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HomeMy WebLinkAboutGRD2007-00010 Stormwater Plan multi-parcels Drainage Report Nov-19-2000 - GRD Engineering / Geo-Tech Reports - 1/5/2009 MASON COUNTY PUBLIC WORKS DIRECTOR/COUNTY ROAD ENGINEER 1 Shelton, Washington 98584 AWN Cd�� DATE: January 5, 2009 INTER-DEPARTMENTAL COMMUNICATIONS TO: Rebecca Hersha PARCEL # 12220-33-00210 FROM: Fred Perryman/Engineer Tech III-PW PERMIT NUMBER: GRID 2007-00010 SUBJECT: Stormwater Review NAME: Sherwood Creek Rebecca, The stormwater checklist for Sherwood Creek located off of SR3 has been received and reviewed by Public Works. The package included the checklist explaining where in the report or plans each item on the checklist has been addressed. The checklist is stamped and signed by a licensed engineer. This review has determined that all the minimum requirements, as outlined in the stormwater checklist, have been addressed. However this review is not intended to be a technical review. Mason County Public Works recommends acceptance of the stormwater plan based on the provided checklist. All engineers recommendations, of the stormwater plan and drainage report, should be made conditions of permit issuance. Please feel free to contact me at 625 if you have any questions regarding these comments. Sincerely. Fred Perryman Michael F. Wnek, P.E. Consulting Civil Engineer 3388 NW Byron St, Suite 200, Silverdale, WA 98383 360-692-3802 (fax)-692-1051 LETTER OF TRANSMITTAL To: REBECCA HERSHA DATE: 11/17/2008 Mason County Planning Department P.O. BOX 279 PROD. NO. 340 Shelton, WA 98584 RE: Sherwood Creek — Jack Johnson Stormwater Checklist The following attached items, are submitted for your review. COPIES DATE NO. DESCRIPTION 3 11-14-08 - Mason County Stormwater Checklist- Page 1 COMMENTS: The front page of the stormwater checklist mailed out was not edited to include the correct project name. Please replace the front page with the included sheet. If you have any questions, or need additional information, please contact me at 360-692-3802. BY: MICHEAL F.WNEK,P.E. THESE PLANS MUST BE ON THE JOB SITE FOR INSPECTION cc: Jack Johnson (by e-mail) G:\CivilEng\340\Storm\Checklist\TRANSMIT_1 I-17-08_MQ_#2.doc SHERWOOD CREEK Mason County Stormwater Checklist Minimum Requirements of 1992 Stormwater Manual The stormwater checklist identifies the minimum requirements of the 1992 Stormwater Manual. The checklist is intended to identify the locations within the plan that addresses the minimum requirements. Mason County will not perform a technical evaluation of the submittal. Rather,the checklist provides a guide to allow Mason County to review the submittal and determine if the applicant has addressed the minimum features that make up a stormwater plan. It is incumbent upon the applicant and his/her engineer to fulfill all the applicable requirements of the 1992 Stormwater Plan as it relates to the proposed project. Review by Mason County is intended to determine if the plan has addressed the minimum requirements and should not be considered a review for technical accuracy of the plan. During construction of the project,the stormwater plan engineer of record or his/her authorized representative shall inspect the site to ensure the stormwater plan is being implemented as designed. Upon completion of the project,the engineer or his authorized representative shall be required to certify that the stormwater plan has been implemented as designed. Failure to meet the minimum requirements could result in delay or rejection of the application until the deficiencies are corrected. N#1: Erosion and Sediment Control. All new development and redevelopment that includes land disturbing activities of one acre or greater shall comply with erosion and sediment control requirements 1 through 14, below. Compliance with the Erosion and Sediment Control Requirements shall be demonstrated through implementation of a large parcel erosion and sediment control plan. All new development and redevelopment that includes land disturbing activities of less than one acre shall oomply with the small parcel minimum requirements found in Section 14.48.130, Compliance with the small parcel requirements shall be demonstrated through implementation of a small parcel erosion and sediment control plan. Erosion and Sediment Control Requirement#1:Stabilization and Sediment Trapping. Seepage/paragraph ESC#1, PLAN SHEET C-2 Erosion and Sediment Control Requirement#2: Delineate Clearing and Easement Limits. Seepage/paragraph ESC#2, PLAN SHEET C-2 Erosion and Sediment Control Requirement#3: Protection of Adjacent Properties. Seepage/paragraph ESC#3, PLAN SHEET C-2 Erosion and Sediment Control Requirement#4: Timing and Stabilization of Sediment Trapping Measures. Seepage/paragraph ESC#4, PLAN SHEET C-2 1 SHERWOOD CREEK Mason County Stormwater Checklist Minimum Requirements of 1992 Stormwater Manual The stormwater checklist identifies the minimum requirements of the 1992 Stormwater Manual. The checklist is intended to identify the locations within the plan that addresses the minimum requirements. Mason County will not perform a technical evaluation of the submittal. Rather,the checklist provides a guide to allow Mason County to review the submittal and determine if the applicant has addressed the minimum features that make up a stormwater plan. It is incumbent upon the applicant and his/her engineer to fulfill all the applicable requirements of the 1992 Stormwater Plan as it relates to the proposed project. Review by Mason County is intended to determine if the plan has addressed the minimum requirements and should not be considered a review for technical accuracy of the plan. During construction of the project, the stormwater plan engineer of record or his/her authorized representative shall inspect the site to ensure the stormwater plan is being implemented as designed. Upon completion of the project,the engineer or his authorized representative shall be required to certify that the stormwater plan has been implemented as designed. Failure to meet the minimum requirements could result in delay or rejection of the application until the deficiencies are corrected. ❑X #1: Erosion and Sediment Control. All new development and redevelopment that includes land disturbing activities of one acre or greater shall comply with erosion and sediment control requirements 1 through 14, below. Compliance with the Erosion and Sediment Control Requirements shall be demonstrated through implementation of a large parcel erosion and sediment control plan. All new development and redevelopment that includes land disturbing activities of less than one acre shall comply with the small parcel minimum requirements found in Section 14.48.130, Compliance with the small parcel requirements shall be demonstrated through implementation of a small parcel erosion and sediment control plan. Erosion and Sediment Control Requirement#1: Stabilization and Sediment Trapping. See page/paragraph ESC#1, PLAN SHEET C-2 Erosion and Sediment Control Requirement#2: Delineate Clearing and Easement Limits. Seepage/paragraph ESC#2, PLAN SHEET C-2 Erosion and Sediment Control Requirement#3: Protection of Adjacent Properties. Seepage/paragraph ESC#3, PLAN SHEET C-2 Erosion and Sediment Control Requirement#4: Timing and Stabilization of Sediment Trapping Measures. See page/paragraph ESC#4, PLAN SHEET C�2 , . THESE PLANS MUST SITE BE 1 ON THE FOR INSPECTION SHERWOOD CREEK Mason County Stormwater Checklist Minimum Requirements of 1992 Stormwater Manual The stormwater checklist identifies the minimum requirements of the 1992 Stormwater Manual. The checklist is intended to identify the locations within the plan that addresses the minimum requirements. Mason County will not perform a technical evaluation of the submittal. Rather,the checklist provides a guide to allow Mason County to review the submittal and determine if the applicant has addressed the minimum features that make up a stormwater plan. It is incumbent upon the applicant and his/her engineer to fulfill all the applicable requirements of the 1992 Stormwater Plan as it relates to the proposed project. Review by Mason County is intended to determine if the plan has addressed the minimum requirements and should not be considered a review for technical accuracy of the plan. During construction of the project,the stormwater plan engineer of record or his/her authorized representative shall inspect the site to ensure the stormwater plan is being implemented as designed. Upon completion of the project,the engineer or his authorized representative shall be required to certify that the stormwater plan has been implemented as designed. Failure to meet the minimum requirements could result in delay or rejection of the application until the deficiencies are corrected. X❑#1: Erosion and Sediment Control. All new development and redevelopment that includes land disturbing activities of one acre or greater shall comply with erosion and sediment control requirements 1 through 14, below. Compliance with the Erosion and Sediment Control Requirements shall be demonstrated through implementation of a large parcel erosion and sediment control plan. All new development and redevelopment that includes land disturbing activities of less than one acre shall comply with the small parcel minimum requirements found in Section 14.48.130, Compliance with the small parcel requirements shall be demonstrated through implementation of a small parcel erosion and sediment control plan. Erosion and Sediment Control Requirement#1: Stabilization and Sediment Trapping. Seepage/paragraph ESC#l, PLAN SHEET C-2 Erosion and Sediment Control Requirement#2: Delineate Clearing and Easement Limits. Seepage/paragraph ESC42, PLAN SHEET C-2 Erosion and Sediment Control Requirement#3: Protection of Adjacent Properties. Seepage/paragraph ESC43, PLAN SHEET C-2 Erosion and Sediment Control Requirement#4:Timing and Stabilization of Sediment Trapping Measures. �. See page/paragraph ESC#4, PLAN•SHEET C-2 THESE P1 kNS h1UST BE 1 ON TLLJ�BSITE FOR INSPECTION 7 ` Michael F. Wnek, P.E., PS Consulting Civil Engineer 3388 NW Byron St, Suite 200, Silverdale, WA 98383, 360-692-3802 Drainage Report Addendum SHERWOOD CREEK PARCELS ACCESS ROAD Sherwood Creek Rd 12229 22 00320 12220 33 00210 12220 33 90223 12220 33 90222 12220 33 90221 located in MASON COUNTY prepared for: JACK JOHNSON P.O. BOX 1119 BELFAIR, WA 98528 360-275-5400 Original Report- July 27, 2007 Addendum - April 22, 2008 MFW Project Number: 340 t-- By the seal and signature here affixed. 1 certify that the enclosed report was accomplished by myself, and that I am currently a registered engineer of good standing in the State of Washington. STORMWATER MANAGEMENT 1ANUAL FOR THE PUGET SOUND BASIN Figure 111-2.1 - Nomograph for Sizing Circular Drains Flawing Full -- - -- --i000 04-22-08 Addendum r 900 --- eoo ; to 07-27-07 Drainage Report 000l-, z 0 '� : 18"Cab- 0.5% criteria goo added to chart for Basin-1 0002- t=,*500 culverts (apgrox. 50% basin flow ; Minimum .0003 Allowable ' t0 ec7C 0004 400 ' �- .0001 Velocity ti..............................' � .0006— (Flowing � 3.0 300 120 v 10008=.0002 Full) t 08 p 001--T: --.0003 200 46 �-.0004 90 c .002�-.0005 4.0 -84 Cr 0006 1? O .003 .0008 66 W .005 5.0 100 60 O 006 _N O 90 -54 8 .002 o z 00 r-48 18"@ .01 O / � 6.0 10 CA ,42 0.5%qjj 003 c /// u: 60 OD4Z 36 .0 .005' 0 w 7-0 O V 50 Z 33 W r- Z 008 Q, ►u 8.0 w 40 20 •••• .05 04 .010 O tWi -- C7 ••. Z 9.0 36 Q 30 ' p 24 ••••• 08 .020 10.0 • .10 .030 U 20 F- 18 ••• 040 O 24"@ Q 18••• 060 j 2% q, .08C •• 12"@ 100 10 ••• 10 5% SAMPLE USE 1 8 24" Oia. CMP @ 2% slope yields 20.0 6 17cfs @ 5.2 FPS velocity (n - 0.024) 5 • • 6 •4 Values per Manning's Equation 4 = { 1.49) A R'/'j s 3 n 02 I 30.0 This table can be converted 04-22-08 Addendum to to other"n" values by applying 2 07-27-07 Drainage Report formula. 12"@ 5% criteria °0.0 01 1 added to chart - t Amax = BASIN-1 100 yr= 7.5 cfs rEBRt1ARY, 1 � C-11 r Michael F. Wnek, P.E., PS Consulting Civil Engineer 3388 NW Byron St, Suite 200, Silverdale, WA 98383, 360-692-3802 Drainage Report Addendum SHERWOOD CREEK PARCELS ACCESS ROAD Sherwood Creek Rd 12229 22 00320 12220 33 00210 12220 33 90223 12220 33 90222 12220 33 90221 located in: MASON COUNTY prepared for: • JACK JOHNSON P.O. BOX 1119 THESE PLA,?4S MUST BE BELFAIR, WA 98528 0`S Ti-f`jop S "� 360-275-5400 FOR INSPECTION Original Report- July 27, 2007 Addendum - April 22, 2008 MFW Project Number- 340 f By the seal and signature here affixed. 0 a if that the enclosed report was 1 certify p accomplished by myself, and that l am "� - currently a registered engineer of good -- -- ------ standing in the State of Washington. xl?gas o f; + cu STORMWATER MANAGEMENT MANUAL FOR THE PUGET SOUND BASIN Figure III-2.1 - Nomograph for Sizing Circular Drains Flawing Full -- �.............................. 1000 00 04-22-08 Addendum-900 am : to 07-27-07 Drainage Report clioo1� 20 700 : 18"na 0.5% criteria : 80o added to chart for Basin-1 Doorto- 500 culverts (approx. 50% basin flow : 0003J Minimum .— 4 each) 4004 Allowable 400 .....� 0005-� owl Veioclty t.......................... .000E-- lFlowing�� 3.D 300 Full; 120 v •0008 -.0002 CNI 108 p 001- o .0003 200 96 90 c .002-:r-.0005 4.0 84 Cr �--000E T p .003- 0008 66 W .004 00 5.0 005 100 60 p 006 N p 008 .002 p O 80 N 8 18'•@ /� 6.0 70 w •42 0.5% 003 cn 60 '2 36 .0 .005 C) w 7.0 4 v 5C 00E ? 