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HomeMy WebLinkAboutStorm Drainage Analysis for Short Plat 1545 - PLN General - 12/11/1998 STORM DRAINAGE ANALYSIS AND TEMPORARY SEDIMENT POND SIZING RECEIVED FOR: DEC I b 1998 MASON CO. PLANNING DEPZ BIEHL SHORT PLAT # 1545 PORTION OF THE EAST 1/2 , SEC. 30, TWP. 22N, RGE. 1W, W.M. MASON COUNTY, WASHINGTON CLIENT: MR. BOB BIEHL, ABR WINDERMERE REAL ESTATE 5801 SOUNDVIEW DRIVE, SUITE 101 GIG HARBOR, WA 98335 (253) 851-7374 (253) 858-6753 FAX cam. od PREPARED BY: v N.L. OLSON AND ASSOCIATES, INC. 2453 BETHEL ROAD SE PORT ORCHARD, WA 98366 (360) 876-2284 (360) 876-1487 FAX JOB NO. 4958-98 �p,N L. gQ'�oF wAsy�ticS 2 -'� 1409$ expams: Z DECEMBER 11, 1998 I. INTRODUCTION• The Biehl Short Plat is situated in the East 1/2 of Section 30, Township 22 North, Range 1 West, Willamette Meridian, Mason County, Washington. The total 5 . 15 site is divided into two basins . The site is surrounded on three sides by a 30' wide utility/ROW easement of 0 . 89 acres . The remaining 4 . 26 acres will be cleared and logged for four single family gg 9 Y residences . The developed 2 . 87 acre drainage basin improvements includes clearing and logging of 2 .42 acres for homes and landscaping (2 . 28 acres of lawn and landscaping and 0 . 11 acres for two residences of 2500 SF each) , 0 . 34 acres of natural buffer area and 0 . 25 acres of graveled roadway and driveway area (0 . 11 acre gravelly access roadway and 0 . 14 acres for three (3) driveways of 2000 SF each) with a biofiltration swale for quality control mitigation. All roof runoff will utilize an individual roof infiltration systems located on each lot . Basin #2 consists of 1 . 39 acres and will not be analysed in this report . (less than 5000 Sf of impervios area) . The temporary Erosion and Sedimentation Control measures for the Biehl Short Plat # 1545 site (See Vicinity Map, Figure 1 in Appendix A) include the use of a Temporary Sediment Pond, designed in accordance with the Department of Ecology Stormwater Management Manual for the Puget Sound Basin, section II-5 . 8 . 7 BMP E3 .40 . The proposed Sediment Pond will serve a contributing area of 2 . 87 acres, 2 .42 acres of which will be cleared and graded, 0 .34 acres natural buffer area and a 0 . 11 acre gravel access road. (See Basin Map, Figure 2 in Appendix A) . This report gives the design parameters, assumptions and calculations used to size the proposed Temporary Sediment Pond. Site soils are classified by the USDA Soil Conservation Service as predominantly Alderwood Gravelly Sandy Loam (Ac) (Hydrological Group C) and Everett Gravelly Sandy Loam (Eh) (Hydrological Group A) . Given the soils, the curve numbers will be assumed at Hydrologic Group 'B' for site runoff . (See Runoff Curve Numbers, Figure 3 in Appendix A) 1 II. PARAMETERS• 1 . The Water Quality Treatment Facility will be designed to meet the criteria set forth by the Department of Ecology (DOE) Stormwater Management Manual for the Puget Sound Basin. Water Quality treatment shall be provided by the use of a biofiltration swale designed to treat the peak runoff rate for the 6-month, 24-hour water quality design storm for developed conditions . 2 . Runoff shall be computed using the SCS-based hydrograph method, Santa Barbara Urban Hydrograph (SBUH) , given a Type lA rainfall distribution. See Figure 3 in Appendix A for Runoff Curve Numbers (CN) used in flow calculations, Figure 4 for "n" and "k" values used in Time of Concentration calculations, and Figures 5, 6 and 7 for the 2-year, 10-year and 100-year Precipitation Isopluvials respectively. 3 . Technical requirements will be as per the Mason County Department of Public works in conjunction with the DOE Stormwater Management Manual for the Puget Sound Basin and using WATERWORKS SOFTWARE FOR HYDROLOGY (Version 4 . 11c) by Engenious Systems, Inc . 4 . The Temporary Sediment Pond will be designed in accordance with D.O.E . , using a design settling particle of medium silt with a diameter of 0 . 