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HomeMy WebLinkAboutStorm Drainage Analysis Report - PLN General - 8/22/2003 STORM DRAINAGE ANALYSIS REPORT FOR WOLF/GOODELL OFFICE BLDG, PARCEL No. 12328-50-00001 WOLF-GOODELL, P.O.Box 1298 Belfair, WA 98528 (360) 275-9505 Z E. e0 WAS T j, 10 Al. EXPIRES 11 5 Zl � J.B. ENGINEERING CONSULTANTS, INC. P.O.BOX 3307 SILVERDALE, WASHINGTON (360)698-5852 Job#1561 August 22,2003 TABLE OF CONTENTS PROJECTOVERVIEW.....................................................................................................2 EXISTING SITE CONDITIONS.......................................................................................2 DEVELOPED SITE CONDITIONS..................................................................................2 UPSTREAM INVESTIGATION........................................................................................3 DOWNSTREAM INVESTIGATION................................................................................3 HYDRAULICANALYSIS.................................................................................................3 EROSION AND SEDIMENT CONTROL.........................................................................3 APENDIXES VARIOUSMAPS.........................................................................................APPENDIX A SOILS INFO, Cn VALUES & ISOPLUVIALS .........................................APPENDIX B BASIN RUNOFF CALCULATIONS & DETENTION DESIGN DATA..APPENDIX C WATER QUALITY (STORMCEPTOR CALLS.)....................................APPENDIX D J.S Engineering Consultants,Inc. Page I of 3 Storm Report PROJECT OVERVIEW The 0.45-acre site is located on the east side of State Route 3 just off of Cokelet Lane in Belfair Washington in the Southwest quarter of Section 28, Township 23N, Range 1 W, W.M. in Mason County, Washington. Water runoff modeling for this report is prepared using the Santa Barbara Urban Hydrograph method and the Waterworks software application. All design methodology is based on requirements as found in the Department of Ecology Stormwater Management Manual for the Puget Sound Basin, 1992 The Water Works software program by Engenious Systems, Inc. has been used for hydrograph calculations and Level Pool Routing. EXISTING SITE CONDITIONS The site is currently cleared and vacant. The site slopes from southeast to northwest at approximately 13 percent. Soil Conservation Service (SCS) maps for the area shows that the soil is Everett gravelly sandy loam belonging to hydrologic soil group `A', however, the soils have been scraped off of this site during the construction of the business park exposing the less permeable soils underneath. This is substantiated by the onsite septic designer limiting the location of the drainfield to the southwest portion of the site. The soils on the site are more in the hydrologic soil group `C', which was used in the design calculations. A copy of the SCS map for the site is attached with this report. Existing peak storm runoff rates and volumes have been calculated (see attached WaterWorks printouts) for the 2-year, 10-year, and 100-year return period, 24-hour with the following results: STORM EVENT O (cfs) Volume (c f) 2 year, 24 hour storm event - 0.14 cfs 2,791 c.f. 10 year, 24 hour storm event - 0.24 cfs 4,517 c.f. 100 year, 24 hour storm event - 0.40 cfs 7,093 c.f. DEVELOPED SITE CONDITIONS This project proposes to construct a 4,626 s.f office building with associated parking, sidewalks (8,445 s.f.) and stormwater conveyance to an underground 4' diameter detention pipe with a Stormceptor for water quality before the detention pipe and detention control structure. The post-developed impervious area will be 13,071 s.f, or 0.30 acres. Developed peak storm runoff rates have been calculated (see attached WaterWorks printouts) for the 2-year, 10-year, and 100-year return period, 24-hour with the following results: STORM EVENT O (cfs) Volume (c f) 2 year, 24 hour storm event- 0.29 cfs 4,700 c.f. 10 year, 24 hour storm event - 0.41 cfs 6,676 c.f. 100 