33 U j 40 30 • '008 uF- w 8.0 a. .010 O W uw 27 5 j � 6 Z 4.0 30 24 -- p 1 ••• 08 .020 10.0 = t0 vV1 18 .030 O Q 20 �- •' .040 w w ,• 24'•@ 0 .050 2% Q .060 I Q• .G8C ••' 12„@ 100 10 •• 10 5% SAMPLE USE 7 8 24" Oia. CMP @ 2%slope yields 20.0 6 1 7cfs @ 5.2 FPS velocity 6.1•' (n - 0.024) 6 •4 Values per Manning's Equation Q = ( 1— ) AR=/, 5% 3 n l 30.0 Tthis table can be converted 04-22-08 Addendum to to other'n' values by applying 2 j 07-27-07 Drainage Report formula. iII 12"@ 5% criteria eo.o jadded to chart _j °2 = �z Qmax = BASIN-1 100 yr= 7.5 cfs rEBRUARY, 1992 THESE P ,q-?Vs MUST BE 0 SHE JOf3 Sty - c_11 FOR IiNSPECTiON Michael F. Wnek, P.E., PS Consulting Civil Engineer 3388 NW B,yron St, Suite 200, Silverdale, WA 98383, 360-692-3802 Drainaqe Report SHERWOOD CREEK PARCELS A ROAD Sherwood Creek Ind 12229 22 00320 12220 33 00210 12220 33 90223 �� 3 O'7 12220 33 90222 " 12220 33 90221 located in: MASON COUNTY prepared for. THESE JACK JOHNSON E PI'ANS MUST BE P.O. BOX 1119 ON Tl4 C!Og S;-, BELFAIR, WA 98528 FOR INSPEC'i Lry 360-275-5400 July 27, 2007 THESE PLANS MUST BE ON THE.:JB SITE FOR INSPECTION MFW Project Number 340 By the seal and signature here affixed, -. �'� a 6f;00� �`; l ceftify that the enclosed report was �"�t��. r�'sT ` accomplished by myself, and that l am siaNAL currently a registered engineer of good standing in the State of Washington: Ra=s a7i�aro�� I SherwoodR�eport Creek Parcels Access Road Michael F. Wnek, P.E., PS Dralna a July 27, 2007 TABLE OF CONTENTS I. VICINITY MAP............................................................................................ PROJECT DESCRIPTiON........... .................................................................................. a- Type of Permits....................................... 2 b. Size and Location of Project S(133............................:.................................................................................................................................2 ................................. 2 C. Legal Description....................................................................».............. d. Proposed Land Use&Site Improvements 2 e. Proposed Impervious Surfaces 2 ................ ..............................................................................................3. EXISTING CONDITIONS...................................... ................................................. ........................................................... 2 b. Land Cover...................... ................................................................................................2 ................................................... C. Adjacent Environmental Features d. Wells................................................................................................................ ........2 e. Soils... ......................................................... . 3 f. Groundwater...... . .................................................. g- Adjacent Drainage Facilities............................... ................................................................... .....3 h. Drainage Discharge Points.............. »............................................................................................. i. Relevant Reports................................................................................................... 3 DEVELOPED SITE DRAINAGE CONDITIONS.................. ».......................................................................3 a. Proposed Land Cover4. .................. :...................................... ...............3 b. Potential Storm Runoff Quantity&Quality Impacts..................... ............................ 3 ................................. c. Proposed ............................................................ 3 Storm Collection&Conveyance................. d. Proposed Storm Mitigation Measures................. ».....................,................................................ 3 e. Discharge Point.......... ................................................................... .4 ........................................................ ............ S. WATERSHED BASIN DESCRIPTION..................... .................4 .......... 6. DESCRIPTION OF UPSTREAM BASIN.................................................................................. 7. DOWNSTREAM CONDITION. 4 8. SOILS 9. BASIN MAPS.................................................................................................................................................................................................4 a. Project Boundaries........................ .......................................................................................»...................................................................................4 b. Off-Site Contributing Basins... ...........4 ...................................................................................... C. Project Drainage Basin.............. ...................................................4 d. Storm Runoff Downstream Route..............................................................................................................................................................4 10. HYDROLOGIC ANALYSIS...................................................................................... ................ a. Methodology... ................................................................................. .5 b. Curve Numbers(CN).................. .......................................................................................5 C. Time of Concentration............. ».............................................................................5 d. Runoff Volumes&Peak Discharges................................................ .......... e. Upstream Run-off................ :................ ............5 f. Bypass ........ . 5 g. Quantity Mitigation........................................... .....».................................................................................5 h. Quality Mitigation....................... i. Piping,.............................. ................................................... 5 11. EROSIO19 CONTROL.................................................................................................................. ...........................................................6 .............................................................................................6 VICINITY MAP APPENDIXES PROPERTY REPORT#1 A-1 PROPERTY REPORT#2 A-2 AERIAL PHOTO A-3 ASSESSORS MAP A-4 USGS CONTOUR MAP&UPSTREAM/DOWNSTREAM EXHIBIT A-5 SOILS MAP A-7 A-8 FIGURE 25 ISOPLUVIALS OF 2-YR 24HR PRECIPITATION FIGURE 27 ISOPLUVIALS OF 10-YR 24-HR PRECIPITATION B-1 FIGURE 30 IS . UVIALS OF 100-YR 24-HR PRECIPITATION B-2 TABLE III-1.3 SCS WESTERN WASHINGTON RUNOFF CURVE NUMBERS B-3 TABLE ill-1.6 HYDROLOGIC SOIL GROUPS FOR SOILS IN THE PUGET SOUND BASIN B-4 B-5 IMPERVIOUS AREA COMPUTATIONS HYDROLOGY CALCULATIONS Basin-1 5 paqes C-0 HYDROLGOY CALLULATIONS Basin-2 4 pages) C-1 HYDRAULIC CALCULATIONS,Ditch&Pie C-6 FIGURE III-2.1 PiPE FLOW C-10 FIGURE III-2.15 HEADWATER DEPTH C-11 C-12 BASIN PLAN TM 9 D-1 ++ : : C i �f C FOR INSPECe,Ov Sherwood Creek Parcels Access Road Michael F. Wnek, P.E., PS Drainage Re ort Jul 27, 2007 1. VICINITY MAP See attached Vicinity Map, Appendix A. 2. PROJECT DESCRIPTION a. Type of Permits BUILDING PERMIT MC Dept. of Com. Development GRADING PERMIT MC Dept. of Com. Development SHORT PLAT MC Dept. of Com. Development BOUNDARY LINE ADJUSTMENT MC Dept. of Com. Development b. Size and Location of Project Site Parcel Size: 11.9 Acres Project Size: 5.18 Acres (clearing area) Site Address: Sherwood Creek Rd c. Legal Description Assessor's Parcel Number: 12229 22 00320 12220 33 00210 12220 33 90223 12220 3390222 12220 33 90221 Legal Description: Attached Zoning: Rural & Residential d. Proposed Land Use & Site Improvements Access road & residential construction. Nine proposed lots will be configured through five existing lots, via short plat& boundary line adjustment. e. Proposed Impervious Surfaces 77,000 square feet= 1.77 acre (new impervious) 3. EXISTING CONDITIONS a. Topography Maximum Slope— 66% Declivity- Southeasterly Defined Channels- None b. Land Cover Project property— Rural Residential General area - Rural Residential c. Adjacent Environmental Features Creeks, Lakes, Ponds, Wetlands— Sherwood Creek, flows to Case Inlet Ravines, Gulleys, Steep Slopes- None Springs, Env. Sensitive Areas- None 2 Sherwood Creek Parcels Access Road Draina a Re ort Michael F. V16'nek, P.E., pS Jul 27 2007 d. Wells The project site and the neighbor to the east both have wells. e. Soils Per the USDA Soils Survey for Mason County: Alderwood Sinclair Both are considered Hydrological Group C f. Groundwater Seasonal perched water tables, typical to the local soils. g. Adjacent Drainage Facilities Roadway cross culverts in Sherwood Creek Road. h. Drainage Discharge Points Southeasterly as shallow channel flow. i. Relevant Reports Project Geotechnical Report for steep slopes 4. DEVELOPED SITE DRAINAGE CONDITIONS a. Proposed Land Cover The project includes constructing an access road to existing tax parcels. The road Provides access to the flatter terrain at the higher elevation (ridge) on the parcels. Clearing and grading of the ridge for future house sites will also be accomplished. There is an existing one-lane gravel road, in the southern parcel of the project, coming up from Sherwood Creek Road. The project access road starts at a point 440-ft up the existing access road, from the Sherwood Creek Road approach. The project area is shown on the attached exhibit: AERIAL PHOTO. b. Potential Storm Runoff Quantity& Quality Impacts The project will create greater than 5,000 square feet of new impervious area; and will require greater than 1 acre of clearing. Therefore storm runoff uanti mitigation is required. Peak flows for the 10-year & 100-year events will need to be attenuated so that the developed condition does not exceed the existing condition. Runoff will flow to a stream (Sherwood Creek) before entering an adequate receiving body (Case Inlet), therefore "streambank erosion control' criteria is required: the 2-year developed-condition event will need to be detained to release at 50% of the existing- condition peak.. C. Proposed Storm Collection & Conveyance Roadside ditches. Cross culverts. Detention Pond 3 p erwood Creek Parcels Access Road ains a Re ort Michael F. Wnek, P.E., PS Jul 27, 2007 d. Proposed Storm Mitigation Measures Due to the topography, 2 separate detention systems are warranted. Quantity Control: Detention Ponds (2 each) C�,uality Control: None warranted e. Discharge Point Roadway ditches of Sherwood Creek Road, 5. WATERSHED BASIN DESCRIPTION Sherwood Creek watershed. See attached USGS map 6. DESCRIPTION OF UPSTREAM BASIN See attached USGS map &Assessor's aerial photo, Appendix-A. 7. DOWNSTREAM CONDITION See attached USGS map&Assessor's aerial photo, Appendix-A. 8. SOILS See attached SOILS MAP, Appendix-A. 9. BASIN MAPS a. Project Boundaries See attached ASSESSORS MAP, Appendix-A b. Off-Site Contributing Basins The existing plat of Lakeland Village abuts the project to the north &west. Lakeland Village parcels to the north drain to the project basin. C. Project Drainage Basin See attached BASIN PLAN. The crest of the new access road will divide the area into two separate sub-basins. For hydrology calculations they are designated: Basin-1 Northern Sub-basin Basin-2 Western Sub-basin d. Storm Runoff Downstream Route The upstream & project basins flow to the roadway ditch of Sherwood Creek Road, and cross under the road to Sherwood Creek at various locations. 4 She70- od Creek Parcels Access Road Michael F. Wnek,L27 , PS Dra Re ort Jul007 10. HYDROLOGIC ANALYSIS a. Methodology The detention system is sized to meet the criteria listed in paragraph 4.b. The hydrological analysis is based on Santa Barbara Urban Hydrogragh methodology. The storm type is "'I A". b. Curve Numbers (CN) Alderwood: Group C. Sinclair: Group C. c. Time of Concentration Existing: See attached exhibit: BASIN PLAN Developed: No calculations, apply minimums d. Runoff Volumes & Peak Discharges See Appendix C. e. Upstream Run-off Due to the steep topography between the proposed building sites (upland bench) it is not practical to separate the upstream runoff (Lakeland Village) from the project runoff. Deflecting this flow around the project would concentrate the flow & increase the likelihood of erosion damage. Lakeland Village is considered part of the "existing condition"for hydrology calculations. f. Bypass All project storm runoff can be captured and routed through the treatment system. There will be no un-detained or untreated runoff from the project. g. Quantity Mitigation Computations are attached in the Appendix h. Quality Mitigation Not applicable, the percentage of driving surfaces within the sub-basins are minimal; contamination of runoff with hydrocarbons is unlikely. i. Piping 24-inch piping will be required at locations that carry the full basin peak runoff. Basin-1 will need to transport flows down the steep slope to the detention pond. Above ground, anchored, 12" HDPE pipe will be used for this application. The invert at the upstream catch basin will need to be set so that the 100-year peak flow will create sufficient headwater depth to overcome entrance control. Calculations are attached. THF;-r f';' r,41S r'llUST QE FOR MSPECTiGN n wood Creek Parcels Access RoadMichael F. Wnek, P.E., PS a a Re ort July 27, 2007 11. EROSION CONTROL Temporary erosion & sedimentation control measures will be implemented to treat the road construction & the lot clearing, and include: Sediment traps Wood Chip Berm or Filter Fabric Fence Straw Bale Barriers Rip-rap lined ditches 340/ST0RM/340_Storm_2.doc 6 Sherwood Creek Parcels Access Road Michael F. W/nek, P.E., PS Drains a Re ort Jui 27, 2007 VICINITY MAP CEDAR �O E LUCAS CREEK RD E SK1f1 ARK CT I Dawes- ke Iu P�'° i lu ha' CL I Q_ W. h� w At a _ 1 °Co LakP0*10k�.