:J HPA COMMUNITYPART5 SITE - • BASIN Community MEW CASTLE Drainage Basin E&s`tG kE ZCEdjALZ /��VEQ F3 A 5.;,Q PART 6 SITE CHARACTERISTICS F-1 River E:1 Floodplain 0 Stream 0 Wetlands Critical Stream Reach 0 Seeps/Springs i Depressions/Swales 0 High Groundwater Table Lake 0 Groundwater Recharge Steep Slopes NZ Other Nic.E VNFoi2EsTi--b L4-A-ab Lakeside/Erosion Hazard / G i AJ'L L.9: S(AP c,—;-S 1 SOILS Soil Ty Slo s Erosion Potential Erosive Velocities A-LDECZ40oo D -7 Lo(J L o%.J ? °fin L-o %J Additional Sheets Attatched 1/90 Page 2 of 2 King County Building and Land Development Division TECHNICAL INFORMATION REPORT (TIR) WORKSHEET PARTS DEVELOPMENT LIMITATIONS REFERENCE LIMITATION/SITE CONSTRAINT 0 Ch.4-Downstream Analysis a 0 0 0 0 0 Additional Sheets Attatched PART 9 ESC REQUIREMENTS MINIMUM ESC REQUIREMENTS MINIMUM ESC REQUIREMENTS DURING CONSTRUCTION FOLLOWING 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 NGPES Construction Sequence 0 Other E::1 Other PART 10 SURFACE WATER SYSTEM Grass Lined Channel Tank E::1 Infiltration Method of Analysis Pipe System E:�J Vault E=] Depression '5 B cn t+ Open Channel [=1 Energy Dissapator Flow Dispersal Compensation/Mitigation ® Dry Pond Wetland Waiver of Eliminated Site Storage Wet Pond Stream OmRegional Detention Brief Description of System Op �/eration S Iti�i�RGE ��Woti" o G 6 S 'to f�P�D CDNUEyr4�lCE 5Y5 ew `�ti O lh.4tF S iDA2r17o�C De-tex-t-tb,, �bi to 7ro CCJ. —tile,, F/OSAWs,f!.P Facility Related Site Limitations F-1 Additional Sheets Attatched Reference Facility Limitation PART 11 STRUCTURAL ANALYSIS PART 12 EASEMENTS/TRACTS (May require special structural review) 0 Drainage Easement [=1 Cast in Place Vault 0 Other Access Easement 0 Retaining Wall 0 Native Growth Protection Easement Rockery,4'High ( Tract �� �e7chT��,, �o N L—) Structural on Steep Slope 0 Other PART 14 SIGNATURE OF i PROFESSIONAL I or a civil engineer under my supervision have visited the site. Actual site conditions as observed were incorporated into this worksheet and the attatchments. To the best of my knowledge the information provided here is accurate. SbM�• I/90 s N xlusloE tx o N1 moE64 lleoo uE 7DxsT6 � Y "ayYf ky ~ ,J�h e M H _.. E .. Y Si - -Pyo -- C, N 4,,C nsE ,v T S SE •^ Sn m �` SE J r ""'sr ✓ r ,cy�ut, �' ` FSI `.'°�°PIONEERT m 3 # '< _ i s x a sEsr6s 6 N 71E SE< �xior �' 8 �� 6 7M =' ^SE 72ND^ SE r.r $rE 2 D ,r C ST ,� p< ST L LN $ < < 2 7 j � 27��< E 81 tiQs S .1,. i HAZELMDOO sF sE 7BRD r r�� a PL is F^ D T SE Ilsr sT< 5T r 30.. " -5. z. s. PK L€ , a $ S7 7 N W C A ST L E $`�`� E sr azro S � 'SE 72ND'PL' s, � sr � w 'd,sE s IN &� <I.M Sf16 sE Is � c ST � T ` � _767H " „� � SE 7 ✓ m i '�" ,� � � F >r°1 sDO 7 S a _ 1 i SE I601Y?� �' SE 2 ^SE 75TH PL UK \ At'[ i 4 ]piM' 11 < 7% O ��•kb"'SF>B ~ P!RFN C�rN SE SE"i y`- PL m f N sF. tETI S uKxJ�� >h Av 'h y i•gSSE 7arx III L 79TH sr ST eh r Es, BOTH rx 139TH AV �` R SE eeao N P13� ]i600 N PL w rr N qKE < IQq slr 79TH usnl�'e j 78 S h Q- BUCH 11200 �n BLS m E 9TN PL15 Sr 3 PARK / p= I w m xElr+Os eA St / c., mI3 BD EN 7Aj PLS.v esa _ inls ix. �Lx sr sE eD sr L" E�°•' /L a s BSPna Ic PAR `Fa L .. 1 SE M � $T SEQ l>D I POPQ�. a0 `" E___ wr' SEB N 40TH ST I y.,' E 85TN B: s BgjN 0 ST,7.3 n� AVALDN N 36TH ST 8 sr� sE 7H sr 8 Sr N� N,,'g.r Nm Sr 86� ` ^ 'p( sE em Sr ex, a^; �m� JF. P( $7 9 ,n s x '`�' x 371N 5T ;Zs ✓� — Eel $E yWY 88TH________-^ Q 4 7� 3 ST 36TH KENNYOALE 1 0� BEACH PARK35TH 3 ST SE ' 14TH ¢ ST S 9OTH errx a - 91ST $m CREE�Y' :i. 91s m SE r 33RD PL ST SE s NE 33RD 91ST ST SOIIrN F'OINI / m N 33RD ST x �acEK w sE 4 MIY CO!ChLUd I 700' N 31ST ST 5S 'l'R*q*.� a H"J x�$E IV c�.s VA I m g3R0 a� .� [ I'O1NT �y, 4N 700 N 291'H 13.00 ♦� NE 28TH ST_ V '• SE N��_ � N �4 _ `ab se 0M SIERRA - N y H_ -3f z NE E^ 27TH ST E *.27Trr sE L 99TH sr HEIGHTS E• G < a Sn 6 271H 2100 z 4 L _ 25TH CT PARK X 1� - CJ 51N CT SE 100Tx LAKE � SE 10oN5 PL DL N 1 sE., 100TH LAKE *, N 26TN 5r z KENNYD v DL N LIONS SE _ "R ]02N0 102N0 4TH ST �+ 1 < NE RD- PL SE E a N - ST NE ST , s S 1950 ST 9< XO PL < SE '� SHINGTON £ NE 20TX'X 3 �/�1/ sT N zNo ST 4 400 y 5T �E ,"� `' SE loaTH 5 2 �< ETI �V < .xs �.. n C,&f SF 05TH - Z G y1 XE 9 '1 ST TH ,11P•'l�+fi' I S i ^'< 1♦r�' ST 1 SE k s i SE 105TH ST 06Tx STD NE Ii� I �'� S•ti k � Q L G < � z 67j/,.: � IM n � NE� s,x / 1 si O BOAT UU H •nl >p� ..�,. I < � � � L4rx � sT �fT 1 � < 1� F� > J �-ti-. � 57 � _ I_ E S/j q9W S t urx sr 1B' NE s 12TH: ST SE 11 ST Y ss uxs.u 6 GENE. t4300 ::.C ■ - _z -ME IN 'F. MDktAL�, N � 12 �250 swsEr i P 3 z- 3700 s w u SsxM a •,S� �' p0. s BUG/PARK \ W /8 I .. OL fR M ss- Ra JPo1 II xE 1 x x G =I N4 sl w S ^9112TH �ST L 113 `..1$1" \ ✓ EI P�p.RK "�� Q ,p `�' TM sQ 1 rW `I .• < y ST"' r _ RENTON ST S 1 T 115 $7 S AIRPORT V�s �� ✓ s } < lOTH Lx PE S__^ n ._115 PL a T UUACH - - OTM ST` a HE H 5T ST a& S_.__1 < .-. - -ST- ,: -"i BOEIAG \\ / K NE 9TH PL 91H W 91'H - ,,, K13yANTS S .•I SE llerx<_G�ST TH _ST s 1 RENTON h HE 9 <'z '< Yt +'4 'Farb PARKo x, 12 E L $ 17TH PL x 's, PLANT �- � < 1' <' 718TH r $ < e7oa � ¢ J NE �'•�: c a ;� � sE 1zotN sT f`3 laNMR r S 1 9TH a owr '< N 1H.. ST h NE xPARK ^ p0 W NE < a� r hz- SASE 1215i S7 'PARK 9'M NE 1TH ST -x;E 7TX S — SN 1120TH ST9 a 0 ST > 1 CPI - % a CT RR �E 122 M Fl RR T <$ S 1215T $ COULON s Sxssl s,> PARK. S 5 122ND $T NN 7TN ST ✓�„ 7TH < - NE 6TM `q t2^S S 123RD $ NAP nwsrs SEE H. PRELI VHNARY CONDITION SUMMARY November 10, 1994 OFFICE OF THE HEARING EXAMINER CITY OF RENTON NOV REPORT AND RECOMMENDATION APPLICANT: CARA S. LEWIS WEST VIEW PRELIMINARY PLAT File No.: LUA-94-116, PPN/W/ECF LOCATION: South side of NE 12th Street, approximately 300 feet west of Aberdeen Avenue NE. SUMMARY OF REQUEST: Applicant seeks to subdivide 2.02 acres into twelve(12) residential lots for development of single family homes. Miriimlim iot siZc. is approXuitatcly 4,503 sf A variance from the fifty foot road right-of-way, and a waiver of the light standards are requested. SUMMARY OF ACTION: , Development Services Recommendation: Approve with conditions. DEVELOPMENT SERVICES REPORT: The Development Services Report was received by the Examiner on October 18, 1994. PUBLIC HEARING: After reviewing the Development Services Report, examining available information on file with the application, field checking the property and surrounding area; the Examiner conducted a public hearing on the subject as follows: MINUTES The following minutes are a summary of the October 25, 1994 hearing. The official record is recorded on tape. The hearing opened on Tuesday, October 25, 1994, at 9:02 a.m. in the Council Chambers on the second floor of the Renton Municipal Building. Parties wishing to testify were affirmed by the Examiner. The following exhibits were entered into the record: Exhibit No. 1: Yellow file containing the original Exhibit No. 2: Vicinity map. application, proof of posting, proof of publication and other documentation pertinent to this request. Exhibit No. 3: Subdivision map. The hearing opened with a presentation of the staff report by MARK PYWELL, Project Manager, Development Services, City of Renton, 200 Mill Avenue South, Renton, Washington 98055. The Environmental Review Committee (hereinafter"ERC") issued a Determination of Non-Significance Mitigated (hereinafter"DNSM") O CARA S. LEWIS WEST VIEW PRELIMINARY PLAT File No.: LUA-94-116, PPN/W/ECF November 10, 1994 Page 7 CONCLUSIONS: Preliminary Plat 1. The proposed plat generally appears to serve the public use and interest although there is a trade-off necessary between density standards and street standards. The subdivision will provide additional housing choices in an area with urban services. The development should not tax either the road system or the existing utility infrastructure. Development of the additional lots will also increase the tax base of the City. 2. The proposed plat will also permit infill in an area with services and avoid urban sprawl. 3. The proposed lots are generally rectangular providing reasonable building envelopes. As proposed, the plat will provide a density of approximately 8 dwelling units per acre but requires that the road serving the site be less than the required 50 feet wide. In addition, the proposed lots are the first in this area that comply with the new Zoning standards and are, therefore, significantly smaller than those in this area. This smaller size is mandated by the underlying densities of the zoning on the site and by the Comprehensive Plan's policies. 4. Since the proposed lot does deviate so dramatically from the existing development pattern and requires a variance from roadway width it seems appropriate to consider an alternative platting arrangement that is more in keeping with neighborhood character and does not require the roadway variance. An alternate arrangement would create lots more compatible in size with the older Zoning standards and surrounding lots. It would provide a road that meets code standards and creates a plat that would not meet the density standards enunciated by the new Zoning Code and Comprehensive Plan. An alternative arrangement would create a similar two-tier arrangement of lots, but with wider(rather than shallower) lots. An arrangement of 75 foot deep lots would permit a standard road, fifty(50) feet wide. Lots could then be configured at approximately 100 feet wide. While this configuration appears to provide shallow lots, ranch or split level homes can take advantage of such a building envelope. 5. It is clear that approval of the plat will require the applicant to provide an acceptable method of providing sewer service to the interior lots. Since the proposed systems could require City maintenance or calls on private lots, the City Council should specifically address this issue and approve the flexibility suggested by staff. 6. In addition to the sewer pump station, the applicant will be developing a common drainage area; therefore, a homeowners' association will need to be created to maintain any common areas or improvements. 7. While staff recommended that a fence be erected, fencing is generally a private matter in single family residential neighborhoods. In this instance, the disparity and potential for a number of intersecting property lines is generated by the division of this site into smaller parcels. This potentially complicates property demarcation; therefore, the applicant shall erect a fence along its east and west property lines. CARA S. LEWIS WEST VIEW PRELIMINARY PLAT File No.: LUA-94-116, PP/V/W/ECF November 10, 1994 Page 8 Variance from Fifty Foot.of Right of Way g• Variances may be granted when the property generally satisfies all the conditions described in part below: a• The applicant suffers undue hardship caused by special circumstances such as: the size, shape, topography, or location where code enforcement would deprive the owner of rights and privileges enjoyed by others similarly situated; b• The granting of the variance would not materially harm either the public welfare or other property in the vicinity; C. The approval will not constitute a special privilege inconsistent with the limitations on other property in the vicinity; and d. The variance is the minimum variance necessary to allow reasonable development ofthe subject site. The applicant's property appears ripe for the variance requested, although again, consideration of the alternate plat could eliminate the need for the variance. 9. The division of the site into reasonable parcels is constrained by the subject site's relatively narrow and deep lot layout. As indicated above, while there is an alternative that creates a plat with less overall density that will meet road standards, the only way to create reasonable lots that required by the Comprehensive Plan and the Zoning Code is t meet the density o create a series at interior lots with access from a less than standard width roadway. Therefore, to permit reasonable development of the site some form of variance relief is necessary. 10. Since the road will provide pavement of the normal width, will have sidewalks for pedestrian safety, and will primarily serve only the internal needs of this plat--there should be no harm to the general public or nearby property from approval of the variance. In addition, the cul-de-sac and roadway width will be able to accommodate emergency vehicles. 11. Due to the nature of the site and the fact that private roads, easements and pipestems have been permitted for access to interior portions of lots that cannot otherwise be reasonably divided --approval of this variance would not constitute the granting of a special privilege. 