year, 24 hour storm event - 0.58 cfs 9,479 c.f. J.R Engineering Consultants,Inc. Page 2 of 3 Storm Report t I UPSTREAM INVESTIGATION This site slopes generally to the northwest and there is an existing gravel drive on the southwest side of the property, which intercepts any offsite runoff coming onto the site. DOWNSTREAM INVESTIGATION After runoff flows through the Stormceptor and detention pipe, it enters the existing storm drainage system on Cokelet Lane and is conveyed southwesterly along State Route 3, then under State Route 3, through the Safeway complex to a conveyance ditch and culverts to Hood Canal. HYDRAULIC ANALYSIS Stormwater runoff rates were estimated utilizing the Santa Barbara Urban Hydrogragh Method (SBUH). The printouts provided in the Appendix are from the WaterWorks Hydrologic Modeling Program by Engenious, Inc. The detention pipe was sized for the '/2 the 2-year/24 hour storm event, the 10-year/24 hour storm event and the 100-year/24 hour storm event. EROSION AND SEDIMENT CONTROL An erosion control plan has been prepared which includes notes and procedures regarding inspections and implementation in the field. Treatment is in accordance with the Stormwater Management Manual for the Puget Sound Basin utilizing typical Best Management Practices for the removal of potential sediment and other contaminants. J.R Engineering Consultants,Inc. Page 3 of 3 Storm Report APPENDIX A � Various Maps 1 I MM , I I cc I . I ' u- I ' I W ' I I M I I � , I � , I , I � I I I I TIMBERLINE DR McKN19' ` ---------------- I------- ---- c ' -------- ---------------------- RD sa��- DAVIS FARM RID L FS 2-1 PARK O I I , I RIDGE POINT B4vu FERN , I WAYLu , O � I IC7*0' I :51 0 J I O � COK:?ET LN z z �Q. �o ' -- - ----------- �- ------------ ---- -- - ------------------=------- ------------------ ALDERWOOD CLt�FC�Nl MASCN CCUNTY N I PL fro COURTHOUSE ANNEX z 00 2> BL LFAIR i � j BELFAIR 7 �� i�� ST I 1Y j VICINITY MAP I Scale: 1"=1000' ---- - --I-^-------------------------- cc l r. - % � Z I l 1, _ ,�. �� ,`•�; sir Of ray 11 - /, ___ � ..�,• -. ■ N 11 . „„ Wile. It all 352 - - 1 III II •' I • II 11 •• • / ilea r • • • 1 II / t3 M 3 (� - • f elf& — • 348x U. S. G. S. MAP >,'� 00 >. • - 3. Scale: 1"=1000' it � �1 a,' ►..c �� .,� = j ,"' �, %' ,� /� (Joins sheet 4) .,..,� VT M v,w 46 �y� • t ) (Lj Oa • N d Ong tV • +'� �a�'� '! 'fit w 1r1• !. .• ..\ ..v.• ' � ♦ �►r• rE! �Tt! I �^.�' �•+.• 1�••�' '.. Y : � �� ` � � 1: .:J v��.rv� f ..�.,N'Yr .A,:. „�•r1`.i .•, r,w !Y•' , � y,• 1 d q. + . 4 •..,p4A lk Ap '� r. w�)r�4'►'�. r 1� 1� it)�� �,yP'4# •.+,I" � L'�1 t •\ .jf• -�1�i♦�/J • `�t IV ,. �.L , �i^ �,• ter_ • 'I ^t•. � ��•: v • �. 'x SOILS MAP 1 �w .^'�• Scale: 1"=1000' APPENDIX B Soils Information Cn Values Isop[uvials 24- BOIL SURVEY SERIES 1951, NO. 9 ,Tile EId soil occurs only in the extreme soiit.l►ern en Inn.torin.l flint is extremely loose and ►orous. however, of the countyy. It dilrols front file Alit Cown soils n in places, this malerial will sland in�tudts. The color having a redder surface soil and subsoil, SOIIIe fa ll•y of this mitteria.l is largely determined by t.lte gritvel, developed shot, and stronger red and yellow stair •ng of coarse sand, and cobbles, which are olive gray, little the subsoil. olive, yellowish brown light brownish gray, gray, and Eld silt loam, 0 to 3 percent slopes (Ec).—' 11S soil is (lark �•rn.y. Many of the .0t) Ies, as well aS 11111CiI of the at file Mend of oyster Bay. 'Tito surface so' is reddish- gravel, are fainl.ly to nloderate.ly stained by iron. brown, granular and friable silt loan►, to 10 inches The amount, of gravel ranges from about 20 percent Io Chick, Ihat: contains it few very soft sit '1']tis layer is 50 porcont ill the subsoil to its much its 80 percent in the underlain by it reddish-brown, lulu • ay loam Chat. has Substratum. The soil is inedium to strongly acid soil A subangular blocky structure, is hi fly stained by iron, becomes less acid wif.h del)111. and contains considerable ainomt of Shot. At depths Use and suitability.