-. ��* on % CREST OR'— E COROW LN� � gANO- / du fELAK.I PROJECT LOCATION �r- f _ � ASE/HtE QO � j g9 �� �l 4 s 4r i b a/I Cr An nd� ° 4/ O 3 4L 5071ft AIUST BE SITE FOR INSPECTION A-1 Sherwootl:Creek Parcels,Access,Load Michael f- Wnek, to p3 Orairia a Re ort Parcel number: 122292200320 wie Map Owner Information JACK JOHNSON CONSTRUCTION INC PO BOX 1119 BELFAIR WA 98528-1 1 1 9 Taxpayer Information JACK JOHNSON CONSTRUCTION INC PO BOX 1119 Legal Description BELFAIR WA 98528-1119 PCL 5 OF BLA#06-23 REV I SURVEY 32/61 Site Address Reval Area 2 Field Sheet FS 03308:01 Land Size* 2.26 Land Use K� VACANT LAND 5 ACRES & UNDER Tax Code 201 Tax Code Description 1 403 A P3 E3 L H Census Tract Click Here * if the value is .00(zero)then the property is most likely in a plat and acreage is not usually carried on platted lots Parcel number: 122203300210 y1e Owner Information JACK JOHNSON CONSTRUCTION INC PO BOX 1119 BELFAIR WA 98528-1119 Taxpayer Information JACK JOHNSON CONSTRUCTION INC PO BOX 1119 BELFAIR WA 98528-1119 Legal Description PCL 6 OF BLA#06-23 (R)AF #1877210 SURVEY 32/61 Site Address 373 E SHERWOOD CREEK RD ALLYN Q Reval Area 2 Field Sheet FS 03305: Land Size* 2.52 Land Use VACANT LAND 5 ACRES & UNDER Tax Code 202 Tax Code Description 1 403 A P3 E5 L H Census Tract Click Here * if the value is .00(zero)then the property is most likely in a plat and acreage is not usually carried on platted lots i-AN; MUST13E A-2 c SITE FOR INSPECTION EDrai7na ood Creek Parcels Access Road Michael F. Wnek, P.E., PS a Re ort July 27, 2007 Parcel number: 122203390221an 1eW M FA Owner Information JACK JOHNSON CONSTRUCTION INC PO BOX 1119 BELFAIR WA 98528-1119 Taxpayer Information JACK JOHNSON CONSTRUCTION INC PO BOX 1119 BELFAIR WA 98528-1 1 1 9 Legal Description PCL I OF BLA#06-23 REV I SURVEYS 9/6& 32/61 Site Address Revel Area 2 Field Sheet =' FS 03303:01 Land Size* 6.01 Land Use VACANT LAND 5 ACRES& UNDER Tax Code ' 215 Tax Code Description 1 403 A P3 F5 L H Census Tract Click Here * if the value is .00(zero)then the property is most likely in a plat and acreage is not usually carried on platted lots TF'. Sc� "15 MUST SE lr,'3 SITE A-3 FOR INSP ECTION Sherwood Creek Parcels Access Road MichaiF• Wnek, P.E., PSDraina a Report J 20 72 AERIAL PHOTO Alwtl AL a $ `.. & -folk Woc 41. Si Y M M1 YY J k . a PROJECT x J '! Sit- 40 rx y w yy, # {+ # ..> _"% ' ••zq*4:. .n +fib dJ _ '�': •� Sherwood Creek Parcels Access Road Michael F. 1lllnek, N.E., PS Draina a Re ort It 27, 2007 ASSESORS MAP !2205400091 '~ 12220��100032 122205400030 122205400105 '' 122205400094 �"�-_>-_ ��r� 122205400103 !220540001.12 122205400095 122205400100 122205400104 12220540009I3 1222054000 96 122205400099 12220 5400102 387 122205400097 122205400101 ueueeeeeeueeueueeeenunneet��(d � $eeeeeneeeeneeeueneneneeneeeeun� 22205400CIA 00085 122203390223 12 122203390222 122205400433 :eeeeeeeeeeeeeeeeeeeeeeel7 03396221 10082 _ 122203300320 1:&203390224 - - 122203300210 i22 88888 � '�' �► i!205400074 = - 175 : e 12229 5100005 122205400973 229y 004 PROJECT 122295100003 0330023 !220540007:0 = 122203300290 IY � K =+eeeeeeeeeeeeaeee� V2295100002 112220330021't 140 122292200320 122295100001 122292200280 .22307600041 122292200390 ;eeeuneneeuennnnt * 122299999999 122292200310 a� 122292200330 122292290344 100010 THF,p p�.ar�'s ; OPy TPL 2081UJrT I13F FOR INSP 5'' F ECTION A-5 Sherwood Creek Parcels Access Road Draina a Report Michael F. 'Wnek, P.E., PS July27, 2007 USGS CONTOUR MAP IF *F ! �o �f� titt Y 1 1�1•^ f ■ A � r '¢ yM j 4 ■ : f� d�y ,��' ■'' pie•..-^ �n....r'r",., ■ .d y�1`. PROJECT LOCATION oft f � ■ f— A-6 pDrai7nage ood Creek Parcels Access Road Report e ort Michael F. Wnek, P.E., PS Jul 27, 2007 SOILS 14'IIAP in LL =a iP PROJECT LOCATION W, a �pf � y r nla i i Ac =Aiderwood So = Sinclair rEi zs A,NS MUST BE o � r 3S1T FOR INSPECTioV A-7 • r MW MAW 1 Ir ® t r Wsibmli • ram• ✓�' �� 1!' .. � Oil , ti • • STORMWATER MANAGEMENT MANUAL FOR THE PUGET SOUND BASIN 124 123 122 121 II ll( z s El 40 ': r _A FkIG4Y HAf2I f \ +— v �7 S7AM1:' 70 j5 8085 �\ 3 , A 10 B 25. 1 �g 48 75. ' �" .35- .2 \, 3 5 5 1 Akio 75 85. 45 V ito90 10001 5 ss .s k i Q (� , Q E to s 90 1 40 , POP 6 , \ , � AT 1 `4I0 q iC 1 Sal .5 555. tit 0 47 I 3 3 \ � 7.0 cs +� r.l ��a s C� 705 E T Rs 70s o n r c�� so z 100 +s 22 YAK � c �} • _...�. 45 � �55 t 0 ' M ) n + 80 s a s T s j 1 0 46 I 60 o yr 1 AD M1 �f j (� &� 5 _ 'BiASt1INt,1T41\ 40 1 �50 40 ; trKil 10 0 10 20 30 40 EN E --�-1—� MILES 40� ss so1535 -- . ifigure 30 I NOAA ATLAS 2, volume(x ISOPLUVIALS F 100-YR 24-HR PRECIPIT/�TION 45 50 65 Prepared by U.S.Dn rt 55 60 !Naup�iOceanican At�e 1� mminutreuon IN TENTHS OF N INCH Nations!weather Service,Office of Hydrology I Prepared for U.S.Department of A utture. ' Sop Conservation Service,Engineer g Division i24 123 122 12i III-1-46 FEBRUARY, 1992 B-3 STORMWATER MANAGEMENT MANUAL FOR THE PUGET SOUND BASIN Table III-1.3 SCS Western Washington Runoff Curve Numbers (Published by SCS in 1982) Runoff curve numbers for selected agricultural, subuland use for Type lA rainfall distributionban and n 24-hour storm duration. LAND USE DESCRIPTION CURVE NUMBERS BY HYDROLOGIC SOIL GROUP A B C D Cultivated land 1 winter condition 86 91 94 95 Mountain open areas: low growing brush & grasslands 74 82 89 92 Meadow or pasture: 65 78 85 89 Wood or forest land: undisturbed 42 64 76 el Wood or forest land: young second growth or brush 55 72 81 86 Orchard: with cover crop 81 88 92 94 Open spaces, lawns, parks, golf courses, cemeteries, landscaping. [Gravel ood condition: grass cover on Z75% of the 68 80 86 90 area air condition: grass cover on 50-75% of 77 85 90 92 the area roads & parking lots: 76 85 89 91 Dirt roads & 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/Grose Acre %Impervious(3) Separate curve number 1. DU/GA 15 1.5 shall be selected for 2.0 DU/GA 20 pervious & impervious 2.5 DU/GA 30 DU/GA 25 portions of the site � 3.0 DU/GA 34 or basin 3.5 DU/GA 38 4.0 DU/GA 42 4.5 DU/GA 46 5.0 DU/GA 48 5.5 DU/GA 50 6.0 DU/Gib 52 6.5 DU/GA 54 7.0 DU/GA 56 PUD's, condos, apartments, %impervious commercial businesses & must be industrial areas computed (1) For a more detailed description of agricultural land use curve numbers refer to National Engineering Handbook, Sec. 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. - III-1-12 FEBRUARY, 1992 THESE PLANS MUST BE B4 ON THE JOB SITE FOR INSPECTION N p Ok uzz ❑ zanuuwwmana < mntuuan ❑ n o nn ❑ x •.,zzzzuzzzm Uam UUoa ❑ zam ❑ znamuu�u:nwznto z a EE+ y w a u �77 ur Gl O C7 O 0 o 0x x x x n .�, ai a d a N y vZ rn u� y C L .i —oo y 7 }} h h Enh KR.h In h h E% N h 0 ••• 47 u m w u m m u a u m n ❑ U c0 u z z u m m m d m u W u U u p m u a : U zz Umzz zU W oCU ❑ zmy rm � cG QQ Q z e � z i w r x p N H F c � u z z z z 1 � I STORMWATER MANAGEMENT MANUAL FOR THE PUGET SOUND BASIN Soil T >e =Graup Hydrologic Soil Yi- Type Group Newberg B Spaneway A/B Nisqually B Springdale B Nooksack C Sulaavar B Norma C1D Sultan C Ogarty C Sultan variant B Mae ND Sumaa C Ok>nioumt C Swantown ND 01ya ric B Tacoma D Oft" D Tanwax ND Oridia D Tealwhit ND Otting ND Tenino C O°o C Tisch D oval] C Tokul ND Punk C Townsend C Keeney C Triton ND Phelan ND Tukwila D Piichuck C Tukey ND Potchub C Urban variable Poulaho C Yailton B Prather C verlot C Puget D Wapato C Puyallup B Warden ND Queets ND Whidbey Quikene ND Wilkeson ND Ragnar B Winston B RdiR1er C Woodinville B Raught B Yclm� L.Reed ND Zynbsr B 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 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 clay layer at or near the surface, and shallow soils over nearly impervious material. These soils have a very slow rate of water transmission. ND Data not currently available for this soil type. *From SC:S, TR-D:.,, second Edition, June 19 , Exh bit A-1. Revis ons made from SC.S, Soil Interpretation Record, Form 15, September 1988 and various county soi, ^ surveys. III-1-1 FEBRUARY, 1992 B-6 Sherwood Creek Parcels Road Access Michael F. Wnek, P.E., P3 Drainage Report hiki 27, 2007 DEVELOPED IMPERVIOUS AREA COMPUTATIONS BASIN-1 BASIN-2 ROAD ROAD = I *w = 708.9112' *20' = 1 *w = 1320.4786' *20' 14178.224 sf = 26409.572 sf = 0.325 acre = 0.606 acre HOUSE & DRIVEWAY HOUSE & DRIVEWAY @ 4,000 sf/lot, 6 lots @ 4,000 sf/lot, 3 lots = 6 *4,000 sf = 3*4,000 sf = 24,000 sf = 12,000 sf = 0.651 acre = 0.275 acre EXISTING IMPERVIOUS LOTS (house/driveway) Existing lots = 3 acres =70 % impervious =2.1 acre TOTAL IMPERVIOUS TOTAL IMPERVIOUS = 0.325 + 0.551 + 2.1 = 0.606 + 0.275 = 2.98 acre = 0.881 acre F MUST BE G� � i i� 1 � St7-E FOR ►NSPEC T ION c-o Sherwood Creek Parcels Road Access Michael F. YYnely PEE,, PS Drainage.Report Jul 27 2007 PRECIPITATION Event Precip(in) 2 year 3.5000 ear 8000 [10 y ,100 year 6.6000 BASIN-1 LPOOL-1 SUMMARY using Puls Start of live storage: 16.9000 ft Even t Match Q(cfs) Peak Q(cfs)iPeak Stg(ft)I Vol(ct) Vol(acft) Time to Empty 2 year 1..0583 I.0554 22.9001 95 11.58 [ 0.2184 25.33 r10 year [-�.2047 3.0791 r 23.6147 11659.92 0.2677 � 25. 77 [100 year 4.7905 F 4.5710 F 24.9754 16346.69 0.3753 27.00 HYDROGR4PH SUMMARY Hyd1D [Peak Q(cfs) Peak T(hrs) Peak Vol(ac-ft)[font Area(ac) 2 year out r 1.0554 9.33 F 1.2467 i r 5.5000 year out 3.0791 8.331�---1. 10g092 F 5.5000 100 year out F 4.5710 8.33 F 2.6110 F 5.5000 [BASIN SUMMARY _ BasinID Event Peak Q Peak T [Peak Vol(ac-cf)(Area(ac)(M�ethod/Loss Raintype ______. ��(�s)�I (his) _I �R BAS^ -- ---- I �IN-1 2 year 2�1165 �8.00 0."98 5.% SB SCS FTYPEIA f DEVELOPED-1 2 year r 3.5213 �8 00 F 1.2411 r 5.50 �SBUH/SCS �TYPEIA IO year r 3.2047 �8 00_ 1.5241 �r 5.50 F s- [ SCS FTYPEIA DEVELOPED-1 10year r 5.1661 F-8.00 F 1.8096 7 -50 rSBEWSCS TYPEIA BASIN-I 100 year 4.7905 I 8.00 F 2.2848 5.50 SBUH/SCS FTYPEIA DEVELOPED-1 100 year 7.4702 1 8A0 F�2.6114 5.50 SBLIH/SCS �TYPEIA G1 Sherwood Creek Parcels Road Access , PSF ra W Dna a Report .E.lJu207 Record Id: BASIN-1 Design Method [ SBLIH -[IZainfall type --`TYPEIA �DYd Inh' 10A0 min-[Peaking Factor 484.00 �- _ Ar- -Abstraction Coeff _ `�-0.20 Pervious Area(AMC 2) 3 40 ac DCIA `F- 2.10 ac CPervious CN t - --- _ �78.21 !DC CN 98,00 Pervious TC 60.96 min ADC TC 5.00 min --- _ Pervious CN Calc - Description - - Descri p � ___- � I SubArea � Sub cn Wood/forest land(Undisturbed/2nd growth) 2.50 ac i Open spaces,lawns,parks(>75%grass) 0.60 ac 86.00 Wood/forest land(young 2nd growth/brush) 0.30 ac I` 81.00 Pervious Composited CN(AMC 2) - 78.21 Pervious TC Calc Type Description r Length Slope Coeff Misc F TT Sheet Woods or forest with light underbrush.:0.40 197 66 ft 1. 0%0.-4 3.50 in �46.61 min Sheet I r`'oods or forest with light underbrush.:0.40 105.00 ft 20.00% 0.4000 3.50 in 8.50 min [Shallow Forest w/heavy ground litter&meadows(n=0.10) 88.00 ft 30.00% 0.1000 F-[0.83 min Shallow Forest w/heavy ground litter&meadows(n=0.10)- 158A0 ft 51.00% 0.1000 -�1.15 min Shallow Forest w/heavy ground litter&meadows(n=0.10) 211.00 ft 8.00% 0.1000 F-`3.87 min F Pervious TC �60.96 min Directly Connected CN Calc Description -- SubArea Sub en F - Impervious surfaces(pavements,roofs,etc) 2.10 ac F 9 000 DC Composited CN(AMC 2) 98A0 F Directly Connected TC Calc _ Type F Description Length F Slope F Coeff F-N1sc r- -TT FF rixed _� -- I - ----- 5.00 min Directly Connected TC S.00min C-2 Sherwood Creek Parcels Road Access Michel Ma ina a Re ort Record Id: DEVELOPED-1 Design Method r SBUH^ Rainfall type — 'I y-- �TYPEIA Hyd Intv �10.00 min Peaking Factor F 484.00 r -Abstraction Coeff 0.20 Pervious Area(AMC 2) �f 2.52 ac �DCIA 2.98 ac (Pervious EN +�^ 85.41�- IDC CN— 98.00 Pervious TC DC � TC r5.00 min F _ Pervious CN Calc Description ---- - r - i SubArea F-Sub cn I Open spaces,lawns,parks(>75%grass) --1.62 ac f- 86. 00 Open spaces,lawns,parks(>75%grass) 0.60 ac 86.00 r� Wood/forest land(young 2nd growth/brush) 0.30 ac [ 81.00 I - Pervious Composited CN(AMC 2) 85.41 ___ Pervious TC Cale TYPe r Description ngth ��Slope Coeff ( TT Fixed I -F -- _ 10.00 min Pervious TC _ I 10.00 min Directly Connected CN Calc r� Description i _ SubArea Sub cn I _ Impervious surfaces{pavements,roofs,etc) 0.32 ac 98.00 Impervious surfaces(pavements,roofs,etc) 0.55 ac [ 8.00 F- Impervious surfaces(pavements,roofs,etc) ' 2.10 ac F-98.00 DC Composited CN(AMC 2) f-98.00 Directly Connected TC Cale TYPe Description F Length I Slope T Coeff Misc [-TT Fixed F -- _ i 5.00 min Directly Connected TC S.00mi]n Record Id: LP00L-1 Descrip: �evel Pool Routing jIncrement 0. 00 ft Start El. �16.5000 ft Max El. 25.0000 ft Storage Node rOND-1-GRADED ischarge Node'ORIFICE-1 THESE PLANS ON THE!OB UST BE ITE FOR INSPECT ON C-3 Sherwood Greek Par..ceis Road Access Michael F. Wnek, CIE , PS Draina a`R orE Jul 27;:200 Record Id: ORIFICE-1 [Descrip: Prototype Structure Increment 0.10 ft Start EI. r17.0000 ft `Max El. 25.0000 ft f rif Coei Fo.62 Lowest Orif El. 15.00 Lowest Diam'4.0000 in Dist to next y F.9000 ft [62- 9.250 Dist to next 0.0000 ft Stage Discharge Rating Curve 19.0000 ft 0.6140 cfs 23.1000 ft r2.1108 cfs 17.0000 ft 0.0000 cfs 2 1.1000 ft Vi792 cfs 19.1000 ft 0.6292 cfs 23.2000 ft 2.3529 cfs 17.1000 ft 10.1373 cfs;21.2000 ft,10.8898 cfs 19.2000 ft j0.6440 cfs`23.3000 ft 2.5583 cfs - ft0 _ � 417.2000 ft 1 .19 . . �_ _ . 000 ft f2. 47 23 cfs 17.3000 ft J0.2378 cfs,21.4000 ft 10.9108 cfs 19.4000 ft[0.6726 cfs 23.50 - ft 2.9055 cfs 17.4000 ft F0.2746 cfs 21.5000 ft 0.92 11 cfs 19.5000 ft)0 6865 cfs 23.6000 ft[3A581 cfs 17.5000 ft 0.3070~cfs 21.6000 ft 0.9312 cfs .19.6000 ft 0.7001 cfs 23.7000 ft�3 2007 cfs _ . 17.6000 ft 0.3363 cfs 21.7000 ft 0.9413 cfs 19.7000 ft�0.7135 cfs'23.8000 ft r3.3350 cfs 17.7000 ft 0.3633 cfs 21.8000 ft 0.9513 cfs 19.8000 ft 0.7265 cfs 23.9000 ft 3.4624 cfs 17.8000 ft 0.3884 cfs'21.9000 ft r0.9611 cfs 19.9000 ft 0.7394 cfs 24.0000 ft T5 48 0 cfs 17.9000 ft 0.4119 cfs 22.0000 ft 0.9709 cfs 20.0000 ft 0.7520 cfs 24.1000 ft�3.7005 cfs 18.0000 ft j0.4342 cfs 22.1000 ft 0.9805 cfs 20.1000 ft 0.7645 cfs 24.2000 ft 3.8124 cfs 18.. . 