02 millimeters and a settling velocity of 0 . 00096 feet per second. The required settling volume will be determined by providing adequate residence time to settle out the medium silt particle using the 10-year design storm inflow rate and the given particle settling velocity. 5 . Rainfall Precipitation for the project is as follows : P6m = 2 . 21 Inches @ 6-month, 24-Hour Precipitation P2 = 3 .45 Inches @ 2-Year, 24-Hour Precipitation Plo = 5 . 00 Inches @ 10-Year, 24-Hour Precipitation Pioo = 6 . 90 Inches @ 100-Year, 24-Hour Precipitation (See Figures 5, 6 and 7 in Appendix A) 2 III. DESIGN CALCULATIONS: A. T.E.S.C. Contributing Basin Area = 2 .87 acres: Soil Type Hydrologic Group B (1) Pervious Area 2 . 76 acres CN Pervious 80 .26 (2) Pervious Tc 10 . 77 minutes (3) Impervious Area 0 . 11 acres CN Impervious 98 (4) Impervious Tc 5 . 0 minutes (5) Q 2-year 0 . 94 CFS Q 10-year 1 . 81 CFS (1) See S.C.S . Soils Map, Figure 6 in Appendix A (2) 2 .42 acres at CN = 82 , Bare Dirt 0 . 34 acres at CN = 68, Undisturbed Forest (64) / Second Growth Forest (72) Avg. CN = (2 .42 * 82 + 0 . 34 * 68) / 2 . 76 = 80 . 26 (3) Ll = 235' sheet flow, s = 3 . 57%, ns = 0 . 6, P2 = 3 .45 L2 = 14' shallow flow, s = 201, ks = 27 L3 = 175' channel flow, s = 1%, ks = 20 L4 = 220' channel flow, s = 5 . 33%, ks = 20 L5 = 80' channel flow, s = 0 . 25%, ks = 20 (4) 0 . 11 acres at CN = 98, Gravel Roadway Surface (5) Ll = 14 ' sheet flow, s = 2%, ns = 0 . 011, P2 = 3 .45 L2 = 175' channel flow, s = 1%, ks = 20 L3 = 220' channel flow, s = 5 . 33%, ks = 20 L4 = 80' channel flow, s = 0 . 25%, ks = 20 (See Basin Map and Curve Numbers, Figures 2 and 3 in Appendix A) (See "n" and "k" Values, Figure 4 (See WaterWorks Data in Appendix B) 3 III. DESIGN CALCULATIONS CONT'D: B. Settling Volume: Using a settling depth of 2 ' the particle settling velocity of 0 . 00096 feet per second, and the design inflow of 1 . 81 CFS, the required settling volume is as follows : Volume = (Inflow * Depth) / Settling Velocity Volume = (1 . 81 *. 2) / 0 . 00096 Volume = 3 , 771 cubic feet The proposed Sediment Pond will provide the required 3 feet of dead storage per D.O.E. , with 2 feet of additional live storage settling volume, and one foot of freeboard. The live storage volume provided is 5,200 cubic feet, which provides a factor of safety F.S. = 1.38 (See WaterWorks Data in Appendix B) . 4 III. DESIGN CALCULATIONS CONT'D: C. Developed Contributing Basin Area = 2 .76 acres: Soil Type Hydrologic Group B (1) Pervious Area 2 . 51 acres CN Pervious 80 . 54 (2) Pervious Tc 18 . 38 minutes (3) Impervious Area 0 . 25 acres CN Impervious 98 (4) Impervious Tc 5 . 0 minutes (5) Roof Area 0 . 11 acres Q 6-month 0 .35 CFS Q 2-year 0 . 88 CFS Q 100-year 2 . 65 CFS (1) See S.C.S . Soils Map, Figure 6 in Appendix A (2) 2 . 17 acres at CN = 82 . 5, Lawn/Landscaping 0 . 34 acres at CN = 68, Undisturbed Forest (64) / Second Growth Forest (72) Avg. CN = 2 . 17 * (80 + 85/2) + 0 . 34 * 68 / 2 . 51 = CN = 80 . 54 (3) Ll = 235' sheet flow, s = 3 . 571, ns = 0 . 15, P2 = 3 .45 L2 = 14 ' shallow flow, s = 20-. , ks = 27 L3 = 175' channel flow, s = 1%, ks = 17 L4 = 230' channel flow, s = 5 . 3301, ks = 17 L5 = 160' channel flow, s = 3 . 8201, ks = 17 (4) 0 . 25 acres at CN = 98, Gravel Roadway Surface (5) Ll = 14' sheet flow, s = 201, ns = 0 . 011, P2 = 3 .45 L2 = 175' channel flow, s = 196, ks = 17 L3 = 230' channel flow, s = 5 . 33%, ks = 17 L4 = 160' channel flow, s = 3 . 82%, ks = 17 (See Basin Map and Curve Numbers, Figures 2 and 3 in Appendix A) (See "n" and "k" Values, Figure 4 in Appendix A) (See WaterWorks Data in Appendix B) * All lots will utilize a Roof Infiltration System for roof drainage . 5 III . DESIGN CALCULATIONS CONT'D: D. Biofiltration Swale Design: The biofiltration swale has a length of 200 feet . The swale was sized using the Haestad Methods Software with the following input parameters (See Appendix B) : 6-month Flow Rate 0 . 35 CFS 100-year Flow Rate 2 . 65 CFS Swale Length 200 Feet Swale Width 8 Feet Maximum Side Slopes 3H: 1V Longitudinal Slope 3 . 