--I his soil is too dronghl.y for ranging from 20 to 32 inches he clay loan► rests (►r► most tilled clops—it (tries oil(, before crops mature. a layer of fairly compact, Sin tied slua(1 and gravel chat Only it very small acreage is cultivated, and this is is prominea►Ily stained I,y i n. Rounded glacial gravel, oI•dinar•ily farmed nlong with better adincent•soils. Alost mixed Willi subangular i attic gravel, is scattered on of Ibis soil is in brush and trees, for which it is suiled the surface and through to soil. best. It is one of the belle• soils for ►iowing Dmiglns- '1.'he soil is 1nedil in nd throughout. Surface (leainnge lies that are cut for Chrislnuts trees. 'his is an it or- is Moderately well ablished Ihongh Small swiales may I,aut nso Of (.ho soil; largo acreages are used forCheisl.- Stay wet. for it lot little. Subsurface dramage Is fitirly mas trees. slot- because o is slowly receding, .fairly high Witter This soil is ill capability subclass VIs and in Silo table. class 4 for Douglas-fir. Use.. and tti.tability.—Most of file soil is used for Everett gravelly sandy loam, 0 to 5 percent slopes pasture o �•,train. ]1lanngeuent is similar'to that of ft).—'Phis soil oeclllrle8 Ii10 Smoother out,wash terraces in liytow Rilt ]Darn, 0 1.0 3 percent slopes, but yields are nssoCilttioll with outer Everef.t soils. It differs from Slight lower. Everett gravelly sandy lon.iu, 5 to 15 percent slopes, in 1' S soil is in capability subclass 11 CS; it is good for Chat its surface layer is generally 2 to 3 inches thicker; fi redeedar, herllock, and decidlions Irees. 111e profile is less variable; and the substratum, or miler- >SVBAF.TT BSi(IEs lying m usually alerial, is usual) more stratified. , Use and suitability.—,.rho use of this soil is Similar to '.file Everett series consists of somewilat excessively that of Everett gravelly sandy loam, 5 to 15 percent drained, pale-brown gravelly soils. They occur as inex- slopes. The soil is in trees anal brusl►, except for a few tensivo •ravel ridges on the glacial nlorairles, or, more Sn►all cleared areas. '1'11e growing of Douglas-fir for connnonty, as fairly} continuous olllwash channels be- (;hristmns trees is gaining in importance. 'This Soil is in tween ridges of Alderwood soils. 'T1ie3 have developed site class 4 for Douglas-fir and nt capability Subclass VIS. neon assorted glacial till and outwas i material. 'fife r rainfall is 45 to 60 inches a year. 'Tito vo•eCati()1t is Everett gravelly sandy loam, 15 to 30 percent slopes t, (Ek)•—'This soil is on t.ho sleeper slopes of glacial moraines, mainly drought-resistant nuadrone, ma.nzanila, anal ](in- sides of giillies, and terrace fronts. It is closely nsso- nil(iunick• cinted with other F,vetett soils anal the Alderwood 14'vorett,soils are di-mighty because the loose gravol and gravelly sandy lonins. sandy Subsoil and subsfratwn offer little resistance to This soil is more variablo than Everett gravelly Sandy downward movement of water. The capacity of the Sur- lon.in, 5 to 15 percent Slopes. The depth to snbStrat,nn► face soil to ]told available moisture is low. ra.uges from 12 to 3G inches, and the amount. of gravel Everett soils are in iite eastern Iialf of the ccmnf•y, in in the surface soil a.11(1 subsoil varies greatly from place association with the Alder•wood soils. They also occur• to pihice. Where the soil is in close association Willi file Ill intricale palfe•ns with the Kllsap and I11(llaliolia soils. Alderwood soils, the substratum, in places, is compact Compared to the Grove soils, tile Everett soils have a and weakly cemented. littler 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. ---&k.._Everett gravelly sandy loam, 5 to 15 percent slopes Uses mid szti.tability.—'Phis soil is snitoble, only for (EN.—'This is the most extensive I.verett soil. In undis- forestry because it is;troll Iv slopin r, (iron I►fy, and low lurbed forests 1 to 2 inches of very dark grayish-brown in fertility. It is in capatility s►tbelass Vfs and in site material, it mixture of needles, leaves, twigs, cones, moss, class 5 for Douglas-fir. n.1141 roots, cover's the surface. The surface soil is loose, Everett gravelly loamy sand, 0 to 5 percent slopes shir�,le-grained, pale-brown, gravelly sandy loam, 6 to 8 (Ed).