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Home My WebLink AboutStorm Drainage Analysis Report - PLN General - 4/21/2004 RECEIVED Michael F. Wnek, P.E., PS JUL 0 g ?(?(14 Consulting Civil Engineer COUNTY PUBLIC WORKS 1665 NW Sherwood Drive, Bremerton, WA 98311, 360-692-3802 STORM DRAINAGE ANALYSIS REPORT FOR RECEIVED Eger Workshop `JUL' 0 8 2004 BELFAIR OFFICE Located in the NE 1/4 of SEC 23, T 28, R 1E X.M. Mason County Assessor's Account No. 1 2328-23-900 1 0 Richard Eger 8128 187th St SW Edmonds WA. 98026-5843 (425) 778-7485 April 21, 2004 L F Michael F. Wnek, P.E. `Z'P W Consulting Civil Engineer 16550NW Sherwood Drive , Bremerton, Washington 98311 (360)-692-3802 � 02 60 �� Job#304 OSS ANAL April 21, 2004 EXPIRES 07/13/05 TABLE OF CONTENTS PROJECT OVERVIEW---------------------- --------------------------- ............... 1. EXISTING SITE CONDITIONS............................................................. DEVELOPED SITE CONDISTIONS....................................................... DOWNSTREAN ANALYSIS................................................................ EROSION CONTROL.......................................................................... 2 WATER QUALITY DESIGN............................................................... 2 APPENDICES Appendix A—Various Maps Appendix B— Soils information, Cn Values, Isopluvials Appendix C—Basin Runoff Calculations Appendix D—Water Quality PROJECT OVERVIEW The site is 3.7 acres total and is located in the Northeast quarter of the Northeast quarter of Section 23 Township 28 range 1 E in Mason County, Washington. The storm drainage analysis and design will be reviewed by Mason County and based in requirements as found in the Dept. of Ecology, Storm Water Management Design Manual for the Puget Sound Region. The Santa Barbara Urban Hydrograph method will be used to compare the peak runoff rates for the existing site conditions and the proposed changes to the site, modeling the 100 year, 24 hour storm events. The StormShed 2G software program by Engenious Systems, Inc. has been used for hydrograph calculations and Level Pool Routing. Infiltration is proposed as the method of meeting the requirements for runoff quantity control. There will be no off site improvements required. Storm water runoff from the site does not discharge directly into a stream, so a Hydraulic Project Approval application is not required. EXISTING SITE CONDITIONS The site is currently undeveloped with trees and brush. The site slopes from the east to west with an average slope of 20 percent. Access to the site will be from Roy Boad Road. The area for the proposed building and access road has already been cleared and partially graded. Soil Conservation Service maps for the area show that the soil is typically found to be "Everett gravelly loamy sand" belonging to the Hydrologic Group "A". A copy of the SCS maps for the site is attached with this report. Existing peak storm runoff rate calculations are not warranted, since there will be no post development discharge, due to the infiltration system. DEVELOPED SITE CONDITIONS Development of the 3.7 acres will consist of 0.33 acres of impervious surface (roof- top, asphalt parking, and driveways). The pervious area will be in the form of native vegetation. The soil where the infiltration pit will be placed is coarse sand and gravel. The infiltration rate from Table I11-3.1 (attached in Appendix C) is 20in/hr. A safety factor of 2 is applied to the rate, therefore 10 inches per hour is used in the system calculations. The 100-year, 24-hour event is the basis for sizing the infiltration system. DOWNSTREAN ANALYSIS OF CONVEYANCE SYSTEM The upstream potion of the