82 Percent Manning "n" For Quality 0 . 20 Manning "n" for Quantity 0 . 035 Flow Depth for Quality 4 Inches Maximum (0 . 33) Residence Time for Quality 5 minutes Minimum Velocity for Capacity 3 Feet Per Second Biofiltration swale sizing results are as follows (See Trapezoidal Channel Analysis results in Appendix B) : Swale Bottom Width 2 . 25 Feet 6-month Flow Depth 0 . 24 Feet (2 . 88 Inches) 6-month Flow Velocity 0 .48 Feet Per Second 6-month Residence Time 200/0 .48 = 417 Seconds or 7 Minutes 100-year Flow Depth 0 . 28 Feet 100-year Flow Velocity 3 . 00 Feet Per Second 6 APPENDIX A FIGURES 0� �0 SHERWOOD CREEK ROAD �p0 RT CREEK 37 STEWARpPD 5� �L umn si rE CO* � Z -33 0 D 0 a 0 VICINI T Y MA P NOT TO SCALE lABRIC FENCE (SEE DUAX 9 EET 2) \ \ \ \\\JTOUR(5-INTERVALS). \ \�1)T ELEVATION. 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 89 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 they 68 80 86 90 area Fair condition: grass cover on 50-75% of 77 85 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 1100 1100 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'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 �i cq. 3 STORMWATER MANAGEMENT MANUAL FOR THE PUGET SOUND BASIN Table III-1.4 "n" AND "k" Values Used in Time Calculations for Hydrographs "n," Sheet Flow Equation Manning's Values (for the initial 300 ft. of travel) n. Smooth surfaces (concrete, asphalt, gravel, or bare hand packed soil) 0.011 Fallow fields or loose soil surface (no residue) 0.05 Cultivated soil with residue cover (s<- 0.20 ft/ft) 0.06 Cultivated soil with residue cover (s> 0.20 ft/ft) 0.17 Short prairie grass and lawns 0.15 Dense grasses 0.24 Bermuda grass 0.41 Range (natural) 0.13 Woods or forest with light underbrush 0.40 Woods or forest with dense underbrush 0.80 *Manning values for sheet flow only, from Overton and Meadows 1976 (See TR-55, 1986) "k" Values Used in Travel Time/Time of Concentration Calculations Shallow Concentrated Flow (After the initial 300 ft. of sheet flow, R = 0. 1) k, 1. Forest with heavy ground litter and meadows (n = 0.10) 3 2. Brushy ground with some trees (n = 0.060) 5 3. Fallow or minimum tillage cultivation (n = 0.040) 8 4. High grass (n = 0.035) 9 5. Short grass, pasture and lawns (n = 0.030) 11 6. Nearly bare ground (n = 0.25) 13 7. Paved and gravel areas (n = 0.012) 27 Channel Flow (intermittent) (At the beginning of visible channels R = 0.2) k` 1. Forested swale with heavy ground litter (n = 0.10) 5 2. Forested drainage course/ravine with defined channel bed (n = 0.050) 10 3. Rock-lined waterway (n = 0.035) 15 4. Grassed waterway (n = 0.030) _ -12 5. Earth-lined waterway (n = 0.025) _ 20 6. CMP pipe (n = 0.024) 21 7. Concrete pipe (0.012) 42 8. Other waterways and pipe 0.508/n Channel Flow (Continuous stream, R = 0.4) k,: 9. Meandering stream with some pools (n = 0.040) 20 10. Rock-lined stream (n = 0.035) 23 11. Grass-lined stream (n = 0.030) 27 12. Other streams, man-made channels and pipe 0.807/n** III-1-16 FEBRUARY, 1992 �16i - 4 STORMWATER MANAGEMENT MANUAL FOR THE PUGET SOUND BASIN 124 123 122 121 49 25 — 25 s r • +a w MAnni so t3 p p 2 EL a 1 s MM BE n OLGA i 1. is \ " ' 1 ' I1fV - s \ FRIDAY HARBOR PORT STA LEY 30 s r40 \ MT V is R( r40 — ,�= 11J 55 35 5 302520 15/ 100 I1 48 K� \ C / ERETT ri 40�5\ 11 /15 A I ; 25 C 50\ so /25 — _ r m a i 40 !1 a 15 c 501 30 S �J S �' 45 1 . ,\ - s AT , x w M 35 ATC�t 40 r J 35' 55 20 3 45 40 35 COMAS 1 47 Ll _ AB RDE N 30 /0 y —— 2 70 ' ( 35 , 13 5 15 ,. 40 • CENT ' c M 4� 20 33 r 55. 10 YAKI O 3 - ,0 f 20 M � 35 46 3 1 E �v �s v ,e 4 35 55 45 s — — — WASHINGTON p 3 25 B K 10 0 10 20 30 40 PPL EN E ---7 MILES 20( I' 1�1�0 15 FlgUf@ 25 NOAA ATLAS 2, Volume IX 25�— ISOPLUVIALS F 2 YR 24 HR PRECIPITATI N IN Prepared by U.S.Department of Commerce TENTHS AA INCH National oceanic and Atmospheric ministration N a 3 NCH tional Weather Service,Office of Hydrology Prepared for U.S.Department of A riculture, Soil Conservation Service,Engineer ng Division 124 123 122 121 III-1-44 FEBRUARY, 1992 c MIR -.0. S ' STORMWATER MANAGEMENT MANUAL FOR THE PUGET SOUND BASIN 124 123 122 - 121 49 ——� 4 4 80 6 s 45-2.1 EL — 40—�\ F 2 S 40 { 0 10 40, 10 FRIL•-Y HAR O R .PORT S1ANL' - d Plop r \ `•• 0 NE180A5 \` 3. 