—'Phis soil occupies the Smoother terraces or outwnsh inches thick. 'fire upper 2 or 3 incl►es normally contains plains in close association with other Everett soils. It aggregates flint are slightly hard and redder than file differs from Everett gravelly sandy loam, 5 fo 15 percenl. ()liters in Lite layer. TO depths ranging from 18 to 24 slopes, in having a finer surface soil anal a slightly inches, (.lie subsoil is loose single-grained, light: yellow- coarser subsoil. ish-brown gravelly sandy loam or gravelly loamy sand. Use and, suitability.—Ilse and inanngemett are sintiln.r Tire amount of shot decreases with depth; in (lie lower to those for Everett, gravelly sandy loam, 5 to 15 ►ereett part only it few shot occur. slopes.. This soil is poorer for forest than E'ver•ett The subsoil grades to a substratum of poorly assorted, gravelly sandy 1()am, 0 to 5 percent Slopes. It is in pI•edOininnnfly yellowish-brown sand, gravel, and cobbey capabilit sub y class VIs and in site elites 5 for Douglas-fir. MASON COUNTY, WASHINGTON 25 Everett gravelly loamy sand, 5 to 15 percent slopes Tito subsoil is it ligl►t-brown, very gravelly loauly sand. (Ee).--This soil is similar to Everett gravelly loamy sand It is loose, is single grained, and contains no shot.. At 0 to 5 percent slopes, but its profile is more varial le anei dept.lis ranging from 24 to 32 inches, the subsoil grades the thicknesses of the surface soil and subsoil are slightly to the substratum" of loose gravel,cobbles,and sand. Tito less. doininant colors are gray,grayish brown,yellowisll brown Use an(I euitabilita.--Practically all of this soil is in and light brown. Atuch of Cho gravel is Ili rllly stained trees and 1►tush. Palest use is for Christmas trees. This with nearly black rind reddish-Crown mnteria In places soil is Ill capability Subclass V1s and in site class 5 for Clio upper 24 inches of the substratum►is compact or Weakly Douglas-fir. co»►ented. Everett gravelly loamy sand,15 to 30 percent slopes Included with this soil are about 250 acres occurring (El).—'Except for slopes, this soil is similar to I►:verett on gently sloping fans, colluvial slopes, allot terraces. gravelly lonmy sand], 5 to 15 percent slopes. Profile The parent material of the included soils is it mixture characteristics vary greatly from place to place, espe- of local basic igneous rock and mixed glacial nutlerial. cially on the steeper slopes. The profile is similar to that, of (wrove gravelly sandy Use and 81titability.—All of this soil is in trees and loam, 0 to 5 plercent slopes, but it, chillers ill being browli brush, and its best use is forestry. It is in silo class 5 and yellowish brown, snore variablo in texture and in for Douglas-fir and in capability subclass VIS. deg�ree of stratification, and in conlaining nluell engnlar and snbangula.r gravel. GRAVEL rrr '.L'his soil is strongly to ineditim acid and less acid wiLL '1.'his miscollauoous land type consists of opon pits front depth. Surface rumoir is very slow because of the rapid Which Lilo Soil and underlyilig material have been exca- permeability of the Soil a.nd the smooth topography. vated. Tito pits are about 1 to 5 acres in size and are 118e crud sleitability.—Except, for it very small acreage shown on Clio soil map by the letter symbol Ga. Pits in farn►s producing mainly for Cho farm m household, ibis sallor than 1 acre are shown oil the snap by convontiolutl soil is in forest, a use for Which it is best smiled. ]1e- syntbols. Most gravel pits are in soils of Lhe l:veroLt, douse of droughtiness and low rort.ilitx, it., is not suitable Grove, and Carstairs series. Tito excavated gravelly for hay or pasture. sit suitability, this soil is similar to manorial lifts been used mainly for road construction. Clio 14"verett gravelly sandy lotun, 0 to 5 percent slopes, GROVE SERIES exce rt that 11, is ill classes 3 and 4 for Douglas-fir, tt►art�y because of the higher rainfall. Areas in You rr '19te Grove series consists of somewhat excessively I)ouOas-fir are managed for Christmas trees. The soil drained reddish-brown gravely soils. It occupies the is ill capability subclass VIs. largo glacial outwash plains. 