0.4554 cfs 22.2000 ft F0.9901 cfs 20.2000 ft 0.7767 cfs 24.3000 ft 3.9204 cfs _ �_ 18.2000 ft 0.4756 cfs,22.3000 ft j0.9996 cfs 20.3000 ft 0.7887 cfs 24.4000 ft I49024cfs 18.3000 ft0.4951 cfs 22.4000 ft 00 ft4.1261 cfs 0ft �1.00 . 0ft8006 cfs . 4.224 cfs 1.0183 cfs 0.8123 cfs 24.6000ft18.40 . . . 18.5000 ft 0.5318 cfs 22.6000 ft 1.0275 cfs 20.6000 ft 80 238 cfs 24.7000 ft 4.3200 cfs 18.6000 ft 0.5492 cfs 22.7000 ft�1.0366 cfs 20.7000 ft 0.8352 cfs 24.8000 ft 4.4132 cfs 18.7000 ft; .5041 0.5661 cfs 22.8000 ft r1.0457 cfs 20.8000 ft!0.8464 cfs 24.9000 ft 4 cfs 18.8000 ft 0.5825 cfs 22.9000 ft 1.0546 cfs 20.9000 ft 0.8575 cfs 25.0000 ft 4.5928 cfs 18.9000 ft 10.5985 as'23.0000 ft 1.7978 cfs C-4 Sherwood �r..eekParc�is Road,Access - Ni�c1�a¢I Drains a Rig orE Jiai .2?� 347 Record Id: POND-I-GRADED [Descrip: Graded Construction Pond jlncrement 1,0.10 ft Start El. 16.9000 ft `[M-a�El. 25.0000 ft Stage Area �� Stage(ft) Area(st) 16.90 17.00 ~ rr 363.0000 �� 25.00 F-�3742.0000�-� Stage Storage Rating Curve 18.9000 ft F1470.2367 cf,23.0000 ft'9=907ticcf 16.9000ft�0,0000cf ,21.0000ft 4849.1499cf 19.0000 ft 1588. 9999 cf'23.1000 ft 10 17.0000 ft 18.1499 cf 21.1000 ft 15056.5117 cf 19.1000 ft 1711.7867 cf 23.2000 ft 10386.7969 cf ---- 17.1000 ft i 56.5617 cf ;21.2000 ft 5268.0972 cf i 19.2000 ft 1838. 9973 cf j23.3000 ft 10687.0820 cf 17.2000 ft 74 _ cf 21.300 ft0ft 5483.9067cf 19.3000 1970.2317 cf 23.4000 ft 10!WI598 cf i 17.3000 ft`14b.0567 cf 21.4000 ft 5703.93 99 cf 19.4000 ft r2105.7898 cf'23.5000 ft ri1300. 2213 cf 17.4000 ft 197.1399 cf 21.5000 ft r5928.1968 cf 19.5000 ft 2245.5718 cf 23.6000 ft 11613.2773 cf 17.5000 ft 252.4467 cf ``21.6000 ft i 6156.6772 cf 19.6000 ft 2389.5774 cf 23.7000 ft f 11930.4570 cf 17.6000 ft 711.9774 cf 21.700o ft 6 983 3818 cf 19.7000 ft 2537.8066 cf 23.8000 ft j 12251.8594 cf ---- _- - - 17.7000 ft 375.7318 cf 21.8000 ft j 6626.3101 cf 19.8000 ft 2690.2598 cf 23.9000 ft 12577.4863 cf �. 1846.9368cf400ft2907.3369 cf17.8000 ft 4437099 cf 21.900 687.4619 cf 0ft .. 0 17.9000 ft 515.9117 cf 22.0000 ft�112.8374 cf 20.0000 ft 3007.8374 cf,24.1000 ft 13241.4121 cf _. _ 18.0000 ft'S92.3373 cf ;221000 ft 7362.4365 cf 20.1000 ft 3172.9617 cf:24.2000 ft 13579.7100 cf - _ 18.1000 ft 672.9868 cf 22.2000 ft 7616.2598 cf 20.2000 ft i3342.3098 cf24.3000 ft 13922.2314 cf 18.2000 ft 5j8�94 cf 22.3000 ft 17874.3066 cf 20.3000 ft�3515.8818 cf;24.4000 ft�14268. 7775 cf 18.3000 ft F846.9567 cf 1:22.4000 ft 8136.5771 cf -20.4000 ft 3693.. 7772 cf ft1461 9.9463 cf24.5000 18.4000 ft 940.2773cf ;22.5000 24. _ . 9968 cf, .6000 ft 14975.1396 cf `18.5000 ft 1037.8218 cf 22.6000 ft 8673.7900 cf 20.6000 ft 4061.9399 cf 24.7000 ft 15334.5566 cf 18.6000 ft 1139.5898 cf,22.7000 ft 8948.7314 cf 20.7000 ft;4 52 2 4067 cf 24.8000 ft 5561 8 11973 cf 18.7000 ft[1245.5818 cf 22.8000 ft[9227.8975 cf 20.8000 ft4447.0972 cf 24.9000 ft'16066.0615 cf 18.8000 ft 1355.7974 cf;22.9000 ft 9511.2871 cf -�� 25.0000 ft j16438.1504 cf Cry Sherwood Creek Parcels Road Access . �Ylrchael F.,V1tn�e , PEE., S Drama a Re ort BASIN-2 LPOOL-2 SUMMARY using Puls Start of live storage: 19.9000 ft Ev Match Q(cfs)jPeak Q(cfs);Peak Stg(ft) Vol(CO Vol(acft) Time to ent Empty 2 Year �0.5352 0.5344 6 0344 8745.58 10.2008 (10year 2.1349 -� 2.0651 -_ 29.I7 _ _ _ 26.5633 10121.39 0.2324 31.00 ]00 year 3.7937 + 3.7654 27.9829 14300.79 0.3283 31.17 (BASIN SUMMARY I BasinID Event reafk Q peak T(hrs)!Peak Vol ac-c Area ac Method/Loss Raintype ) ----- ( ( ) BASIN-2 iI -' _ F-2 year i l F . j 8.17 j 0.6371 5.60 SBUH/SCS TYPE,A (DEVELOPED-2�_�2-year2.26i 6-r 8.00 _-ru-0.8852 jTYPEIA � 5.60 SBUH/SCS �ASIN-2 10yeaz 2.1349_F 8.17 L1067 5.60 pBUH/SCS TYPEIA EErVLOPED-2 I O year F3796. 2 0 5. SBw 8.0 1467 60 rHri; 3.7937 .17BASIN-2 100ye F18215 5.60 SBUH/SCS �TYPEIA 5 8,00E-iI71 5.60 SBUH/SCSaz_�EVLOPED-2 100 y 6057 TYPEIA Record Id: BASIN-2 Design Method SBUH _--Rainfall type -�-TYPEIA �yd Inty _ 10.00 min Peaking Factor 484.00 - Abstraction Coeff 0.20 rvious Area(AMC 2) 5.66 ac DCIA 0.00 ac [e Pervious CN 76.00 0. Pervious TC _ 25.57 min - DC TC 0.00 min Pervious CN Calc Description SubArea F Sub cn F- Wood/forest land(Undisturbed/2nd growth) 5.60 ac Pervious Composited 76.00 _ f CN(AMC 2 00 _ Pervious TC Cale Type Description_ Length Slope Coeff Misc TT �(Sheet Woods or forest with light underbrush.:0.40 j298.00 ft 27.00% 0.4000 3.50 in 17.37 min -i _ �� -�F_ f Shallow Fo er�st w/hea !` heavy ground litter&meadows(n=0.10) ;149.00 ft 19.00% 0.1000 _ � � �T(1.77 min Shallow Forest w/heavy ground litter&meadows(n�.10) 1 3.00 ft 19.00% 0.1000 -- _ I---.� --F-r82 min :Shallow ;Forest w/hea - -�+ �'�heavy ground litter&meadows(n�.10) 132.00 ft 26.00% 0.1000- -- -. ----- ��1 34 min ------- - - - ---- Shaliow Forest w/heavy ground litter&meadows(n�.10) �$9.00 ft r2.00% 0.1000 3.27 min _� - - Pervious TC 25.57 min THESE P1,,..ANS jP4UST BE JO 3 SITE c-s FOR INSPECTION heru�tood,Creek Parcels Road Access Mcha¢t f ,111/ Drairla a Re ort Ift .�u1 Record Id: DEVELOPED-2 rDesign Method S FTYPEIA 1Hyd Intv 00 min Peaking Factor I 484.00 -Abstraction Coeff I- 0.20 Pervious Area(AMC 2} v 4.72 ac FD-dA i 0.88 ac Pervious CN -� _-80.07 v_-_DC CN Pervious TC_ ~�~N i -F- 10.00 min DC TC F-5.00 min Pervious CN Calc -_ - Description -�-^� SubArea Sub cn Open spaces,lawns,parks(>75%grass) 1.92 ac 86.00 - Wood/forest land(Undisturbed/2nd growth) 2.80 ac 76.00 Pervious Composited CN(AMC 2) - 80.07 Pervious TC Calc -Type F Description FLength F Slope � Coeff �Misc �-TT Fixed - -RO 00 min Pervious TC _ 10.00 min 7 v Directly Connected CN Calc Description -+ SubArea Sub cn _ Impervious surfaces(pavements,roofs,etc) - 0.61 ac 98.00 A Impervious surfaces(pavements,roofs,etc) r 0.28 ac F 98.00 DC Composited CN(AMC 2) 98.00 � Directly Connected TC Calc - r-Type �_ DescriptionF`- Length Slope �s Coeff c F--TT _ 5.00 min F I -_ Directly Connected TC F 5.O-0min HYDROGRAPH SUMMARY HydID ;Peak Q(cfs) PeakPeak T rs) Peak Vol(ac-ft) Cont Area(ac) i2 year out-2 0.5344 , 12.67 1-0.8852! 5.6000 �10 year out-2 2.0652 8.50 1.4067 5.6000 100 year out-2 3.7654 8.33 -2.1712 5.6000 Record Id: LPOO1-2 Descri __p: !Prototype Record ;Increment 10.I0 ft -- tart EI. F19.9000 ft lines El. 28.0000 ft Storage Node POND-2-GRADED;Discharge Node 10RIFICE-2 G7 Sherwood Greek Parcels Rbad Access M chae! F.:Nlnek, P,E , P$ Dalna a Re ort Record Id: POND-2-GRADED IDescrip: Graded Construction Pond Increment�0.10 ft IStart El. 19.9000 ft Max El. [28.0000 ft Stage Area- ____ - ��. 19.94 -J�_.____384.0000 m- 28.00 3200.0000 I Stage Storage Rating Curve 21.9000 ft 1384. 5599 cf 26.0000 ft 8659.2002 cf 19.9000 ft I-0.0000 cf 24.0000 ft�371.1997 cf ; 22.0000 ft 1491.1998 cf 26.1000 ft�8910.5596 cf 20.0000 ft I-I9-l9 99 cT 24.1000 ft F 4552.1597 cf 22.1000 ft 1601.7599 of 26.2000 ft 9165.4395 cf 20.1000 ft 159.3599 cf 24.2000 ft 1 4736 6 c963 f 22.2000 ft F1715.8398 cf 26.3000 ft'9423.8398 cf 20.2000 ft 103.0399 cf .24.3000 ft 4924.6396 cf ,22.3000 ft 1833.4398 cf 26.4000 ft 9685.7598 cf 20.3000 ft 150.2399 cf 24.4000 ft 5116.1597 cf 22.4000 ft 1954.5598 cf 26.5000 ft 9 - 9 1.2002 cf - 20.4000 ft 200.9599 cf :24.5000 ft 15311.1 997 cf '22.5000 ft 2079.2000 cf 26.6000 ft,10220.1602 cf 20.5000 ft 255.1999 cf ;24.6400 ft r556-7598 cf 22.6000 ft 2207.3599 cf 26.7000 ft I10492.6 996 cf' 20.6000 ft 312.9598 cf .24.7000 ft 15711.8398 cf 22.7004 ft 2339.0398 cf 26.8000 ft 10768.6396 cf - _ 20.7000 ft 1374.2399 cf 24.8000 f3 5917.4399 cf 22.8000 ft 2474.2397 cf 26.9000 ft 11048.1602 cf 20.8000 ft 439.0399 cf 24.9000 ft 6126.5601 cf 22.9000 ft 2612.9600 cf 27.0000 ft 11331.2002 cf 20.9000 ft 507.3599 cf 25.0000 ft r6339.1997 cf 23.0000 ft 2755.2000 cf 27.1000 ft 11617.7598 cf ,21.0000 ft 579.1998 cf !25.1000 ft 6555.3599 cf 23.1000 ft 2900.9600 cf 27.2000 ft 111907.8398 cf 21.1000 ft 654.5599 cf ;25.2000 ft 16775.0400 cf 23.2000 ft[33050.2397 cf 27.3000 ft 12201.4395 cf 21.2000 ft 1733.4399 cf 25.3000 ft I-6998.2397 cf 23.3000 ft 13203.0398 cf 27.4000 it'12498.5596 cf 21.3000 ft 815.8398 cf 25.4000 ft 17224.9600 cf 23.4000 ft 3359.3599 cf 27.5000 ft 12799.2002 cf ,21.4000 ft 1901.7598 cf ;25.5000 ft 7455.1997 cf ' 23.5000 ft I3519.2000 cf'27.6000 ft 13103.3594 cf 4 - ..-- k 12l.5000 ft 991.1998 cf 25.6000 ft!7688.9600 cf f 23.6000 ft 3682. 5598 cf 27.7000 ft 13411.04 00 cf 21.6000 ft 1084.1599 cf 25.7000 ft(7926.2397 cf 23.7000 ft 3849.4399 cf 27.8000 ft 13722.2402 cf -[I ft II 180.6399 cf'25.8000 ft 8167.0400 cf 23.8000 ft 4019. 3398 cf,27.9000 ft 14036.9600 cf 21.8000 ft F 1280.6399 cf 25.9000 ft 8411.3594 cf r I 28.0000 ft 14355.2002 cf G8 Sherwood Creek Parcels Road Access Michael F. Wnek, P.E., PS Drainage Re ort .1ii1xi 27, 20Q7 Record Id:ORMC&2 Dip: Prototype Stricture Increment 0.10 ft ,Start El 19.9000 ft Max EL 28.0000 it Orif Coeff 0.62 Lowest Orif El. 17.90 Lowest Diam 2.8198 in Dist to next 6.2400 ft ILA 9.2500 in ^�Dist to next 0.0000 ft Stage Discharge Rating Curve 21.9000 ft 0.3052 cfs 26.0000 ft 0.5329 cfs 0.000 ft0.4369fs 0ft M.1000 ft19 9000 ft � . 0.5373 cfs - ,20 0000 ft 0.0682 cfs 241000 ft�0.4422 cfs I22.1000 ft 0.3200 cfs 26.2000. ft 1.1103 cfs } � 1 j201000 ft 0�0965 cfs 24.2000 ft 10.44 47 cfs j22.2000 ft 0.3272 cfs;26.3000 ft 1.47,i cfs j20.2000 ft 0.1182 cfs i24.3000 ft 0.4526 cfs I22.3000 ft 0.3343 cfs 26.4000 ft 1.7341 cfs __ 040 ft 0.1365 cfs 124.4000 ft 0.4577 cfs j22.4000 ft Z.3412 cfs 26.5000 ft 1.9475 cfs ,20.4000 ft 0.1526 cfs24.5000 ft 0.4628 cfs _ ,22 5000 ft 10.3479 cfs,26.6000 ft 2.1333 cfs 320.5000 ft 0.1671 cfs'24.6000 ft 0.4678 cfs - - - E I22.6000 ft 0.3546 cfs 26.7000 ft 2.3002 cfs 20.6000 ft 0.165 cfs;24.7000 ft 0.4727 cfs ;22.7000 ft 0.3611 cfs j26.8000 ft 2.4531 cfs f _-__... ----_-___.__. 7000 ft O.I930 cfs 24.8000 ft 0.4776 cfs 22.8000 ft 0.3675 cfs 126.9000 ft 12.5951 cfs 20.$000 ft�0 2047 cfs 24.9000 ft 0.4825 cfs 22.9000 ft 0.3737 cfs'27.0000 ft 2.7282 cfs fs, _.- f_____._.._.-_____.__ ,..___...____�._._ 20.9000 ft 0.2158 cfs 25.0000 ft 0.4873 cfs �23.0000 ft 0.3799 cfs}27.1000 ft 2.8540 cfs 21.0000 ft 0.2263 cfs 25.1000 ft 0.4920 cfs J23.1000 ft 0.3860 cfs�27.2000 ft 2.9736 cfs 21.1000 ft 0.2364 cfs 25.2000 ft z0.496 c8 fs i23.2000 ft 0.3920 cfs'27.3000 ft 3.0878 cfs r---- -- .-_-. _ l21.2000 ft 0.2460 cfs 25.3000 ft 0.5014 cfs 23 3000 ft 0.3979 cfs 27.4000 ft 3.1973 cfs j213000 ft 0.2553 cfs 25.4000 ft 0.5060 cfs j23.4000 ft 0.4037 cfs 27.5000 ft 3.3026 cfs _ _ f21.4000 ft 0.2643 cfs 25.5000 ft 0.5106 cfs j23.5000 ft 0.4094 cfs 27.6000 ft 3.4043 cfs f 21.5000 ft 0.2729 cfs,25.6000 ft O.S152 cfs -- - _ _ - �~ 123.6000 ft 0.4151 cfs'27.7000 ft 3.5027 cfs . - 7.8000 ft'2 .7ft0.420cfs �.5981_cfs3cf2570ftS197[216000ft0.28 Ocfs 000 ft 2 .800 0r2_J_0 9 ft .4261 cfs27.900�23. 0 ft 13.6907 cfs 121.8000 ft 0.2974 cfs 25.9000 ft 0.5 cfs285 -- _- � _ 28.0000 ft 3.78 88 cfs i THESE PLANS MUST BE OINT►::'j08S;iE FOR INSPECTOR! C-9 Sherwood Creek ktCel 1K41d Access _ Michael„f. Wn Drein�' eRe 07; PIPE HYDRAULICS 100-YEAR FLOW TRAPEZOIDAL CHANNEL ANALYSIS RATING CURVE COMPUTATION July 30, 2007 DESCRIPTION PROGRAM INPUT DATA VALUE -------- --- Channel Bottom Slope (ft/ft) ........ 0.14-- Manning's Roughness Coefficient (n-value) ............. 0.035 Channel Left Side Slope (horizontal/vertical) ............... Channel Right Side Slope (horizontal/vertical) .............. 1 0 3. Channel Bottom Width (ft) ........., 1 Minimum Flow Depth (ft) ............................... 0.1 Maximum Flow Depth (ft) .......................... 1.1 Incremental Head (ft) ............. • COMPUTATION RESULTS Flow Flow Flow Froude Velocity Energy Flow To Depth Rate Velocity Number Head Head Area Width (ft) (cfs) (fps) (ft) (ft) (sq ft) (ft) ------------------- 0.1 0.068 2.264 1.6293 0.0796 0.1796 0.03 0.5 0.2 0.339 3.388 1.7918 0.1784 0.3784 0.1 0.9 0.3 0.91 4.335 1.9016 0.2921 0.5921 0.21 1.3 0.4 1.867 5.185 1,9863 0.4177 0.8177 0.36 1.7 0.5 3.283 5.968 2.056 0.5535 1.0535 0.55 2.1 ---> 0.6 5.228 6.703 2.1155 0.6981 1.2981 0.78 2.5 0.7 7.768 7.398 2.1676 0.8506 1.5506 1.05 2.9 0.8 10.965 8.062 2.2141 1.0101 1.8101 1.36 3.3 0.9 14.877 8.7 2.2562 1.1763 2.0763 1.71 3.7 1.0 19.562 9.315 2.2946 1.3484 2.3484 2.1 4.1 1.1 25.073 9.91 2.3301 1.5263 2.6263 2.53 4.5 HYDROCALC Hydraulics for Windows, Version 1.2a Copyright (c) 1996 Dodson & Associates, Inc., 5629 FM 1960 West, Suite 314, Houston, TX 77069 Phone: (281)440-3787, Fax:(281)440-4742, Email:software@dodson-hydro.com All Rights Reserved. Q100-year = 4.7905 Cf5 G10 STORMWATER MANAGEMENT MANUAL FOR THE PUGET SOUND BASIN Figure III-2.1 - Nomograph for Sizing Circular Drains Flowing Full #000 900 SW -0001 700 Soo 2.0 .0002 Soo Minimum 400 .000 Allowable A004 .00fJ 1 .0006 Velocity 300 .0006-�- tFlowing 3.0 120 v .0008�-.0002 Full) #08 p .001 -.0003 200 9g }.0004 84 c 002- •.0005 4.0 78 Cr 003 .0006 72 .0008 66 U. •004 .001 100 60 0 .006 N Q90 5,d 8i0 4 y oaa .002 O 70 w 4 w.003 -42 c avi 60 004 6.0 u_ fi0 36 .0 .006 p w 7.0 33 .006 u. a z 40 30 .03 .008 a w 8.0 Uj w (ODa 27 :05 .010 -j IL cc 30 a 24 .06 En 9.0 Q U 1 .08 .020 10.0 tf .10 p 20 18 .030 0 W .040 J .¢ 15 .060 > 080 12 .100 10 10 24"@ SAMPLE USE 7 2% g 24"die. CMP @ 2%slope yields 20.0 6 17cfs @ 5.2 FPS velocity 5 (n- 0.024) 6 4 Values per Manning's Equation Q l 1.49l AFt/'S%z 3 n 30.0 Ttlis table can be converted 2 to other"n"values by applying formula: ©1 40.0 _ n1 ©2 n2 - Qmax= BASIN-1 100 yr= 7.5 cfs rESRUARY, 1992 TNI-::,e ;,: NS MUST BE !�f?B SI T E FOR 1NS;�EC T f0N c-i1 STORMWATER MANAGEMENT MANUAL FOR THE PUGET SOUND BASIN Figure III-2.15 - Headwater. Depth for Corrugated Pipe Culverts With Inlet Control 180 10,000 I6B 8,000 EXAMPLE I y 156 7 6,000 D-36'nckoet3.0 teed 6 (`L} 5.000 0.66 ell 144 4,000 Is 5 fi (3) 132 3,000 o (t..) ENTRANCE TYPE 6. 