30 10 6 0' \ 5 5 10 6 0 Y1 I � � \ 0A5 3 ?� \ � . 55 I� I 5��1 —,\ I '��� 3 OK 4 8 15 A I nDll 15 80 —— 5 45 o 85. 1 7 lOq 40 — 7 1 I 90 a 5 AT 1 Tic \�40 a 1, 0\ 1oo JV { 60t 00 5 s 4 . 55, �..C L.V 6 35� 47 ' 5 aBE E N 65 y S 70 5 g E T R L Jp ri 2 21 ri YAK 1°° if 55 I 6 } 45 10 6 ]per 2 s� F 80 s s w { 55 65 1�+ T 0 0 65 60 550 w {p 1 `.8 (' AD M }�-30 1­125, 46 s q Sil 40 tC K L I WASHINGTON '° i 1.0 P' EN E 10 0 10 20 30 40 qU 802 LMU I MILES gfj 55$04535_ �f Figure 30 I = NOAA ATLAS 2, Volume IX 4 Prepared by U.S.Department of 5 50 6$ ! Cmerce tSOPLUVIALS F 100 YR 24 HR PRECIPIT TION 55 60 I National Oceanic and Atmosphericggqgqq������ministration IN TENTHS OF N INCH National weather Service,Office of Hydrology I _ U.q I U Prepared for U.S.Department of A iculture, 017 Soil Conservation Service,Engineer ng Division 124 123 122 12i III-1-46 FEBRUARY, 1992 • L fYI�.V-iN• T ••�".r1/7t � � � s ''.�. ''�/ fr.J.yj/rr "�!'.•? t �' S %•K�!:4� _ss�'l S- ,x+►.� .�. ��`j�,��l�:�'..�yy��}}���' .� �I,i�•• �'�' �. � ��•R1'!� /(' t'�.- rti '•• � Y '+ 1 ti P ■ I Ir at- ILI Wo . � � `�'= ��:' �� ��.`�;, .�",�°„• • ! .jam►- •�-�!'�� ''` S� ' 16 r��J '�• �-<-1 ��F<- x+ v�, y= .: '�.`?f-'s:�s' S'? "l� 4`Z �'�' , /VfGi' r +•+T+�' +}r :r 1'7� / � .r r�ua�. •, ,s ~ .. `�•, �-f ,a;' .ry�'^.V,+/. 1'�-itil •.•"'t�L. • �/ ,�, 'r lb of IL •�� � _ ..r.. �'1�':j=+� � _ •' � .fit\, .1 .f•�,•_•� 1j.�i• • '• \.;�, t � � ^ •' •'ems 'P .•\�` "-Q• •+1-� ,'y ,'� •1.,;1�`�1�-T\\ L.• �,tLr r ' '. /��►��r�{,'./ f ��/� •ti `' �' ;wYb?\i:�:� '•' ♦ ~•�7 'l� `f' ,♦ y,```r �, �` w• 46 1r ,j �� .1r tt STORMWATER MANAGEMENT MANUAL FOR THE PUGET SOUND BASIN Table III-1.6 Hydrologic Soil Groups foa Soils in the Puget Sound Basin Hydrologic Soil Hydrologic Soil Soil Type Group Soil Type Group Agnew C Colter C Ahl B Custer ND Aits C Dabob ND Alderwood C Delphi D Arents,Alderwood B Dick ND Arent&, Everett B Dinal D Ashoe B Dupont D Baldhill B Eadmoot C Barnestoo C Edgewick C Baumgard B Eld B Beausite B Elwell B Belfast C Esquatzel B Bellingham D Everett Bellingham variant C Everson D Boistfort B Galvin D Bow D Getchell A Briscot D Giles B Buckley C Godfrey D Bunker B Gmenwater A Cagey C Grove C Carlsborg ND Harstine C Casey ND Hartnit ND Cassolary C Hoh ND Cathcart B Hoko ND Centralia B Hoodsport ND Chehalis B Hoogdal C Chcaaw A Hoypus ND Cinebar B Huel ND Clallam C Indianola ND Clayton B Jonas B Coastal beaches variable Jumpe ND Kapowsin CID Kalaloch C Katula C Renton D Kilchis C Republic B Kitsap C Riverwash variable Klaus ND Rober C KJone ND Salal C Latex C Salkum B Lebam B Sammamish D Lummi ND San Juan ND Lynnwood ND Scamnan D Lystair ND Schneider B Mal C Seattle D Manley B Sekiu ND Mashel B Semiahmoo D Maytown C Shalcar D McKenna D Shano B McMurray ND Shelton C Melbourne B Si C Menzel ND Sinclair C Mixed Alluvial variable Skipops D Molson B Skykomish B Mukilteo CID Snahopish ND Naff B Snohomish D Nargar A Solduc B National ND Solleks ND Neilton A Spana D +'' III-1-9 FEBRUARY, 1992 U. S. DEPARTMENT OF AGRICULTURE SOIL CONSERVATION SERVICE MASON COUNTY, WASHINC SOIL LEGEND SYMBOL NAME SYMBOL NAME Aa Alderwood gravelly loam, 5.15 percent Mopes Ha Harsline gravelly sandy loam, 5-15 p Ab Alderwood gravelly sandy loam, 5.15 percent s;opiras Hb Harsline gravelly sandy loam, 15-30 .U� Alderwood nravelly sandy loarn, 15 30 percent stone:_ He Hoodsport gravelly sandy loam, 0-5 Hd Hoodsport gravelly sandy loam, 5.15 A Alderwood gravelly sandy loam, percent slopes He Hoodsport gravelly sandy loam, 15.3 Ae Aslona silt Loam, 515 percent slopeslopes Hf Hoodsport gravelly sandy loam, At Astoria silt loam, 15 30 percent slopes H6 Hoodsport stony sandy loam, 5.1515 p Ba Belfast sandy loam, 0-3 percent slopes Hh Hoodsport stony sandy loam, 15 30 Bb Belfast silt loam, 0.3 percent slopes Hk Hoquiam gravelly silt