'file Grove soils have do- r veloped from Vasholl glacial drift, modified considerably k).— a gravelly sandy loam, a to 15 percent slopes by illchisiOlis of local basaltic ruck and mixed nlateriitl IGkI.—L► ►laces Iho surface soil and subsoil of this soil ore from► the Olympic Alountaiit glaciers. Tito rainfall :1 to (i imclies Thinner than those of (wrove gravelly slimly b , • � � loan►, 0 to 5 percent slopes. riuig.es front (10 to 100 inches a year. The vegetation is . . coniferous forest, with nu uudet•stor dOlnina eel b t.l►© l/se crud suitability.—The use of ll►is soil is similar to Y Y that of Glove gravelly sandy loam, 0 to 5 poreent slopes. loiter growing mosses, kinllikirillick and Silowberr•y, and 1;iko that soil, it is best suited to forestry. Tile soil is in these mixed with huckleberry, sa]al, and Oregon-grape• ca.lxtbilil,y subclass Vls; it is in site classes 4 and 5 for The drought-resistant mailzanita is especially common Dollglas-fir. Olt (lie Grove soils. The cover is not so profnso nor so Grove gravelly sandy loam, 15 to 30 percent slopes rank as I1►at on the adjacent Sl►olton Saul 1[oodsp°t•t• (Gm1.-'.L9lis soil occupies Cho slopes bordering oil terrace soils. Logged areas restock slowly to I)ouglas-fir, a.nd fronts. some pure stands of lodgopole pine are on these soils. Tito profile is similar to that of Grove gravelly sandy The (�ravo soils occur nt the western cart of Iho r ,,,, county, in association Willi Iho Shelton anc� lGrodsport, teams, 0 Co 5 peleemt slopes, except that depths to the gravel and sand of file substrailnu range from 18 to '10 soils. Grove soils diner from the 14weretl., soils farther niches. The anionuC Of gravel in the profile itlse► varies casts l an parent material and in ]raving redder Sur- gr.elttly :from place to place. Surface runoff is more faces soil and subsoil. rapid than :froin Grove soils having slopes of less than Grove gravelly sandy loam, 0 to 5 percent slopes lit pereenl (Ghl.-2rhis soil occupies near] level outwash ►loins. • . Y 1 l/sc, a»,l. st�itabili.. — tr. 1 his soil s n] is suitable only for L► forested areas there is a 1- to 2-inch layer of forest bev:mse of its slopes, droughtiness, and low for- needles, ]eaves, twigs, roots, and moss. Tito lower part lilit.y. 'I'liis soil is in capability subclass VIs and in site is moderately decoinposed and very dark grayish brown. class 4 for Douglas-fir. 'Pilo surface soil consists of reddish-brown, gravelly Grove gravelly sandy loam, 30 to 45 percent slopes sandy ]Olin, G inches thick. It is very friable, is singlo (Gn).—Alost of this soil occurs oil short,, steep slopes and grained,and contains a few shall,round shot. Tho upper in rough areas bordering valleys or terrace fronts. It Part of this layer contains a few flan, irregular, more differs from, (wcovo gravelly sandy ]pant, 15 to 11 por- ruldish aggregates. The next htyor extends 1,0 depths cent slopes, in slopes and topography. Ill addition, file ranging from 12 to 14 inches. It is similar to the surface depths to file substrahnn eltange ill fil101'l: dislances front soil,except that it is more gravelly,contains less shot.,and less than 12 inelles to as muelt as 3(i inches. Tim stir- the gravel is stained and coated with dark reddish-brown face soil and subsoil normally contain 50 percent or fine material, more of gravel. r Z66T 'Auv ivead 6—T—III ❑ rurdS V (IN uorl!aN 1 8 12110S (IN Iruo�rN anpl°S V no�rN ❑ 4rnuogouS a ON 4v!doq-S JJrN (1/J Onl!InW 8 48!