site encompasses 3.42 acres and will be diverted around the infiltration facility with a cut-off ditch. The project impervious-area drainage will flow through a Biofiltration Swale to a infiltration system, which will deliver the water to the ground. The overflow will go to an existing storm system on the East side of Roy Boad Rd. The storm system flows under Roy Boad Road in a 24" culvert to the west side, which connects to an existing stream that carries the flows east to Lynch Cove. The storm system along Roy Boad Road has been recently constructed by Mason County project CRP#1702. EROSION CONTROL A silt and erosion control plan for this site is included with the final construction plans. WATER QUALITY All of the runoff water from the paved surface and buildings will be treated in a biofiltration swale prior to discharge from the site. The length of the Bioswale has been shortened to 1/4 by proportionally increasing the width. Swale design can be found in Appendix D of this report. APPENDIX A VARIOUS MAPS AND SOIL INFO Vicinity Map Al USGS Map A2 Soils Map A3 Soil Description A4 Soil Group. A5 ' � S I C N REEK -----vimtx�SILE'BlUD6--------- --------- r-----'- 7------------------ i f------ MdV°" �nhsoALN akgBW STEELHEAD DR SOUTH STEELHEAD DR NORTH �a4 eun �NlSslgy CREEK ,o ci RD ; " LA iv y, URSON RARJBOW LN RW, R W W y DR ;3 s l m f as yo ; CHINOOK DR O -- -- r--�------------------� T ---- '----------------- -- --i-------- ----------- ---------- Ag RD LARSON LAKE LN Z ; G 3X A F F► o 6a RIDGE TOP COD p mph a y00 � DAVEY kqD , C = < .KIHES CT - --------- �---'------ '-=--='- --•----1------ ---- -----�!m - - -',-`---------- ---------- -------- ----------- ---------- }� qF ALLION LN m Om�, ROESSEL RD ; m CD X m 41 0 an FOSTER; STER OR ED < m 1 r --r ' w i 7mo ------------------'----------------- - '------ T ---------- D--�-r -----------------L----- >----- 3 Z -- ------ �' k i m ; --- ------ - �t` 9 �o OLD '° BELFAIR r� OY -„ o yc R `7 7 z T p Z Z[ RIVERHILL HLL RD D c YAEGER CREST i m DR --------------------;---------------------- -,--- - -------------- ' —- --� - - --------- - ------ H� � = 1N---------------------- 4 (�2o�E�T �oC, �tlot� MASON ` COUNTY KrFSAP c COUNTY ' At ) 6 Qh- ravel P iklk ZZ8 J1 • 1p 'Tr Pf low .3 ov 300 kk m 43 Belfair t 34a All, 0 n 14 el A2- COUNTY, WASHINGTON SHEET NUMBER 7 Uoins slice} 4) Eh .�•' Au �y s)(�''' Ib �V rr s `�` - �� 9 � � � • r f r *e NJ�• +`!1 �1 `. .. N;_ ch , LatKan Yaw�r. d-�J. f .J �rs•� Frt1�.L' 'ti 1� .., - _:'>; M� •'?�� fit • o - I C J. .r _ � r ! •IR a i•3 � +a ° .r _ _; 1 ', ,r♦i� tii' le � f r, �' : � s, Ua ,, .'` ..��. �..' At •.G �� •. r`• � h w;_+ � Nd�1 dvaC�i ».AI[. 2 �. •c f•�,j.• F'�• 25 1 :�"' fc •t + J f .'� fS ti Ili_ j p Ad E11 r � riC t' w �� S� Et )�f •' ' � r +l A tb z�t�` h r 1 , t i •• • w P r f,LT'/ Ab y .� r' r'Eh..' e�(�>� �• ,mot''"" +;D . er c �;^ r{.�', + f Ab ,r: a 1�• ;0§ �'.� fi: , / �! ••. � �',`S(ib- ��'�' 11 Tn f'',�r ��•.� 4} ��._: .. Tn - •gr JJJJ r r ,'" �. [f�J�• .r '-at ram?'-. L' - .) '�., '�. -e, ?� r! �.., � a F�`f `oE • r%1rX 4 _+} r;r Cc- .• � �Ep :. ,N' :�.1� '.� f1f ••1.�. s.�._ �� .�•�` .�y. r.�l�i "s �`r �'� +f.�.F• EG t r�. r IZ? a� `�Q . � _ D\, •rn •.�•- �jr { ��s.�}t� 'd' ri��, �r�.:��:� i- .Eh t 115 t' .� � •:'j r •�itiM _��`�� ^' S� * ~��`��itpt't�C,`✓ ' i E'd .Tyr• •..� � z' • Y4• � � r • �• rt'.fzi' -•\ 9 r +� it �� `� - n x�� t ^4; rrt J r a r1 i' f r :Ea. EU ,�•r, 7/rt 4 ram,. - '•` IVA; �. •�....'�'� a,�`�7 _ �.�. {-•. s D r�e fit�1,1 � ' .'�ra1. St. '�s3}t p�'�.,y��y! �c t '7• r .��y= i, 3. Id ...��-�- _ � .. ` 7• t� �4 .� i�.�ry�14 a _ .>� �tezy �R / ...� q: `Surisei 7 ruuG Ab Mf �, t eft ` Lake Ack �Ar. �ryT< - .�.- �.• t ;c \�.. .