loam, 5-15 per BC Belle silt loam, 0-5 percent slopes Hen Hoquiam gravelly silt loam, 15.30 p Bd Bellingham silt loam, 0 3 percent slopes Her Hoquiam loam, 15.30 percent slope Be Bellingham silty clay loam, 0.3 percent slopes Ho Hoquiam silt loam,0-5 percent slop Ca Carstairs gravelly loam, 0.5 percent slopes Hp Hoquiam silt loam, 5.15 percent slo Cb Cloquallum sill loam, 0.5 percent slopes Hr Hoquiam silt loam, 15.30 percent sl Cc Cloquallum silt loam, 5.15 percent slopes Hs Hoquiam and Astoria silt loams, 5- Cd Cloquallum silt loam, 15-30 percent slopes Ht Hoquiam and Astoria silt loams, 15 Ce Cloquallum silt loam, moderately shallow over la Indianola loamy card, 0.5 percent s cemented till, 5.15 percent slopes lb Indianola loamy sand, 5-15 percent Cf Cloquallum silty clay loam, 5-15 percent slopes Ic Indianola loamy sard, 15.30 percent Cg Coastal beach, 0.2 percent slopes Id Indianola sandy loan, 0.5 percent s Da Deckerville gravelly loam, 0.2 percent slopes 1e Indianola sandy loam, 5-15 percent Db Deckerville gravelly silty clay loam, 0.2 percent slopes Ja Juno gravelly sandy loam, 0.3 perce Dc Deckerville silt loam, 0.2 percent slopes Jb Juno loam, 0.3 percent slopes Dd Deckerville silty clay loam, 0.2 percent slopes Jc Juno loamy sand, D-3 percent slope De Delphi gravelly loam, 5.15 percent slopes Jd Juno sandy loam, 0.3 percent slope Df Delphi gravelly loam, 15.30 percent slopes Dg Dungeness fine sandy loam, 0.2 percent slopes Ka Kitsap silt loam, 0.5 percent slopes Dn Dungeness fine sandy loam, shallow, 0.2 percent slopes Kb Kitsap silt loam, 5.15 percent slope Dk Dungeness silt loam, 0.2 percent slopes Kc Kitsap silt loam, 15-30 percent stop Kd Kitsap silty clay loam,0-5 percent Ea Edmonds fine sandy loam, 0-2 percent slopes Ke Kitsap silty clay loam, 5-15 percent Eb Edmonds silt loam, 0.2 percent slopes Kf Koch gravelly loam,0-3 percent slo Ec Eld silt loam, 0.3 percent slopes Kg Koch gravelly sandy loam, 0.3 perc Ed Everett gravelly loamy sand, 0.5 percent slopes Kh Koch sill loam, 0.3 percent slopes Ee Everett gravelly loamy sand, 5.15 percent slopes Ef Everett gravelly loamy sand, 15.30 percent slopes La Le Bar silt loam, 05 percent slope Eg Everett gravelly sandy loam, 0-5 percent slopes Lb Lystair loamy sand,0-5 percent slot FG. Everett gravelly sandy loam 5-15 percent slopes Lc Lystair loamy sand,5.15 percent sl Ek Everett gravelly sandy loam, 15-30 percent slopes Ld • Lystair sandy loam,0.5 percent slo Le Lystair sandy loam, 5-15 percent sl Ga Gravel pit Lf Lystair sandy loam, 15-30 percent Gb Grove cobbly sandy loam, 0-5 percent slopes Ma Made land Gc Grove cobbly sandy loam, 5.15 percent slopes Gd Grove cobbly sandy loam, 15-30 percent slopes Mb Maytown silt loam,0-3 percent slo Ge Grove gravelly loam, 0.5 percent slopes Mc McKenna gravelly loam, 0.3 percen Gf Grove gravelly loam, 5-15 percent slopes Md McKenna loam, 0-3 percent slopes Gg Grove gravelly loam, basin phase, 0-5 percent slopes Me McMurray peat, 0-2 percent slopes Gh Grove gravelly sandy loam, 0.5 percent slopes Mf McMurray peat, shallow over gravel Gk Grove gravelly sandy loam, 5.15 percent slopes Mg Mukilteo peat, 0.2 percent slopes Gen Grove gravelly sandy loam, 15-30 percent slopes Mh Mukilteo peat, shallow over gravel, Gn Grove gravelly sandy loam, 30-45 percent slopes Na Nasel gravelly loam, 0-5 percent sl Go Grove gravelly sandy loam, basin phase, 0-5 percent slopes Nb Nordby loam, 0.5 percent slopes Go Grove stony sandy loam, 0.5 percent slopes I I i Soils surveyed 1941-51 by R. H. Fowler and R. G. Parvin, Washington Agricultural Experiment Station, and A. 0. Ness, U. S. Department of Roberts, U. I V Correlation by R. C. oberts, U. S. Department of Agriculture. STORMWATER MANAGEMENT MANUAL FOR THE PUGET SOUND BASIN Table III-1.5 Values of the Roughness Coefficient, "n" Type of Channel Manning's Type of Channel Manning'; and Description -n' and Description -n•' (Normal) (Normal) A. Constructed Channels 6. Sluggish reaches, weedy 0.070 a. Earth, straight and uniform deep pods 