-OIXrIS 8 ❑ rdod! uorlOW J CIS a!grurn IrrnnllV Pax!yW ngowS J is HN Iozuaw ow a 6 uotlayS ON AaL WIoW ouryS ❑ ❑ ruua)IoW ❑ nalryS J umoy(rW oowynwaS (IN nipS fl Ia4rrW ❑ doNrW alrrros J a Jap!au43S low ❑ ON ururwroS ON mw�( ON urn f urS ON P°O nuw ❑ yr!wwwrS 8 � Jwr u'n'IIrS r�w r'I [Vies ON auolx J algrurn ON 4rrnUanr� rnwrA g drrl!x oggndad J a u0Iuaa 0 r!4ol!7l J g3oll a/J ON adwo!sodr}I a a nion algrurn rayoroq aIrnroO ruof 8 ON rloun uoldrpul J I:) ON Iany wallala argau!J ON 8 md,(o}I V IrpBoo}I mnayJ ON Podrpooll 8 nlryarlJ ON 010H 8 nlurooJ ON 8 t�roy�rJ ON I!uufH (IN 40H kJalorrq J au2W f a ON oJ09rNrJ V JaIr,ruaaap daoq 8 O A�JPo`J �o J dung a taI!rJ ❑ dahlong V llo4o�aJ waru8❑ AhCIa ❑ ulnlr0 8 ❑ uouana J IJOJ1r!O8 lox V IUrtlrn wryouylo8 pa�ana ❑ jazlwnbaH wr4ou!llo8 8 I12n+13 H 1'rJlaB a P1a a)!rnra8 8 pnownr8 401AWopa 3 oaraw 'odnU a a n!4PIaa a I.w!a oogrV 8 ON pa iana 'qryuaV!a 8 ❑ P°OAUoPIV'quajV 10120 J POO'UaPIV ON gogra J ON n!V »rrnJ 8 J Ja11°J lqv J mauoV LVOS narrJodXj I!oS dnoiD3-1-9PAII od(L 1!OS I!OS o!eolwpoli uu98 puns ta8nd ato u!spoS rroJ rdnoiD lion o!8o!cupdH 9.1-111 olgr.L NISKB UNn0S Jaond SHI Ii0a 'IKnNVW ZNHWHDVNVW 2i3LKMW2iOLS 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 orpasture: 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 the 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. / g8) 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'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 49 124 123 122 121 15 — • 'A on ? EL BE F Jy \ FRIDAY HARBOR PORT STA LEY p (� r40 5 ( 1) MT V 30 „ tit �\ AM 40 351 301520 /7 4 40\ _ ERETi 45 `, f 15 21� 1 3s 25 rf m 50 25 — ; 5 fa c ^�4� 20 15 c 30 S 45 ff f S AT !{ N' 35 ARCH 5 40 ' 3 1 35 55 / 20 40 35 COM 2 47 3 , �> ABERDE N 30 !f 25 4 CENT 20 10 • YAKI 2 30 20 45 s 40 ADA 46 5 3 2 Is SS 3 s' 45 `t— _ WASHINGTON T5 B K 10 0 10 20 30 40 I PPL EN E ! �" MILES 20 Ll�lof(5 ( Figure 25 \ . I � ''C 25�` NOAA ATLAS 2, Volume IX ISOPLUVIALS F 2-YR 24-HR PRECIPITATI N IN Prepared by U.S.Department of Cdnmerce TENTHS OF A INCH NationalOceanicandAtmospherie ministration National Weather Service,Office of Hydrology Prepared for U.S.Department of A :culture, Soil Conservation Service,Engineer g Division 124 123 122 121 III-1-44 FEBRUARY, 9992 I� n I'' • I � yr�� ���"` {.«�: �� �' 1 •y�'`1111 %j 11r.. STORMWATER MANAGEMENT MANUAL FOR THE PUGET SOUND BASIN 124 __ 173 122 171 ---- -- 14q6 40 I r A C 1 55 44� IF if:�Y HARE(��k' . .pE,pT SIANI' diao 1, 0 ` 5 w65 \ 330 f t 0 5 f ��90� \ Js 5 RQ 6 4 8) 1� ' 134 75,� 15 3 5 035 1 -.\ ` 55 so N S is 0\ I , 5 45 0 1 00 � s s s __ 190 so E 2 1 40 60 AT / �40 tr P ` , I 6 00 7 47 r; ' r,1 � rs --3� \ I 65 1 � 2 _ N S r 'W. 105 4 .t r R L ' C ,00 s n Z22 '.YAK �Ob 56j � • � 45 u o I55 is t to 5 s a� 65 1SL ,� o '1,a0 60 55 I w \ ('r.' 2k 46 S 6 6 WASHINGTON '° 1 s° 4 : llfKll 1910 'FI EN E 10 0 10 20 30 40 16 -�� MILES 40( ' iMu 1 \ . rri ssse4535— Figure 30 1 ,5 NOAA ATLAS 2, Volume IX 65 ,P ISOPLUVIALS F 100-YR 24-HR PRECIPIT TION 05 60 Prepared by U.S.Department of C merce IN TENTHS OF N INCH 'National Weather otional Oceanic Service,nd OHce of Hydrologyspheric on — Prepared for U.S.Department of Apiculture, Soil Conservation Service,Engineer g Division 124 123 122 121 III-1-46 FEBRUARY, 1992 APPENDIX C Basin Runoff Calculations & Detention Design Data 7/9/03 2 : 27 : 9 pm JB Engineering page 1 WOLF/GOODELL OFFICE BUILDING Job #1561 ---------------------------------------------------- BASIN SUMMARY BASIN ID: Bl NAME: 2-.Yr, PRE SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0 .45 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPElA PERV IMP PRECIPITATION. . . . : 3 .50 inches AREA. . : 0 .45 Acres 0 . 00 Acres TIME INTERVAL. . . . : 10 .00 min CN. . . . : 81 . 00 0 .00 ABSTRACTION COEFF: 0 . 20 TC. . . . : 15 . 17 min 0 . 00 min � TcReach - Sheet L: 178 . 00 ns : 0 .4000 p2yr: 3 .50 s :0 . 1350 PEAK RATE: 0 .14 cfs VOL: 0 .06 Ac-ft TIME: 480 min BASIN ID: B2 NAME: 10-Yr, PRE SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0 .45 Acres BASEFLOWS : 0 .00 cfs RAINFALL TYPE. . . . : TYPElA PERV IMP PRECIPITATION. . . . : 4 . 75 inches AREA. . : 0 .45 Acres 0 . 00 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 81 . 00 0 . 00 ABSTRACTION COEFF: 0 .20 TC. . . . : 15 . 17 min 0 .00 min TcReach - Sheet L: 178 . 00 ns : 0 .4000 p2yr: 3 . 