12. The proposed reduction in roadway width appears to be the minimum necessary, given the density standards that should be applied to the site as well as the need to provide reasonable building envelopes. The applicant has proposed the elimination of the parking or landscape strip that usually accommodates utilities outside the paved street or concrete sidewalks. Since both the standard dimensions, the reduction requested appears reasonable. street and sidewalks will be of Waiver of Street Light Standard 13. There seems to be no justification to waive the requirements for street lighting. While some modification might be reasonable the vagueness of the request, coupled with the absence of any analysis of the implications of shifting installation, and more specifically maintenance, to individual property owners seems premature and inappropriate. C CARA S. LEWIS WEST VIEW PRELIMINARY PLAT File No.: LUA-94-116, PP/V/W/ECF November 10, 1994 Page 9 14. As noted above, it would be difficult to address by conditions who and how individual lights are to be maintained. Who would replace bulbs? How soon after failure? What about unoccupied homes where power has been turned off? While the issues may not be insurmountable, they have not been fully explored and it would be inappropriate to approve something so untested or unanalyzed. 15. In conclusion, this office has taken the unusual step of recommending two plat configurations to the City Council. One plat meets the density requirements of the new Zoning Code and Comprehensive plan, yet deviates substantially from the neighborhood character and requires a variance from the normal roadway width. The alternative plat does not meet density standards, but comports more with existing neighborhood character while providing a standard roadway configuration. COMMENDATION: Preliminary Plat ff The City Council should approve a Preliminary Plat for the subject site as follows: 1. In the form of the plat proposed by the applicant. OR 2. In the alternative form of lots approximately 75 feet deep and approximately 100 feet wide. f� 1�n 3. The City Council should approve the sewer pump determination. 4. The applicant shall comply with the conditions imposed by the ERC. 5. The applicant shall establish a homeowners' association to maintain all common areas and improvements such as a common pump station if it is constructed and not dedicated and accepted by the City. 6. The applicant shall carry out its obligations under the Parks Mitigation Fee agreement. 7. The applicant shall erect a fence along its east and west property lines. Variance from Fifty Foot Right-of-Way The variance is approved if the applicant's proposed plat is adopted by the City Council. x. 1 CARA S. LEWIS '+ WEST VIEW PRELIMINARY PLAT File No.: LUA-94-116, PP/V/W/BCF November 10, 1994 Page 10 Waiver of Street Light Standard The waiver is denied. ORDERED THIS 1 Oth day of November, 1994. FRED J. KAU N HEARING E MINER TRANSMITTED THIS 1 Oth day of November, 1994 to the parties of record: Ann Bellmondo Cynthia Burns 5415 Pleasure Point Lane Bob Casserd Bellevue WA Point 2007 NE 12th Street John L. Scott Real Estate Renton WA 98056 64 Rainier Avenue South Renton WA 98055 Hal Grubb Robyn Lee Barghausen Consulting Engineers 1171 Aberdeen Avenue NE Cara S. Lewis CSL Development 18215 72nd Avenue South Renton WA 98056 Kent WA 98032 2506 Nob Hill Avenue North Seattle WA 98109 Lauree Maher Phyllis Nelson 1208 Lincoln Place NE 2008 NE 12th Street Dave Olson 15807 SE 116th Renton WA 98056 Renton WA 98056 Renton WA 98059 Jeff Potter Neil Watts Barghausen Consulting Engineers Development Services Division 18215 72nd Avenue South City of Renton Kent WA 98032 200 Mill Avenue South Renton WA 98055 M. OFF SITE ANALYSIS OFF-SITE ANALYSIS DRAINAGE SYSTEM TABLE Surface Water Design Manual, Core Requirement#2 Basin: ���C/✓ ��il/O+� Subbasin Name: EArsl-L.4ka WA Subbasin Number: GE-DA r Symbol Drainage Drainage Component Slope Distance Com onent T e, Ex�stingi Potent(al' Qbservations of freed ins ecta"`p , YP DigsCrippon ::. ::.:: m sate .. p: ame ;and..Slze '' :: :; .. :: teso r e:re:ur ::.;;:..:::.;:::•::.:: ;<:. . u c ...:. wer, or.;resr�#ett. Th eet 1 ;;..: .. YPe. f}Q e . see ma t ;. :.:.: . ,. :: ....: .;...::..:,;.;;;:.:.... .::..::.::::::........ ..:::cats dc�ohs. ::: P.. hantt�(, ars .a :::::.;:.:::::::......:.::,:............... ... pdin ;....: ... .::. .............: __ :::: ...:..::...;�.. g . an,.cover;.:; ... .96:.::::: m:.. :. :.. .....:.:.:..:.... . ;:.::.;;::.;•::..:::.::::: . overk.... n i :.. ,: ... pond5[ze,diameter ><. ;::d >.;,;;;:.;:..>;•;:.. :;;;:.;l;;>;::. .:. :::::::.:::: p::. ,:floodal :hatslt:ar: :•:. ,.;;�:.;• ...... g !1.:tf►.:: rib�}a :;area:::iike!(h ...ePth�:�Yp�.ofsensafive,areavolume.. :::..:;:<:::::;< .�>..:.::;>: : ::.>. :::.:.:..,:::<.: � :: ..:.�.,.,.,.`...:... ......:.:: :::::::.. !Y ...:.�.......ooc€rtf. ratite ::;.;,;:;:..:.:. . .::. ..... estructio e area....... ... ....:..................:..................:::. .........::::.<.;:.;;:.::::.:::::::::::,:::::.::.::::::.::::::::::::::::.:.;.................. ............ ...... .. . •.. ...:::. .:::...:;;:.:::.;.:;::•::;� 9 vertlrnw. ..t...... �: ....... ; <. .;•:.:..:.;::,:<:;:::;: ,>:<:;>:.:>::•.:;:: ;::>::>.: .. .:.......: .:•: ..;:..::;:.;::::::;•;;::.:;;pa;hways,.po•::.....,,�edimentation���ifinclsfon~other:erosloh:.>> . •:><:>�::::>:::::<::;::>::>::•.>:;:>:;:..':�<.::.::•...:•>;.::: 3G, Piaw -�,••; G►-�ts , bru,s � 6 acfc r'Cs, Grasr �bwsL,. Saner +rtes , n•o dr+4ti.e,1 Cad o� �—200� �cG� -I�v b ins 4r-> cv� e'(-- •f o e c;S S-7 ac►-cs tins nc.caJ. t� _ V T;I I G{ �d D r-46(� Wv I�crT 1 a I.1Lp�Q Z-3 I< a)"c Sawn clylJPPG., JogJ!� u ace. Ifoo �� ✓r,,,�,• y ����—�qQ0 V�ay}-e dw YIP N.CS-t'i�-ia L1Table.doc 11092 U.6 U AC. 0 U411 1.143b U2 Cc 00 55 U., 1:N 2S 1 Ls. ,. /?-e _' cl /oz. 14 rN X100 (2!fP[ "Z' . . I :n Lq4 CN L-91124 tz- tq ;1 0 5197 oe C. 5 60 - --- W, 7 14 .4 '1 16 lop (o q 25 u. c) 16 10 ------T------- r 1413 141 17 r '--r33- 10 5182190 23f, & .-- --:�l U3 '----I--_; - -C.' of 1 2 CZ99 246 �p .. :1- L 0 2. "o 7. SO, 3 80.0e m T_ — G. 14001 f R i A 14 ST eso?6 F NE. TH 20 130 Lio 9 so 70 Q, 'J= -8 62 IR I N.L,8 wj 5q Aos -F SP 80 1 /0/ 101 10336 OPEN m 350 :. 131; �R i 11 Lu 9 Do �R (3) (2) A 1 6,� ?1 4 24 1 ! ? 75.96 -_-68 (A) pL (c) ip 1 SP 73-674 2,4 S.P 077-89 NWb;2„ ME C�37 A R S.P 846- 3. 78 Li 1 0 8 ------- 734e 60 973 Yr 't --I- . J-------j "Z�� 252.3 _Q6 T 01 �"IC4",/ 0 ca i 't- 1 7 L ZZ 1A ", 12a PT 0 6 T.C. 5 (fin) -:) El I 22 ou : ... 25,?.3o 6911 �21 288 -16 k r :230 1 ti p A 312 313 k pr, co !'-z ____j I_ 6175 1 ,373 cc-152�6 � 0ss SS 'p 15 56 c 08; U T retso 70 d58 150 y od 1�?TH 7?.50 7e.5o =7ST > 60 Ore. - - - : , , - 73 90, 94 36 C44N p ow 0.5ZAc' -(A V - '�)l I SP.27 0.3)Ac. TL 100 92 7.z. IZI. '2T e 11?10 I Tt 1/r '75 A :1. 4 94.ff o ci; 116 OVAc. V 0 n ' n ca 2A( 0.43 AcJj e x 174.11 /irl I 3> 30 T118e uvlr 04 G 3 0)0.31 AC.Gov'f LLJ R 0 , 1E] 0 041 At.N 313> 13 so 103.67 8c (po 0 0 n n e r c M c 3 g 12. c V 201 (ryp RpSS 27 6 �ti S pL3 n V11 4.58 66,78-- 0( 56 UNIT TAVERN -A 6v 23 783S R L -HEIGH cF VA ci CONDOMINIUM OL -143 Z��7 60 61-- 14.46- --o "I f3 45 0 21 WZ41 r 17 V4 ;�,'ioio "o ",ilim SUNSET APT. LP �G :E .64 AC. 62 AC PINES 11 M N, /0 f I---- - - Th \ `Y HORA7 LLES 0 ----- - -- F L4395 H L. ('426? 617138 0.44Ac OI - , r--, n U NATTA ; � ' mw " T. C, �� ( l I Vn Ll - - - � - -- O z 1 v /3354 288 R) 1209 I 1 /33./3 l�. 3 075 2,12 O I :37 3 i /�S I I �'S�. ss SS ijz&^ I � 7 ;5 s T p P E N 5 E2.08i i- G C,04 � •� . µ - 1 I - -- - --- Ii214 0.62 Ac. SITE z 4.11 116 0 • N, • • , ",:)o jG L7tT t. 155 3 ! ! 5 ( 0.31 Ac AREA60 ToMAL a T_L.90 1-4 • � . 11 477 n 5, r c�� / UPSTREAM DRAINAGE AREA MAP NORTH SCALE : 1" = 100' aCE 5�a N°• 5 I So w_6TVIEW PLAT IV. RETENTION/DETENTION ANALYSIS AND DESIGN TRACT "A" DETENTION POND 2/ 7/95 Barghausen Engineers page 1 PRELIMINARY PLAT OF WESTVIEW RENTON, WA PRELIMINARY STORM DRAINAGE CALCULATIONS REVISED 2-7-95 BY REH -----------_ BASIN SUMMARY BASIN ID: lA NAME: EX 2YR CONDITIONS SBUH METHODOLOGY TOTAL AREA. . . . . . . : 2. 86 Acres BASEFLOWS: 0. 00 cfs RAINFALL TYPE. . . . : USER1 PERVIOUS AREA PRECIPITATION. . . . : 2 . 00 inches AREA. . : 2 . 43 Acres TIME INTERVAL. . . . : 10. 00 min CN. . . . : 81. 00 TIME OF CONC. . . . . : 28. 35 min IMPERVIOUS AREA ABSTRACTION COEFF: 0. 20 AREA. . : 0. 43 Acres CN. . . . . 98 . 00 TcReach - Sheet L: 300. 00 ns: 0. 2400 p2yr: 2 . 00 s: 0. 0700 TcReach - Shallow L: 160. 00 ks: 5. 00 s: 0. 0700 PEAK RATE: 0. 32 cfs VOL: 0. 19 Ac-ft TIME: 480 min BASIN ID: 1B NAME: DEV. 2YR CONDITIONS SBUH METHODOLOGY TOTAL AREA. . . . . . . : 2 . 86 Acres BASEFLOWS: 0. 00 cfs RAINFALL TYPE. . . . : USER1 PERVIOUS AREA PRECIPITATION. . . . : 2 . 00 inches AREA. . : 1. 37 Acres TIME INTERVAL. . . . : 10. 00 min CN. . . . : 90. 00 TIME OF CONC. . . . . . 0. 00 min IMPERVIOUS AREA ABSTRACTION COEFF: 0.20 AREA. . : 1. 49 Acres CN. . . . . 98 . 00 PEAK RATE: 1. 43 cfs VOL: 0. 35 Ac-ft TIME: 470 min BASIN ID: 2A NAME: EX 10YR CONDITIONS SBUH METHODOLOGY TOTAL AREA. . . . . . . : 2 .86 Acres BASEFLOWS: 0. 00 cfs RAINFALL TYPE. . . . : USER1 PERVIOUS AREA PRECIPITATION. . . . : 2 . 90 inches AREA. . : 2 . 43 Acres TIME INTERVAL. . . . : 10. 00 min CN. . . . : 81. 00 TIME OF CONC. . . . . : 28 . 35 min IMPERVIOUS AREA ABSTRACTION COEFF: 0. 20 AREA. . : 0. 43 Acres CN. . . . . 98 . 00 PEAK RATE: 0. 68 cfs VOL: 0. 35 Ac-ft TIME: 480 min 2/ 7/95 Barghausen Engineers page 2 PRELIMINARY PLAT OF WESTVIEW RENTON, WA PRELIMINARY STORM DRAINAGE CALCULATIONS REVISED 2-7-95 BY REH BASIN SUMMARY BASIN ID: 2B NAME: DEV. 10YR CONDITIONS SBUH METHODOLOGY TOTAL AREA. . . . . . . : 2 .86 Acres BASEFLOWS: 0. 00 cfs RAINFALL TYPE. . . . : USER1 PERVIOUS AREA PRECIPITATION. . . . : 2 . 90 inches AREA. . : 1. 37 Acres TIME INTERVAL. . . . : 10. 00 min CN. . . . : 90. 00 TIME OF CONC. . . . . : 7. 00 min IMPERVIOUS AREA ABSTRACTION COEFF: 0. 20 AREA. . : 1. 49 Acres CN. . . . . 98 . 00 PEAK RATE: 1. 72 cfs VOL: 0. 55 Ac-ft TIME: 480 min BASIN ID: 3A NAME: EX 25YR CONDITIONS SBUH METHODOLOGY TOTAL AREA. . . . . . . : 2 .86 Acres BASEFLOWS: 0. 00 cfs RAINFALL TYPE. . . . : USER1 PERVIOUS AREA PRECIPITATION. . . . : 3 . 40 inches AREA. . : 2 . 43 Acres TIME INTERVAL. . . . : 10. 00 min CN. . . . : 81. 00 TIME OF CONC. . . . . : 28. 35 min IMPERVIOUS AREA ABSTRACTION COEFF: 0. 20 AREA. . : 0. 43 Acres CN. . . . . 98 . 00 PEAK RATE: 0. 91 cfs VOL: 0.44 Ac-ft TIME: 480 min BASIN ID: 3B NAME: DEV. 25YR CONDITIONS SBUH METHODOLOGY TOTAL AREA. . . . . . . : 2 . 86 Acres BASEFLOWS: 0. 00 cfs RAINFALL TYPE. . . . : USER1 PERVIOUS AREA PRECIPITATION. . . . : 3 . 40 inches AREA. . : 1. 37 Acres TIME INTERVAL. . . . : 10. 00 min CN. . . . : 90. 00 TIME OF CONC. . . . . : 7 . 00 min IMPERVIOUS AREA ABSTRACTION COEFF: 0. 20 AREA. . : 1. 49 Acres CN. . . . . 98 . 00 PEAK RATE: 2 . 08 cfs VOL: 0. 66 Ac-ft TIME: 480 min 2/ 7/95 Barghausen Engineers page 3 - PRELIMINARY PLAT OF WESTVIEW RENTON, WA PRELIMINARY STORM DRAINAGE CALCULATIONS REVISED 2-7 95 BY REH BASIN SUMMARY BASIN ID: 4A NAME: EX 100YR CONDITIONS SBUH METHODOLOGY TOTAL AREA. . . . . . . : 2 . 86 Acres BASEFLOWS: 0. 00 cfs RAINFALL TYPE. . . . : USER1 PERVIOUS AREA PRECIPITATION. . . . : 3 .90 inches AREA. . : 2 . 43 Acres TIME INTERVAL. . . . : 10. 00 min CN. . . . : 81. 00 TIME OF CONC. . . . . : 28 . 35 min IMPERVIOUS AREA ABSTRACTION COEFF: 0. 20 AREA. . : 0. 43 Acres CN. . . . . 98 . 00 PEAK RATE: 1. 15 cfs VOL: 0. 54 Ac-ft TIME: 480 min BASIN ID: 4B NAME: DEV. 100YR CONDITIONS SBUH METHODOLOGY TOTAL AREA. . . . . . . : 2 . 86 Acres BASEFLOWS: 0. 00 cfs RAINFALL TYPE. . . . : USER1 PERVIOUS AREA PRECIPITATION. . . . : 3 . 90 inches AREA. . : 1. 37 Acres TIME INTERVAL. . . . : 10. 00 min CN. . . . : 90. 00 TIME OF CONC. . . . . : 7 . 00 min IMPERVIOUS AREA ABSTRACTION COEFF: 0. 20 AREA. . : 1. 49 Acres CN. . . . . 98 . 00 PEAK RATE: 2 . 44 cfs VOL: 0. 78 Ac-ft TIME: 480 min 2/ 7/95 Barghausen Engineers page 4 PRELIMINARY PLAT OF WESTVIEW RENTON, WA PRELIMINARY STORM DRAINAGE CALCULATIONS REVISED 2-7-95 BY REH HYDROGRAPH SUMMARY PEAK TIME VOLUME HYD RUNOFF OF OF Contrib NUM RATE PEAK HYDRO Area cfs min. cf-AcFt Acres --------------------------------------------- --------------------------------------------- 1 0. 318 480 8102 cf 2 . 86 2 1. 427 470 15038 cf 2 .86 3 0. 684 480 15078 cf 2 .86 4 1. 720 480 23846 cf 2 .86 5 0. 913 480 19303 cf 2 . 86 6 2 . 081 480 28837 cf 2 . 86 7 1. 153 480 23696 cf 2 . 86 8 2 . 444 480 33871 cf 2 . 86 9 0. 317 530 15038 cf 2 . 86 10 0. 684 520 23846 cf 2 . 86 11 0. 291 540 14960 cf 2 . 86 12 0. 572 530 23768 cf 2 . 86 0 13 0. 795 520 28759 cf 2 . 86 14 1. 844 500 33793 cf 2 . 