�` ,�i� j s P�•y��IC ,�. -. r _ ' ,t E IV` _ •`�3 �'� _ 17 �!( .i 'f n7r ilk` ♦ �; y: . y, `�/'^1.....�..f Ace `� N f• :d.: - -r } 1 Ah �- 'S ? , _ y.. ly ,le ....- tirow..c?j K� •tom,- .r 1 c. {;.�' '�<r.x�,� '.�' -- ,:f1•• i �t fig:, 3 24 SOIL SURVEY SERIES 1951, NO. 9 The Eld soil occurs only in the extreme southern end material that is extremely loose and porous. However. of the county. It differs from the Maytown soils in in places, this material will stand in banks. The color having a redder surface soil and subsoil, some faintly of this material is largely determined by the gravel, developed shot, and stronger red and yellow staining of coarse sand, and cobbles, which are olive gray, pale the subsoil. olive, yellowish brown, light brownish gray, gray, and Eld silt loam, 0 to 3 percent slopes (Ec).—This soil is dark gray. Many of the cobbles, as well as much of the at the head of Oyster Bay. The surface soil is reddish- gravel, are faintly to moderately stained by iron. brown, granular and friable silt loam, 6 to 10 inches The amount of gravel ranges from about 20 percent tc thick, that contains a few very soft shot. This layer is 50 percent in the subsoil to as much as 80 percent in the underlain by a reddish-brown, firm clay loam that has substratum. The soil is medium to strongly acid and a subangular blocky structure, is highly stained by iron, becomes less acid with depth. and contains considerable amounts of shot. At depths Use and suitability.—This soil is too droughty for ranging from 20 to 32 inches? the play loam rests on most tilled crops—it dries out before crops mature, a layer of fairly compact, stratified sand and gravel that Only a very small acreage is cultivated, and this is is prominently stained by iron. Rounded glacial gravel, ordinarily farmed along with better adjacent soils. Most mixed with subangular basaltic gravel, is scattered on of this soil is in brush and trees, for which it is suited the surface and through the soil. best. It is one of the better soils for growing Douglas- The soil is medium acid throughout. Surface drainage firs that are cut for Christmas trees. This is_an impor- is moderately well established though small swales may Cant use of the soil; large acreages are used for Christ- stay wet for a long time. Subsurface drainage is fairly mas trees. slow because of a slowly receding, fairly high water This soil is in capability subclass VIs and in site table. class 4 for Douglas-fir. Use and Suitability.—Most of the soil is used for Everett gravelly sandy loam, 0 to 5 percent slopes pasture or grain. Management is similar to that of ft).—This soil occupies the smoother outwash terraces in Maytown silt loam, 0 to 3 percent slopes, but yields are association with other Everett soils. It differs from slightly lower. Everett gravelly sandy loam, 5 to 15 percent slopes, in This soil is in capability subelass IM; it is good for that its surface layer is generally 2 to 3 inches thicker; fir, redcedar, hemlock, and deciduous trees. the profile is less variable; and the substratum, or under- gvn3sEIrr SEMES lying material, is usually more stratified. Use and Suitability.—The use of this soil is similar to The Everett series consists of somewhat excessively that of Everett gravellysand loam 5 to 15 percent drained, pale-brown gravelly soils. They occur as inex- slopes. The soil tees and brush, except fo few tensive gravel ridges on the glacial moraines, or, more small cleared areas. The growing of Douglas-fir for common , as fairly continuous outwash channels be- Christmas trees is gaining in importance. This soil is in tween ridges of Alderwood soils. They have developed site class 4 for Douglas-fir and in capability subclass VIs. upon assorted glacial till and outwash material. The Everett gravelly sandy loam, 15 to 30 percent slopes rainfall is 45 to 60 inches a year. The vegetation is (Ek).