50 s : 0 . 1350 PEAK RATE: 0 .24 cfs VOL: 0 . 10 Ac-ft TIME : 480 min BASIN ID: B3 NAME: 100-Yr, PRE SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0 .45 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPElA PERV IMP PRECIPITATION. . . . : 6 .50 inches AREA. . : 0 .45 Acres 0 .00 Acres TIME INTERVAL. . . . : 10 .00 min CN. . . . : 81 .00 0 . 00 ABSTRACTION COEFF: 0 .20 TC. . . . : 15 . 17 min 0 . 00 min TcReach - Sheet L: 178 .00 ns : 0 .4000 p2yr: 3 .50 s : 0 . 1350 PEAK RATE: 0 .40 cfs VOL: 0 . 16 Ac-ft TIME: 480 min I 7/9/03 2 :27 :27 pm JB Engineering page 1 WOLF/GOODELL OFFICE BUILDING Job #1561 BASIN SUMMARY SUMMARY BASIN ID: B4 NAME: . 2-Yr, POST SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0 .45 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE . . . . : TYPElA PERV IMP PRECIPITATION. . . . : 3 .50 inches AREA. . : 0 . 15 Acres 0 .30 Acres TIME INTERVAL. . . . : 10 .00 min CN. . . . : 86 . 00 98 .00 ABSTRACTION COEFF: 0 .20 TC. . . . . 5 .00 min 5 . 00 min PEAK RATE: 0 .29 cfs VOL: 0 . 11 Ac-ft TIME: 480 min BASIN ID: B5 NAME: 10-Yr, POST SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0 .45 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPElA PERV IMP PRECIPITATION. . . . : 4 . 75 inches AREA. . : 0 . 15 Acres 0 .30 Acres TIME INTERVAL. . . . ; 10. 00 min CN. . . . : 86 . 00 98 . 00 ABSTRACTION COEFF: 0 .20 TC. . . . : 5 . 00 min 5 . 00 min PEAK RATE: 0 .41 cfs VOL: 0 . 15 Ac-ft TIME: 480 min BASIN .ID: -B6 NAME: 100-Yr, POST SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0 .45 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPElA PERV IMP PRECIPITATION. . . . : 6 . 50 inches AREA. . : 0 . 15 Acres 0 .30 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 86 . 00 98 . 00 ABSTRACTION COEFF: 0 .20 TC. . . . : 5 . 00 min 5 . 00 min PEAK RATE: 0 .58 cfs VOL: 0 .22 Ac-ft TIME: 480 min 7/9/03 2 :34 :46 pm JB Engineering page 1 WOLF/GOODELL OFFICE BUILDING Job #1561 STAGE STORAGE TABLE UNDERGROUND PIPE ID No. Sl Description: Storage Structure Diameter: 5 .50 ft . Length: 78 .47 ft . Slope. . . : 0 .0000 ft/ft upstr: dnstr: STAGE <----STORAGE----> STAGE <----STORAGE----> STAGE <----STORAGE----> STAGE <----STORAGE----> (ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-_Ft- --------------------------------------------------------------------- 90.30 0.0000 0.0000 91.89 4-11.89 0.0095 93.30 1040 0.0239 94A0 1633 0.0375 90.40 7.7169 0.0002 91.90 150.71 0.0103 93.40 1083 0.0249 94.90 1ff5 1.0392 90.50 21.70E 0_.0005 92.00 490.26 0,0113 93.50 1125 0.0258 95.00 1697 0.0389 90.60 39.652 0,0009 92.10 530.46 0.0122 93.60 1168 0.0268 95.10 1726 0.0396 90.70 60.702 0.0014 92.20 571.24 0,0131 K.70 1210 0,0278 95,20 054 0,0403 90.80 84.346 0.0019 92.30 612.53 0.0141 93.80 1252 0.0287 95.30 1780 0.0409 90.90 110.23 0.0025 92.40 654.26 0.0150 93.90 1293 0,0297 95.40 1804 0.0414 91.00 138.09 0.0032 92.50 696.38 0.0160 94.00 1334 0.0306 95.50 1825 0.0419 91.10 167.70 0.0038 92.60 738.81 0.0170 94.10 1374 0.0315 95.60 1843 0.0423 91.20 198.90 0.0046 92.70 781.51 0.0179 94.20 1414 0.0325 95.70 1857 0.0426 91.30 231.52 0.0053 92.80 824.41 0.0189 94.30 1452 0.0333 95.80 1864 0.0428 91.40 265.44 0.0061 92.90 867.45 0.0199 94.40 1490 0.0342 95.90 1864 0.0428 91.50 300.54 0.0069 93.00 910.58 0.0209 94.50 1528 0.0351 91.60 336.70 0.0077 93.10 953.73 0.0219 94.60 1564 0,0359 91.70 373.85 0.0086 93.20 996.86 0.0229 94.70 1599 0.0367 CORRECTION FACTOR 0.30 = 67% IMPERVIOUS 0.45 (67-20)(0.375) +20 = 37.63 MULTIPLY PIPE LENGTH (ABOVE) BY 1.3763 7/9/03 2 :31 :45 pm JB Engineering page 2 WOLF/GOODELL OFFICE BUILDING Job #1561 - -------------- STAGE DISCHARGE TABLE MULTIPLE ORIFICE ID No. D1 Description: Control Structure Outlet Elev: 90 . 80 Elev: 88 . 80 ft Orifice Diameter: 1 .2500 in. Elev: 93 . 80 ft Orifice 2 Diameter: 2 . 