120 "I ''° ° HEADWALL PLAN 2,000 (2) z.l 6.3 5 4 131 2.2 6.6 4. 108 a '0 is test 3• 96 1,000 3 Boo ac 3. 84 w 600 + 500 400 — "-- 2 MITERED TO 72 f 2 CONFORM z 300 /�� 3 1.5 — TO SLOPE fio u 200 z SECTION 1.5 I.s c 54 100 W � / Q ? aB °"` Sol_-, E-- 12"HDPE � a � U _ 60 z PROJECTING U 42 50 x 1.0 1.0 SECTION cc /' 40 a 1.0 W � — W 36 30 H SCALE ENTRa tr w a 33 E 20 a 9 �y tq 8 30 24"CULV. (21 witerea to conform. a � W (/ }} �` to .lap. 2_ A— l3/ 27 10 0) P.etectnno I 0 8 7 .7 z 24 6 .7 21 5 To met keel•12)or(!)project — — 4 Aorclawtallp to last• It),leew we atroipal .nNinea 1.wo tnroesA '6 .6 3 0 awa 0 stole*, ar rererlo a• .6 IB J u�/ral�a. 2 15 I— .5 1.0 .5 12 Qmax = BASIN-1 100 yr=7.5 cfs III-2-35 FEBRUARYr 992 C-12 SHERWOOp-CREEK PARCELS ROAD ACCESS Michael F. Wnek Drainage Report July 27, 2007 BASIN PLAN 200 �_ 1� ```�i ► OF Lk.E LA—E : 0. is Gar-A I r I ti iAcres SCALF z \f i ► r r_ oo•,' g` i f �� „; � r1• � i j r'1 'I tt" 75 1, i-- ,-_ � _ -�'!�-_�•'! , -_- '��`--4�.`�,�\.^'~,, -'��-�{�_+fJ t, { �-•--% q-i- ��'� -.--'�-'--f�uooeoa�e�raonvF-- BASIN 2' 5>_" 4 �~ 5.6 Acre' •��~' .��; ; r +"� ��� / / i O 2 ?► ' r I ¢ % t J �'�/ / to / .j�_ `Z—.__- ✓, _ f f' r�.`..� 100 D-1 MUST BE FOR INSPECTION I SECTION 20, T22Nr R1Wr W.M. $ 1 r ,-,/+ / f^ '� 1 ` h• DETAIL ABOVE-GROUND STORM INSTALLATION, `iioS� Ol1TFALL DISTRIBUTION HEADER I f /l,♦ o -- `� �� ,rlit x t` i \``\``1�N♦ r c i. "- _ "..-� 1 \ '� ✓ _ c x xa I IT \ '1 I I \ %'1")'\I ll`,Ir/��- - ii`� --,�„i i•^-- "__,�i i- \ ` •V\ /'/X l- i owi�io� 0 m3 / 1�,'.!/, ;1`e `3• ; / ,;/;111„ ; _;--,_';- _-- ^ —----- 'S -+-� J �C \ l Y : \; ' - C)u ' i 1' •'J 11 ` \ ` `\ j I rl ; \\\\```,``\1,,1\\ +_i\'' i •` Iif SCALE I `1 r tac-mir.0 nSmBurua If.o[.': •; \ \ / ) -D to A '\�-. / / l \ �� \� \:11\ _ \\ \.1111 111 1 1 >\+ t •-/ PRQn F NEW , I ♦ \ \ \ \\ \`\ I 1 1 1 1 1 Ialol.rz»x[s towms rac[R wa[u ta,Vu raro[o \1 1 1+1 I 1,I +1 _ /Ak�-/ w nos wx lY[aaorus H[., m ca[v. " 8 1 � I ,+ ` ��\ 1 \\I'I 'j'//�/// 1 / <Y�)/^' tEHt warm�sl(HS / fm putrzas �♦' P '/ rroo<aooaAY� B�_ o r r' •/ / / i / / /�/ ,\ \ :r rac, � 1 /, t 1 1 •E 11 t �„ tcmauwrmj x[s (J I \i�\1111\`\`i i i i < 1, :' / t\ / /� ` /•i• /\�j\�'j\Yj >, \ `� Q'."F r�� W 1 ,// _-^�—/ , .. \\\�\I 1\I11,1 1 1`\ + / `+.^s / \ •��\�, ',[\ \ ` uunw['iY ,/! I JI . .\ \�1 11\ 1 I 5 /' '.7" �`/\\% N' y kcu '_.1 �+.. j 1 !�^'/—�� +—'^`_� ''�' , � i 111'1 i11 1\I 1 I I, I''� ,l/ / '�l \ � \�\\/ '\ cua»� I �/ �,�-^ ,^_---` `'r_ / C},; I IIt"I I I I III I I\\�I I i 1 i i is ♦/ ! \.�.. R,rxrlio9i i I/f / I 11j111\I,I1111f,!, , / ;, , / 11„1 �/ /--�\�- ^_, /, 1,511111 j 1 ,1,/I 1+ �T �i_� • ! �. \ .'.M�`/' Q •s - / FI FVA710N B—B SEC110N A—A g..� N j 1' O 1 ULL % i Nii i i i f j�i �!•— _ / - _i{(', i.'i i i i i r'j 1 1 ``,-\ ( ' -•,:�' 1twlsoc«unws srun socaiur-s ra ww rzsea .�u­Kxaas wr I-we \ / +1 11t/1/irl/ 1 1 \` Q.. 1 i i/ii ) />ir' 1� ; i.�� .,� i 1�11�11 ,11 r'11, ' ^� ` , , 1 ,/ O t\` z ru msR+c unaaaw ununcs s«u ec rm lorwrm rawx ro casmxnni. no[rs.eu ra , i�S 1 i, , / / / 1� � • � 11, //11I11 / 1 r^= nt�/ f j, , ) ��:I`C uRltt taros i-ero-.x1-5555. d I/ 1 1 , / / / / ! ! f / /�\!fi. .• I�'1 1 1\\\, i / '�\ \ 1 �- ` /Ev I arm noses cwtaa swea teaxo.YE sEn c-: Q) i I 1 \VA".*.EI , W:� I A.+ M`\ `i\`I 1\ • ` \ �\\\,I Z \ ,- P / r - rH tstv.:mrn �4 a a \l 1 1 1 I \ 1 1 \ \ \ - EX� , ; �1,� 1 � \ � \ \ \ ; RO`AD�`�\\�\\\\\`\\ .�•v '-EX AICESS \\\\\\ Ift ROAD + /^\I 1 1 >\1 1 \ 1 , 1 / _ B :I 1 1 1 1 I. $y—I I I 1 ,,1t / . / 1 I \ 1 J^ —_- 11 111 'I;/ 1" 71}• , I `\"; �( ' "1 /iL/j i � — ..�=�r�• ► _ I�/1 11 % ''j'1 IN / r 1/; ;;••;^—• , I r " yV / y IN d ZQ 4J I I J Op ' I O ---- a. g QntF+- PR _ HOR2. SC AL : 1' 40' T TERRAIN A C—t Z-0 w JA W4, w f, w Z. m U t I IVOS 780H o .2 H. .3 19OUT V"S Fn —MlmvN x,NYfedNII SL A.-J. MI las WWd 14 1.1 nil-1.Alltl\m N RIMIA 23d=�KLM,,,, M5—4 ft 3 Ift lW w.M Si 3MM I" �.-S ..K, um sNlte'lima VOit L(�'j M nm 7�Id MA-6-L4'M 3awam MMS IOHLNW NOfSOV3 LN3NVM83d A-t-I—m IMM L� in 1-1 :OM�E .%-w rAmw 13�3W IZ�,"IWII Sol ift I �Anj mu" —i .0 n­ N- �jm�, limi m 3w Gail s3lij A3 W'21 M� A3 W1, 01" DIM■m QJZ16gs 33 woo 21 39vam cmIrx - .101fil W11,11A 3u jo Im a im"M -------- •- 3SnI.)(IM DNIQ335 1"03 MO6OM3 AW"VaL -A HS— -------- j -------------- ------ • i -> s ox .0 No z z SO 0 in 09 'Z7 F r, i) \ IN 2i 1 y N `l` ♦�^'--^ \l\~` 1 ♦\I1 l ;'rl—�—�—�_ ` __��_\�\�\ oh yJ� \� !� // / %/ ,\�` \ !,�`% /% _ `♦`�`��\\\N;1;it — �—� i —`— '` 1 r.� —:♦.' II, � Y/I `-t ��` 1 r, ,\Illll,\j l � Vrt' o.pa [ `Ar ```\� !•r'` `1 " 8: i/'i'^—♦ `^ '7 1 ' , 1+lllllllll`,/ ................ C _-.,.....y......R• :L:: � ,, �/ `♦�\-�, ` � i)ills ;II1\`` oor i`\;� I�I�`j5 i ili�iiiirr\ �I OD .� h--. _''Y�t�i -• � : ' • ` 1, 1\III//lll//i -`v-__I- 1-h.-'• 1 `\_ l/ll\+\t\,y)1,+11/ / \ 'tiii IN I I �__ , , 1 1,\ l/♦`\,11,111,//,ll:,— 11 I I`^;` — 1 ^_ '+ ' , 1 ._ III Ir17 \,\IIIIII/Ill rl —\.. ., IN / I ,VINA Ili \.,;, �lr , \ ♦ 1 � - I eee///TTTyyy�S +',\ i INII ifill ,j\ 1 ^�! j �I `_'1�'ll/// 1//Il jl li 1 I , / `I __J♦ v gill' I it p 0 •t N. ` 0 IN IN N IN \111\\ I 'y I A I I i"""Its` II I011lIt116 wA It DRAINAGE PLAN 9Y y�yt:1'•60' R.Wbra ......w n MICFIAFL F.WNEI(,P.E.,PS 0''" 01-0 ? JACK JOHNSON t-- "a u9r — P.O.BO%1119 SHERV*X CREEK PROPERTY 1—rr. wW III, WA 9e52E (RAGING .snwcra h EROSION CONTROL PHASE �wa*wi vw�rwii MA-en — v (na)n,-»n (.n)l91-19l� (iq}77D-ssoo <rr�-775-9\99 / -._ / � ,� / /� / / _ ram•\-�- _�-_��_ / _ -�.r_.•. O t I e l / rl t- —RI __I m- U REWIRED DETENTION VOLL!IEI (f� rl[V.tla Il. x�•r Et WIN n•1.rY•r raW[.11.]SO ar ImlMl BASIN-2 GRADING`— oowoo I I r�'ts•n 11j ►L 'I :,- i 1 I , '> i i ats _ - •• 911riY .i , :-t /r i �\ j �\/r � r K U{�D CREEK AD- ,I :•. p•.� �ynllnw-- GI � : n DETAIL a-1. �--� `\I i i ;YLLIIC'.1..733 cr ----•---------•------•-------------- `•-' i BASIN—] POND ;. ' D TAIL • ! BASIN-2 POND J I SCALE:20\ I i i r Ir _^ 1HIM, I\ N Mv. --g•-- v 1\ Yh Ad § 3 ' £ C..1•S Pful \ W 6 y jig ° 11 16501 S410I z a. z z I r Pfl� (L oz HORZ.SCALE: 1'.20' �$t VERT.SCALE: 1'.S' _ O tJ `\ rrAc fIACC 7.40 Ir uN V %I IN I F La?4 It or IY ov d b TERRAIN GRAD Z V)CJ --- _ d •°0°i •6!R _ - » wao w> WQQ3 [ C Z M IrtpgMY �] pi101 V r•w, PROFRE 'IA-IA' PROFILE 'BASIN-1 STORM SK' 0 2� HWL SCALEI 1'.20' HORZ.SCALE: 1'.2(f. ~ Oy VOL SCALE- 1'.D' VERT.SCALE: 1'.D' N ® 1 I II- • • o n o.w ww I• C-4 SECTION 20, T22N, R1W, W.M. P !MIT MATO.AL \ r^ z In°'P MINIMUM < / xu x•r.rodn i .` �CONDARY RISER STACK $CAU::NO SGLLF S 6 (iTY2 Oq i I SBCOMPACTIONS COMPACTI REMOVE ON .. LwMN ..,e r.om AS PERM57D Oi,YETNOO'C rrrurr vp m,A+a e.r.,tln warrWl viva.°A ROOTS ORGANIC x•r w...+• 00'r Lary •.�:�".'::.':PON .�'. ORGANIC MATERIAL, NOVO m..+.x«...n.. d.r.A.r „ ..•,;f-: .� ;, AND UNSUITABLE 11010 F.r,K.nx',... i:•S.%EM9A(J,1(M€N,T,'",. ova mo..vmu. r w,rA.ra..,am .� 'ti'.l,t•.�ai`�� t;.t :ja y�if i�i. _ SUBS. COMPACT aut r a..as a '+r.� '; ::\`� .+r'^•., SUBCRADE. CUTOFF/KEY' PERVIQUS STRATUM ,TRENCKI 'HARDPAN LAYER rrr.Y.,J r..ra1M ' Ru Mort, NOTES: 1.BOTTOM MOTH OF CUTOFF/KEY TRENCH SHALL BE 501L OF 1.r,. .,wvon rYwAs,.wr'w w[e...,.wd.adw.+m.n,.v.w.aa EMBANKMENT TOP OFF / BUT NOT LESS THAN{FEET. .v,uytlar.A.,d,wvw nwvw.w„,.�wa.l.vs-uya....wi..v.�„ry, 2.DEPTH OF CUTOFF/KEY TRENCH SHALL BE SOR CH EMBANKMENT j emo.s sw.wvwr ow ww.ar. HEIGHT, t,BUT NOT LESS THAN 2 FEET INTO HARPAN LAYER. i `s M m.wed,N«.w.dwa.,..lyd u.law..�.um..u,..wndaavtl.w., 3.THE KEY-CUTOFF TRENCH AND EMBANKMENT MATERIALS SHALL MEET 2 �cowww� A)USDA TEXTURAL IU54FlCA710N: ` ... 1 TMwnuMduW auetr.e ramw dw,mwq wwuY; 50%%CLAY.MINMAXIMUM 60%SILT, MAXIMUM 602 SILT,MLAIMUki SS. B)UNIFIED SO l CUSS 0.06r Cdrv0ur0AWH.W 9w1 PaNM q .oerum...+wr,.n..,u.�w...mws,u earo.sosa nudrvs SY'OR'F TENCH AN N BE XCAVATED INTO H s 8 J ipi0..r.vd,..A.,.scams wvp A,IF THE REASONABLE DE TRENCH CAN NOT EXCAVATED NTO HARDPAN AT A REASONABLE BLA THE POND EMBANKMENT Y111 REQUIRE RE-DESIGN t, A yTM.o.�d.y o,.�.,w�wo v.6nrrm��viw..e. FOR AN IMPERVIOUS BIAHKET. T. wvaw.naum.e.d.4.w.wn.w.n.cm,au..w,wsau.n wwatuea». :NO wM,r.v.w„W�a.rma.b.4l.uve.d uaa � QEyq fie« ,.•...u..,.,. ' ,our Aro a nAro� �w.w.`..nwW,.e:`.m�..aiw. f SSA ti �^ .+v w..dwuwwwa we..avwwnw a E E }� .nAe..., L,uuv O.0 mr tlrr.uw...utl e,0,v k^ y.ati. nrJn.nop.rM1iadN o.mwwaer uaw cap nc.—...uw ue, SJOOM R �a R"F- - g f la yt �f J C""..w T la 2 WITH DETAIL FLOW RISTRICTOR ter k- k fJ TAIL BASIN-1 DETAIL: BASIN-2 ,flOW ti pFTFfLOW RESTRICTDR D�FT�N110N5,FLDW RE5IRICT()R O �� f f�YYtt ti�71TC�71d}iY+ C—5 ` Michael F. Wnek, P.E., PS Consulting Civil Engineer 3388 NW Byron St, Suite 200, Silverdale, WA 98383, 360-692-3802 Drainage Renort N O V 1 9 Z000 MASON CO. , SHERWOOD CREEK PARCELS ACCESS ROAD Sherwood Creek Rd 12229 22 00320 12220 33 00210 12220 33 90223 12220 33 90222 12220 33 90221 located in: MASON COUNTY prepared for: JACK JOHNSON P.O. BOX 1119 BELFAIR, WA 98528 360-275-5400 July 27, 2007 MFW Project Number: 340 By the seal and signature here affixed, ca,� o I certify that the enclosed report was accomplished by myself, and that I am �J1 currently a registered engineer of good ; u' h 3i�a standing in the State of Washington. I Sherwood Creek Parcels Access Road Michael F. Wnek, P.E., PS Drainage Report July 27, 2007 TABLE OF CONTENTS 1. VICINITY MAP...............................................................................................................................................................................................2 2. PROJECT DESCRIPTION.............................................................................................................................................................................2 a. Type of Permits.........................................................................................................................................................................................2 b. Size and Location of Project Site..............................................................................................................................................................2 C. Legal Description.......................................................................................................................................................................................2 d. Proposed Land Use&Site Improvements................................................................................................................................................2 e. Proposed Impervious Surfaces.................................................................................................................................................................2 3. EXISTING CONDITIONS...............................................................................................................................................................................2 a. Topography...............................................................................................................................................................................................2 b. Land Cover................................................................................................................................................................................................2 C. Adjacent Environmental Features..............................................................................................................................................................2 d. Wells..........................................................................................................................................................................................................3 e. Soils...........................................................................................................................................................................................................3 f. Groundwater.,............................................................................................................................................................................................3 g. Adjacent Drainage Facilities......................................................................................................................................................................3 h. Drainage Discharge Points........................................................................................................................................................................3 i. Relevant Reports.......................................................................................................................................................................................3 4. DEVELOPED SITE DRAINAGE CONDITIONS.............................................................................................................................................3 a. Proposed Land Cover................................................................................................................................................................................3 b. Potential Storm Runoff Quantity&Quality Impacts...................................................................................................................................3 C. Proposed Storm Collection&Conveyance...............................................................................................................................................3 d. Proposed Storm Mitigation Measures.......................................................................................................................................................4 e. Discharge Point.........................................................................................................................................................................................4 