86 0 2/ 7/95 Barghausen Engineers page 5 PRELIMINARY PLAT OF WESTVIEW RENTON, WA PRELIMINARY STORM DRAINAGE CALCULATIONS REVISED 2-7-95 BY REH STAGE STORAGE TABLE CUSTOM STORAGE ID No. 1 Description: PRELIMINARY POND SIZE STAGE <----STORAGE----> STAGE <----STORAGE----> STAGE <----STORAGE----> STAGE <----STORAGE----> (ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft- 230.00 0.0000 0.0000 231.60 1036 0.0238 233.20 2718 0.0624 234.80 5284 0.1213 230.10 55.700 0.0013 231.70 1116 0.0256 233.30 2865 0.0658 234.90 5458 0.1253 230.20 111.40 0.0026 231.80 1196 0.0275 233.40 3013 0.0692 235.00 5631 0.1293 230.30 167.10 0.0038 231.90 1276 0.0293 233.50 3160 0.0725 235.10 5838 0.1340 230.40 222.80 0.0051 232.00 1356 0.0311 233.60 3307 0.0759 235.20 6045 0.1388 230.50 278.50 0.0064 232.10 1463 0.0336 233.70 3455 0.0793 235.30 6252 0.1435 230.60 334.20 0.0077 232.20 1569 0.0360 233.80 3602 0.0827 235.40 6459 0.1483 230.70 389.90 0.0090 232.30 1676 0.0385 233.90 3750 0.0861 235.50 6666 0.1530 230.80 445.60 0.0102 232.40 1783 0.0409 234.00 3897 0.0895 235.60 6872 0.1578 230.90 501.30 0.0115 232.50 1890 0.0434 234.10 4070 0.0934 235.70 7079 0.1625 231.00 557.00 0.0128 232.60 1996 0.0458 234.20 4244 0.0974 235.80 7286 0.1673 231.10 636.90 0.0146 232.70 2103 0.0483 234.30 4417 0.1014 235.90 7493 0.1720 231.20 716.80 0.0165 232.80 2210 0.0507 234.40 4591 0.1054 236.00 7700 0.1768 231.30 796.70 0.0183 232.90 2316 0.0532 234.50 4764 0.1094 231.40 876.60 0.0201 233.00 2423 0.0556 234.60 4937 0.1133 231.50 956.50 0.0220 233.10 2570 0.0590 234.70 5111 0.1173 2/ 7/95 Barghausen Engineers page 6 PRELIMINARY PLAT OF WESTVIEW RENTON, WA PRELIMINARY STORM DRAINAGE CALCULATIONS REVISED 2-7-95 BY REH STAGE STORAGE TABLE CUSTOM STORAGE ID No. 2 Description: FINAL POND DESIGN @ 30% PLUS STAGE <----STORAGE----> STAGE <----STORAGE----> STAGE <----STORAGE----> STAGE <----STORAGE----> (ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft- 230.00 0.0000 0.0000 231.60 1451 0.0333 233.20 3805 0.0873 234.80 7398 0.1698 230.10 78.000 0.0018 231.70 1563 0.0359 233.30 4011 0.0921 234.90 7640 0.1754 230.20 156.00 0.0036 231.80 1674 0.0384 233.40 4218 0.0968 235.00 7883 0.1810 230.30 234.00 0.0054 231.90 1786 0.0410 233.50 4424 0.1016 235.10 8095 0.1858 230.40 312.00 0.0072 232.00 1898 0.0436 233.60 4630 0.1063 235.20 8306 0.1907 230.50 390.00 0.0090 232.10 2047 0.0470 233.70 4837 0.1110 235.30 8518 0.1955 230.60 468.00 0.0107 232.20 2197 0.0504 233.80 5043 0.1158 235.40 8730 0.2004 230.70 546.00 0.0125 232.30 2346 0.0539 233.90 5250 0.1205 235.50 8942 0.2053 230.80 624.00 0.0143 232.40 2496 0.0573 234.00 5456 0.1253 235.60 9153 0.2101 230.90 702.00 0.0161 232.50 2645 0.0607 234.10 5699 0.1308 235.70 9365 0.2150 231.00 780.00 0.0179 232.60 2794 0.0642 234.20 5941 0.1364 235.80 9577 0.2198 231.10 891.80 0.0205 232.70 2944 0.0676 234.30 6184 0.1420 235.90 9788 0.2247 231.20 1004 0.0230 232.80 3093 0.0710 234.40 6427 0.1475 236.00 10000 0.2296 231.30 1115 0.0256 232.90 3243 0.0744 234.50 6670 0.1531 231.40 1227 0.0282 233.00 3392 0.0779 234.60 6912 0.1587 231.50 1339 0.0307 233.10 3598 0.0826 234.70 7155 0.1643 2/ 7/95 Barghausen Engineers page 7 PRELIMINARY PLAT OF WESTVIEW RENTON, WA PRELIMINARY STORM DRAINAGE CALCULATIONS REVISED 2-7-95 BY REH STAGE DISCHARGE TABLE MULTIPLE ORIFICE ID No. 1 Description: PRELIMINARY SIZING Outlet Elev: 230. 00 Elev: 228 . 00 ft Orifice Diameter: 2 . 5869 in. Elev: 233 . 20 ft Orifice 2 Diameter: 3 . 4570 in. STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> STAGE -DISCHARGE---> (ft) ---CfS-- ------- (ft) ---CfS-- ------- (ft) ---CfS-- ------- (ft) ---CfS-- ------- 230.00 0.0000 231.60 0.2297 233.20 0.3249 234.80 0.8081 230.10 0.0574 231.70 0.2368 233.30 0.4325 234.90 0.8249 230.20 0.0812 231.80 0.2436 233.40 0.4799 235.00 0.8412 230.30 0.0995 231.90 0.2503 233.50 0.5174 235.10 0.8572 230.40 0.1149 232.00 0.2568 233.60 0.5497 235.20 0.8728 230.50 0.1284 232.10 0.2632 233.70 0.5786 235.30 0.8881 230.60 0.1407 232.20 0.2694 233.80 0.6052 235.40 0.9030 230.70 0.1519 232.30 0.2754 233.90 0.6300 235.50 0.9177 230.80 0.1624 232.40 0.2813 234.00 0.6533 235.60 0.9322 230.90 0.1723 232.50 0.2871 234.10 0.6754 235.70 0.9464 231.00 0.1816 232.60 0.2928 234.20 0.6965 235.80 0.9603 231.10 0.1905 232.70 0.2984 234.30 0.7167 235.90 0.9740 231.20 0.1989 232.80 0.3039 234.40 0.7362 236.00 0.9875 231.30 0.2071 232.90 0.3093 234.50 0.7550 231.40 0.2149 233.00 0.3145 234.60 0.7732 231.50 0.2224 233.10 0.3197 234.70 0.7909 2/ 7/95 Barghausen Engineers page 8 PRELIMINARY PLAT OF WESTVIEW RENTON, WA PRELIMINARY STORM DRAINAGE CALCULATIONS REVISED 2-7-95 BY REH STAGE DISCHARGE TABLE RISER DISCHARGE ID No. 2 Description: RISER Riser Diameter (in) : 12 . 00 elev: 234 . 14 ft Weir Coefficient. . . : 3 .782 height: 236. 00 ft Orif Coefficient. . . : 9 .739 increm: 0. 10 ft STAGE -DISCHARGE---> STAGE <--DISCHARGE---> STAGE -DISCHARGE---> STAGE -DISCHARGE---> (ft) ---CfS-- ------- (ft) ---CfS-- ------- (ft) ---CfS-- ------- (ft) ---CfS-- ------- 234.14 0.0000 234.60 2.5651 235.10 3.7056 235.60 4.5698 234.20 0.1431 234.70 2.8302 235.20 3.8938 235.70 4.7237 234.30 0.6233 234.80 3.0725 235.30 4.0733 235.80 4.8728 234.40 1.2911 234.90 3.2971 235.40 4.2453 235.90 5.0174 234.50 2.1036 235.00 3.5073 235.50 4.4105 236.00 5.1580 2/ 7/95 Barghausen Engineers page 9 PRELIMINARY PLAT OF WESTVIEW RENTON, WA PRELIMINARY STORM DRAINAGE CALCULATIONS REVISED 2-7-95 BY REH STAGE DISCHARGE TABLE COMBINATION DISCHARGE ID No. 3 Description: COMBINED ORIFICE AND RISER Structure: 1 Structure: Structure: 2 Structure: Structure: STAGE -DISCHARGE---> STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> (ft) ---CfS-- ------- (ft) ---CfS-- ------- (ft) ---CfS-- ------- (ft) ---CfS-- ------- 230.00 0.0000 231.60 0.2297 233.20 0.3249 234.80 3.8806 230.10 0.0574 231.70 0.2368 233.30 0.4325 234.90 4.1219 230.20 0.0812 231.80 0.2436 233.40 0.4799 235.00 4.3485 230.30 0.0995 231.90 0.2503 233.50 0.5174 235.10 4.5627 230.40 0.1149 232.00 0.2568 233.60 0.5497 235.20 4.7666 230.50 0.1284 232.10 0.2632 233.70 0.5786 235.30 4.9614 230.60 0.1407 232.20 0.2694 233.80 0.6052 235.40 5.1483 230.70 0.1519 232.30 0.2754 233.90 0.6300 235.50 5.3283 230.80 0.1624 232.40 0.2813 234.00 0.6533 235.60 5.5020 230.90 0.1723 232.50 0.2871 234.10 0.6754 235.70 5.6701 231.00 0.1816 232.60 0.2928 234.20 0.8396 235.80 5.8331 231.10 0.1905 232.70 0.2984 234.30 1.3400 235.90 5.9914 231.20 0.1989 232.80 0.3039 234.40 2.0274 236.00 6.1455 231.30 0.2071 232.90 0.3093 234.50 2.8586 231.40 0.2149 233.00 0.3145 234.60 3.3383 231.50 0.2224 233.10 0.3197 234.70 3.6211 2/ 7/95 Barghausen Engineers page 10 _ _ PRELIMINARY PLAT OF WESTVIEW RENTON, WA PRELIMINARY STORM DRAINAGE CALCULATIONS REVISED 2 7 95 BY REH LEVEL POOL TABLE SUMMARY MATCH INFLOW -STO- -DIS- <-PEAK-> STORAGE <--------DESCRIPTION---------> (cfs) (cfs) --id- --id- <-STAGE> id VOL (cf) 2YR .......................... 0.32 1.43 1 1 233.05 9 2499.69 10YR ......................... 0.68 1.72 1 1 234.14 10 4140.05 2YR ROUTING .................. 0.32 1.43 2 3 232.57 11 2753.55 10YR ROUTING ................. 0.68 1.72 2 3 233.67 12 4784.08 25YR ROUTING ................. 0.91 2.08 2 3 234.17 13 5873.36 100YR ROUTING ................ 1.15 2.44 2 3 234.37 14 6361.55 File Basin Hydrograph Storage Discharge Level pool Barghausen Engineers 2eeeeeeeeeeeeeeeeel �eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeie@eeeeeeeeeeeeeeeeeeeeeei ° ROUTING COMPARISON TABLE ° ° MATCH INFLOW STO DIS PEAK PEAK OUT ° ° DESCRIPTION PEAK PEAK No. No. STG OUT HYD ° ° °2YR 0.32 1 .43 1 1 233.05 0.32 9 ° ° 10YR 0.68 1 .72 1 1 234. 14 0.68 10 ° °2YR ROUTING 0.32 1 .43 2 3 232.57 0.29 11 ° ° 10YR ROUTING 0.68 1 .72 2 3 233.68 0.57 12 ° °25YR ROUTING 0.91 2.08 2 3 234. 17 0.79 13 ° ° 100YR ROUTING 1 . 15 2.44 2 3 234.37 1 .84 14 ° Press any key to exit ° a eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeaeeeeeeeeeeeeeeeef Overlay loaded to Expanded Memory Available Memory remaining: 94824 bytes Current Data Set Name: d:\works2\5150 ,CMF/ZGE;,uCy OvE2FLoW SPILL yvc,�y F7oti �'OIAva s - (a/OO /( 3-?-1 W;A). C5c-r- tiexT NNN V.SE ; ► O,� 141;Aj LUW� W W W W W W xxx N N N too = Z • y4 nn -ra aav rrr 6? Z • 4y y ( ) I EMERG ENGy oVE2 FLoHi i = % WATi512 SvoeF,4cF Top= Z35,p Val EL.c 7- 34.50 R%p RA?ff p � vs�wy 2oc.� QvA,�y Spa�lLs � k,IAJ bE?Tff r KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL o Design of emergency overflow spillways require the analysis of a broad-crested trapezoidal weir. The following weir section is required for the emergency overflow spillway: FIGURE 4.4.4A WEIR SECTION FOR EMERGENCY OVERFLOW SPILLWAY wATF-cz 6 VR F#4r_ 4 L 'Pizctp peg IAbIL g,3•bq o The emergency overflow spillway weir section shall be designed to pass the 100-year, 24-hour design storm event for developed conditions as follows: For this weir, Q,. = C (2g)112(2/3LH3/1 + 8/15 Tan&H5/2) using C = 0.6 (discharge coefficient); Tan = 3 (for 3:1 slopes); = 720; The equation becomes: Q,,), = 3.21 (LH3/2 + 2.4111i201 ) To find width L, the equation is rearranged to use the computed 0,0 (peak flow for the 100-year, 24- hour design storm) and trial values of H L0.2 JaQt minimum). L = (Q,./(3.21 H3/2)) - (2.4H2); 6 feet minimum Access/Maintenance: on access Facts and roads are required when ponds do not abut public right-of- way. Road(s) shall provide access to the control structure and along side(s) of the pond as necessary for vehicular maintenance.. For ponds with bottom widths of 15 feet or more, the access road shall extend to the pond bottom and an access pad provided to facilitate cleaning. For ponds less than 15 feet in width, an access road must extend along one side. o Roads and pads shall meet the following criteria: - Maximum Grade: 15% to control structure, 20% into pond. - Provide 40' minimum outside turning radius on the access road to the control structure and the turnaround to the pond bottom. Fence gates shall be provided for access roads at straight sections of road. Access roads shall be 15' in width on curves and 12' on straight sections. Access pads shall be 15' in width and 25' in length. o Manhole and catch basin lids must be at either edge of an access road or pad and be at least three feet from a property line. o Access shall be limited by a double-posted gate if a fence is required or by bollards. Bollards shall consist of two fixed bollards on each side of the access road and two removable bollards equally located between the fixed bollards. o Access roads and pads shall be constructed by utilizing one of the following techniques: 4.4.4-2 1/90 BIOFILTRATION SWALE SIZING CALCULATIONS Trapezoidal Channel Analysis & Design Open Channel - Uniform flow Worksheet Name: WESTVIEW PLAT 5150 Comment: BIOFILTRATION SWALE QUALITY DESIGN Solve For Depth Given Input Data: Bottom Width. . . . . 0. 00 ft Left Side Slope. . 3 . 00: 1 (H:V) Right Side Slope. 3 . 00: 1 (H:V) Manning's n. . . . . . 0. 350 Channel Slope. . . . 0. 0200 ft/ft Discharge. . . . . . . . 0. 32 cfs Computed Results: Depth. . . . . . . . . . . . 0. 63 ft Velocity. . . . . . . . . 0.27 fps Flow Area. . . . . . . . 1. 19 sf Flow Top Width. . . 3 . 78 ft Wetted Perimeter. 3 .99 ft Critical Depth. . . 0. 23 ft Critical Slope. . . 3 .9161 ft/ft Froude Number. . . . 0. 08 (flow is Subcritical) 7.56 s, _ �'. �f� t=L��w %off WoiH 1ZEad Open Channel Flow Module, Version 3 .41 (c) 1991 Haestad Methods, Inc. * 37 Brookside Rd * Waterbury, Ct 06708 Trapezoidal Channel Analysis & Design Open Channel - Uniform flow Worksheet Name: WESTVIEW PLAT 5150 Comment: BIOFILTRATION SWALE QUALITY DESIGN Solve For Depth Given Input Data: Bottom Width. . . . . 8 . 31 ft Left Side Slope. . 3 . 00: 1 (H:V) Right Side Slope. 3 . 00: 1 (H:V) Manning's n. . . . . . 0. 350 Channel Slope. . . . 0. 0200 ft/ft Discharge. . . . . . . . 0. 32 cfs Computed Results: u s E c.<.agaAJ Depth. . . . . . . . . . . . 0. 19 ft Velocity. . . . . . . . . 0. 19 fps Flow Area. . . . . . . . 1. 69 sf (,Jt,DTff Flow Top Width. . . 9 .45 ft Wetted Perimeter. 9.51 ft Critical Depth. . . 0. 04 ft Critical Slope. . . 5. 4584 ft/ft Froude Number. . . . 0. 08 (flow is Subcritical) U 5E cL�4 Open Channel Flow Module, Version 3 . 41 (c) 1991 Haestad Methods, Inc. * 37 Brookside Rd * Waterbury, Ct 06708 KPB I - lu Krl ii I! --. \ r JP I fl � v J AgC II n 1r, II AkF 4 r. AgCI Gn:C J! � ter• Il �...i...� BeD igh .n m BM Pleasure B 20 g I BM 22 Point 21 ; F I 5 ilia S 22 AgC �. AmC InC 5h I AkF P� AgC AkF I ----- -- pp BN Bra B D 29 2 32 •AgC J m 42 — — 1 BeC — -- ----- Kp8 5 AgC 1 'Pin I I Newpo I AgD J Ur HMS BeC InA 'I AgC - - - -�- y Ur •o n W AmC 0 n Ev8 y 1 — KpD gII __ � BeC Ur ♦ . . l� LEAo k , Ct C pa• 2 AgD 14, 3 O New p • ' _ 3M 390 EvC BeD 'eC AgC 58 AmC � I �• Bh •� •• -�� Bh •♦ AgC AgC May e KpC rQ •EvC OvD _ = B� ' AgD ------ .\, --�L------ i - ---6 0A&Bm - -Q 692 No o� .� 2 AgC I. 