1. Clean; recently completed 0.018 7. Very weedy readies, deep 0.100 2. Gravel, uniform section, 0.025 pools, or floodways with clean heavy stand of timber and 3. With short grass, few 0.027 underbrush weeds b. Mountain streams, no vegetation b. Earth, winding and sluggish 0.025 in channel, banks usually steep, 1. No vegetation 0.025 trees and brush along banks 2. Grass, some weeds 0.030 submerged at high stages j 3. Dense weeds or aquatic 1. Bottom: gravel, cobbles, and 0.040 plants In deep channels 0.035 few boulders 4. Earth bottom and rubble 2. Bottom: cobbles with large 0.050 sides 0.030 boulders 5. Stony bottom and weedy B-2 Flood plains banks 0.035 a. Pasture, no brush 6. Cobble bottom and clean 1. Short grass 0.030 sides 0.040 2. High grass 0.035 j c. Rock lined b. Cultivated areas i 1. Smooth and uniform 0.035 1. No crop 0.030 2. Jagged and irregular 0.040 2. Mature row crops 0.035 d. Channels not maintained, 3. Mature field crops 0.040 weeds and brush uncut c. Brush 1. Dense weeds, high as flow 1. Scattered brush, heavy 0.050 depth 0.080 weeds 2. Clean bottom, brush on 2. Ught brush and trees 0.060 sides 0.050 3. Medium to dense brush 0.070 3. Same, highest stage of 4. Heavy, dense brush 0.100 flow 0.070 d. Trees 4. Dense brush, high stage 1. Dense willows, straight 0.150 B. Natural Streams 0.100 2. Cleared land with tree 0.040 B-1 Minor streams (top width at stumps, no sprouts flood stage < 100 ft.) 3. Same as above, but with 0.060 a. Streams on plain heavy growth of sprouts 1. Clean, straight, full stage 4. Heavy stand of timber, a few 0.100 no rifts or deep pools 0.030 down trees, little 2. Same as above, but more undergrowth, flood stage stones and weeds 0.035 below branches 3. Clean, winding, some 5. Same as above, but with 0.120 pods and shoals 0.040 flood stage reaching 4. Same as above, but some branches weeds 0.040 5. Same as 4, but more stones 0.050 i III-1-17 FEBRUARY, 1992 PI C-1- t I APPENDIX B WATERWORKS DATA 12/10/98 3 : 15 : 18 pm NL Olson & Assoc . Inc . page 1 Biehl Short Plat Tempoary Erosion/Sedimentation Control Sediment Pond Sizing --------------------------------------------------------------------- --------------------------------------------------------------------- BASIN SUMMARY BASIN ID: tesc-10 NAME: T. E . S .C. Pond - 10yr, 24hr SBUH METHODOLOGY TOTAL AREA. . . . . . . : 2 . 87 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPElA PERV IMP PRECIPITATION. . . . : 5 . 00 inches AREA. . : 2 . 76 Acres 0 . 11 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 80 . 26 98 . 00 TC. . . . . 10 . 77 min 5 . 00 min ABSTRACTION COEFF : 0 . 20 TcReach - Sheet L: 235 . 00 ns : 0 . 0600 p2yr: 3 . 45 s : 0 . 0357 TcReach - Shallow L: 14 . 00 ks : 27 . 00 s : 0 . 0200 TcReach - Channel L: 175 . 00 kc : 20 . 00 s : 0 . 0100 TcReach - Channel L: 220 . 00 kc : 20 . 00 s : 0 . 0533 TcReach - Channel L: 80 . 00 kc : 20 . 00 s : 0 . 0025 impTcReach - Sheet L: 14 . 00 ns : 0 . 0110 p2yr: 3 .45 s : 0 . 0200 impTcReach - Channel L: 175 . 00 kc : 20 . 00 s : 0 . 0100 impTcReach - Channel L: 220 . 00 kc :20 . 00 s : 0 . 0533 impTcReach - Channel L: 80 . 00 kc :20 . 00 s : 0 . 0025 PEAK RATE : 1 . 81 cfs VOL: 0 . 71 Ac-ft TIME: 480 min BASIN ID: tesc-2 NAME: T.E.S .C. Pond - 2yr, 24hr SBUH METHODOLOGY TOTAL AREA. . . . . . . : 2 . 87 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 3 .45 inches AREA. . : 2 . 76 Acres 0 . 11 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 80 . 26 98 . 00 TC. . . . . 10 . 77 min 5 . 00 min ABSTRACTION COEFF: 0 .20 TcReach - Sheet L: 235 . 00 ns : 0 . 0600 p2yr: 3 . 45 s : 0 . 0357 TcReach - Shallow L: 14 . 00 ks :27 . 00 s : 0 . 0200 TcReach - Channel L: 175 . 00 kc :20 . 00 s : 0 . 0100 TcReach - Channel L: 220 . 00 kc :20 . 00 s : 0 . 0533 TcReach - Channel L: 80 . 00 kc :20 . 00 s : 0 . 0025 impTcReach - Sheet L: 14 . 00 ns : 0 . 0110 p2yr: 3 .45 s : 0 . 0200 impTcReach - Channel L: 175 . 00 kc : 20 . 00 s : 0 . 0100 impTcReach - Channel L: 220 . 00 kc :20 . 00 s : 0 . 0533 impTcReach - Channel L: 80 . 