—This soil is on the steeper slopes of glacial moraines, mainly drought-resistant madrone, manzanita, and kin- sides of gullies and terrace fronts. It is closely asso- nikinnick. ciated with oler Everett soils and the Alderwood Everett soils are droughty because the loose gravel and gravelly sandy loams. sandy subsoil and substratum offer little resistance to This soil is more variable than Everett gravelly sandy downward movement of water. The capacity of the sur- loam, 5 to 15 percent slopes. The depth to substratum face soil to hold available moisture is low. ranges from 12 to 36 inches, and the amount of gravel Everett soils are in the eastern half of the county, in in the surface soil and subsoil varies greatly from place association with the Alderwood soils. They also occur to pplace. Where the soil is in close association with the in intricate patterns with the Kitsap and Indianola soils. Alderwood soils, the substratum, in places, is compact Compared to the (trove soils, the Everett soils have a and weakly cemented. paler surface soil and subsoil and, in development, were Included are a few areas having slopes slightly greater dominated more by acid igneous parent rock. than 30 percent. Everett gravelly sandy loam, 5 to 15 percent slopes Use and suitability.—This soil is suitable only for (Eh).—This is the most extensive Everett soil. In undis- forestry because it is strongly sloping, drougghty, and low turbed forests 1 to 2 inches of very dark grayish-brown in fertility. It is in capability subclass VIs and in site material, a mixture of needles, leaves, twigs, cones, moss, class 5 for Douglas-fir. and roots, covers the surface. The surface soil is loose, Everett gravelly loamy sand, 0 to 5 percent slopes single-grained, pale-brown, gravelly sandy loam, 6 to 8 (Ed).—This soil occupies the smoother terraces or outwasb inches thick. The upper 2 or 3 inches normally contains plain in close association with other Everett soils. It aggregates that are slightly hard and redder than the differs from Everett gravelly sandy loam, 5 to 15 percent others in the layer. To depths ranging from 18 to 24 slopes, in having a finer surface soil and a slightly inches, the subsoil is loose single-grained, light yellow- coarser subsoil. ish-brown gravelly sandy foam or gravelly loamy sand. Use and Suitability.—Use and management are similar The amount of shot decreases with depth; in the lower to those for Everett gravelly sandy loam, 5 to 15 percent part only a few shot occur. slopes. This soil is poorer for forest than Everett The subsoil grades to a substratum of poorly assorted,, gravelly sandy loam 0 to 5 percent slopes. It is in predominantly yellowish-brown sand, gravel, and cobbly capability subclass Vis and in site class 5 for Douglas-fir. �4 T OF AGRICULTURE DN SERVICE MASON COUNTY, WASHINGTON SOIL LEGEND SYMBOL NAME SYMBOL NAME Aa Alderwood gravelly loam, 5-15 percent slopes He Horstine gravelly sandy loam, 5-15 percent slopes Ab Aiderwood gravelly sandy i0sm, 5.15 percent slopes Hb Harstins gravelly sandy loam, 15.30 percent slopes AC Alderwood gravely sandy loam, 15-30 percent slopes He Hoodsport gravelly sandy loam, 0.5 percent slopes Ad Alderwood gravely sandy loam, 30-45 percent slopes Hd Hoodsport gravelly sandy loam, 5-15 percent slopes Ae Astoria silt loam, 5.15 percent slopes He Hoodsport gravelly sandy loam, 15-30 percent slopes At Astoria silt loam, 15.30 percent slopes Hoodsport gravelly sandy loam, 30-45 percent slopes Be Belfast sandy loam, 