'AgC rr. \ BMA ct �,I• - ` I 605 OVD .r A C - ` AgC i ••`� BeC g AgD AgD 4�I 34 �+ AgD AgC .U�•• .. ' ��P I' II Kennydale a 0. •InC AkF I ,� f ..I I AkF 'AgC EvB rti. AkF �• i I I BeG EvC 3n Poln Q,' ; Py �• t• GRPAT EL AkF• p co 306 'InA' 1 I i ''" AgC /— ,^ —* .G B C AgD n �-- ---- --•— _ ll BM11 fivB . g m n ' 'BM'90ff 1 ' L n 1 m EvC/¶ PL PVC AgD p " AgC B M' u '•i '. �� AkF a a r N K4, • m6i� I, s—'_---- - .. Sm In it AgD° Ev AkF •I ,L�7 I u Ir I •'Sm Ur r I• R ry ir. R •` B DY j• • �a1 I " -I1 E. / ` • II 1V •EvC i Plant / �1� •� ]i 1V ' � R ON �� Ire .: j AgC %�2dE d; GUIDE TO MAPPING UNITS For a full description of a mapping unit, read both the description of the mapping unit and that of the soil series to which the mapping unit belongs. See table 6, page 70, for descriptions of woodland groups. Other information is given in tables as follows: Acreage and extent, table 1, page 9. Town and country planning, table 4, page 57. Engineering uses of the soils, tables 2 and 3, Recreational uses, table 5, page 64. pages 36 through 55. Estimated yields, table 7, page 79. Woodland Described Capability unit group Map on symbol Mapping unit page Symbol Page Symbol AgB Alderwood gravelly sandy loam, 0 to 6 percent slopes---------- 10 IVe-2 76 3d2 AgC Alderwood gravelly sandy loam, 6 to 15 percent slopes--------- 8 IVe-2 76 3dl AgD Alderwood gravelly sandy loam, 15 to 30 percent slopes-------- 10 VIe-2 78 3dl AkF Alderwood and Kitsap soils, very steep------------------------ 10 VIIe-1 78 2dl AmB Arents, Alderwood material, 0 to 6 percent slopes _ ------- 10 IVe-2 76 3d2 AmC Arents, Alderwood material, 6 to 15 percent slopes 1/--------- 10 IVe-2 76 3d2 An Arents, Everett material 1/----------------------------------- 11 IVs-1 77 3f3 BeC Beausite gravelly sandy loam, 6 to 15 percent slopes---------- 11 IVe-2 76 3d2 BeD Beausite gravelly sandy loam, 15 to 30 percent slopes--------- 12 VIe-2 78 3dl BeF Beausite gravelly sandy loam, 40 to 75 percent slopes--------- 12 VIIe-1 78 3dl Bh Bellingham silt loam------------------------------------------ 12 IIIw-2 76 3w2 Br Briscot silt loam--------------------------------------------- 13 IIw-2 75 3wl Bu Buckley silt loam--------------------------------------------- 13 IIIw-2 76 4wl Cb Coastal beaches----------------------------------------------- 14 VIIIw-1 78 --- Ea Earlmont silt loam-------------------------------------------- 14 IIw-2 7S 3w2 Ed Edgewick fine sandy loam-------------------------------------- 15 IIIw-1 75 2ol EvB Everett gravelly sandy loam, 0 to 5 percent slopes------------ 15 IVs-1 77 3f3 EvC Everett gravelly sandy loam, 5 to 15 percent slopes----------- 16 VIs-1 78 3f3 EvD Everett gravelly sandy loam, 15 to 30 percent slopes---------- 16 VIe-1 77 3f2 EwC Everett-Alderwood gravelly sandy loams, 6 to 15 percent slopes------------------------------------------------------ 16 VIs-1 78 3f3 InA Indianola loamy fine sand, 0 to 4 percent slopes------ ------ 17 IVs-2 77 4s3 InC Indianola loamy fine sand, 4 to 15 percent slopes------------- 16 IVs-2 77 4s3 InD Indianola loamy fine sand, 15 to 30 percent slopes------------ 17 VIe-1 76 4s2 KpB Kitsap silt loam, 2 to 8 percent slopes----------------------- 17 IIIe-1 75 2d2 KpC Kitsap silt loam, 8 to 15 percent slopes---------------------- 18 IVe-1 76 ?d2 KpD Kitsap silt loam, 15 to 30 percent slopes--------------------- 18 VIe-2 78 2dl KsC Klaus gravelly loamy sand, 6 to 15 percent slopes------------- 18 VIs-1 78 3fl Ma Mixed alluvial land------------------------------------------- 18 VIw-2 78 2ol NeC Neilton very gravelly loamy sand, 2 to 15 percent slopes------ 19 VIs-1 78 3f3 Ng Newberg silt loam--------------------------------------------- 19 IIw-1 74 2ol A Nooksack silt loam-------------------------------------------- 20 IIw-1 74 2ol No Norma sandy loam---------------------------------------------- 20 IIIw-3 76 3w2 Or Orcas peat---------------------------------------------------- 21 VIIIw-1 78 --- Os Oridia silt loam---------------------------------------------- 21 IIw-2 75 3wl OvC Ovall gravelly loam, 0 to 15 percent slopes------------------- 22 IVe-2 76 3dl OvD Ovall gravelly loam, 15 to 25 percent slopes------------------ 23 VIe-2 78 3dl OvF Ovall gravelly loam, 40 to 75 percent slopes------------------ 23 VIIe-1 78 3dl Pc Pilchuck loamy fine sand-------------------------------------- 23 VIw-1 78 2sl Pk Pilchuck fine sandy loam-------------------------------------- 23 IVw-1 76 2sl Pu Puget silty clay loam----------------------------------------- 24 IIIw-2 76 3w2 Py Puyallup fine sandy loam-------------------------------------- 24 IIw-1 74 2ol RaC Ragnar fine sandy loam, 6 to 15 percent slopes---------------- 25 IVe-3 77 4sl RaD Ragnar fine sandy loam, 15 to 25 percent slopes--------------- 26 VIe-2 78 4sl RdC Ragnar-Indianola association, sloping: 1/---------------------- 26 -------- -- Ragnar soil--------------------------------------------- -- IVe-3 '7 4sl Indianola soil------------------------------------------- -- IVs-2 77 4s3 RdE Ragnar-Indianola association, moderately steep: 1/------------ 26 -------- -- Ragnar soil--------------------------------------------- -- VIe-2 78 4sl Indianola soil------------------------------------------- -- VIe-1 77 4s2 V. S. GOVERNMENT PRINTING OFFICE:1973 0-468-266 KING COUNTY, WASHINGTON, SU.RFACE WATER DESIGN MANUAL FIGURE 3.5.2A HYDROLOGIC SOIL GROUP OF THE SOILS INKING COUNTY HYDROLOGIC HYDROLOGIC SOIL GROUP GROUP" SOIL GROUP GROUP` Orcas Peat - D Arents, Alderwood Material C Oridia D Arents, Everett Material B Oval[ C Beausite C Pilchuck C Bellingham D Puget D Briscot D Puyallup B Buckley D Ragnar B Coastal Beaches Variable Renton D Eadmont Silt Loam D Riverwash Variable Edgewick C Sala[ C Everett A Sammamish D Indianola A Seattle D Kitsap C Shacar D Klaus C Si Silt C .Mbced Alluvial Land Variable Snohomish D Nelton A Sultan C Newberg B Tukwila D Nooksack C Urban Variable Normal Sandy Loam D Woodinville D HYDROLOGIC SOIL GROUP CLASSIFICATIONS t A. (Low runoff potential). Soils having high infiltration rates,even when thoroughly wetted,and consisting chiefly of deep,well-to-excessively drained sands or gravels. These soils have a high rate of water transmission. B. (Moderately low runoff potential). Soils having moderate infiltration rates when thoroughly wetted, and consisting chiefly of moderately fine to moderately coarse textures- These soils have a moderate rate of water transmission. C. (Moderately high runoff potential). Soils having slow infiltration rates when thoroughly wetted, and consisting chiefly of soils with a layer that impedes downward movement of water, or soils with moderately fine to fine textures. These soils have a slow rate of water transmission. D. (High runoff potential). Soils having very slow infiltration rates when thoroughly wetted and consisting chiefly of clay soils with a high swelling potential, soils with a permanent high water table, soils with a hardpan or day layer at or near the surface, and shallow soils over nearly impervious material. These soils have a very slow rate of water transmission. From SCS, TR-55, Second Edition, June 19W. Exhibit A-1. Revisions made from SCS. Soil Interpretation Record. Form #5. September 1988. KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TABLE 3.5.2B SCS WESTERN WASHINGTON RUNOFF CURVE NUMBERS SCS WESTERN WASHINGTON RUNOFF CURVE NUMBERS (Published by SCS in 1982) Runoff curve numbers for selected agricultural, suburban and urban land use for Type 1A rainfall distfibution, 24-hour storm duration. CURVE NUMBERS BY HYDROLOGIC S ROUP LAND USE DESCRIPTION A B C D Cultivated land(1): winter condition 86 91 94 95 Mountain open areas: low growing brush and grasslands 74 82 89 92 Meadow or pasture: 65 78 85 89 Wood or forest land: undisturbed 42 64 76 81 Wood or forest land: young second growth or txush 55 72 81 86 Orchard: with cover crop 81 88 92 94 Open spaces, lawns, parks, golf courses, cemeteries, landscaping. good condition: grass cover on 75% or more of the area 68 80 86- 90 fair condition: grass cover on 50% to 75%of the area 77 85 90 92 Gravel roads and parking lots 76 85 89 91 Dirt roads and parking lots .72 82 87 89 Impervious surfaces, pavement, roofs, etc. 98 98 98 98 Open water bodies: lakes, wetlands, ponds, etc. 100 100 100 100 Single Family Residential (2) Dwelling Unit/Gross Acre % Impervious (3) 1.0 DU/GA 15 Separate curve number 1.5 DU/GA 20 shall be selected 2.0 DU/GA 25 for pervious and 2.5 DU/GA 30 impervious portion 3.0 DU/GA S tTt— 2.o7 q.L 34 of the site or basin 3.5 DU/GA Q� _ f Z 38 4.0 DU GA 42 4.5 DU/GA Du/GA= � o� = 46 5.0 DU/GA ` 48 5.5 DU/GA 50 6.0 DU/GA �'�O D 16A 52 6.5 DU/GA 54 7.0 DU/GA (A 56 b Planned unit developments. % impervious condominiums, apartments, must be computed commercial business and industrial areas. (1) For a more detailed description of agricultural land use curve numbers refer to National Engineering Handbook, Section 4, Hydrology, Chapter 9, August 1972. (2) Assumes roof and driveway runoff is directed into street/storm system. (3) The remaining pervious areas (lawn) are considered to be in good condition for these curve numbers 3.5.2-3 1/90 PIN maw Ml son Rdo OR 04 III 0A VL ��► yak r �' 190 iy log A G • • ra � . WT wms IBWOOW;2 nit' � ss Kin C ��•w•� ►/fir' ,- • • • • • : ,; . F w.aw.im. jr Flo it ellAM . ,. gal IN „I resw �� - V�t►� 1 MILL al, W5 Mal ISO Orw*1w Vpq IFOUR _ 1 lull 46; t� %.`�,a p��!�rf or �� V. CONVEYANCE SYSTEM DESIGN AND ANALYSIS PIPE SIZING DRAINAGE AREA MAP _ , ROAD ADRAINAGE PLAN ND 1 40 4 A PORTION, OF THE NE 1/4 SEC. 8, TW . 23 N., RGE. 5 E., dNST LL: BUILD UP ASPHALT EX. SS MH KIN COUNTY,, WASHI GTON G A '.'BER 3" HIGH ALONG TAPER 0151 RIM=253.46 TO IRECT STORM DRAINAGE 0155 IE-249.71 �8': PVC N,E) TO HE PROPOSED GUTTER. it O T INSTALL: FENCE ALONG THE ENTIRE IE=249.71 6' STU OUT TO 0145 .-CONTRACTOR 0 EX. 10' SANITARY _- EASTERN AND WESTERN PROPERTY LINES PER DEVELOPERS EX. SS MH " 30, SEWER EASEMENT DIRECTION. MAXIMUM HEIGHT F FENCE SHALL BE FEET RIM=264.23 I S 00'28'25" W 506.18' j0140 UNLESS APPROVED BY THE CI . 0131 5 n ��O —�x x x xx IE=249.10 (8" PVC E,W) ?- - ` _ ----r- IE=249.10 8" S) 260 ___sue- 255 --- - _ -- ------ -- - cB#- _ SAWCUT EX. EP ' I. r r _ �NSTALL: 6' HIGH WOOD 1 FENCE PER DETAIL. MATCH PAVEMENT I AND SEAL JOINT. i44 i ' o / �. 1 ; 3 ; 44; 6 �� 5° WHEELCHAIR_, of / o RAMP (TYP) I I 1 ;: NI 1 I r to NI `CO / �4656 i N 1 12 SD M o / D� - WHEELCHAIR W 12 SD 1 CB�6 1 ^• RAMP (TYP) N OV28*25" E EX. PP W/GUY / f m R� Ate. N.E•`° �5 CB CB f1 T REMAIN - CB#5 ISTURBED CO . CO 1 J EX. CB 6'�rbIA. SD ' FOR I x 6 LOCATION SHOWN ....,,CONNECTIONOF FOOTINGS Nj N1 APPROX. ONLYDRAINS AN DOWNSPOUTS I I �- I) (TYP) SEE DETAIL. 1 It; 12 11 10�r= ; ; - ' 7 I III I E I • j `"� I SEWER PUMP EXISTING { I{ Yee i 4 STATION. EDGE OF I _ _f._._► c, 3 PAVEMENT { III Q 9' --- _ -#° ` ' k �� 78 LF 12" SD 240A�`_' --- =- _-____-____ _____-____-_- ® 4. 162 LF:f 2'' C _ _ _ _ 80% 1-' SD S 00'28-25-W 'A'8 II �, 383.96 f II 1 I I CHAINLINK II I '2:1 TAPER (TYP) BOTH SIDES ':f€NCE TO REMAIN II 0161) Foa pop, EX. CB TYPE I I It I 30' RIM=244.19 r. ' /w R W PIPE.-SIZ, BA N- .MAP IE=242.34 (12 CONC.) II / REA . . I ' r i Ckt> E L = b o � } 0N JOB 0 5 5 I ... 1 " I' 0 0 0 BAR6'HAUSEN CON5ULTIN6 ENINEERS - PIPE FLOW CALCULATOR A = Contributing Area <Ac> Qd = Design Flow <efs> using the Rationa r. l Method & Manning Formula C = Runaff Coefficient Of = Full Capacity_ Flow <cfs> SEATTLE-RENTON 25 YEAR STORM Tc = Time of Concentration <min> Vd = Velocity_ at Design Flow <fps> I = Intensity at Tc !inihr> Vf = Velocity at Full Flow <fps> O=FAULT C= 0.50 r,= 0.014 d= 12 Tc= 10.0 d = Diameter of Pipe <in> s = Slope of pipe <%> Note: Set. deF'ault values before entering data. L = Length oF' Pipe <ft> n = Manning Roughness Coefficient JOB u 5150 JOB NAME. WILDERNESS FLAT D = Water Depth at Qd (in) Tt = Travel Time at Vd Cmin> BY REH < 2-18-95 > FROM TO A s L d Tc n C SUM A A*C SUM A*C I Qd Qf Qd/QP X Did D Vf VdlVf Vd Tt CB8 CB6 0.80 7.19 167.0 12 10.0 0.014 0.90 0.80 0.72 0.72 2.00 1.44 8.87 0.162 0.260 0.270 3.24 11.30 0.732 8.28 0.34 CB6 C54 0.87 5.38 158.0 12 10.3 0.014 0.50 1.67 0.44 1.16 1.97 2.28 7.67 0.297 0.360 0.373 4.47 9.77 0.871 8.51 0.31 C54 C82 0.81 1.23 120.0 12 10.6 0.014 0.50 2.48 0.41 1.56 1.95 3.04 3.67 0.829 0.580 0.694 8.32 4.57 1.117 5.22 0.38 C52 POND 0.20 1.00 34.0 12 11.0 0.014 0.50 2.68 0.10 1.66 1.92 3.18 3.31 0.962 0.780 0.782 9.39 4.21 1.138 4.80 0.12 CB7 C56 0.43 1.56 32.0 12 10.0 0.014 0.50 0.43 0.22 0.22 2.00 0.43 4.13 0.104 0.200 0.219 2.63 5.25 0.643 3.38 0.16 C55 CB4 0.39 1.56 32.0 12 10.0 0.014 0.50 0.39 0.20 0.20 2.00 0.39 4.13 0.094 0.200 0.206 2.47 5.26 0.517 0.16 C53 CB2 0.20 1.07 90.0 12 5.3 0.014 0.90 0.20 0.18 0.18 2.47 0.44 3.42 0.130 0.240 0.244 2.93 4.36 0.683 2.98 0.50 POND CBS 0.00 0.05 25.0 24 11.1 0.014 0.50 0.00 0.00 1.66 1.91 3.17 4.70 0.674 0.580 0.500 14.39 1.50 1.070 1.60 0.26 CB1 SWALE 0.00 1.00 50.0 12 11.4 0.014 0.50 0.00 0.00 1.66 1.88 3.13 3.31 0.945 0.760 0.768 9.22 4.21 1.136 4.79 0.17 31ALE C69 0.00 4.80 78.0 12 11.6 0.014 0.50 0.00 0.00 1.66 1.87 3.10 7.25 0.428 0.440 0.459 5.50 9.23 0.968 8.94 0.15 C69 E:<C6 0.00 39.92 162.0 12 11.7 0.014 0.50 0.00 0.00 1.66 1.85 3.08 20.90 0.147 0.240 0.258 3.09 25.63 0.711 18.92 0.14 VI. SPECIAL REPORT AND STUDY i ."