00 kc :20 . 00 s : 0 . 0025 PEAK RATE: 0 . 94 cfs VOL: 0 .40 Ac-ft TIME : 480 min 12/10/98 3 : 15 : 19 pm NL Olson & Assoc. Inc. page 2 Biehl Short Plat Tempoary Erosion/Sedimentation Control Sediment Pond Sizing STAGE STORAGE TABLE TRAPEZOIDAL BASIN ID No. sedpond Description: Sediment Pond Length: 50 . 00 ft . Width: 40 . 00 ft . Side Slope 1 : 3 Side Slope 3 : 3 Side Slope 2 : 3 Side Slope 4 : 3 Infiltration Rate : 0 . 00 min/inch STAGE <----STORAGE----> STAGE <----STORAGE----> STAGE <----STORAGE----> STAGE <----STORAGE----> (ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft- 217.89 0.0000 0.0000 218.40 1092 0.0251 219.00 2569 0.0590 219.60 4270 0.0980 217.90 20.027 0.0005 218.50 1323 0.0304 219.10 2837 0.0651 219.70 4576 0.1050 218.00 223.28 0.0051 218.60 1560 0.0358 219.20 3110 0.0714 219.80 4889 0.1122 218.10 432.02 0.0099 218.70 1804 0.0414 219.30 3390 0.0778 219.90 5202 0.1194 218.20 646.30 0.0148 218.80 2053 0.0471 219.40 3677 0.0844 218.30 866.21 0.0199 218.90 2308 0.0530 219.50 3970 0.0911 Triangular Channel Analysis & Design Open Channel - Uniform flow Worksheet Name : Biehl Short Plat Comment : Interceptor Ditch capacity verification Solve For Depth Given Input Data: Left Side Slope. . 1 . 50 : 1 (H:V) Right Side Slope. 1 . 50 : 1 (H:V) Manning' s n. . . . . . 0 . 018 Channel Slope . . . . 0 .0100 ft/ft Discharge. . . . . . . . 1 . 81 cfs Computed Results : Depth. . . . . . . . . . . . 0 . 61 ft Velocity . . . . . . . . . 3 . 29 fps Flow Area. . . . . . . . 0 . 55 sf Flow Top Width. . . 1 . 82 ft Wetted Perimeter. 2 . 18 ft Critical Depth. . . 0 . 62 ft Critical Slope. . . 0 . 0089 ft/ft Froude Number . . . . 1 .05 (flow is Supercritical ) Open Channel Flow Module, Version 3 . 41 (c) 1991 Haestad Methods , Inc. * 37 Brookside Rd * Waterbury, Ct 06708 f - Triangular Channel Analysis & Design Open Channel - Uniform flow Worksheet Name : Biehl Short Plat Comment : Interceptor Ditch capacity verification Solve For Depth Given Input Data: Left Side Slope. . 1 . 50 : 1 (H:V) Right Side Slope. 1 . 50 : 1 (H:V) Manning' s n. . . . . . 0 .018 Channel Slope. . . . 0 .0533 ft/ft Discharge. . . . . . . . 1 . 81 cfs Computed Results : Depth. . . . . . . . . . . . 0 . 44 ft Velocity . . . . . . . . . 6 . 17 fps Flow Area. . . . . . . . 0 . 29 sf Flow Top Width. . . 1 . 33 ft Wetted Perimeter . 1. 59 ft Critical Depth. . . 0 . 62 ft Critical Slope. . . 0 .0089 ft/ft Froude Number. . . . 2 . 31 (flow is Supercritical ) Open Channel Flow Module, Version 3 . 41 (c) 1991 Haestad Methods , Inc. * 37 Brookside Rd * Waterbury, Ct 06708 Triangular Channel Analysis & Design Open Channel - Uniform flow Worksheet Name: Biehl Short Plat Comment : Interceptor Ditch capacity verification Solve For Depth Given Input Data: Left Side Slope. . 1 . 50 : 1 (H:V) Right Side Slope . 1 . 50 : 1 (H :V) Manning' s n. . . . . . 0 . 018 Channel Slope. . . . 0 . 0025 ft/ft Discharge. . . . . . . . 1 . 81 cfs Computed Results : Depth. . . . . . . . . . . . 0 .79 ft Velocity. . . . . . . . . 1 . 96 fps Flow Area. . . . . . . . 0 . 92 sf Flow Top Width. . . 2 . 36 ft Wetted Perimeter . 2 . 83 ft Critical Depth. . . 0 . 62 ft Critical Slope. . . 0 . 0089 ft/ft Froude Number . . . . 0 . 55 (flow is Subcritical ) Open Channel Flow Module, Version 3 . 41 (c) 1991 Haestad Methods , Inc. * 37 Brookside Rd * Waterbury, Ct 06708 12/11/98 8 :47 : 3 am NL Olson & Assoc . Inc . page 1 Biehl Short Plat Tempoary Erosion/Sedimentation Control Biofiltration Swale Design BASINSUMMARY=====_______________________ BASIN ID: Dev-100 NAME: Developed 100-yr, 24-hr storm SBUH METHODOLOGY TOTAL AREA. . . . . . . : 2 . 76 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPElA PERV IMP PRECIPITATION. . . . : 6 . 90 inches AREA. . : 2 . 51 Acres 0 . 25 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 80 . 54 98 . 00 TC. . . . . 18 . 38 min 5 . 00 min ABSTRACTION COEFF: 0 . 20 TcReach - Sheet L: 235 . 00 ns : 0 . 1500 p2yr: 3 .45 s : 0 . 0357 TcReach - Shallow L: 14 . 00 ks : 27 . 00 s : 0 . 0200 TcReach - Channel L: 175 . 