0-3 percent slopes Hg Hoodsport stony sandy loom, 5-15 percent slopes BD Belfast silt loam, 0-3 percent slopes Hh Hoodsport stony sandy loam, 15-30 percent slopes Bc Belle silt loam,0-5 percent slopes Hk HoQuiam gravely slit loam, 5.15 percent slopes Hm Hoquism gravely silt loom, 15-30 percent slopes B Bellingham silt loam, percent scopes Hn Hoquism loam, 15.30 percent slopes Be Bellingham silty clay loom, 0-3 percent slopes Ho Hooulam silt loom,0-5 percent slopes Co Carstairs gravely loam, 0.5 percent slopes Hp Hoqulam silt loam, 5-15 percent slopes Cloquallum silt loam, 0.5 percent slopes Hr Hoquism silt loam, 15-30 percent slopes Cloqusllum silt loam, 5.15 percent slopes Hs Hoquism and Astoria slit looms, 5-15 percent slopes Cloquallum silt loam, 15-30 percent slopes Ht Hoquism and Astoria silt looms, 15-30 percent slopes Cloquallum sift loam, moderately shallow over la Indianola )oa camsnted till, 5.15 percent slopes my sand, 0-5 percent slopes Cf Cloquallum silty cloy loam, 5.15 percent slopes lb Indianola loamy sand, 5.15 percent slopes ca Coastal beach, 0-2 percent slopes Ic tndlanofs loamy sagd, 15.30 percent slopes Id Indianola sandy loam, 0-5 percent slopes Ds Deckerville gravelly loam, 0-2 percent slopes Is Indianola sandy loom, 5.15 percent slopes Deckerville gravelly silty clay loam, 0-2 percent slopes Deckerville silt loam, 0-2 percent slopes Ja Juno gravelly sandy loom, 0-3 percent slopes Dd Deckerville silty clay loam, 0-2 percent slopes Jb Juno loam,0-3 percent slopes M. Delphi gravelly loom, 5.15 percent slopes Jc Juno loamy sand, 0-3 percent slopes Delphi gravelly loom, 15-30 percent slopes Jd Juno sandy loam, 0.3 percent slopes Dg Dungeness fine sandy loam, 0.2 percent slope Ka Kitsap slit loam, 0.5 percent slopes Dungeness fine sandy loam, shallow, 0-2 percent slopes Kb Kitsap silt loam, 5-15 percent slopes Dungeness silt loam, 0.2 percent slopes Kc Kitsap silt loom, 15-30 percent slopes Ea Edmonds fine sandy loam, 0-2 percent slopes Kd Kitsap silty clay loam, 0-5 percent slopes Eb Edmonds silt loom, 0-2 Ke Kitsap silty cloy loom, 5-15 percent slopes percent slopes Ec E Kf Koch gravelly loam, 0.3 percent slopes E Everett gravelly loamy sand, 0-5 percent slopes silt loam,0 3 percent slopes Kg Koch gravely sand/ loam, 0.3 percent slopes Ee Everett gravelly loamy sand, 5.15 percent slopes Kh Koch silt loam, 0.3 percent slopes Ef Everett gravelly loamy sand, 15-30 percent slopes LA La Bar silt loam, 0.5 percent slopes Eg Everett gravely sandy loam, 0-5 percent slopes Lb Lystair loamy sand, 0-5 percent slopes Eh Everett gravelly sandy loom, 5-15 percent slopes Le Lystair loamy send,5-15 percent slopes Ek Everett gravelly sandy loom, 15-30 percent slopes Ld Lystair sandy loam, 0-5 percent slopes Go Gravel pit Le. Lystair sandy loam, 5-15 percent slopes Gb Grove cobbly sandy Igom, 0-5 percent slopes Lf Lystair sandy loam;15.30 percent slopes Gc Grove cobbly sandy loam, 5.15 percent slopes Me Made land Gd Grove cobbly sandy loam, 15-30 percent slopes Mb Maytown silt loam,0.3 percent slopes Go Grove gravelly loam, 0-5 percent slopes Mc McKenna gravely loam, 0-3 percent slopes 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 Mcfdurray peat, 0-2 percent slopes Gh Grove gravelly sandy loam, 0-5 percent slopes Mf McMurray peat, shallow over gravel,0-2 percent slope Gk Grove gravelly candy loam, 5-15 percent slopes Mg Mukilteo peat, 0.2 percent slopes Gm Grove gravelly sandy loom, 15.30 percent slopes Mh Mukitteo peat, shallow over gravel, 0.2 percent slopes Gn Grove gravelly sandy loam, 30-45 percent slopes l gravelly Na Nasal loam, 0 5 percent slopes Go Grove gravelly sandy loom, basin phase, 0.5 percent slopes Nb Nasa loam, log