•• ! :�'�•���iJr 1 `�K'.r.,y�Y � 7�T•e;� �• 5 t�'.'R{�. � s �' 3� �_ Z'.�tsl J l `�°+� �/ �' iti . MUNITAXI t i it vlt e—V ITT Will i■fRtlrn!-c.'�� fe,.��8� �� y4 i.f1A $ �s -;mr..l■■■ �}� �. '` "(lam f�. �r � �l.C �S �rs�..® tr - • .ram Til1� 0■.is hu.uwava ��►..\gh p3v:��'.�a.. 'y ' 1 ,e. ■q �;yil.'f - �'0 �\ ' •8` �grk 3Y1 C'� un. -.i �81ilYs- .1•'�.(� a \k _ � � '� �:��. L-��i�istli�.r�cr.•ai �.�.\��A� �7 �l�'R�►�.�.� 9y*I�/ �tt'I ■ `� $ ���f�- x - �1�� —,WadWO „y t - .MJF .=: Vll �11�(1 - �ydl■Gi � Ir\ �� 1t ;,J11 1 ter_ 1 �}. It. IA M14U a A Alf 4"R id, If IMAWk 3u: sv:r�.l A� ♦ tp'@p�g 4 � act t ;pay�'agwvvz ' WMFA JUfM. � @��r►; ..ors . rqgljg _ aAH, �..D_z . � ��' dlN`�.'�-fll� s .c a+"r.`,� ;�•` +��_ Sift:'a4l�yFll'A`ira .9'►'%'�r,/�1 `f s al r f i�'9� iim ��4`y u au hil ME e- Rik ,. , ,peg MIN IT LOU RON ,�► ,;�� ,..nsra r AIM ,��� ���: R S11!'i@Ca gRAW Hill d � Moo ArqGt Mal ra a all) iVAIL willow IMP 11 ...�Cr �. `¢ i i � ► a me ��11►�,y� 111plima ,� ! '� �• 6 � � ���' � ���i1ir;R:i'�'; � "� Vie' ; �� �o � +� a •� - . on imp 11 r DuffMo. „ a �P! 2 INN e. Ord ��:;? '`•�`�'`�,.IIGg 1 t�7� � sa ,�.���� A.4 El�, i f t Mal vs ME 'A wit , ti Ril1MUM I • __ I it � a i l SO � WAR Will M ��� \�j t T�� � "� �'��I Iy �a,'-rj�►lfr,�'�i y .rr... 'w mill MAI mg- tl■ ��� tlR1q � �j itpt Run ZVER WIN I r_ a �i f.y� law grvlak }� i /'vSIG�c .20 mill Igo ON =494is will all iQG i6VIr } 1, `'1 .• ��— ice.��n� ,� ■� i r _ ' � r a Ikk lit ; �4� �-w an win'"rhw1win RM H1ii „dLIMAwJPIA ♦ �� F YL L31 1 Sm WHIR MR fit Am 21M6 �11 �rn14f1� '��r `�k��i 'C C �� .r. t'>• i1 ®��j�1'q I y/i iu•-. Gi r tug MOM �j�jf, �( 51 SIR. TOP �c$ �`�► � .\ n-ems__ i4' IN all gg. : i/ gni'uel) a i � � ! 4 ��9 � � 'fir- � ����r� ASF gmo �Il � r•� �►y� � +I �g{ a9 ZZ A L .•` ' �9dq�' �� � ��� � k�'VA, l .r...i i1ir 3 �a +.rig sa ON ' n A \.v.es.or. �•killL� , gm MANI Ll y� e pllti,■NO ` 1141 k WIT _d Coll Ltd fill ,� s :'7'���r- ��:9 � �e� �'� ��r r���fi� _ ,+, .� "ems a.++►Ei► �� '' .�� e���t..�,� �(1���� ��1 '" � ter. ��•�� ,V� ���� r= -4 VI. 100-YEAR FLOOD PLAIN STUDY VII. BASIN AND CONEMNITY PLAN AREAS v✓ a w Q r � Z to . 11 ,i > i. ,'._.•4N•a:,;•„ : �,,/ r-1 O Z 'n;`to �� Y I, +!„ 1! I, ^r/.•'( .i .. '�,�J ,_J1 `1 ram. 1� 1 y� 1 •• if if it ell ° if iri� •.> "\sue ,\ , �� � 1 � y �. I, � W 1 1J Ir1 ' It If LU LU w N Nr:Aww.- \ /Mwll 4„MIA•r J amnrn.sn R•.a. Gnaw 3 W,fty SKYKOMISH ww R F .� fits jll RIVER - ` � SN ( U MIE �, \ Nwcn Fork a •�• _'.. C ek $noqunnk Ri.rr .. BASIN __ :�:_- RIVER MCI T 1:wll Vi t di _fi .� d `�. PUGET , SIN Cw M sort Fo k Ix w sow ` j VFXl.k...Ah CRRk. OUN C•a _ 11 7` k \� l DesMt.les SoutnFolk J� : Figure E-7 t. - !�k" `^.�i• C`c— t r 'a `.. � , t^'' •��\`�• — silovwknle Rik t. t uao« tic' e°a.At..t ' 'T o> F4t[-, DRAINAGE BASINS ! King County i 1 °± .985 __._DRAINAG •aTTOFSE:TTEEM.TEIISMEo .--- —_._. r` _ ter-'-- � 1 � _� �" •F t �nl '...i"r .+. r r- ��' ..._ - - F Major Basin Boundary TACCOA �owc� r - Sub-Basin Boundary T. t q� S i RKW. Source: King County Sensitive Areas -_ -- Map Folio,Wetlands Supplement GIY OF IAGJTa♦WATERSHED a w,iNo� — Ef.sT" LA Ae VVASff. \9IVER NIA�o R — G EDf�R R tvER _ BASIN U 1 2 1 4 5 ,, 7 8 Mdes VIH. OTHER PERMITS IX. EROSION/SEDMIENTATION CONTROL DESIGN KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL ------------ e. Grid Pavers - modular concrete units with interspersed void areas which can be used to armor the streambank while maintaining porosity and allowing the establishment of vegetation. 5.4.3.6 VEGETATIVE STREAMBANK STABILIZATION Purpose To protect streambanks from erosion through the use of vegetation. Conditions Where Practice Applies Creek, stream and river banks downstream from, or within, a construction site which may be adversely affected by excess runoff resulting from construction activities. Design Criteria/Specifications l4 o Design must be prepared based on criteria and input/review from a qualified fisheries biologist. See Chapter 4, Section 4.3.7, Open Channels, Bioengineered Channels and Bank Stabilization. 5.4.4 SEDIMENT RETENTION A sediment trap of sediment pond must be used as the primary structural control measure to treat silt- laden runoff from exposed areas, wherever feasible. Permanent peak rate runoff control facilities (except infiltration systems) may also be used for sediment retention. They must be thoroughly cleaned prior to construction approval. C In those cases where site constraints will not allow small areas to be served by a sediment trap or sediment pond, one or more of the other measures described in this section shall be employed. q§Rdimenl: raps are used lor;dr Triage areas tip to`3 aC7es and sediment ponas used for drainage areas up to 10 acres. These limitations on drainage areas will`require that several or more sediment retention measures will be required for any project with drainages areas of more than 10 acres. Figure 5.4.4A illustrates the use of these ESC structural practices. 5.4.4.1 SEDIMENT TRAP Purpose To collect and store sediment from site cleared and/or graded during construction. It is intended for use on drainage areas with no unusual drainage features, and for projects with anticipated short build-out time (approximately 6 months or less). It is a temporary measure with a design life less than 1 year. It is to be maintained until the site area is permanently protected against erosion by vegetation and runoff from impervious surfaces is directed to permanent drainage facilities. Conditions Where Practice Applies Where the tributary drainage area is 3 acres or less. '. Design Criteria/Specifications The sediment trap may be formed completely by excavation or by construction of a compacted embankment. It shall have a 1.5 foot deep sump for sediment storage. The outlet shall be a weir/spillway section, with the lower 2 feet acting as a filter for sediment and the upper foot as the overflow spillway depth. A filter fabric fence must be provided to filter the runoff from the trap prior to discharge from the site. o See Figure 5.4.4E for detail. (C. 5.4.4.1-1 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL o The temporary sediment trap volume is the volume of sediment storage computed (not to exceed 1.5' in depth) plus the volume resulting from providing a 2' deep settlement zone above the sediment storage, while not exceeding trap side slopes of 3:1. o Computing the sediment storage volume - The sediment storage volume required is the volume required to contain the annual sediment yield to the trap and can be estimated by using the Universal Soil Loss Equation (USLE) developed by the United States Department of Agriculture. ASED = R*K*LS*CV*PR Where AsED = annual sediment yield in tons per acre R = rainfall erosion index; use R'=2.22(P2)2z; where P2 is the 2 year/24 hour precipitation in inches (See 2 year - 24 hour Isopluvial Map in Figure 3.5.1 C) K = soil erodibility factor, from Table 5.4.4A or as determined by field and laboratory testing by a geologist, soil scientist, or geotechnical engineer. LS = length-slope factor; from Table 5.4.4E (note, lengths measured are horizontal distance from a plan view) CV = cover factor, use 1.0 which represents no ground cover during the construction process. PR = erosion control practice factor; use 1.3 which represents compacted and smooth slopes. Note, the USLE rainfall erosion index equation for the SCS Type 1A storm region is R=10.2 (P2)2.2, where P2 is the total precipitation for the-2 year, 6 hour duration design storm. Since the total precipitation for the 2 year, 6 hour duration design storm is equal to exactly one-half of the total precipitation for the 2 year, 24 hour duration design storm, the equation can be rearranged as shown. o Annual sediment yield calculation, step-by-step procedure: a. Compute the R value by obtaining the P2 value from the 2-year/24-hour Isopluvial Map in Figure 3.5.1 C. b. Divide the site into areas of homogeneous SCS. soil type and of uniform slope and length. C. Note the K value from the SCS soils chart (Table 5.4.4A) for each soil type. d. Determine the LS value for each uniform area (See Table 5.4.413). e. Compute the annual sediment yield (A,,,) in tons per acre for each homogeneous/uniform area by multiplying R times the K and LS values for each area. f. Multiply the annual sediment yield (A,,) fof.each area by the acreage to be exposed (only that area to be cleared)`of each area. Sum the results to compute the total annual sediment load (in tons) to the trap (L,J. o The sediment storage volume MJ is then determined by dividing the total annual sediment load in tons (L,,) by an average density for the sediment deposited (� ). UseP�= 0.05 ton per cubic foot. VSed 9 1\ 5.4.4.I-2 1/90 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL o To complete the design of the temporary sediment trap: a. The "Pond Geometry Equations" section in the "Reference" portion at the back of the Manual may also be useful in designing the sediment trap- b. A 3:1 aspect ratio between the trap length and width o the trap is desirable. Length is defined as the average distance from the inlet to the outlet of the trap. This ratio is included in the computations for Figure 5.4.4C for the surface area at the interface between the settling zone and sediment storage volume. C. Determine the bottom and top surface area of-the sediment storage volume to be provided (see Figure SAAC) while not exceeding 1.5' in depth and 3:1 side slope from the bottom of the trap. Note the trap bottom should be level. d. Determine the total trap dimensions by adding an additional 2' of depth above the surface of the sediment storage volume, while not exceeding 3:1 side slopes, for the required settling volume. (see Figure 5.4.4C) TABLE 5.4.4A HYDROLOGIC SOIL GROUP OF THE SOILS IN KING COUNTY SOIL SOIL EROD- EROD- HYDROLOGIC IBIUTY HYDROLOGIC IBILITY _SOIL GROUP GROUP' FACTOR,'K' SOIL GROUP GROUP' FACTOR,-K' Alderwood C 0.1 Orcas Peat D 0.00 Arents, Alderwood C 0.15 Oridia D 0.49 Arents, Everett B 0.17 Oval( C 0.17 Beausite C 0.15 Pilchuck C 0.10 Bellingham D 0.32 Puget D 0.28 Briscot D 0.32 Puyallup B 0.28 Buckley D 0.32 Ragnar B 0.32 Coastal Beaches Variable 0.05 Renton D 0.43 Earfmont Silt Loam D 0.37 Riverwash Variable - Edgewick C 0.32 Salal C 0.37 Everett - -A 0.17 Sammamish D 0.37 Indianola A 0.15 Seattle D 0.00 Kitsap C 0.32 Shacar D 0.00 Klaus C 0.17 SI Silt C 0.37 Mixed Alluvial Land Variable 0.10 Snohomish D 0.32 Neilton A 0.10 Sultan C 0.37 Newberg B 0.32 Tukwila D 0.00 Nooksack C 0.37 Urban Variable - Norm. Sandy Loam D 0.24 Woodinville D 0.37 HYDROLOGIC SOIL GROUP CLASSIFICATIONS A. (Low runoff potential). Soils having high Infiltration rates• even when thoroughly wetted, and consisting chiefly of deep, well-to-excessively drained sands or gravels. These soils have a high rate of water transmission. B. (Moderately low runoff potential). ,Soils having mode�ptte Infiltration rates when thoroughly wetted, and consisting chiefly of moderately fine to moderately coarse textures. These soils have a moderate rate of water transmission. C. (Moderately high runoff potential). Soils having slow Infiltration rates when thoroughly wetted, and consisting chiefly of soils with a layer that Impedes downward movement of water, or soils with moderately fine to fine textures. These soils have a slow rate of water transmission. D. (High runoff potential). Soils having very slow Infiltration rates when thoroughly wetted and consisting chiefly of clay soils with a high swelling potential, soils with a permanent high water table, soils with a hardpan or clay layer at or near the surface, and shallow soils over nearly Impervious material. These soils have a very slow rate of water transmission. From SCS, TR-55, Second Edition, June 19m, Exhibit A-1. Revisions made from SCS. Soils Interpretation Record, Form #5, September 1988. 