5. WATERSHED BASIN DESCRIPTION...........................................................................................................................................................4 6. DESCRIPTION OF UPSTREAM BASIN........................................................................................................................................................4 7. DOWNSTREAM CONDITION........................................................................................................................................................................4 8. SOILS.............................................................................................................................:..............................................................................4 9. BASIN MAPS.................................................................................................................................................................................................4 a. Project Boundaries....................................................................................................................................................................................4 b. Off-Site Contributing Basins......................................................................................................................................................................4 C. Project Drainage Basin..............................................................................................................................................................................4 d. Storm Runoff Downstream Route..............................................................................................................................................................4 10. HYDROLOGIC ANALYSIS.....................................................:..................................................................................................................5 a. Methodology..............................................................................................................................................................................................5 b. Curve Numbers(CN).................................................................................................................................................................................5 C. Time of Concentration...............................................................................................................................................................................5 d. Runoff Volumes&Peak Discharges.........................................................................................................................................................5 e. Upstream Run-off......................................................................................................................................................................................5 f. Bypass.......................................................................................................................................................................................................5 g. Quantity Mitigation.....................................................................................................................................................................................5 h. Quality Mitigation.......................................................................................................................................................................................5 i. Piping.........................................................................................................................................................................................................5 11. EROSION CONTROL...............................................................................................................................................................................6 APPENDIXES VICINITY MAP A-1 PROPERTY REPORT#1 A-2 PROPERTY REPORT#2 A-3 AERIAL PHOTO A-4 ASSESSORS MAP A-5 USGS CONTOUR MAP&UPSTREAM/DOWNSTREAM EXHIBIT A-7 SOILS MAP A-8 FIGURE 25 ISOPLUVIALS OF 2-YR 24HR PRECIPITATION B-1 FIGURE 27 ISOPLUVIALS OF 10-YR 24-HR PRECIPITATION B-2 FIGURE 30 ISOPLUVIALS OF 100-YR 24-HR PRECIPITATION B-3 TABLE III-1.3 SCS WESTERN WASHINGTON RUNOFF CURVE NUMBERS B-4 TABLE III-1.6 HYDROLOGIC SOIL GROUPS FOR SOILS IN THE PUGET SOUND BASIN B-5 IMPERVIOUS AREA COMPUTATIONS C-0 HYDROLOGY CALCULATIONS Basin-1 5 pages) C-1 HYDROLGOY CACLULATIONS Basin-2 4 pages) C-6 HYDRAULIC CALCULATIONS,Ditch&Pie C-10 FIGURE III-2.1 PIPE FLOW C-11 FIGURE III-2.15 HEADWATER DEPTH C-12 BASIN PLAN D-1 1 Sherwood Creek Parcels Access Road Michael F. Wnek, P.E., PS Drainage Report July 27, 2007 1. VICINITY MAP See attached Vicinity Map, Appendix A. 2. PROJECT DESCRIPTION a. Type of Permits BUILDING PERMIT MC Dept. of Com. Development GRADING PERMIT MC Dept. of Com. Development SHORT PLAT MC Dept. of Com. Development BOUNDARY LINE ADJUSTMENT MC Dept. of Com. Development b. Size and Location of Project Site Parcel Size: 11.9 Acres Project Size: 5.18 Acres (clearing area) Site Address: Sherwood Creek Rd c. Legal Description Assessor's Parcel Number: 12229 22 00320 12220 33 00210 12220 33 90223 12220 33 90222 12220 33 90221 Legal Description: Attached Zoning: Rural & Residential d. Proposed Land Use & Site Improvements Access road & residential construction. Nine proposed lots will be configured through five existing lots, via short plat & boundary line adjustment. e. Proposed Impervious Surfaces 77,000 square feet = 1.77 acre (new impervious) 3. EXISTING CONDITIONS a. Topography Maximum Slope — 66% Declivity- Southeasterly Defined Channels- None b. Land Cover Project property— Rural Residential General area - Rural Residential c. Adjacent Environmental Features Creeks, Lakes, Ponds, Wetlands— Sherwood Creek, flows to Case Inlet Ravines, Gulleys, Steep Slopes - None Springs, Env. Sensitive Areas - None 2 Sherwood Creek Parcels Access Road Michael F. Wnek, P.E., PS Drainage Report July 27, 2007 d. Wells The project site and the neighbor to the east both have wells. e. Soils Per the USDA Soils Survey for Mason County: Alderwood Sinclair Both are considered Hydrological Group C f. Groundwater Seasonal perched water tables, typical to the local soils. g. Adjacent Drainage Facilities Roadway cross culverts in Sherwood Creek Road. h. Drainage Discharge Points Southeasterly as shallow channel flow. i. Relevant Reports Project Geotechnical Report for steep slopes 4. DEVELOPED SITE DRAINAGE CONDITIONS a. Proposed Land Cover The project includes constructing an access road to existing tax parcels. The road provides access to the flatter terrain at the higher elevation (ridge) on the parcels. Clearing and grading of the ridge for future house sites will also be accomplished. There is an existing one-lane gravel road, in the southern parcel of the project, coming up from Sherwood Creek Road. The project access road starts at a point 440-ft up the existing access road, from the Sherwood Creek Road approach. The project area is shown on the attached exhibit: AERIAL PHOTO. b. Potential Storm Runoff Quantity & Quality Impacts The project will create greater than 5,000 square feet of new impervious area; and will require greater than 1 acre of clearing. Therefore storm runoff quantit mitigation is required. Peak flows for the 10-year & 100-year events will need to be attenuated so that the developed condition does not exceed the existing condition. Runoff will flow to a stream (Sherwood Creek) before entering an adequate receiving body (Case Inlet), therefore "streambank erosion control" criteria is required: the 2-year developed-condition event will need to be detained to release at 50% of the existing- condition peak.. c. Proposed Storm Collection & Conveyance Roadside ditches. Cross culverts. Detention Pond 3 Sherwood Creek Parcels Access Road Michael F. Wnek, P.E., PS Drainage Report July 27, 2007 d. Proposed Storm Mitigation Measures Due to the topography, 2 separate detention systems are warranted. Quantity Control: Detention Ponds (2 each) Qualitv Control: None warranted e. Discharge Point Roadway ditches of Sherwood Creek Road. 5. WATERSHED BASIN DESCRIPTION Sherwood Creek watershed. See attached USGS map 6. DESCRIPTION OF UPSTREAM BASIN See attached USGS map &Assessor's aerial photo, Appendix-A. 7. DOWNSTREAM CONDITION See attached USGS map &Assessor's aerial photo, Appendix-A. 8. SOILS See attached SOILS MAP, Appendix-A. 9. BASIN MAPS a. Project Boundaries See attached ASSESSORS MAP, Appendix-A b. Off-Site Contributing Basins The existing plat of Lakeland Village abuts the project to the north &west. Lakeland Village parcels to the north drain to the project basin. c. Project Drainage Basin See attached BASIN PLAN. The crest of the new access road will divide the area into two separate sub-basins. For hydrology calculations they are designated: Basin-1 Northern Sub-basin Basin-2 Western Sub-basin d. Storm Runoff Downstream Route The upstream & project basins flow to the roadway ditch of Sherwood Creek Road, and cross under the road to Sherwood Creek at various locations. 4 Sherwood Creek Parcels Access Road Michael F. Wnek, P.E., PS Drainage Report July 27, 2007 10. HYDROLOGIC ANALYSIS a. Methodology The detention system is sized to meet the criteria listed in paragraph 4.b. The hydrological analysis is based on Santa Barbara Urban Hydrogragh methodology. The storm type is "W'. b. Curve Numbers (CN) Alderwood: Group C. Sinclair: Group C. c. Time of Concentration Existing: See attached exhibit: BASIN PLAN Developed: No calculations, apply minimums d. Runoff Volumes & Peak Discharges See Appendix C. e. Upstream Run-off Due to the steep topography between the proposed building sites (upland bench) it is not practical to separate the upstream runoff (Lakeland Village) from the project runoff. Deflecting this flow around the project would concentrate the flow & increase the likelihood of erosion damage. Lakeland Village is considered part of the "existing condition" for hydrology calculations. f. Bypass All project storm runoff can be captured and routed through the treatment system. There will be no un-detained or untreated runoff from the project. g. Quantity Mitigation Computations are attached in the Appendix h. Quality Mitigation Not applicable, the percentage of driving surfaces within the sub-basins are minimal; contamination of runoff with hydrocarbons is unlikely. i. Piping 24-inch piping will be required at locations that carry the full basin peak runoff. Basin-1 will need to transport flows down the steep slope to the detention pond. Above ground, anchored, 12" HDPE pipe will be used for this application. The invert at the upstream catch basin will need to be set so that the 100-year peak flow will create sufficient headwater depth to overcome entrance control. Calculations are attached. 5 Sherwood Creek Parcels Access Road Michael F. Wnek, P.E., PS Drainage Report July 27, 2007 11. EROSION CONTROL Temporary erosion & sedimentation control measures will be implemented to treat the road construction &the lot clearing, and include: Sediment traps Wood Chip Berm or Filter Fabric Fence Straw Bale Barriers Rip-rap lined ditches 340/ST0RM/340_Storm_2.doc 6 Sherwood Creek Parcels Access Road Michael F. Wnek, P.E., PS Drainage Report July 27, 2007 VICINITY MAP E LUCAS CREEK Rb J E'CEdAR ST akk E SKY CT j` § Ffi,J,O� '�r a rza uu t.::aka � j 40 `i t d c0off try yt ' '¢ < E corisua LN vat, zakexndersOn y°° --ECREBpR`�� scar �1 ��ka} r g A-1 Sherwood Creek Parcels Access Road Michael F. Wnek, P.E., PS Drainage Report July 27, 2007 Parcel number: 122292200320 V IF a Owner Information JACK JOHNSON CONSTRUCTION INC PO BOX 1119 BELFAIR WA 98528-1119 Taxpayer Information JACK JOHNSON CONSTRUCTION INC PO BOX 1119 BELFAIR WA 98528-1119 Legal Description PCL 5 OF BLA#06-23 REV I SURVEY 32/61 Site Address Reval Area ? 2 Field Sheet FS 03308:01 Land Size* 2.26 Land Use VACANT LAND 5 ACRES &UNDER Tax Code ? 201 Tax Code Description 1 403 A P3 E3 L H Census Tract Click Here * if the value is .00(zero)then the property is most likely in a plat and acreage is not usually carried on platted lots Parcel number: 122203300210 View Ma Owner Information JACK JOHNSON CONSTRUCTION INC PO BOX 1119 BELFAIR WA 98528-1119 Taxpayer Informatiion JACK JOHNSON CONSTRUCTION INC PO BOX 1119 BELFAIR WA 98528-1119 Legal Description PCL 6 OF BLA#06-23 (R)AF#1877210 SURVEY 32/61 Site Address 373 E SHERWOOD CREEK RD ALLYN Reval Area ? 2 Field Sheet 9 FS 03305: Land Size* 2.52 Land Use 12' VACANT LAND 5 ACRES &UNDER Tax Code ? 202 Tax Code Description ? 1 403 A P3 E5 L H Census Tract Click Here * if the value is .00(zero)then the property is most likely in a plat and acreage is not usually carried on platted lots A-2 Sherwood Creek Parcels Access Road Michael F. Wnek, P.E., PS Drainage Report July 27, 2007 Parcel number: 122203390221 =Map Owner Information JACK JOHNSON CONSTRUCTION INC PO BOX 1119 BELFAIR WA 98528-1119 Taxpayer Informatiion JACK JOHNSON CONSTRUCTION INC PO BOX 1119 BELFAIR WA 98528-1119 Legal Description PCL 1 OF BLA#06-23 REV I SURVEYS 9/6&32/61 Site Address Reval Area ! 2 Field Sheet ' FS 03303:01 Land Size* 6.01 Land Use `.' VACANT LAND 5 ACRES &UNDER Tax Code . 215 Tax Code Description ? 