percent slopes Go Grove stony sandy loam, 0-5 percent slopes by �61 by R, H. Fowler and R. G. Parvin, hf Experiment Station, and A. O. Ness, Agriculture. Roberts, U. S. Department of Agriculture. APPENDIX B BASIN MAPS Post Developed Basin Map B 1 SAII , s , 12* , o IJ �, �oi� // EXISTING /�/ �� Per��oUs Area - p ' 2 acre14 C,2 OnN y//�' 100' WELL RADIU //Y S89'09'28"E S T 407.81' / E-- - --- ---C----E 30' Road & Utility Easement EXISTING ROCK—LINED DITCH E----- _ '�---------------------------------------------------------- --------- APPENDIX C BASIN RUNOFF CALCULATIONS & DESIGN Isopluvial Maps 2—YR 24-HR CI 10-YR 24-HR C2 100 -YR 24-HR C3 SCS Curve Numbers C4 Infiltration Values C5 Hydrology Calculations C6-C7 i 4,0/ag" BtGA � �- v ti• Nam44 +' MT NE lz MIA L Wit' ,tom �' � _ _.� •�� ,1 1 �.- .�1, .� ^�►,•�-,...�;may.�' ��I I t � r 1 1 1 1 t t t fi • � 1 � • 11 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 IA rainfall distribution, 24-hour storm duration. LAND USE DESCRIPTION CURVE NUMBEM7681 HYDROLOGIC S A B Poodor land 1 : winter condition 86 91 en areas: low growing brush & grasslands 74 82 asture: 65 78 est land: undisturbed 42 64 Wood or forest land: young second growth or brush 55 72 81 86 Orchard: with cover cro 81 88 92 94 Open spaces, lawns, parks, golf courses, cemeteries, landscaping. VD ition: grass cover on z758 of the 68 80 86 90 area ition: grass cover on 50-75% of 77 85 90 92 the area ads & parking lots: 76 85 89 91 s & parkinglots: 72 82 87 89 s surfaces, pavement, roofs etc. 98 98 98 98 r bodies: lakes, wetlands, nds etc. 100 100 100 100 ily 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 STORMWATER MANAGEMENT MANUAL FOR THE PUGET SOUND BASIN Table III-3.1 Soil Properties Classified by Soil Texture U d Q C7 < < < m m U U A 0 A 0 0 v — �` O � y _T O O O O O O O O O O O w � L 3 up � C C � t O O O O O O O O j w 'B a o: e V) T 'O c L` y C u a c c u g + u RY, p t N jb N O O O O O O O O 94 2 u 6. + u u � s � K 4 V 1 � U � 4 U � V V V pq y + c _ o u • t F- U G a a u c _ T U U III-3-8 FEBRUARY, 1992 r� RICHARD EGER WORK SHOP ROY BOAD ROAD, BELFAIR i HYDROLOGY CALCULATIONS I PRECIPITATION: Event Precip 6 month 2.4000 2 year 3.6000 .................._-_------.___._._. 10 year 14.8000 _ 100 year 6.8000 BASIN ID: DE - . .._._..............._... Design Method SBUH jRamfall type TYPElA - - �_...... _... y ( 10.00 min IPeaking Factor 3 484.00 _..._...... ._ __....�__-- jAbstraction Coeff 0.20 :Pervious Area 0.00 ac DCIA J 0.33 ac Pervious CN ! 0.00 IDC CN -r- 98.00 - . ........._. _.... .... . .............. __......_...- ...--- Pervious TC ; 0.00 min IDC TC 6.00 min ..._..................................._ ------ -._ . Directly Connected CN Calc- --- - .............- --- ... - ... _._._........_..... Sub cu Description SubArea _._..........._.__._-- I Impervious surfaces (pavements, roofs, etc) 0.33 ac 98.00 _._ ..._. _ .... ... DC Composited CN (AMC 2) 98.00 --..- .._ _-__ ...._..... _..--- Directly Connected TC Calc Type Description Length Slope Coeff Misc TT Fixed :MINIMUM ;6.00 min ...._............... Directly Connected TC 6.00min EVENT SUMMARY: BasinID Event Peak Q Peak T Peak Vol (ac Area Method/Loss(Ra�IItype -24 hour 1 (cfs) (hrs c f7 (ac IDE 6 month 0.1766 8.00 0 0597 0.33 �SBUH/SCS �TYPEIA !DE 2 year �0.2699 8.00 0.0926 0.33 ISBUH/SCS TYPEIA E 10 year 0.3625 8.00 0.1255 0.33 ;SBUFU** TYPEIA ._._ DE 100-year 0.5161 8.00 01804 0.33 ISBUH/SCS �TYPEIA C6 RICHARD EGER WORKSHOP ROY BOAD ROAD, BELFAIR HYDROLOGY CALCULATIONS STORAGE ID: POND-STORAGE Descrip: Storage of Infiltration Pond Increment 0.10 ft Start El. 72.0000 ft Max El. 75.0000 ft Stage Volume _ ft Stage ( Volume c ) 72.00 0.0000 --._... _. _ 72.50 230.0000 ._............ -- ----__ 73.00 522.0000 ...--._..._-........_.._-__... 73.50 880.0000 74.00 1308.0000 _ 74.50 1810.0000 .._....... 75.00 2390.0000 Stage Storage Rating Curve 72.0000 ft 0.0000 cf 73.6000 ft 965 6000 cf j 72.1000 ft 46.0000 cf 73.7000 ft 1051.2000 cf 72.2000 ft 92.0000 cf 73.8000 ft 1136.8000 cf 72.3000 ft 138.0000 cf'73.9000 ft 1222.4000 cf 72.4000 ft 184.0000 cf 74.0000 ft 1308.0000 cf 72.5000 ft 230.0000 cf 74.1000 ft:1408.4000 cf' 72.6000 ft 288.4000 cf 74.2000 ft 1508.8000 cf 72.7000 ft 346.8000 cf 74.3000 ft 1609.2000 cf' 72.8000 ft 405.2000 cf 74.4000 ft 1709.6000 cf 72.9000 ft'463.6000 cf 74.5000 ft 1810.0000 cf 73.0000 ft'522.0000 cf 74.6000 ft 1926.0000 cf 73.1000 ft 593.6000 cf 74.7000 ft 2042.0000 cf' 73.2000 ft 665.2000 cf;74.8000 ft 2158.0000 cf' 73.3000 ft 736.8000 cf 74.9000 ft 2274.0000 cf 73.4000 ft'808.4000 cf 75.0000 ft 2390.0000 cf 73.5000 ft 880.0000 cf 75.1000 ft 2506.0000 cf' C7 RICHARD EGER WORKSHOP ROY BOAD ROAD, BELFAIR HYDROLOGY CALCULATIONS DISCHARGE ID: RET-POND Descrip: Infiltration Discharge Increment 0.10 ft Start El. 72.0000 ft ;Max El. 75.0000 ft Stage (ft) Discharge(cfs) 72.00 0.0000 72.010.0930 _ 72.50 0.1260 73.00 0.1650 73.50 ' 0.2090 74.00 0.2580 74.50 _ 0.3130 t _.__.. ......_-........... 75.00 0.3730 ......- . .._ ._ .......-. _.- ..._. i __._..___._.._._-------._._..._........_..__..........._........... __-�Stage Discharge Rating Curve 72.0000 ft 0.0000 cfs 73.6000 ft 0.2188 cfs 72.1000 ft 0.0991 cfs 73.7000 ft 0.2286 cfs 72.2000 ft 0.1058 cfs 73.8000 ft 0.2384 cfs 72.3000 ft 0.1125 cfs 73.9000 ft 0.2482 cfs 72.4000 ft'0.1193 cfs 74.0000 ft 0.2580 cfs'` 72.5000 ft 0.1260 cfs 74.1000 ft 0.2690 cfs' 72.6000 ft 0.1338 cfs 74.2000 ft,0.2800 cfs 72.7000 ft 0.1416 cfs 74.3000 ft 0.2910 cfs 72.8000 ft 0.1494 cfs 74.4000 ft 0.3020 cfs 72.9000 ft 0.1572 cfs 74.5000 ft'0.3130 cfs 73.0000 ft 0.1650 cfs 74.6000 ft 0.3250 cfs I 73.1000 ft 0.1738 cfs 74.7000 ft 0.3370 cfs ......._............... 73.2000 ft 0.1826 cfs 74.8000 ft 0.3490 cfs 73.3000 ft 0.1914 cfs 74.9000 ft 0.3610 cfs 73.4000 ft 0.2002 cfs 75.0000 ft0.3730 cfs 73.5000 ft 0.2090 cfs 75.1000 ft 0.3730 cfs 75.0000 10.3730 cfs C8 RICHARD EGER WORKSHOP ROY BOAD ROAD,BELFAIR HYDROLOGY CALCULATIONS ROUTING ID: LEVEL-POOL _ .. _ .................... Descrip: Level Pool Routing'Increment 0 10 ft __.._...._ ..._...............I Start El. 72.0000 ft Max El. 74.0000 ft .....----......_._..._- Storage Node POND-STORAGE Discharge Node RET-POND _ ..... LEVEL-POOL SUMMARY using Puls _.__..... - _ Event Match Q i Peak Q Peak Stg Peak Stg Vol Vol Time to (cfs) (cfs) (ft) (elevation) (cf) (acft) Empty 2 year 0.2699 0.1367 0.6366 72.64 309.77 0.0071 24.83 _ ..-_.-. --- --I 10 year 0.3625 ' 0.1653 1.0033 73.00 j524.36 E 0.0120 24.83 --- - ------.._.._.... ._._....._..... _..__... _----------- ----_r_---- --- 100 year 0.5161 0.2177 1.5892 73.59 956.35 0.0220 24.83 C9 304-ret-pond.xls PROJECT: RICHARD EGER WORKSHOP FILE: ICIVILENG13041STORM1304-ret-pond.XLS DEPT. OF ECOLGY, STORMWATER MGT. MANUAL - PUGET SOUND REGION SECTION III-3.4 INFILTRATION POND CALCULATION VARIABLES: Gravel USDA SOIL CLASSIFICATION 3.00 min/inch (F) PERMEABILITY RATE 20.00 inch/hour 2 (d) PERC RATE SAFETY FACTOR ("2" RECOMMENDED) 3.0 ft (h) MAX. HEIGHT OF STANDING WATER IN FACILITY 10 ft (L) BOTTOM OF INFILTRATION MEDIA TO WATER TABLE/BEDROCK CALCULATED INFILTRATION FLOW: 0.83 fUhour (Fd) PERC RATE (CONVERTED TO FEET PER HOUR) AND ADJUSTED BY SAFETY FACTOR SYSTEM PARAMETERS: 50.00 ft (X) BOTTOM LENGTH 8.00 ft (Y) BOTTOM WIDTH 2.00 :1 SIDE SLOPES 100% VOID RATIO FORMULA: Q = Fd * i *A where - i = (h+L)/L A = X *Y STAGE STORAGE AND DISCHARGE POND GROSS NET NET h i AREA Q ELEV VOLUME