00 kc : 17 . 00 s : 0 . 0100 TcReach - Channel L: 230 . 00 kc : 17 . 00 s : 0 . 0533 TcReach - Channel L: 160 . 00 kc : 17 . 00 s : 0 . 0382 impTcReach - Sheet L: 14 . 00 ns : 0 . 0110 p2yr: 3 .45 s : 0 . 0200 impTcReach - Channel L: 175 . 00 kc : 17 . 00 s : 0 . 0100 impTcReach - Channel L: 230 . 00 kc : 17 . 00 s : 0 . 0533 impTcReach - Channel L: 160 . 00 kc : 17 . 00 s : 0 . 0382 PEAK RATE: 2 . 65 cfs VOL: 1 . 11 Ac-ft TIME : 480 min BASIN ID: Dev-2 NAME : Developed 2-yr, 24-hr storm SBUH METHODOLOGY TOTAL AREA. . . . . . . : 2 . 76 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 3 .45 inches AREA. . : 2 . 51 Acres 0 . 25 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 80 . 54 98 . 00 TC. . . . . 18 . 38 min 5 . 00 min ABSTRACTION COEFF: 0 . 20 TcReach - Sheet L: 235 . 00 ns : 0 . 1500 p2yr: 3 . 45 s : 0 . 0357 TcReach - Shallow L: 14 . 00 ks : 27 . 00 s : 0 . 0200 TcReach - Channel L: 175 . 00 kc : 17 . 00 s : 0 . 0100 TcReach - Channel L: 230 . 00 kc : 17 . 00 s : 0 . 0533 TcReach - Channel L: 160 . 00 kc : 17 . 00 s : 0 . 0382 impTcReach - Sheet L: 14 . 00 ns : 0 . 0110 p2yr: 3 .45 s : 0 . 0200 impTcReach - Channel L: 175 . 00 kc : 17 . 00 s : 0 . 0100 impTcReach - Channel L: 230 . 00 kc : 17 . 00 s : 0 . 0533 impTcReach - Channel L: 160 . 00 kc : 17 . 00 s : 0 . 0382 PEAK RATE: 0 . 88 cfs VOL: 0 . 41 Ac-ft TIME: 480 min 12/11/98 8 :47 :4 am NL Olson & Assoc . Inc . page 2 Biehl Short Plat Tempoary Erosion/Sedimentation Control Biofiltration Swale Design BASIN SUMMARY BASIN ID: Dev 6m NAME : Developed 6-month, 24-hr storm SBUH METHODOLOGY TOTAL AREA. . . . . . . : 2 . 76 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 2 . 21 inches AREA. . : 2 . 51 Acres 0 . 25 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 80 . 54 98 . 00 TC. . . . : 18 . 38 min 5 . 00 min ABSTRACTION COEFF: 0 . 20 TcReach - Sheet L: 235 . 00 ns : 0 . 1500 p2yr: 3 .45 s : 0 . 0357 TcReach - Shallow L: 14 . 00 ks : 27 . 00 s : 0 . 0200 TcReach - Channel L: 175 . 00 kc : 17 . 00 s : 0 . 0100 TcReach - Channel L: 230 . 00 kc : 17 . 00 s : 0 . 0533 TcReach - Channel L: 160 . 00 kc : 17 . 00 s : 0 . 0382 impTcReach - Sheet L: 14 . 00 ns : 0 . 0110 p2yr: 3 . 45 s : 0 . 0200 impTcReach - Channel L: 175 . 00 kc : 17 . 00 s : 0 . 0100 impTcReach - Channel L: 230 . 00 kc : 17 . 00 s : 0 . 0533 impTcReach - Channel L: 160 . 00 kc : 17 . 00 s : 0 . 0382 PEAK RATE: 0 . 35 cfs VOL: 0 . 19 Ac-ft TIME: 480 min Trapezoidal Channel Analysis & Design Open Channel - Uniform flow Worksheet Name: Biehl Short Plat Comment : 6-month Biofiltration Swale Solve For Depth Given Input Data: Bottom Width. . . . . 2 . 25 ft Left Side Slope. . 3 .00 : 1 (H:V) Right Side Slope. 3 .00 : 1 (H :V) Manning' s n. . . . . . 0 . 200 Channel Slope . . . . 0 .0382 ft/ft Discharge. . . . . . . . 0 . 35 cfs Computed Results : Depth. . . . . . . . . . . . 0 . 24 ft Velocity. . . . . . . . . 0 . 48 fps Flow Area. . . . . . . . 0 . 73 sf Flow Top Width. . . 3 . 71 ft Wetted Perimeter . 3 . 79 ft Critical Depth. . . 0 .09 ft Critical Slope. . . 1 . 3775 ft/ft Froude Number. . . . 0 . 19 (flow is Subcritical ) Open Channel Flow Module, Version 3 . 41 (c) 1991 Haestad Methods , Inc. * 37 Brookside Rd * Waterbury, Ct 06708 Trapezoidal Channel Analysis & Design Open Channel - Uniform flow Worksheet Name: Biehl Short Plat Comment : 100-year Biofiltration Swale Solve For Depth Given Input Data: Bottom Width. . . . . 2 . 25 ft Left Side Slope. . 3 . 00 : 1 (H:V) Right Side Slope . 3 . 00 : 1 (H :V) Manning's n. . . . . . 0 . 035 Channel Slope . . . . 0 . 0382 ft/ft Discharge. . . . . . . . 2 . 65 cfs Computed Results : Depth. . . . . . . . . . . . 0 . 28 ft Velocity . . . . . . . . . 3 . 00 fps Flow Area. . . . . . . . 0 .88 sf Flow Top Width. . . 3 . 96 ft Wetted Perimeter . 4 .05 ft Critical Depth. . . 0 . 30 ft Critical Slope. . . 0 .0298 ft/ft Froude Number. . . . 1 . 12 (flow is Supercritical ) Open Channel Flow Module, Version 3 . 41 (c) 1991 Haestad Methods, Inc . * 37 Brookside Rd * Waterbury, Ct 06708