5.4.4.1 -y a � C7 � z I.S vnlues fur following slope lengths r,rl(m) IS values for following slope lengths 1,fl(m) Slope - ---- Ja Shq c gradient 10 20' 10 10 50 60 70 80 90 100 150 200 250 300 350 400 450 500 600 700 800 900 1000 4a (7 ratio (1.0) (G.1) (9.1) (12.2) (15.2) 0 8.3) (21.3) 42.1.4) (27.4) (10.5) (.tri) (61) (76) (91) (107) (122) (137) (152) (183) (213) (244) (274) (305) C7 r o 0.5 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.09 0.09 0.10 0.10 0.11 0.11 0.12 0.12 0.13 0.13 0.1.1 0.14 0.1.1 0.14 0.15 0.15 C I00:1 1 (1.08 f1,1t9 o.10 0.10 0.11 0.11 0.12 0.12 0.12 0.12 •0.1.1 0,1.1 0.15 0.1G 0.1fi Q:.I(ice 0.17 0.17 0.18 0.18 0.19 0.19 0.2o C z 2 0.10 0.12 0.11 0,15 0.1G 0.17 0.18 0.19 0.19 0.20 0.23 0.25 0.26 0.28 0.29 0.30 0.12 0.13 0.:34 0.36 0.37 0.39 0.40 :1 0.11 0.18 0.20 0.22 0.23 0.25 0.26 0.27 0.28 0.29 0.32 0.35 0.38 0.40 0.42 0.43 0.45 0.46 Oylj 0.51 0.54 0.55 0.57 C •1 0.16 0.21 0.25 0.28 0.10 0.1;1 0.15 0.37 0,18 0,•10 0.47 0.53 0,58 0.62 0.66 0.70 0.73 0.713 0.82 0.87 0.92 0.96 LOU --- 20:1 5 0.17 0.24 0.29 0.34 0.38 0.41 0.45 0.48 0.51 0.53 0.66 0.76 0.85 0.93 1.00 1.07 1.12 1.20 1.31 1.42 1.51 1.60 I.G9 G 0.21 0.30 0.37 0.43 0.48 0.52 0.56 0.60 0.64 0.67 0.82 0.95 1.06 I.I G 1.26 1.34 1.43 1.50 1.65 1.78 1.90 2.02 2.13 7 0.26 0.37 0.45 0.52 0.58 0.64 0.69` 0.74 0.78 0.82 1.01 1.17 1.30 1.43 1.54 1.65 1.75 1.8.1 2.02 2.18 2.33 2.47 2.G1 12'S:1 8 0.31 0.44 0.54 0.63 0.70 0.77 0.83 0.89 0.9.1 0.99 1.21 1.40 1.57 1.72 1.85 1.98 C2 fN2.22 2.42 2.132 2.80 2.97 3.13 7" - 9 (1_37 0.52 0.64 0.74 0.81 0.91 0.98 1.05 1.11 1.17 1.44 LGG 1.85 2.03 2.19 2.35 2.49 2.62 2.87 3.10 3.32 3.52 3.71 .-. 10:I 1.0 0.41 0.61 0.75 0.87 0.97 1.06 1.15 1.22 1.30 1.37 1.68 1.04 2.1 Ci 2.37 2.56 2.74 2.90 3.06 3.35 3.62 3.87 4.11 4.33 z 11 0.50 0.71 0.86 1.00 1.12 1.22 1.32 IAl 1.50 1.58 1.93 2.23 2.50 2.74 2.95 3.16 3.35 3.53 3.87 4.18 4.47 4.74 4.99 C) 8:1 12.5 0.61 0.86 1.05 1.22 1.36 1.49 1.61 1.72 1.82 1.92 2.1.5 2.72 3.04 3.33 3.59 3.84 4.08 4.30 4.71 5.08 5.43 5.76 6.08 15 0.81 1.14 1.40 1.62 1.81 1.98 2.14 2.29 2.43 2.56 3.13 3.62 4.05 4.43 4.79 5.12 5.43 5.72 6.27 6.77 7.24 7.68 8.09 C) 6:1 16.7 0.96 1.36 1.67 1.92 2.15 2.36 2.54 2.72 2.88 3.04 3.72 4.30 4.81 5.27 5.69 6.08 6.45 6.80 7.45 8.04 8.60 9.12 9.62 z 5:1 20 1.29 r1.�2 2.21 2.58 2.88 1.16 3.41 1.65 3.87 4.08 5.00 5.77 6.45 7.06 7.63 8.16 8.65 9.12 9.99 10.79 11.54 12.24 12.90 cn p 4f:1 22 1.51 '213 2.61 3.02 3.37 3.69 3.99 4,27 4.53 4.77 5.84 6.75 7.54 8.2G 8.92 9.54 10.12 10.67 11.68 12.62 13.49 14.31 15.08 C a 4:1 25 1.86 2.63 3.23 3.73 4.16 4.56 4.93 5.27 5.59 5.89 7.21 8.33 9.31 10.20 11.02 11.78 12.49 13.17 14.43 15.58 16.66 17.67 18.63 10 2.51 3.56 4.36 5.03 5.62 6.16 6.65 7.11 7.54 7.95 9.74 11.25 12.57 13.77 14.88 15.91 16.87 17.78 19.48 21.04 22.49 23.86 25.15 3:1 33.1 2.98 4:22 5.17 5.96 6.67 7.30 7.89 8.43 8.95 9.43 11,55 1:1.14 14.91 IG.13 17.64 18.86 20.00 21.09 21.10 24.95 26.67 28.29 20.82 15 1.23 4.57 5.60 6.46 7.23 7.92 8.55 9.14 9.70 10.22 12.52 HAG 1G.16 17.70 19.12 20.44 2I.G8 22.86 25.04 27.04 28.91 30.67 32.32 n M 1 40 4.00 5;riri 6.93 8.00 8.05 9.80 10.59 11.32 12.00 12.65 15.50 17.89 20.01 21.91 23.67 25.30 2G.84 28.29 30.09 33.48 35.79 37.913 40.01 45 4.81 6.80 8.33 9.61 10.75 11.77 12.72 13.60 14.42 15.20 18.62 21.50 24,03 26.33 28.44 30.40 32.24 33.99 37.23 40.22 42.99 45.60 48.07 2:1 50 5.64 7.97 9.76 11.27 12.60 13.81 14.91 15.9.1 16.91 17.82 21.83 25.21 28.18 30.87 33.34 35.65 37.81 39.85 43.GG 47.16 50.41 53.47 56.36 55 6.48 9.16 11.22 12.96 14.48 15.87 17.14 18.32 19.43 20.48 25.09 28.07 32.39 35.48 38.32 40.97 43.45 45.80 50.18 54.20 57.94 61.45 64.78 IY:1 57 6.82 9.64 11.80 11.63 15.24 16.69 18.03 19.28 20.45 21,65 26.40 10.48 14.08 .17.33 40.32 41.10 45.72 48.19 52.79 57.02 G09G G4.GG G8.I5 rn 7.12 10.15 12.G8 14.G4 16.37 17.91 19.37 20.71 21.96 23.15 28.35 32.74 16.60 .10.10 43.31 4G.30 49.11 51.77 5G.71 61.25 65.48 69.45 73.21 Cn I V,,:I GG.7 8.44 11.93 14.61 16.88 18.87 20.67 22.32 23.87 25.31 26.68, 32.68 37.74 42.19 46.22 49.92 53.37 56.60 59.6G 65.36 70.60 75.47 80.05 84,28 70 8,98 12.70 15.55 17.96 20.08 21.99 2:1.75 25.39 26.93 28.39 34.77 40.15 44.89 49.17 63.11 56.78 60.23 61.48 69.54 75.12 80.30 85.17 89.78 75 9,78 13.83 16.94 19.56 21.87 23.95 25.87 27.66 29.34 30.92 37.87 43.73 48.89 53.56 57.85 631.85 65.60 69.15 75.75 81.82 87.46 92.77 97.79 IX:1 80 10.55 14.91 18.28 21.11 23.60 25.85 27.93 29.85 31.66 33.38 40.88 47.20 52.77 57.81 62.44 66.75 70.80 74.63 81.76 88.31 94.41 100.13 105.55 85 11,10 15.98 19.58 22.61 25.27 27.69 29.90 31.97 33.91 35.74 43.78 50.55 56.51 61.91 66.87 71.48 75.82 79.92 87.55 94.57 101.09 107.23 113.03 9(t 12.02 17,00 20.82 24.04 26.88 29.4.1 31.80 34.00 36.06 38.01 4G.55 53.76 60.10 65.84 71.11 76.02 80.63 84.99 91.11 100.57 107.51 114.03 120.20 C 95 12.71 17.97 22.01 25.41 28.41 11.12 13.62 15.94 18.12 40.18 49.21 56.82 6.1.53 69.59 75.17 80.16 85.2.1 89.84 98.42 106.30 113.64 120.54 127.OG z 1:1 100 11.36 18.89 2.1.14 26.72 29.87 32.72 35.34 37.78 40.08 42.24 51.74 59.74 66.79 73.17 79.03 84.49 89.61 94.46 103.48 111.77 119.48 12G.73 133.59 y •Calculated from 1.5 65.41 X ■° + 4.5fi X S + 0.0651( 1 l IS - topographic factor tar + 10,000 7,17 10,000 /\72.5/- I - elope length,ft(m X 0.3048) z s - elope steepness, m - exponent dependent upon slope Steepness (0.2 for slope% < 1 0,0.3 fur Slopes I to 3,7, 0.4 fur slope%3.5 lu 4.5%,and 0.5 for Slapce> 5'%) KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL 10GURE SAAB SEDIMENT TRAP O tr��oiv coh '��fi ey �f�Ga va ft-o�1 4 Min. Z'71 946k 2' gelding OeloA i =ti.•rr,: �i "MaX- __ 1"5'Se✓iMent SfDruge - — —- 3/�u_ Vy �✓Uhti (�VAve� r nGl� CROSS SECTION NO SCALE Murk be �oh�ly ue� by c. cm va�r� or Py bvi Idrpt� a bolm Z _ Ovevf/ocu 6��%/u�Ay b' NltK- 9jidHt C ��� 1,5' I Oepfh of 2 -4" Rock I' O6pth of 514v-/!2" cr/�5l�ed ��uv2t SEDIMENT TRAP OUTLET NO SCALE 5.4.4.1-6 1/90 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL FIGURE S.4.4C SEDIMENT TRAP SIZE AND DIMENSIONS Column Descriptions Assurtiptions Vsed=Sediment storage volume between the interface and bottom areas L/W at interface(unilless)= 3 Vtotal=Volume of sediment trap between the top and bottom areas Side slopes along length,H/L(unitless)= 0_33 Ab,Al=area of the bottom(b)and lop(t)of the trap Side slopes along width,H/W(unitless)= 0.33 Ai=area of the interface ji)between the settling zone and sediment storage Depth from interface to bottom(fl)= 1.5 Lb.Li,Ll=Average length from inlet to outlet at the bottom,interface,and top elevations Depth from top to interface(ft)= 2 Wb,Wi,Wt=Width of the bottom,interface,and top areas Total Depth(11)= 3.5 0 0 Volumes(ft"3 Areas(ft"2) Width;and Lengths(ft) Volumes(ft"3 Areas(ft"2j Wic and terigths(ft) Vsed VtotaI Ab Af At Wb Lb Wl Ll``Wt Lt' Vsed Vf laf Ab AI At l�' V1/( U Wf Lt 162 1.176E 0 243 819E 0 18 9 27 21 39 S,832 16,926E 3,240 4.563 6,579E 30 108 39 117 51 129 221 1,397E 21 300 924: 1 21 10 30 22 42 6,161 17,777E 3.441 4,800 6,864E 31 111 40 120 52 132 288 1,638E /8 363 1,035E 2 24 11 33 23 45 6,498 18,648: 3,648 5.043 1,155E 32 114 41 123 53 135 365 1,901E 81 432 1.1 E 3 27 12 36 24 48 6,845 19,541E 3.861 5292 7,452E 33 117 42 126 54 138 4W 2,184E 120 507 1.275E 4 30 13 39 25 51 7.200 20,454E 4.080 5.547 7,755': 34 120 43 129 55 141 545 2.489E 165 588 1,404E 5 33 14 42 26 54 7.565 21,389E 4,305 5,W8 8,064E 35 123 44 132 56 1 648 2,814E 216 675 1,539E 6 36 15 45 27 57 7,938 22,344: 4.536 6.075 8,379E 36 126 45 135 57 147 761 3,161E 273 768 1,680E 7 39 16 48 28 60 8.321 23,321E 4.773 6.348 8,700E 37 129 46 138 58 a 882 3,528 336 867 1,827E 8 42 17 51 29 63 8.712 24,318E 5.016 6,627 9,027E 38 1'32 47 141 59 153 1,013 3.917E 405 972 1.980E 9 45 18 54 30 66 9.113 25.337E 5.265 6,912 9,360E 3S 135 48 144 60 156 1.152 4,326E 480 1,083 2.M: 10 48 19 57 31 69 9.522 26,376E 5.520 7= 9,699E 40 138 49 147 61 159 1.3011 4,757E 561 1.200 2304E 11 51 20 60 32 72 10.368 28,518E .6.048 7,803 10,395 42 144 51 153 63 165 1,458 5,208E 648 1,323 2,475E 12 54 21 63 33 75 11,250 30,144: 6.600 8,427 11,115E 44 150 53 159 65 171 1.625 5,681: 741 1.452 2,652E 13 57 22 66 34 78 12,168 33,054E 7,176 9,075 11,859E 46 156 55 165 67 177 1.800 6,174E 840 1.587 2,835E 14 60 23 69 35 81 13.122 35,448E 7,T76 9,747 12,627 48 162 57 171 69 183 1.985 6,689E 945 1.728 3,024E 15 63 24 72 36 84 14,112 37,926E 8.400 10,443 13,419E 50 168 59 177 71 189 2,171 7,224: 1 056 1,875 3,219 16 66 25 75 37 87 15.138 40,488; 9.048 11,163 14,235; 52 174 61 193 73 195 2,381 7,781: 1,173 2,028 3,420: 17 69 26 78 38 90 16.200 43,134E 9.720 11.907 15,0751 54 180 63 189 75 201 2.592 8,358E 1.296 2,187 3,627E 18 72 27 81 39 93 17,298 45,864E 10,416 12,675 15,939E 56 186 65 195 77 207 2.813 8,957E 1.425 2.352 3,840E 19 75 28 84 40 96 18,432 48,678E 11.136 13.467 16,827E 58 192 67 201 79 213 3.042 9,576E 1.560 Z523 4,059E 20 78 29 87 41 99 19,602 51,576E 11.880 14,283 11,739E 60 198 69 207 81 219 3.281 10,217E 1.701 2,700 4,2U::: 21 81 30 90 42 102 20,8W 54,558E 12,648 15,123 18,675E 62 204 71 213 83 225 3.528 10,878E 1,848 2,883 4,515E 22 84 31 93 43 105 22,050 57,624E 13,440 15,987 19,635E 64 210 73 219 85 231 3,785 11,561E 2.001 3,072 4,752E 23 87 32 96 44 108 23,328 60,774E 14,256 16.875 20,619E 66 216 75 225 87 237 1.050 12,264E 2.160 3.267 4,995E 24 90 33 99 45 111 24.642 64,008E 15.096 17.787 21,627E 68 222 17 231 89 243 4,325 12,989E 2.325 3,468 5,244E 25 93 U 102 46 114 25.992 67,326E 15.960 18,123 22,659: 70 228 79 237 91 249 4.608 13,734E 2,496 3.675 5,499E 26 96 35 105 47 117 27.378 70,728E 16,848 19.683 23,715E 72 2U 81 243 93 255 4,901 14,501E ZM 3,898 5,760E 27 99 36 108 48 120 28,8W 74,214E 17.760 20.667 24,795E 74 240 83 249 95 261 5.202 15,288E 2,856 4,107 6,027E 28 102 37 111 49 123 30.21-3 77,784E 18,696 21,675 25,899E 76 246 85 255 97 267 5.513 16,097E 3.045 4,332 6,300E 29 105 38 114 50 126 31,752 81,438E 19,656 22,707 27,027E 78 252 87 261 99 273 5.832 16,926E 3.240 4.563 6,579E 30 108 39 117 51 129 33,282 85.176E 20,640 23,763 28,179E 60 258 89 267 101 279 5.4.4.2 SEDIMENT POND Purpose To collect and store sediment from sites cleared and/or graded during construction prior to establishment of permanent vegetation and/or construction of permanent drainage facilities. It is usually a temporary measure with a design life less than 1 year; however, it may be a more permanent facility, especially if required to provide runoff quality control until the site area is permanently stabilized. Conditions Where Practice Applies Where the tributary drainage area is 10 acres or less. �.4.4.2-1 11/9, X. ADDITIONAL DOCUMENTS KInB CmmtY Department of Dndopmmt and Farironmental Scrrkes 1600 Moe Sou we, Moetb gton xast Belke,Ws�¢i 980E006-1400 ;✓C. `,�� �V �� G ��� . Project Name: SIERRA Project No.: Location: Date: �s Sierra Activity No. ` •v: 7�.i ,ut�5� ,:� ?;.� ..:fie. 6 � � ri EROMON/t M MEAT CONTROL Fence,Ot 4 1.30 LY Hydro-seeding .40 SY Jute Mesh 1.00 SY Mulch,by hand,strew,2'deep .35 SY Mulch,by meehine,strew,1'deep ,4G SY Rock Constr Entrance,50'x 15'x 1 1,030.00 Each Rock Constr Erttrenca,10o'x 15,x 1' 1,do0.00 Esoh Seeding,by heed .3b SY ESC SUBTOTAL .6 GENERAL fTEMa Ctear/Removs Mush,by hand .24 SY SUBTOTAL rOM PAGE =wo.�,.ne.rnu�,0 7ire�s� Pape 1 c4�' G Y "3 a L £� .$ , '.r " ''fro 3 t°' a �L,+..o,. e • •.a• • �11E.o-,`'S '�f.,,.;S'. ,.a,�. � c�.>!J: .�t' ,�� '° .3�'.K=. ,¢" 4 A� R •• a h a +v?�,. • `. ht �,}r�:�F>r� '1 S,`zXt•t:�`�«'�E c DZa�..,}a:�, „�zvZ9�,'4,. �;��, h ��"�:( x :e ,� c a ,�` r '• 'k.>.1.. <„% »''tic .�� #s` _ '�. . ?� � .# a ., ^. 8 s ��s s f i 3,�.�. ` �c J� '; �: • ,f �.�.�o s. s s lk Sierra J t n al — s Pf2RIVAtVA ROAD F 2... � dwtHl £sFR£2z'f > TiPRt7VEMENTR ..x. AC Gdndi ,4'mecMne 7.00 SY AC Romovai/Di al/Repair 80.00 SY Barrtoede In 30.00 LF Baricade type i 20.00 LF Curb extruded haft 1.80 LF Curb extruded concrete 1.80 LF Curb A Gutter,rolled 9.30 LF Curb A Gutter,vertical 8.80 LF Demon eel curb&cutter 10 30 LF D--nt10nAX M ekiewetk 22.50 SY Se 3'depth 1.30 LF Se concrete fLer 1'depth 1.10 LF Seelent 70 LF r!-Mer AC see AC ROed SY Shovkiervrel 6.40 SY SldevvWk:4'thick,vertical curb 20.80 SY S3dewelk 5'thlA,rolled curb 23.80 SY Strfpinq,4'renectodzed Rne .20 LF Strip4rg,per pertinhall 2.90 Each ! Thickened Edoe4.70 LF i ROAD StMAC"O 14'rock-2.5 bee.A 1.5't ceuroe) AC Oven 1.5'AC 5.40 SY AC Overt ,2'AC 8.50 BY SUBTOTAL roa PAGE Page 3 f ^•a 9,j'a�,°,�"O„ �!�E'',#3Ly'6 : �le �A�� fi=fa `s`r"3La:7h ��a�.•,y� c of '•�7�as z • a. • N: b • r ar .e 1 6�l�„. �. � � 7s a1'�-;•. EYants.dA��:��D tl.��' •r ��'z. a�.t.. d1«T .a � S.s s� c;.'. $��•_ '�. .: ,�, `g�y � L sa � �a�k R^ 3 o°°. K' �d>. 3x�`'' ss. <.'o' .a a�".�L�'.✓�iza� t..�`ts '�� z ��8e s�k` ��: � �' �a- �a¢'4i�$'.3•� >.r, �,�,��+ ��at��. .£s mom • �X ��:� -�1iv,',�,� .,�, • © ==�_�' . r �_-■ _®■ 1 •• � t a• Sierra Project No, x�t � x' '•' 'F ��: ;�• .• •�� urn ���"kis �'�kf.<t��T�' �M RUC � �p��� ....�..,� . :�`#iC�'�:�s�:t�A r� t�: .. �. ,'?',,1 : :. .. .sJ �`a. �5'. � �t��� ,IIgHC� ,�/i0A1!'y' ,t�K�1 'E� 4 �`�;� '�'' �'"'• '��6�sFang <•ct•s �P +�.6w _ '�> yt�.A�� 'y`�y,N �?� l.. .:YQZ• � �„ � ��>�t ,i � :t. :�a:{Lf•IY.: ,::?$� DRAINAQE(Con't.) <•, �rtt�t C8 Typ4 0 s4•diameter 1 A5n eVA 4'de for eddttfonei d th over 4' 4270.00 +1'd th CB Type 8 80•diameter 00 00 for additional d th over 4' 1,6 ' CB n 0.00 4 4'dd th 72'diameter 2 200.00 4'd th for eddhlonal d th over 4' +520.00 +1'd th h curb h9et Framework IAddY 225.00 Each C1ea PVC 4• 86.00 Each CIO m"t,PVC 6• 115.00 Each Cleanotrt PVC 8• 142.00 Each i Culvert PVC 4• 4.50 LF Culvert,CPP 6• 9.30 LF Cufvert,PVC 6• 8.40 LF Culvert CMP 8• 9.60 LF Cufvart,concrete 8• 12.90 LF Curt cPP 8• 10.00 LF CUlvert,PVC 8• 8.00 I LF CuHart.CMP 12• 14.80 LF Culvert,Concrete 12' 17.90 LF CPP 12• _ 18.66 LF SUN-art,CMP 1s• 18.70 LF 04"rt,Concrete is• 22.60 LF CPP is' 19.60 LF Culvert,CMP, is, 21.90 LF SUBTOTAL FOR PAGE �we.w.Iw,rRU u,. 