1 403 A P3 F5 L H Census Tract Click: Here * if the value is .00(zero)then the property is most likely in a plat and acreage is not usually carried on platted lots A-3 Sherwood Creek Parcels Access Road Michael F. Wnek, P.E., PS Drainage Report July 27, 2007 AERIAL PHOTO F - - , 1 .0, �- IV- r 4 A-4 Sherwood Creek Parcels Access Road Michael F. Wnek, P.E., PS Drainage Report July 27, 2007 ASSESORS MAP 122205400030 122205400105 !2205400091 122205400032 )088 i 122205400103 .1 122205400094 !2205400092 122205400095 122205400100 122205400104 122205400093 122205400096 122205400099 122205400102 )87 122205400097 122205400101 122205400098 22205400084 12 400085 122203390223 122203390222 122205400083 122203390221 10082 122203300320 122203390224 , 122203300210 122208888888 SJjERVVOO .2WO0074 175 122295100005 122295100004 122295100003 12220330023 122203300290 !2205400072 122295100002 140 122203300211 122292200320 122295100001 1222W200280 22307600041 122292200390 f 122292200310 122299999999 122292200330 122292290344 100010 48E A-5 Sherwood Creek Parcels Access Road Michael F. Wnek, P.E., PS Drainage Report July 27, 2007 USGS CONTOUR MAP f i r r ■ j t' � t F �_� a n;_e.•.:� __�,,., r}fjJ1j � z - - -= A-6 Sherwood Creek Parcels Access Road Michael F. Wnek, P.E., PS Drainage Report July 27, 2007 SOILS MAP 01 a AR ` y f • ; x Keg, ems ' I- -' Tk } Ac = Alderwood So = Sinclair A-7 STORMWATER MANAGEMENT MANUAL FOR THE PUGET SOUND BASIN 124 123 122 121 49 25 5 s w a «r N MM374 7S 79 EL s 21 BE N ri 8LGA i FRIDAY HARBOR ' lT� b ` !J PORT STA LEY m ryE�IO l 1f MTV ) tt RC 40 30252p 15 t 1 7' 48 ` ,s I ` ' Kl9 11 1 I - c /f ERETT ?' n 40\ _ 1� / 15 25 Cc ' Pn5f245 50 5` 3 $4� y 424 s AT` t ` I t 4 3 20 3 ` 45 /� CO �. _ 35 MA ' 2.1 47 '' 1 I � A8 DEN - 30 10 3 , 3; 12 25 y s • CENT ,4� 20 - n 55. 11 to ' YAKI 45'I , 0 2 M 1 35— � � 1 1 ADA 2 L1 J 46 55 I 45 y WASHINGTON B x P.PL EN E SO 0 16 20 30 40 � - _ �; Tr--- r—i MILES ' Figure 25 NOAA ATLAS 2, Volume IX 25 fSOPLUVIALS 1 2 YR 24 HR PRECIPI7AT1 N IN Prepared by U,S.Department of merce TENTHS A Ar�INCH National Oceanic and Atmospheric ministration f National Weather Service,Office of Hydrology Prepared for U.S.Department of A4 riculture, Soil Conservation Service,Engines ng Division 124 123 122 121 III-1-44 FEBRUARY, 1992 B-1 • r � � �e �d7�`r1" /(lIiFJ(}�1�,'" �+R�'�Y`r/J/� i CIA F its PC r �AM • Vs7' 1 r ,AM r 1 STORMWATER MANAGEMENT MANUAL FOR THE PUGET SOUND BASIN 124 123 122 121 80 s EL s 43 o s C 40 1 t 55 FFcIG4Y HAR -d n +HOR1 S]AN 7 51085 \` 3 30 / \ I 0 1 6 _ .�— T i - =� 4� 25. , r 75 I�+ �03g�2 -,\ �q 55 48 0^ Alin 65•. � + � s �gp � 1001 4 90� - 7 1 1 S AT 5 60 1 tC 4 P 'I �•,�/Q I 2Do /•' - � a s\ --� • ABE E N ru 165 so 0•- = 1 2 2 , a s 70 so n I/ .E 71? 70 •. 2 YAK f 100 � 55 i 6 { 45 ro 0 55 \ 5t T s ss i (� 7 • C 63`60 55 U w 1 (� AD M� --30 25. 46 , G - 4 �,`� 40 WKLI WASHINGTON '° 1 ! ,a� �� EN E 10 0 10 20 30 40 ' MILES 40 iMtifCJ �y ' �u so 35_ ..... - Figure 30 I 4.5 4 NOAA ATLAS 2, Volume IX + 50 I Prepared by U.S.Department of Commerce 150PLl1VIALS F 100-YR 24•HR PRECfPITATION 60 65 i National Oceanic and Atmospheric ministration 4 IN TENTHS OF N {NCH National weather Service,Office oflHydrology Prepared for U.S Department of A41riculture, SON Conservation Service,Engineering Division 124 123 122 121 III-1-46 FEBRUARY, 1992 B-3 STORMWATER MANAGEMENT MANUAL FOR THE PUGET SOUND BASIN Table III-1.3 SCS Western Washington Runoff Curve Numbers (Published by SCS in 1982) Runoff curve numbers for selected agricultural, suburban and urban land use for Type lA rainfall distribution, 24-hour storm duration. LAND USE DESCRIPTION CURVE NUMBERS BY HYDROLOGIC SOIL GROUP A B C D Cultivated land(1): winter condition 86 91 94 95 Mountain open areas: low growing brush & grasslands 74 82 89 92 Meadow or pasture: 65 78 85 99 Wood or forest land: undisturbed 42 64 76 81 Wood or forest land: young second growth or brush 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 Z75% of the 68 80 86 90 area Fair condition: grass cover on 50-75% of 77 65 90 92 the area Gravel roads & parking lots: 76 85 89 91 Dirt roads & 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) Separate curve number 1.0 DU/GA 15 shall be selected for 1.5 DU/GA 20 pervious & impervious 2.0 DU/GA 25 portions of the site 2.5 DU/GA 30 or basin 3.0 DU/GA 34 3.5 DU/GA 38 4.0 DU/GA 42 4.5 DU/GA 46 5.0 DU/GA 48 5.5 DU/GA 50 6.0 DU/GA 52 6.5 DU/GA 54 7.0 DU/GA 56 PUD'e, condos, apartments, %impervious commercial businesses & must be industrial areas computed (1) For a more detailed description of agricultural land use curve numbers refer to National Engineering Handbook, Sec. 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. III-1-12 FEBRUARY, 1992 B-4 N O� Qt e-1 y � a upon ° AauumwmQa ❑ Qwa < uuAaaauaaAw ° uawpuuwa ° AwnQaAmuuvaw ° awAa o zz z zzzz zzz z .0 z z z z ] Q C7 ( y p( v pa � z w w O 7 H N W K � bo a Ey u .11 i C 3 t � � •E a � •u0 E �. a. � � rd .� _n w �_ u k g E c " 2 ° o • y s _ `� u ° ° m '" 0 9 0 c°.. � a . yy � m� a5� ; ; � = r : � s � eba ., r ; o v y UUAG7C] a � t� l t7i u"1u7m W C7C7C7 f7C7C7X x ]c � x � � x �a .. .o � vco; c+Zo; �n �'nv', "R4- nv, �n �'iUYtnWiiiminrncn0W) vof voi (A u C U w U u w w m m U w w U ❑ U m A a U m u ° U w m m Q w u w a u u U ❑ ° V w ❑ Q (� w m U a ° m A L w zz u z z zz z z A m Q a Q m � u z H >• M 8 PC u H F O w ��aa �a o3a3r � �3 � r o�or r uu iu •uuuu � azzzz 1 , STORMWATER MANAGEMENT MANUAL FOR THE PUGET SOUND BASIN Hydrologic Soil Hydrologic Soil Soii Type Group Soil Type Group Newberg B Spanawsy A/B Nisqually B Springdale B Nookaack C Sulaavar B Norma C/D Sultan C Ogarty C Sultan variant B Ole,* ND Sumaa C Olotnotus C Swantoavn ND Olympic B Tacoma D Oncaa D Tamvax ND Oridia D Tealwhit ND Orting ND Tenino C Oso C Tiach D Ovall C Tokul ND Paatilt C Townsend C Pheeney C Triton ND Phelan ND Tukwila D Pilchuck C Tukey ND Pbtchub C Urban variable Poulabo C Vailton B Prather C Verlot C Puget D Wapato ND Puyallup S Wardtn B Queets ND Whidbey ND Quilcene ND Wilkeson B Ragnar B Winston A Rainier C Woodinvilit B Raught B Yelm C Reed ND Zynbar B 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 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 clay layer at or near the surface, and shallow soils over nearly impervious material. These soils have a very slow rate of water transmission. ND Data not currently available for this soil type. *From SCS, TR-55, Second Edition, June 1986, Exhibit A-1. Revisions made from SCS, Soil Interpretation Record, Form 05, September 1988 and various county soi, surveys. III-1-10 FEBRUARY, 1992 B-6 Sherwood Creek Parcels Road Access Michael F. Wnek, P.E., PS Drainage Report July 27, 2007 DEVELOPED IMPERVIOUS AREA COMPUTATIONS BASIN-1 BASIN-2 ROAD ROAD = I * w = 708.9112' '` 20' = I * w = 1320.4786' * 20' = 14178.224 sf = 26409.572 sf = 0.325 acre = 0.606 acre HOUSE & DRIVEWAY HOUSE & DRIVEWAY @ 4,000 sf/lot, 6 lots @ 4,000 sf/lot, 3 lots = 6 * 4,000 sf = 3* 4,000 sf = 24,000 sf = 12,000 sf = 0.551 acre = 0.275 acre EXISTING IMPERVIOUS LOTS (house/driveway) Existing lots = 3 acres =70 % impervious =2.1 acre TOTAL IMPERVIOUS TOTAL IMPERVIOUS = 0.325 + 0.551 + 2.1 = 0.606 + 0.275 = 2.98 acre = 0.881 acre c-o Sherwood Creek Parcels Road Access Michael F. Wnek, P.E., PS Drainage Report July 27, 2007 PRECIPITATION Event Precip(in) 2 year 3.5000 10 year '4.8000 100 year 6.6000 BASIN-1 LPOOL-1 SUMMARY using Puls Start of live storage: 16.9000 ft Event Match Q(cfs) ;Peak Q(cfs) Peak Stg(ft) Vol(cf) Vol(acft) Time to Empty 2 year 1.0583 1.0554 22.9001 9511.58 0.2184 25.33 10 year 3.2047 [ 3.0791 23.6147 11659.92 0.2677 25.67 100 year! 74 905 4.5710 1 24.9754 16346.69 0.3753 27.00 HYDROGRAPH SUMMARY HydID Peak Q(cfs) Peak (hrs) Peak Vol(ac-ft) Cont Area(ac) 2 year out 1.0554 9.33 1.2407 j 5.5000 10 year out 3.0791 8.33 1.8092 5.5000 100 year out 4.5710 8.33 2.6110 5.5000 BASIN SUMMARY BasinlD Event Peak Q Peak T ''Peak Vol(ac-cf) Area(ac) Method/Loss Raintype (cfs) (hrs) BASIN-1 2 year 2.1165 8.00 0.9998 5.50 SBUH/SCS TYPEIA DEVELOPED-1 2 year 3.5213 8.00 1.2411 5.50 SBUH/SCS TYPEIA BASIN-1 10 year 3.2047 8.00 1.5241 5.50 SBUH/SCS TYPEIA DEVELOPED-1 10 year 5.1661 8.00 1.8096 5.50 SBUH/SCS TYPEIA BASIN-1 100 year 4.7905 8.00 2.2848 5.50 SBUH/SCS TYPEIA ', DEVELOPED-1 100 year 7.4702 8.00 2.6114 5.50 SBUH/SCS TYPEIA ', C-1 Sherwood Creek Parcels Road Access Michael F. Wnek, P.E., PS Drainage Report July 27, 2007 Record Id: BASIN-1 Design Method I SBUH Rainfall type TYPEIA Hyd Intv 10.00 min Peaking Factor 484.00 1 Abstraction Coeff 0.20 Pervious Area(AMC 2) 3.40 ac DCIA v 2.10 ac _.______,� ,._.-.__.-�� ._.. __. -__ Pervious CN 78.21 DC CN 98.00� Pervious TC 60.96 min DC TC 5.00 min Pervious CN Cale Description SubArea Sub cn Wood forest land(Undisturbed/2nd growth) 2.50 ac 76.00 1 Open spaces,lawns,parks(>75%grass) 0.60 ac 86.00 Wood/forest land(young 2nd growth/brush) 0.30 ac 81.00 Pervious Composited CN(AMC 2) 78.21 Pervious TC Cale . Type I Description Length Slope Coeff Misc TT Sheet Woods or forest with light underbrush.:0.40 197.00 ft 1.00% 0.4000 3.50 in 46.61 min Sheet Woods or forest with light underbrush.:0.40 105.00 ft 20.00% ',0.4000 '3.50 in 8.50 min Shallow Forest w/heavy ground litter&meadows(n=0.10) 88.00 ft 30.00% 0.1000 0.83 min Shallow Forest w/heavy ground litter&meadows(n=0.10) 158.00 ft 51.00% 0.1000 1.15 min Shallow ,;Forest w/heavy ground litter&meadows(n=0.10) 211.00 ft '8.00% 0.1000 3.87 mm Pervious TC 60.96 min Directly Connected CN Cale _ I Description SubArea Sub cn Impervious surfaces(pavements,roofs,etc) 2.10 ac 98.00 DC Composited CN(AMC 2) 98.00 µ' Directly Connected TC Cale 3 Type Description Length Slope Coeff Misc TT ' Fixed 5.00 min Directly Connected TC 5 00min C-2 Sherwood Creek Parcels Road Access Michael F. Wnek, P.E., PS Drainage Report July 27, 2007 Record Id: DEVELOPED-1 Design MethodSBUH ;Rainfall type TYPEIA Hvd Intv 10.00 min :Peaking Factor F 484.00 Abstraction Coeff 0.20 Pervious Area(AMC 2) _ 2.52 ac DCIA 2.98 ac Pervious CN 85.41 DC CN ..,_. .98.00 Pervious TC 10.00 min DC TC 5.00 min Pervious CN Cale Description SubArea Sub^c __ n __-__..___.__ _ __�__ _ ___M ___ - _-- _ _ Open spaces,lawns,parks(>75%grass) 1.62 ac 86.00 Open spaces,lawns,parks(>75%grass) 0.60 ac 86.00 Wood/forest land(young 2nd growth/brush) 0.30 ac 81.00 Pervious Composited CN(AMC 2) 85.41 I _ Pervious TC Calc . _ Type Description Length Slope Coeff Misc TT 10.00 min .. ... Pervious TC 10.00 min Directly Connected CN Calc Description SnbArea Sub cn Impervious surfaces(pavements,roofs,etc) 0.32 ac i 98.00 _ ..... _ Impervious surfaces(pavements,roofs,etc) 0.55 ac 98.00 Impervious surfaces(pavements,roofs,etc) 2.10 ac 98.00 _ DC Composited CN(AMC 2) 98.00 1 Directly Connected TC Calc r_.__._ Type 3: Description Length Slope Coeff Misc TT Fixed j 5.00 min Directly Connected TC 5 00mm Record Id: LPOOL-1 Descrip: Level Pool Routing Increment 0.10 ft Start El. 16.5000 ft Max El. 25.0000 ft^ Storage Node POND-I-GRADED Discharge Node ORIFICE-1 C-3 Sherwood Creek Parcels Road Access Michael F. Wnek, P.E., PS Drainage Report July 27, 2007 Record Id: ORIFICE-1 Descrip: Prototype Structure Increment 0.10 ft Start El. 17.0000 ft Max El. 25.0000 ft Orif Coeff 0.62 Lowest Orif El. 15.00 Lowest Diam 4.0000 in Dist to next 5.9000 ft D2 9.2500 in Dist to next 0.0000 ft Stage Discharge Rating Curve 19.0000 ft'0.6140 cfs 23.1000 ft 2.1108 cfs 17.0000 ft 0.0000 cfs 2 1.1000 ft 0.8792 cfs` 19.1000 ft 0.6292 cfs 23.2000 ft 2.3529 cfs' 17.1000 ft 0.1373 cfs 21.2000 ft 0.8898 cfs 19.2000 ft 0.6440 cfs 23.3000 ft 2.5583 cfs 17.2000 ft 0.1942 cfs 21.3000 ft 0.9004 cfs' 19.3000 ft 0.6585 cfs 23.4000 ft 2.7403 cfs' 17.3000 ft 0.2378 cfs 21.4000 ft;0.9108 cfs 19.4000 ft 0.6726 cfs 23.5000 ft 2.9055 cfs' 17.4000 ft 0.2746 cfs 21,5000 ft'0.9211 cfs 19.5000 ft 0.6865 cfs 23.6000 ft 3.0581 cfs 17.5000 ft 0.3070 cfs 21.6000 ft 0.9312 cfs 19.6000 ft 0.7001 cfs 23.7000 ft 3.2007 cfs 17.6000 ft 0.3363 cfs 21.7000 ft 0.9413 cfs 19.7000 ft 0.7135 cfs 23.8000 ft 3.3350 cfs 17.7000 ft 0.3633 cfs 21.8000 ft 0.9513 cfs 19,8000 ft 0.7265 cfs 23.9000 ft 3.4624 cfs' 17.8000 ft 0.3884 cfs 21.9000 ft''0.9611 cfs' 19.9000 ft 0.7394 cfs 24.0000 ft 3.5840 cfs' 17.9000 ft 0.4119 cfs 22,0000 ft'0.9709 cfs' 20.0000 ft 0.7520 cfs 24.1000 ft 3.7005 cfs 18.0000 ft 0.4342 cfs 22.1000 ft'0.9805 cfs' 20.1000 ft 0.7645 cfs 24.2000 ft 3.8124 cfs 18.1000 ft 0.4554 cfs 22.2000 ft'0.9901 cfs 20.2000 ft 0.7767 cfs 24.3000 ft 3.9204 cfs 18.2000 ft 0.4756 cfs 22.3000 ft 0.9996 cfs 20.3000 ft 0.7887 cfs 24.4000 ft 4.0249 cfs 18.3000 ft 0.4951 cfs 22.4000 ft 1.0090 cfs 20.4000 ft 0.8006 cfs 24.5000 ft 4.1261 cfs 18.4000 ft 0.5137 cfs 22.5000 ft 1.0183 cfs 20.5000 ft 0.8123 cfs 24.6000 ft 4.2244 cfs 18.5000 ft 0.5318 cfs 22.6000 ft 1.0275 cfs 20.6000 ft 0.8238 cfs 24.7000 ft 4.3200 cfs 18.6000 ft 0.5492 cfs 22.7000 ft 1.0366 cfs 20.7000 ft'0.8352 cfs 424.8000 ft 4.4132 cfs 18.7000 ft'0.5661 cfs 22.8000 ft 1.0457 cfs 20.8000 ft'0.8464 cfs 24.9000 ft'4.5041 cfs 18.8000 ft 0.5825 cfs 22.9000 ft 11.0546 cfs` 20.9000 ft 0.8575 cfs 25.0000 ft 4.5928 cfs 18.9000 ft 0.5985 cfs 23.0000 ft 1.7978 cfs C-4 Sherwood Creek Parcels Road Access Michael F. Wnek, P.E., PS Drainage Report July 27, 2007 Record Id: POND-1-GRADED Descrip: ,Graded Construction Pond Increment 0.10 ft :Start El. I16.9000 ft Max El. 25.0000 ft' Stage Area Stage(ft) Area(sf) 16.90 0.0000 17.00 363.0000 25.00 3742.0000 Stage Storage Rating Curve 18.9000 ft 1470.2367 cf 23.0000 ft 9798.8994 cf ------------- 16.9000 ft 0.0000 cf 21.0000 ft 4849.1499 cf 19.0000 ft 1588.8999 cf 23.1000 ft;10090.7363 cf 17.0000 ft 18.1499 cf 21.1000 ft 5056.5117 cf 19.1000 ft 1711.7867 cf 23.2000 ft 10386.7969 cf'' 17.1000 ft 56.5617 cf 21.2000 ft, 5268.0972 cf 19.2000 ft 1838.8973 cf 23.3000 ft 10687.0820 cf 17.2000 ft 99.1974 cf 21.3000 ft 5483.9067 cf 19.3000 ft 1970.2317 cf 23.4000 ft;10991.5898 cf 17.3000 ft 146.0567 cf 21.4000 ft 5703.9399 cf 19.4000 ft 2105.7898 cf 23.5000 ft 11300.3213 cf 17.4000 ft 197.1399 cf 21.5000 ft 5928.1968 cf 19.5000 ft 2245.5718 cf 23.6000 ft 11613.2773 cf 17.5000 ft 