VOLUME VOLUME (ft) (fUft) (sf) (cfs) (ft) (cf) (cf) (acre-ft) 0.0 1.0 400 0.093 72.00 0 0 0.00 0.5 1.1 520 0.126 72.50 230 230 0.01 1.0 1.1 648 0.165 73.00 522 522 0.01 1.5 1.2 784 0.209 73.50 880 880 0.02 2.0 1.2 928 0.258 74.00 1308 1308 0.03 2.5 1.3 1080 0.313 74.50 1810 1810 0.04 3.0 1.3 1240 0.373 75.00 2390 2390 0.05 C10 APPENDIX D WATER. QUALITY CALCULATIONS Biofilftation Swale Design D2 &D3 E 1OS W ALE CA L4 TRAPEZOIDAL CHANNEL ANALYSIS RATING CURVE COMPUTATION April 21, 2004 -------------------------- PROGRAM INPUT DATA DESCRIPTION VALUE --------------------------------------- ---------------- Channel Bottom Slope (ft/ft) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.02 Manning's Roughness Coefficient (n-value) . . . . . . . . . . . . . . . . . . . 0.07 Channel Left Side Slope (horizontal/vertical) . . . . . . . . . . . . . . . 3.0 Channel Right Side Slope (horizontal/vertical) . . . . . . . . . . . . . . 3.0 Channel Bottom Width (ft) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.5 Minimum Flow Depth (ft) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.05 Maximum Flow Depth (ft) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.55 Incremental Head (ft) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0. 5 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) -------------------------------------- 0.05 0.01 0.35 0.306 0.002 0.052 0.03 0.8 0.1 0.04 0.51 0.335 0.004 0.104 0.08 1.1 0.15 0.09 0.64 0.353 0.006 0.156 0.14 1.4 --�0.2 0.16 0.75 0.367 0.009 0.209 0.22 1.7 0.25 0.27 0.85 0.378 0.011 0.261 0.31 2.0 0.3 0.39 0.94 0.388 0.014 0.314 0.42 2.3 0.35 0.56 1.03 0.396 0.016 0.366 0.54 2.6 0.4 0.75 1.11 0.404 0.019 0.419 0.68 2.9 0.45 0.99 1.19 0.41 0.022 0.472 0.83 3.2 0.5 1.26 1.26 0.417 0.025 0.525 1.0 3.5 0.55 1.58 1.34 02 III .43 0.028 0.578 1.18 3.8 I 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. (D MONYµ PEAL FLOW C) cis ,N P PPD7- FLOCS I>F-Pl-v} = 0.2� L 3" O,K•) s-rAt-1 DAwb SW ALF- LztK = 200' P9-OPOSEr--) ISWALE LEE- .C'N = SO` vJ I " f L.EtJ�4 ADS U ST M EtJ-r F ACC OR.. LDO E� z00� SO' WN MIA = O.s' x 4 = 2-0� I i i i g�osw.�L� CA,LC, TRAPEZOIDAL CHANNEL ANALYSIS RATING CURVE COMPUTATION April 21, 2004 PROGRAM INPUT DATA DESCRIPTION VALUE -------------------------------------------------------------------------------- Channel Bottom Slope (ft/ft) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.02 Manning's Roughness Coefficient (n-value) . . . . . . . . . . . . . . . . . . . 0.033 Channel Left Side Slope (horizontal/vertical) . . . . . . . . . . . . . . . 3.0 Channel Right Side Slope (horizontal/vertical) . . . . . . . . . . . . . . 3.0 Channel Bottom Width (ft) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.0 Minimum Flow Depth (ft) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.02 Maximum Flow Depth (ft) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.22 Incremental Head (ft) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.02 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) -------------------------------------------------------------------------------- 0.02 0.02 0.46 0.581 0.003 0.023 0.04 2.12 0.04 0.06 0.72 0.648 0.008 0.048 0.08 2.24 0.06 0.12 0.92 0.689 0.013 0.073 0.13 2.36 0.08 0.2 1.1 0.72 0.019 0.099 0.18 2.48 0.1 0.29 1.25 0.743 0.024 0.124 0.23 2.6 0.12 0.4 1.4 0.763 0.03 0.15 0.28 2.72 �0.14 0.52 1..53 0.779 0.036 0.176 0.34 2.84 0.16 0.65 1.65 0.794 0.042 0.202 0.4 2.96 0.18 0.81 1.76 0.807 0.048 0.228 0.46 3.08 0.2 0.97 1.87 0.818 0.054 0.254 0.52 3.2 0.22 1.16 1.97 0.829 0.061 0.281 0.59 3.32 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. lao `(EAR PEA1L r-LOW = 0.S2 C-FS PS P P)Zo), F=LO W O. )+ FT APPPo-�- JELUG-v-i _ I , 53 �pS ✓