7nem, Page 5 ;��a�xic',�r a��..�.Tx+. �$�e ti£3t Jt�`�x�4: --- --- �..r—_--o..— ----- - — — - - -—3�� � - .___�. a: . � .Y>.__ z :• a •.a. s c.. __ - -j ..,a y K6i� P �: •�` &�" 3'v psi` ..a,;� K.: � � C 3t. mG o ,*S;$x. ��'`:;ew� '�'�i����. �•'.. �'�cty � �z;� �i ... � ��. �c 33i�.� 4 Ya� �.,z�_ ,•af � a z ��f3•�'��` ��� � � '�i� �s° �` IeR! J t N o. Y`p.3-SYl r�f•.S ,(.�,r .. r.91 tE. �k ,..:)•.".' y .:::. .: �. ^..tiN,_.�1�,. xp Flt �` R.ki i. 'i.Q L•2Y.w zri0 p�17 R/lAT1E8^AIY. x 4)MqQ'���i� sLk <.. .CEO»f ip: �� .?+S•`F<f • S- i r Mi' Aa DRAINAGE(Con't.) RI r aced 29.00 CY Teak End Reducer 400.00 Eech Trash Reck 12' 160.00 Eech Trash Peck, 15" 195.00 Eech Trash Pack, 19' 210.00 Each Trash Reck 21' 240.00 Ench PARKINS 1LOT SURFACtN0 2'A.C. 2'tm course rock At 4'select borrow 8.10 SY 1.5'top course rook 8 25'hang Calf*, 4.70 SY 4-select borrow 1.75 SY WRITE-1N REM9 SUBTOTAL(SUM ALL PAGES): 30%CONTINGENCY 6 MOBILIZATION: TOTAL: — _ (A) (B) (C) Quantities above were completed by: Slerre Pro)ect No. - Signature: Date: PE Registration Number: Telephone Number: Firm Name: Address: This section to be completed by King County BOND COMPUTATIONS: PERFORMANCE BOND AMOUNTS M_AINTENANCE BONG AMOUNT Stabilization/Erosion Sediment Control (ESC) (D) CEFECT BOND AMOUNT-- Existing Right-of-Way Improvements (E) Future Public Road Improvements (F) Private Improvements (E+F)x 0.25 = R/D Facilities and Conveyance Systems TOTAL M — `— — — — — — — — — — — x 0.15 = PERFORMANCE BOND AMOUNT RIGHT-OF-WAY&SITE RESTORATION BONO (D+E) (First $7,500 of bond shall be cash.) +f 1 X2 PERFORMANCE BOND TOTAL AFTER BOND REDUCTIONS 13 (T-A,B OR C) NOTE The word *bond* is used to represent Original bond computations any financial guarantee acceptable to prepared by: Date: Signature of Person Preparing Bond Reduction King County. t1 12 Date I3 Date NOTE: Total bond amounts Date romelnlrtp after reduction shag not be less then 30%of the original amount or the sum of the maintenance and defect amounts shown above,whichever is greater. Page 8 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL RETENTION/DETENTION SUMMARY SHEET Development Date Location ENGINEER DEVELOPER Name Name Firm Firm Address Address Phone Phone • Developed Site acres Number of Lots • Number of Detention Facilities On Site • Detention provided in regional facility F-1 Regional Facility location • No detention required El Acceptable receiving waters • Downstream Drainage Basins Immediate Major Basin Basin A Basin B Basin C Basin D TOTAL INDIVIDUAL BASIN A B C D Drainage Basin(s) Onsite Area Off site Area Type of Storage Facility Live Storage Volume Predeveloped Runoff Rate 2 year 10 year Postdeveloped Runoff Rate 100 year 2 year 10 year Developed O 100 year Type of Restriction Size of Orifice/Restriction Orifice/Restriction No.1 i No.2 No.3 No.4 No.5 XI. MAINTENANCE AND OPERATION MANUAL KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL MAINTENANCE REQUIREMENTS FOR PRIVATELY MAINTAINED DRAINAGE FACILITIES NO. 1 - PONDS Maintenance Conditions When Maintenance Results Expected Component Defect Is Needed When Maintenance is Performed General Trash&Debris Any trash and debris which exceed 1 Trash and debris cleared from site. cubic foot per 1000 square feet (this is about equal to the amount of trash it would take to fill up one standard size office garbage can). In general, there should be no visual evidence of dumping. Poisonous Any poisonous vegetation which may No danger of poisonous vegetation where Vegetation constitute a hazard to County personnel County personnel or the public might or the public. Examples of poisonous normally be. (Coordination with vegetation include: tansy ragwort,poison Seattle/King County Health Department) oak,stinging nettles,devils club. Pollution Cal,gasoline,or other contaminants of No contaminants present other than a one gallon or more or any amount found surface film. (Coordination with that could: 1)cause damage to plant, Seattle/Kng County Health Department) animal,or marine life; 2)constitute a fire hazard;or 3)be flushed downstream during rain storms. Unmowed Grass/ If facility is located in private residential When mowing is needed,grass/ground Ground Cover area,mowing Is needed when grass cover should be mowed to 2 inches in exceeds 18 inches in height. In other height. areas,the general policy is to make the pond site match adjacent ground cover and terrain as long as there is no interference with the function of the facility. Rodent Holes Any evidence of rodent holes if facility is Rodents destroyed and dam or berm acting as a dam or berm,or any evidence repaired. (Coordination with Seattle/ of water piping through dam or berm via King County Health Department) rodent holes. Insects When insects such as wasps and hornets Insects destroyed or removed from site. interfere with maintenance activities. Tree Growth Tree growth does not allow maintenance Trees do not hinder maintenance access or interferes with maintenance activities. Selectively cultivate trees such activity (i.e.,slope mowing, silt removal, as alders for firewood. vactoring or equipment movements). If trees are not interfering with access, leave trees alone. Side Slopes of Erosion Eroded damage over 2 inches deep Slopes should be stabilized by using Pond where cause of damage is still present or appropriate erosion control measure(s): where there is potential for continued e.g., rock reinforcement, planting of erosion. grass, compaction. Storage Area Sediment Accumulated sediment that exceeds 10% Sediment cleaned out to designed pond of the designed pond depth. shape and depth; pond reseeded if necessary to control erosion. Pond Dikes Settlements Any part of dike which has settled 4 Dike should be built back to the design inches lower than the design elevation. elevation. Emergency Rock Missing Only one layer of rock exists above native Replace rocks to design standards. Overflow/Spillway soil in area five square feet or larger, or any exposure of native soil. A-I I/90 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL NO. 2 - INFILTRATION Maintenance Conditions When Maintenance Results Expected Component Defect Is Needed When Maintenance is Performed General Trash &Debris See'Ponds"Standard No. 1 See`Ponds Standard No. 1 Poisonous See 'Ponds' Standard No. 1 See "Ponds Standard No. 1 Vegetation Pollution See"Ponds"Standard No. 1 See"Ponds Standard No. 1 Unmowed Grass/ See "Ponds"Standard No. 1 See "Ponds Standard No. 1 Ground Cover Rodent Holes See "Ponds" Standard No. 1 See"Ponds Standard No. 1 Insects See"Ponds"Standard No. 1 See "Ponds Standard No. 1 Storage Area Sediment A percolation test pit or test of facility Sediment is removed and/or facility is indicates facility is only working at 90%of cleaned so that infiltration system works its designed capabilities. according to design. Sheet Cover Sheet cover is visible and has more than Shpat cover repaired or replaced. (If Applicable) three 1/44nch holes in it. Sump Flied With Any sediment and debris filling vault to Gean out sump to design depth. Sediment and 10%of depth from sump bottom to Debris (If bottom of outlet pipe or obstructing flow Applicable) into the connector pipe. Titer Bags Filled with Sediment and debris fill bag more than Replace filter bag or redesign system. Sediment and 1/2 full. Debris 40.4ock Filters Sediment and By visual inspection little or no water Replace gravel in rock filter. Debris flows through filter during heavy rain storms. A-2 I/90 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL NO. 3 - CLOSED DETENTION SYSTEMS (PIPES/TANKS) Maintenance Conditions When Maintenance Results Expected Component Defect is Needed When Maintenance Is Performed Storage Area Plugged Air Vents One-half of the cross section of a vent is Vents free of debris and sediment. blocked at any point with debris and sediment. Debris and Accumulated sediment depth exceeds All sediment and debris removed from Sediment 10%of the diameter of the storage area storage area. for 1/2 length of storage 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 1/2 length of tank. Joints Between Any crack allowing material to be All joints between tank/pipe sections are Tank/Pipe Section transported into facility. sealed. Tank/Pipe Bent Any part of tank/pipe is bent out of shape Tank/pipe repaired or replaced to design. Out of Shape more than 10%of its design shape. Manhole Cover not in Place Cover is missing or only partially in place. Manhole is closed. Any open manhole requires maintenance. Locking Mechanism cannot be opened by one Mechanism opens with proper tools. Mechanism Not maintenance person with proper tools. Working Bolts into frame have less than 1/2 inch of thread(may not apply to self-locking lids). I Cover Difficult to One maintenance person cannot remove Cover can be removed and reinstalled by Remove lid after applying 80 pounds of lift. Intent one maintenance person. is to keep cover from sealing off access to maintenance. Ladder Rungs King County Safety Office and/or Ladder meets design standards and Unsafe maintenance person judges that ladder is allows maintenance persons safe access. unsafe due to missing rungs, misalignment, rust,or cracks. Catch Basins See "Catch Basins" Standard No. 5 See "Catch Basins"Standard No. 5 A_3 1/90 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL 40. 4 - CONTROL STRUCTURE/FLOW RESTRICTOR Maintenance Conditions When Maintenance Results Expected Component Defect Is Needed When Maintenance Is Performed General Trash and Debris Distance between debris build-up and All trash and debris removed. (Includes bottom of orifice plate is less than 1-1/2 Sediment) feet. Structural Damage Structure is not securely attached to Structure securely attached to wall and manhole wall and outlet pipe structure outlet pipe. should support at least 1,000 pounds of up or down pressure. Structure is not in upright position (allow Structure in correct position. up to 10%from plumb). Connections to outlet pipe are not Connections to outlet pipe are watertight; watertight and show signs of rust. structure repaired or replaced and works as designed. Any holes—other than designed holes— Structure has no holes other than in the structure. designed holes. Cleanout Gate Damaged or Cleanout gate is not watertight or is Gate is watertight and works as designed. Missing missing. Gate cannot be moved up and down by Gate moves up and down easily and is one maintenance person. watertight. Chain leading to gate is missing or Chain is in place and works as designed. damaged. Gate is rusted over 50%of its surface Gate is repaired or replaced to meet area. design standards. Orifice Plate Damaged or Control device is not working properly Plate is in place and works as designed. Missing due to missing,out of place,or bent orifice plate. Obstructions Any trash,debris,sediment,or vegetation Plate is free of all obstructions and works blocking the plate. as designed. Overflow Pipe Obstructions Any trash or debris blocking (or having Pipe is free of all obstructions and works the potential of blocking) the overflow as designed. pipe. Manhole See "Closed Detention Systems" Standard See 'Closed Detention Systems" Standard No. 3. No,3. Catch Basin See "Catch Basins" Standard No. 5. See 'Catch Basins"Standard No. 5. A_4 1/90 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL NO. 5 - CATCH BASINS Maintenance Conditions When Maintenance Results Expected Component Defect Is Needed When Maintenance Is Performed General Trash & Debris Trash or debris of more than 1/2 cubic No trash or debris located immediately in (Includes foot which is located immediately in front front of catch basin opening. Sediment) of the catch basin opening or is blocking capacity of basin by more than 10%. Trash or debris (in the.basin)that No trash or debris in the catch basin. exceeds 1/3 the depth from 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 Inlet and outlet pipes free of trash or blocking more than 1/3 of its height. debris. Dead animals or vegetation that could No dead animals or vegetation present generate odors that would cause within the catch basin. complaints or dangerous gases (e.g., methane). Deposits of garbage exceeding 1 cubic No condition present which would attract foot in volume, or support the breeding of insects or rodents. Structural Damage Corner of frame extends more than 3/4 Frame is even with curb. to Frame and/or inch past curb face into the street (f Top Slab applicable). Top slab has holes larger than 2 square Top slab is