252.4467 cf `21.6000 ft 6156.6772 cf 19.6000 ft 2389.5774 cf 23.7000 ft 11930.4570 cf 17.6000 ft 311.9774 cf 21.7000 ft 6389.3818 cf 19.7000 ft 2537.8066 cf 23.8000 ft 12251.8594 cf 17.7000 ft 375.7318 cf 21.8000 ft 6626.3101 cf 19.8000 ft 2690.2598 cf 23.9000 ft 12577.4863 cf 17.8000 ft 443.7099 cf 21.9000 ft 6867.4619 cf 19.9000 ft 2846.9368 cf 24.0000 ft 12907.3369 cf 17.9000 ft 515.9117 cf '22.0000 ft 7112.8374 cf 20.0000 ft 3007.8374 cf 24.1000 ft 13241.4121 cf'', 18.0000 ft 592.3373 cf 22.1000 ft 7362.4365 cf 20.1000 ft 3172.9617 cf 24.2000 ft 13579.7100 cf' 18.1000 ft 672.9868 cf 22.2000 ft 7616.2598 cf 20.2000 ft 3342.3098 cf 24.3000 ft 13922.2314 cf' 18.2000 ft 757.8599 cf -22.3000 ft 7874.3066 cf 20.3000 ft 3515.8818 cf 24.4000 ft 14268.9775 cf 18.3000 ft 846.9567 cf 22.4000 ft 8136.5771 cf 20.4000 ft 3693.6772 cf,24.5000 ft 14619.9463 cf' 18.4000 ft 940.2773 cf i22.5000 ft 8403.0713 cf 20.5000 ft 3875.6968 cf 24.6000 ft 14975.1396 cf 18.5000 ft 1037.8218 cf.22.6000 ft 8673.7900 cf 20.6000 ft 4061.9399 cf 24.7000 ft 15334.5566 cf 18.6000 ft 1139.5898 cf 22.7000 ft 8948.7314 cf 20.7000 ft 4252.4067 cf 24.8000 ft 15698.1973 cf 18.7000 ft 1245.5818 cf'22.8000 ft 9227.8975 cf 20.8000 ft 4447.0972 cf 24.9000 ft 16066.0615 cf' 18.8000 ft 1355.7974 cf 22.9000 ft 9511.2871 cf 25.0000 ft 16438.1504 cf' C-5 Sherwood Creek Parcels Road Access Michael F. Wnek, P.E., PS Drainage Report July 27, 2007 BASIN-2 LPOOL-2 SUMMARY using Puls Start of live storage: 19.9000 ft Event Match Q(cfs) Peak Q(cfs) Peak Stg(ft) Vol(cf) Vol(acft) Time to Empty 2 year 0.5352 0.5344 26.0344 8745.58 0.2008 29.17 10 year 2.1349 2.0651 26.5633 10121.39 0.2324 31.00 100 year 3.7937 3.7654 27.9829 1-43 00.79 0.3283 31.17 BASIN SUMMARY BasinID Event P(cf Q Peak T(hrs) Peak Vol(ac-cf)Area(ac) Method/Loss Raintype BASIN-2 2 year 1.0705 8.17 1 0.6371 ; 5.60 SBUH/SCS TYPEIA DEVELOPED-2 2 year 2.2636 8.00 0.8852 5.60 SBUH/SCS E BASIN-2 _ 10 year M2.1349 8.17 1.1067F 5.60 SBUH/SCS TYPEIA DEVELOPED-2 10 year 3.7962 8.00 ( 1.4067 1 5.60 SBUH/SCS TYPEIA BASIN-2 100 year 3.7937 8.17 ( 1.8215 5.60 SBUH/SCS TYPEIA DEVELOPED-2 100 year 6.0575 8.00 ( 2.1712 SBUH/SCS TYPEIA Record Id: BASIN-2 ..... Design Method SBUH Rainfall type € TYPEIA Hyd Intv 10.00 min Peaking Factor 484.00 . .. ... ...... _... ............. Abstraction Coeff 0.20 Pervious Area(AMC 2) j 5.60 ac DCIA 0.00 ac Pervious CN 76.00 DC CN 0.00 Pervious TC 25.57 min DC TC 0.00 min Pervious CN Cale Description SubArea Sub cn Wood/forest land(iJndisturbed/2nd growth) F 5.60 ac 76.00 Pervious Composited CN(AMC 2) 1� 76.00 Pervious TC Calc Type Description Length Slope Coeff Misc TT Sheet Woods or forest with light underbrush.:0.40 298.00 ft 27.00% 0.4000 3.50 in 17.37 min ft10Shalloworestw/heavy ground &meadows(n=0.10) 149.00 90 . 177 min ._ _ Shallow Forest w/heavy ground litter&meadows(n=0.10) 153.00 ft 19.00% 0.1000 1.8�2 min I Shallow Forest w/heavy ground litter&meadows(n=0.10) 132.00 ft 26.00% 0.1000 , 11.34 min Shallow Forest w/heavyround litter&meadows n-0.10 89.00 ft 2.00% 0.1000 g ( ) ___..... _._. Pervious TC 25.57 in I C-6 Sherwood Creek Parcels Road Access Michael F. Wnek, P.E., PS Drainage Report July 27, 2007 Record Id: DEVELOPED-2 Design Method SBUH Rainfall type TYPE I A Hyd Intv 10.00 min Peaking Factor 484.00 Abstraction Coeff 0.20 Pervious Area(AMC 2) 4.72 ac DCIA 0.88 ac Pervious CN 80.07 DC CN 98.00 Pervious TC 10.00 min DC TC 5.00 min Pervious CN Cale Description� �� SubArea Sub cn Open spaces,lawns,parks(>75%grass) 1.92 ac F 86.00 Wood/forest land(Undisturbed/2nd growth) 2.80 ac 76.00 _ Pervious Composited CN(AMC 2) 80.07 ___ -_.- ..__ _ __- - "",.,. .,,__ ..___""-... ... ............_._... ..... .. ..._-_. ..._... _.�_..- _..... ... ._........._:. ...................... 3 Pervious TC Calc Type Description Length Slope-',- Coeffc TT jixed 3 10.00 min _._Pervious TC 10.00 min ..:_...... _-, -_......... _ _. _.. . _...._. _ _. .. .... Directly Connected CN Cale _.. Description SubArea Sub cn Impervious surfaces(pavements,roofs,etc) 0.61 ac 98.00 Impervious surfaces(pavements,roofs,etc) 0.28 ac 98.00 DC Composited CN(AMC 2) j 98.00 - _ -------------- Directly Connected TC Cale Type Description Length Slope Coeff Misc TT Fixed 5.00 min Directly Connected TC 5.00min HYDROGRAPH SUMMARY ... ..............._ __._ .- ____...... ______ HydID Peak Q(cfs) Peak T(hrs) Peak Vol(ac-ft) 'font Area(ac)' 2 year out-2 0.5344 12.67 0.8852 5.6000 10 year out-2 2.0651 8.50 1.4067 5.6000 100 year out-2 3.7654 8.33 2.1712 5.6000 Record Id: LPOOL-2 Descrip: Prototype Record Increment 0.10 ft Start El. 19.9000 ft Max El. 28.0000 ft Storage Node POND-2-GRADED Discharge Node ORIFICE-2 C-7 Sherwood Creek Parcels Road Access Michael F. Wnek, P.E., PS Drainage Report July 27, 2007 Record Id: POND-2-GRADED Descrip: ;Graded Construction Pond Increment 0.10 ft Start El_ 19.9000 ft Max El. 28.0000 ft Stage Area Stage(ft) Area(sf) 19.90 0.0000 20.00 384.0000 28.00 3200.0000 Stage Storage Rating Curve -- - �21.9000 ft 1384.1599 cf�26.0000 ft 8659.2002 cf 19.9000 ft 0.0000 cf '24.0000 ft 4371.1997 cf 22.0000 ft 1491.1998 cf 26.1000 ft 8910.5596 cf 20.0000 ft 19.1999 cf 24.1000 ft 4552.1597 cf 22.1000 ft 1601.7599 cf 26.2000 ft 9165.4395 cf 20.1000 ft 59.3599 cf 24.2000 ft 4736.6396 cf 22.2000 ft 1715.8398 cf''26.3000 ft 9423.8398 cf 20.2000 ft 103.0399 cf 24.3000 ft 4924.6396 cf = 22.3000 ft 1833.4398 cf 26.4000 ft 9685.7598 cf 20.3000 ft 150.2399 cf 24.4000 ft 5116.1597 cf = 22.4000 ft 1954.5598 cf 26.5000 ft 9951.2002 cf _ - - _ --. _., -,..__. _ 20.4000 ft 200.9599 cf 24.5000 ft 5311.1997 cf 22.5000 ft 2079.2000 cf 26.6000 ft 10220.1602 cf 20.5000 ft 255.1999 cf :24.6000 ft 5509.7598 cf f 22.6000 ft 2207.3599 cf 26.7000 ft 10492.6396 cf' 20.6000 ft 312.9598 cf 24.7000 ft 5711.8398 cf 22.7000 ft 2339.0398 cf 26.8000 ft 10768.6396 cf 20,7000 ft 374.2399 cf 24.8000 ft 5917.4399 cf 1 22.8000 ft 2474.2397 cf 26.9000 ft 11048.1602 cf 20.8000 ft 439.0399 cf 24.9000 ft 6126.5601 cf ' 22.9000 ft 2612.9600 cf 27.0000 ft 11331.2002 cf 20.9000 ft 507.3599 cf 25.0000 ft 6339.1997 cf 23.0000 ft 2755.2000 cf 27.1000 ft 11617.7598 cf 21.0000 ft 579.1998 cf '25.1000 ft 6555.3599 cf 23.1000 ft 2900.9600 cf 27.2000 ft 11907.8398 cf 21.1000 ft 654.5599 cf '25.2000 ft 6775.0400 cf ? 23.2000 ft 3050.2397 cf 27.3000 ft 12201.4395 cf' 21.2000 ft 733.4399 cf 25.3000 ft 6998.2397 cf ! 23.3000 ft',3203.0398 cf'27.4000 ft 12498.5596 cf 21.3000 ft 815.8398 cf 25.4000 ft 7224.9600 cf 23.4000 ft 3359.3599 cf 27.5000 ft 12799.2002 cf 21.4000 ft 901.7598 cf '25.5000 ft 7455.1997 cf 23.5000 ft 3519.2000 cf 27.6000 ft 13103.3594 cf 21.5000 ft 991.1998 cf 25.6000 ft 7688.9600 cf 23.6000 ft 3682.5598 cf 27.7000 ft 13411.0400 cf 21.6000 ft 1084.1599 cf 25.7000 ft 7926.2397 cf i 23.7000 ft 3849.4399 cf 27.8000 ft 13722.2402 cf' 21.7000 ft 1180.6399 cf 25.8000 ft 8167.0400 cf 1 23.8000 ft 4019.8398 cf 27.9000 ft 14036.9600 cf' 21.8000 ft 1280.6399 cf'25.9000 ft 8411.3594 cf 28.0000 ft 14355.2002 cf c-8 Sherwood Creek Parcels Road Access Michael F. Wnek, P.E., PS Drainage Report July 27, 2007 Record Id: ORIFICE-2 Descrip: Prototype Structure Increment 0.10 ft Start El. 19.9000 ft Max El. 28.0000 ft Orif Coeff 0.62 Lowest Orif El. 17.90 Lowest Diam 2.8198 in Dist to next 6.2400 ft D2 9.2500 in Dist to next 0.0000 ft Stage Discharge Rating Curve 21.9000 ft 0.3052 cfs 26.0000 ft 0.5329 cfs 19.9000 ft 0.0001 cfs 24.0000 ft 0.4369 cfs 22.0000 ft 0.3127 cfs 26.1000 ft 0.5373 cfs 20.0000 ft 0.0682 cfs 24.1000 ft ',0.4422 cfs'' 22.1000 ft 0.3200 cfs 26.2000 ft 1.1103 cfs' 20.1000 ft 0.0965 cfs 24.2000 ft '0.4474 cfs'; 22.2000 ft 0.3272 cfs 26.3000 ft 1.4746 cfs 20.2000 ft 0.1182 cfs 24.3000 ft',0.4526 cfs 22.3000 ft 0.3343 cfs 26.4000 ft 1.7341 cfs' 20.3000 ft 0.1365 cfs 24.4000 ft;0.4577 cfs 22.4000 ft 0.3412 cfs 26.5000 ft 1.9475 cfs 20.4000 ft 0.1526 cfs 24.5000 ft 0.4628 cfs 22.5000 ft 0.3479 cfs 26.6000 ft 2.1333 cfs 20.5000 ft 0.1671 cfs 24.6000 ft 0.4678 cfs 22.6000 ft 0.3546 cfs 26.7000 ft 2.300 2 cfs 20.6000 ft 0.1805 cfs 24.7000 ft 0.4727 cfs 22.7000 ft 0.3611 cfs 26.8000 ft 2.4531 cfs j 20.7000 ft 0.1930 cfs 24.8000 ft '0.4776 cfs 22.8000 ft 0.3675 cfs 26.9000 ft 2.5951 cfs 20.8000 ft 0.2047 cfs 24.9000 ft'0.4825 cfs 22.9000 ft 0.3737 cfs 27.0000 ft 2.7282 cfs 20.9000 ft 0.2158 cfs 25.0000 ft 0.4873 cfs 23.0000 ft 0.3799 cfs 27.1000 ft 2.8540 cfs 21.0000 ft 0.2263 cfs 25.1000 ft'0.4920 cfs 23.1000 ft 0.3860 cfs 27.2000 ft 2.9736 cfs 21.1000 ft 0.2364 cfs'25.2000 ft'0.4968 cfs 23.2000 ft 0.3920 cfs 27.3000 ft 3.0878 cfs' 21.2000 ft 0.2460 cfs 25.3000 ft 0.5014 cfs 23.3000 ft 0.3979 cfs 27.4000 ft 3.1973 cfs 21.3000 ft 0.2553 cfs 25.4000 ft 0.5060 cfs 23.4000 ft 0.4037 cfs 27.5000 ft 3.3026 cfs' 21.4000 ft 0.2643 cfs 25.5000 ft 0.5106 cfs 23.5000 ft 0.4094 cfs 27.6000 ft 3.4043 cfs' 21.5000 ft 0.2729 cfs 25.6000 ft'0.5152 cfs 23.6000 ft 0.4151 cfs 27.7000 ft 3.5027 cfs 21.6000 ft 0.2813 cfs 25.7000 ft 0.5197 cfs 23.7000 ft 0.4206 cfs 27.8000 ft 3.5981 cfs 21.7000 ft 0.2895 cfs 25.8000 ft'0.5241 cfs' 23.8000 ft 0.4261 cfs 27.9000 ft 3.6907 cfs 21.8000 ft 0.2974 cfs 25.9000 ft 0.5285 cfs 28.0000 ft 3.7808 cfs C-9 Sherwood Creek Parcels Road Access Michael F. Wnek, P.E., PS Drainage Report July 27, 2007 PIPE HYDRAULICS 100-YEAR FLOW TRAPEZOIDAL CHANNEL ANALYSIS RATING CURVE COMPUTATION July 30, 2007 -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- PROGRAM INPUT DATA DESCRIPTION VALUE -------------------------------------------------------------------------------- Channel Bottom Slope (ft/ft) .................... . .. . . ... . . .. 0.14 Manning's Roughness Coefficient (n-value) ...... . . . . . . .. . . . .. 0.035 Channel Left Side Slope (horizontal/vertical) .. .. ... . .. . .. . . 1.0 Channel Right Side Slope (horizontal/vertical) ... .... ... .. .. 3.0 Channel Bottom Width (ft) ... . . .. ... . . .. ..................... 0.1 Minimum Flow Depth (ft) ............ . . ........... . . . ..... .... 0.1 Maximum Flow Depth (ft)......... ... .... .. . ...... . . . ......... 1.1 Incremental Head (ft) ........... ... . ... ... . . .... . .. ......... 0.1 COMPUTATION RESULTS Flow Flow Flow Froude Velocity Energy Flow Top Depth Rate Velocity Number Head Head Area Width (ft) (cfs) (fps) (ft) (ft) (sq ft) (ft) -------------------------------------------------------------------------------- 0.1 0.068 2.264 1.6293 0.0796 0.1796 0.03 0.5 0.2 0.339 3.388 1.7918 0.1784 0.3784 0.1 0.9 0.3 0.91 4.335 1.9016 0.2921 0.5921 0.21 1.3 0.4 1.867 5.185 1.9863 0.4177 0.8177 0.36 1.7 0.5 3.283 5.968 2.056 0.5535 1.0535 0.55 2.1 0.6 5.228 6.703 2.1155 0.6981 1.2981 0.78 2.5 ---> 0.7 7.768 7.398 2.1676 0.8506 1.5506 1.05 2.9 0.8 10.965 8.062 2.2141 1.0101 1.8101 1.36 3.3 0.9 14.877 8.7 2.2562 1.1763 2.0763 1.71 3.7 1.0 19.562 9.315 2.2946 1.3484 2.3484 2.1 4.1 1.1 25.073 9.91 2.3301 1.5263 2.6263 2.53 4.5 -------------------------------------------------------------------------------- HYDROCALC Hydraulics for Windows, Version 1.2a Copyright (c) 1996 Dodson & Associates, Inc., 5629 FM 1960 West, Suite 314, Houston, TX 77069 Phone: (281)440-3787, Fax: (281)440-4742, Email:software@dodson-hydro.com All Rights Reserved. Q100-year = 7•5 CfS C-10 STORMWATER MANAGEMENT MANUAL FOR THE PUGET SOUND BASIN Figure III-2.1 - Nomograph for Sizing Circular Drains Flowing Full -- 1000 r 90Q 800 .0001 700 2.0 800 .0002 5oQ .0003 Minimum 400 .0004 D001 Allowable 0005 Velocity 300 .0006--- tFlowl 3.0 120 •0008 .0002 Full) 1 0 .001 08 CD .0003 200 9966 q }.0004 84 c Oat- •.0005 4.0 79 pc 1 . 72 O .003110)06 .0008 66 .004 W 0051 5.0 100 LL fi0 p .006— Ca 90 54 c j 008 -m2 a O N 48 01 003 O 0 6.0 W 42 c /// V3 60 .004 V 0 005� W LZ 50 Z 36 005 O 7.0 a 6 -33 ? ? 30 .03 .008 0-LL w 8.0 W 40 Uj�_ 27 04 .010 O LL -- 05 9.0 C .06- Z Q 30 O 2, 08� .020 10.0 .10 U y W 18 030 O p 20 w .040.060 w w Q 15 ,060 > In .080 12 .100 10 10 9 8 SAMPLE USE 8 24" dia. CMP @ 2% slope yields 20.0 6 17cfs @ 5.2 FPS velocity 5 (n= 0.024) 6 4 Values per Manning's Equation Q = { 1.49y qRz/�St/� 3 n 30.0 This table can be convened 10 other"n"values by applying 2 formula, 40.0 Ot n1 02 n2 1 FEHRUARY, 9992 C-11 STORMWATER MANAGEMENT MANUAL FOR THE PUGET SOUND BASIN Figure III-2.15 - Headwater Depth for Corrugated Pipe Culverts With Inlet Control 4 80 10.000 168 8,000 EXAMPLE (I 156 6,000 D-36 me ou 43.0 teal l 6. 12� 5.000 O.66 ctr 144 a,00a H" �pf 5' 6' ENTRANCE TYPE 132 3,000 5 (feet) 111 r,6 s, 3' 6. HEADWALLPLAN 120 W 2,000 (2) z.l a 13) 2.2 6.6 4' 109 J ` a aD to tear 3. a- I �.J � V I 96 1,000 U 800 3. a � 04 BOO 2 (1) 500 — MITERED TO 72 ado 2. 2. CONFORM T 300 TO SLOPE SECTION ? u 200 b z 6o 1.5 1.5 A(2) 34Ww 100 cr (D a w 48 cr 80, o x- 60 ? PROJECTING 42 "' 50 2 Lo 1.0 SECTION u / r tJ AO 7 I.0 /36 30 HW ENTRANCE 2 w D SCALE TYPE � r 33 `t 4 20 0 � 30 121 witorad to conlorlm W to Cape Y •ems (�) u I o 27 IO il) v.etac5.np 1 .7 IV .T 0 8 z 24 .7 ,4. 6 To Bea &told 12)or(31 prolact 21 4 Aorirontaltyy to sees• Eli, rao- fi I aea abaipM .nellned I.a• idroada .6 3 0 one D uolea, or ra•ud• oa 6 rl a etrpTad. 18 2 f I.o S � 12 III-2-35 FEBRUARY, 1992 C-12 SHERWOOD CREEK PARCELS ROAD ACCESS Michael F. Wnek, P.E,, PS Drainage Report July 27, 2007 BASIN PLAN CD �QQ AWN 1 ,,"5.5 AcresSCALE ------------ ✓ `� 1, r' _l- f ��� '� —''' -= '�,,�vs.�.�=_--_••..___ �r ,�r_=�! BASIN 6 5.6 AcrelsJ 3 / t tF r i 6`µ D-1 I `•i-' ' �. +/L'♦•i •j�i�• ���a•�•/-�• • �fit••��••, tl 'I:-/� • •• !•Z �. •�i i•••M••• ice•�•••- � •/-�• ••� WWI 0 6*60 At • ••: ����.i•: :Pyy/: ••Y •'•Zoo .0e •/• Y••�••J IV. lot 4.8 IA I one { Plow �° PAN, A � o0 _a � J OZ � v IL Aj i\ i � pq p9y °r I� M621NZZl / as H3�.aooMa3 s °f pOZ OBI. Oq 09 � N 0 �f 4 71 s VOWS poo*ra4S r f 4 ,: `� 08 M�21NZZl Ala� a r P ;z y: 4 III �, it W � 1 V, oti IWO- N � Z rt ` ! c N. 'Lim 091 �o �J G.� o , fv3