free of holes and cracks. inches or cracks wider than 1/4 inch (intent is to make sure all material is running into the basin). Frame not sitting flush on top slab, i.e., Frame is sitting flush on top slab. separation of more than 3/4 inch of the frame from the top slab. Cracks in Basin Cracks wider than 1/2 inch and longer Basin replaced or repaired to design Walls/Bottom than 3 feet,any evidence of soil particles standards. entering catch basin through cracks, or maintenance person judges that structure is unsound. Cracks wider than 1/2 inch and longer No cracks more than 1/4 inch wide at the than 1 foot at the joint of any inlet/outlet joint of inlet/outlet pipe. pipe or any evidence of soil particles entering catch basin through cracks. Settlement/ Basin has settled more than 1 inch or has Basin replaced or repaired to design Misalignment rotated more than 2 inches out of standards. alignment. Fire Hazard Presence of chemicals such as natural No flammable chemicals present. gas,oil, and gasoline. Vegetation Vegetation growing across and blocking No vegetation blocking opening to basin. more than 10%of the basin opening. Vegetation growing in inlet/outlet pipe No vegetation or root growth present. joints that is more than six inches tall and less than six inches apart. Pollution Nonflammable chemicals of more than No pollution present other than surface 1/2 cubic foot per three feet of basin film. length. A-5 1/90 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL NO. 5 - CATCH BASINS (Continued) Maintenance Conditions When Maintenance Results Expected Component Defect Is Needed When Maintenance is Performed Catch Basin Cover Cover Not in Place Cover is missing or only partially in place. Catch basin cover is closed. Any open catch basin requires maintenance. Locking Mechanism cannot be opened by one Mechanism opens with proper tools. Mechanism Not maintenance person with proper tools. Working Bolts into frame have less than.1/2 inch of thread. Cover Difficult o One maintenance person cannot remove Cover can be removed by one Remove lid after applying 80 lbs.of lift; intent is maintenance person. keep cover from sealing off access to maintenance. Ladder Ladder Rungs Ladder Is unsafe due to missing rungs, Ladder meets design standards and Unsafe misalignment, rust,cracks,or sharp allows maintenance person safe access. edges. Metal Grates Grate with opening wider than 7/8 inch. Gate openings meet design standards. (if applicable) Trash and Debris Trash and debris that is blocking more Grate free of trash and debris. than 20%of grate surface. Damaged or Grate missing or broken member(s)of Grate is in place and meets design Missing the grate. standards. A-6 1/90 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL NO. 6 - DEBRIS BARRIERS (e.g. Trash Racks) Maintenance CondMons When Maintenance Results Expected Component Defect Is Needed When Maintenance Is Performed General Trash and Debris Trash or debris that is plugging more Barrier clear to receive capacity flow. than 20%of the openings in the barrier. Metal Damaged/ Missing Bars are bent out of shape more than 3 Bars In place with no bends more than Bars inches. 3/4 inch. Bars are missing or entire barrier Is Bars in place according to design. missing. Bars are loose and rust is causing 50% Repair or replace barrier to design deterioration to any part of barrier. standards. A-7 1/90 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL NO. 7 - ENERGY DISSIPATORS Maintenance Conditions When Maintenance Results Expected Component Defect Is Needed When Maintenance is Performed External: Rock Pad Missing or Moved Only one layer of rock exists above native Replace rocks to design standard. Rock soil in area five square feet or larger,or any exposure of native soil. Dispersion Trench Pipe Plugged with Accumulated sediment that exceeds 20% Pipe cleaned/flushed so that it matches Sediment of the design depth. design. Not Discharging Visual evidence of water discharging at Trench must be redesigned or rebuilt to Water Properly concentrated points along trench (normal standard. condition is a"sheet flow"of water along trench). Intent is to prevent erosion damage. Perforations Over 1/2 of perforations in pipe are Clean or replace perforated pipe. Plugged plugged with debris and sediment. Water Fjws Out Maintenance person observes water Facility must be rebuilt or redesigned to Top of`Distributor" flowing out during any storm less than standards. Catch Basin the design storm or it is causing or appears likely to cause damage. Receiving Area Water in receiving area is causing or has No danger of landslides. Over-Saturated potential of causing landslide problems. Internal: Manhole/Chamber Worn or Damaged Structure dissipating flow deteriorates to Replace structure to design standards. Posts, Baffles, 1/2 or original size or any concentrated Sides of Chamber worn spot exceeding one square foot which would make structure unsound. Other Defects See"Catch Basins"Standard No. 5 See "Catch Basins"Standard No.5 A-8 1/90 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL NO. 8 - FENCING Maintenance Conditions When Maintenance Results Expected Component Defect Is Needed When Maintenance is Performed General Missing or Broken Any defect in the fence that permits easy Parts in place to provide adequate Parts entry to a facility. security. Parts broken or missing. Broken or missing parts replaced. Erosion Erosion more than 4 inches high and 12- No opening under the fence that exceeds 18 inches wide permitting an opening 4 inches in height. under a fence. Wire Fences Damagec, Parts Posts out of plumb more than 6 inches. Posts plumb to within 1-1/2 inches. Top rails bent more than 6 inches. Top rail free of bends greater than 1 inch. Any part of fence (including posts,top Fence is aligned and meets design rails,and fabric)more than 1 foot out of standards. design alignment. Missing or loose tension wire. Tension wire in place and holding fabric. Missing or loose barbed wire that is Barbed wire in place with less than 3/4- sagging more than 2-1/2 inches between inch sag between posts. posts. Extension arm missing, broken,or bent Extension arm in place with no bends out of shape more than 1-1/2 inches. larger than 3/4 inch. Deteriorated Paint Part or parts that have a rusting or scaling Structurally adequate posts or parts with or Protective condition that has affected structural a uniform protective coating. Coating adequacy. Openings in Fabric Openings in fabric are such that an 8- No openings in fabric. inch-diameter ball could fit through. A-9 1/�0 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL `10. 9 - GATES Mal ntenance Conditions When Maintenance Results Expected Component Defect Is Needed When Maintenance Is Performed General Damaged or Missing gate or locking devices. Gates and locking devices in place. Missing Members Broken or missing hinges such that gate Hinges intact and lubed. Gate is working cannot be easily opened and closed by a freely. maintenance person. Gate Is out of plumb more than 6 inches Gate is aligned and vertical. and more than 1 foot out of design alignment. Missing stretcher bar,stretcher bands, Stretcher bar, bands,and ties in place. and ties. Openings in Fabric See "Fencing"Standard No.8 See "Fencing" Standard No. 8 A-10 1190 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL NO. 10 - CONVEYANCE SYSTEMS (Pipes & Ditches) Maintenance Conditions When Maintenance Results Expected Component Defect Is Needed When Maintenance Is Performed Pipes Sediment&Debris Accumulated sediment that exceeds 20% Pipe cleaned of all sediment and debris. of the diameter of the pipe. Vegetation Vegetation that reduces free movement of All vegetation removed so water flows water through pipes. freely through pipes. Damaged Protective coating is damaged; rust is Pipe repaired or replaced. causing more than 50%deterioration to any part of pipe. Any dent that decreases the cross section Pipe repaired or replaced. area of pipe by more than 20%. Open Ditches Trash&Debris Trash and debris exceeds 1 cubic foot Trash and debris cleared from ditches. per 1,000 square feet of ditch and slopes. Sediment Accumulated sediment that exceeds 20% Ditch cleaned/flushed of all sediment and of the design depth. debris so that it matches design. Vegetation Vegetation that reduces free movement of Water flows freely through ditches. water through ditches. Erosion Damage to See"Ponds"Standard No. 1 See "Ponds" Standard No. 1 Slopes Rock Lining Out of Maintenance person can see native soil Replace rocks to design standard. Place or Missing (tf beneath the rock lining. Applicable) Catch Basins See"Catch Basins"Standard No. 5 See `Catch Basins"Standard No.5 Debris Barriers See"Debris Barriers" Standard No.6 See "Debris Barriers"Standard No.6 (e.g.,Trash Rack) A-11 1/90 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL 'JO. 11 - GROUNDS (Landscaping) Maintenance Conditions When Maintenance Results Expected Component Defect Is Needed When Maintenance Is Performed General Weeds Weeds growing in more than 20%of the Weeds present in less than 5%of the (Nonpoisonous) landscaped area (trees and shrubs only). landscaped area. Safety Hazard Any presence of poison ivy or other No poisonous vegetation present in a poisonous vegetation. landscaped area. Trash or Litter Paper,can, bottles,totalling more than 1 Area clear of litter. cubic foot within a landscaped area (trees and shrubs only) of 1,000 square feet. Trees and Shrubs Damage Limbs or parts of trees or shrubs that are Trees and shrubs with less than 5%of the split or broken which affect more than total foliage with split or broken limbs. 25%of the total foliage of the tree or shrub. Trees or shrubs that have been blown Tree or shrub in place free of injury. down or knocked over. Trees or shrubs which are not adequately Tree or shrub in place and adequately supported or are leaning over, causing supported; remove any dead or diseased exposure of the roots. trees. A-12 1�90 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL NO. 12 - ACCESS ROADS/EASEMENTS Maintenance Conditions When Maintenance Results Expected Component Defect Is Needed When Maintenance Is Performed General Trash and Debris Trash and debris exceeds 1 cubic foot Trash and debris cleared from site. per 1,000 square feet,i.e.,trash and debris would fill up one standard size garbage can. Blocked Roadway Debris which could damage vehicle tires Roadway free of debris which could (glass or metal). damage tires. Any obstructions which reduce clearance Roadway overhead clear to 14 feet high. above road surface to less than 14 feet. Any obstructions restricting the access to Obstruction removed to allow at least a a 1G-to 12-toot width for a distance of 12-foot access. more than 12 feet or any point restricting access to less than a 10-foot width. Road Surface Settlement, When any surface defect exceeds 6 Road surface uniformly smooth with no Potholes, Mush inches in depth and 6 square feet in area. evidence of settlement,potholes,mush Spots, Ruts In general,any surface defect which spots,or nuts. hinders or prevents maintenance access. Vegetation in Road Weeds growing in the road surface that Road surface free of weeds taller than 2 Surface are more than 6 inches tall and less than inches. 6 inches apart within a 400-square-foot area. Shoulders and Erosion Damage Erosion within 1 foot of the roadway more Shoulder free of erosion and matching Ditches than 8 inches wide and 6 inches deep. the surrounding road. Weeds and Brush Weeds and brush exceed 18 inches in Weeds and brush cut to 2 inches in height or hinder maintenance access. height or cleared in such a way as to allow maintenance access. A-13 1/90 t Short Plat Sf-rPL N REQUEST FOR PROJECT 11 Prclim. Plat (PPI/ CAGH To: Technical Services Datc [a q5 WOI/ Grcen/t A—I From: Plan Rcvicw/Projcci Manager Project Name ji`J c S T V 1 C t 1 pe— f} j (70 character:max) Description of Project: [ Z 4 T � ry E12� y A v v ST Circle Size of Waterline: ( 81 101, 12" Circle One: New or Extension Circle Size of Sewerline: G 101, 12" Circle One: or Extension Circle Size of Stormline: 12" 15" 18" 24" Circle One: New or Extension Address or Street Name(s) M D N Ley A 1 I ,y(_ Aj E I z .� D vl p r/Contractor/Owner/Cns I t (70 charac+a:max) Check each discipline involved in Project Ltr Drwg H of sheets per discipline Cg----Trans-Storm f � (� L ti 0 9 (Roadway/Drainage) (Off site intprovcmcnts)(includc basin name '+r ) (include TESC sheets) L`) Transportation (Sig-1—i«L qunt,clzit;«�Li�,tin� — 94--Wastewater � � ( G � (✓� �� S — i (S—itiry Sever Main)(include basin name) 14 Water (Mum,valves,({ydrants) �f (lncludc cixnpositc 6c Honzontil Qrl shccts)��,",���� f�� TS Use Only Approved by TSM _ _ Date: orrnslmiscI92-090.DOC/CD/bh