8750 in. STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> (ft) ---Cfs-- ------- (ft) -cfs-- ------- (ft) ---CfS-- ------- (ft) ---Cfs-- ------- 90.80 0.0000 92.10 0.0483 93.40 0.0684 94.70 0.2965 90.90 0.0134 92.20 0.0502 93.50 0.0697 94.80 0.3091 91.00 0.0190 92.30 0.0519 93.60 0.0710 94.90 0.3211 91.10 0.0232 92.0 0.0536 93.70 0.0722 95.00 0.3326 91.20 0.0268 92.50 0.0553 93.80 0.0734 95.10 0.3437 91.30 0.0300 92.60 0.0569 93.90 0.1456 95.20 0.3543 91.40 0.0328 92.70 0.0584 94.00 0.1762 95.30 0.3647 91.50 0.0355 92.80 0.060D 94.10 0.1999 95.40 0.3747 91.60 0.0379 92.90 0.0614 94.20 0.2200 95.50 0.3844 91.70 0.0402 93.00 0.0629 94.30 0.2379 95.60 0.3938 91.80 0.0424 93.10 0.0643 94.40 0.2542 95.70 0.4030 91.90 0.0445 93.20 0.0657 94.50 0.2692 95.80 0.4120 92.00 0.0464 93.30 0.0670 94.60 0.2833 7/9/03 2 :31 :47 pm JB Engineering page 3 WOLF/GOODELL OFFICE BUILDING Job #1561 ------------ LEVEL POOL TABLE SUMMARY MATCH INFLOW -STO- -DIS- <-PEAK-> STORAGE <--------DESCRIPTION---------> (cfs) (cfs) --id- --id- <-STAGE> id VOL (cf) 1/2 2-Yr ..................... 0.07 0.29 S1 D1 93.80 11 1252.43 cf 10-Yr ........................ 0.24 0.41 S1 D1 94.33 12 1463.79 cf 100-Yr ....................... 0.40 0.58 S1 D1 95.63 13 1846.94 cf r • APPENDIX D i Water Quality, Stormceptor Calculations Y �• �S (sl Y +YRv� # r.v .tL _ x -Not, am k PIR ' [ ^ M Files Hate �y„a.t,��i� srssud5� A5Q .............................i • ............................ E� i E + Sizing Design Check Main Menu ajGd {tu �Q 4T 11 c�iF'Pd�a���t d I SWr.mc;epLor ExperL System Version 2 . 0 08/22/2003 14 : 55: 49.590 Comment Lines Company Information Phone # Fax # Contact Person : Timeframe for implementation [months] Rainfall Station Location : SEATTLE PORTAGE BAY Rainfall Station Province/State : Washington Rainfall filename : WA7458 .ndc Rainfall Station Latitude 47 deg 39 min Rainfall Station Longitude 122 deg 18 min Rainfall Station Elevation 19 ft 10 Years of Rainfall Data from 1984 to 1993 Rainfall timestep : 60 minutes Specified Units : US Total # of Stormceptors proposed 1 Individual Stormceptor Details Stormceptor # 1 Drainage Area . 45 ac Imperviousness 67 % Impervious Area . 3 ac Surface Grade : 98 ft Inlet Pipe Invert : 93 . 33 ft Outlet Pipe Invert : 92 . 91 ft Pipe Diameter : 12 in Approximate Excavation depth : 10. 37 ft Cover over pipe : 3 . 67 ft Tailwater Elevation : 0 ft Stormceptor Model Chosen : 450 Stormceptor Type : Concrete Annual Runoff Treated : 99. 3% Estimated TSS Removal : 90. 5% litre eaLLicie Uistrlbution Chosen paxti.p1e Size : 20 um Settling Velocity : . 0003854 ft per sec Percent by Mass Particle Size : 60 um Settling Velocity : . 00157 ft per sec Percent by Mass : 20 Particle Size : 150 um Settling Velocity . 0107 ft per sec Percent by Mass : 20 Particle Size : 400 um Settling Velocity . 065 ft per sec Percent by Mass 20 Particle Size : 2000 um Settling Velocity : .287 ft per sec Percent by Mass : 20 Particle Size : 0 um Settling Velocity 0 ft per sec Percent by Mass 0 % Spec Particle Size : 0 um Settling Velocity 0 ft per sec Percent by Mass 0 % Spec Particle Size : 0 um Settling Velocity 0 ft per sec Percent by Mass 0 % Spec Particle Size : 0 um Settling Velocity 0 ft per sec Percent by Mass 0 % Spec Particle Size : 0 um Settling Velocity 0 ft per sec Percent by Mass 0 % Spec Flocculated Settling for <= 20 um Design Checks Installation depth is acceptable for specified material Minimum Cover Required : 1 ft Cover Provided : 3 . 67 ft Minimum cover is acceptable Pipe diameter accommodated by standard weir : 18 in The pipe diameter is acceptable for the standard by-pass section Pipe diameter accommodated by flexible boot connectors : 42 in Kor-N-Seal pipe connectors will fit the specified pipe diameter Minimum Invert to Grade Allowable : 4 ft Invert to Grade Provided : 4 . 67 ft Invert to Grade acceptable for standard construction Required Elevation difference between inlet and outlet : 1 in Elevation difference provided : 5. 04 in Elevation difference for inlet Stormceptor not applicable Water level depth below outlet invert : -92 . 91 ft No Tailwater Conditions i ' Annual Flow Disft ibution SEATTLE PORTAGE BAY Washington .30 ac 100 , Model Maximum Treated �w, Flowrate 80 Annual 450 .28 � 60 900 .64 Flow , Capture I —1200 .64 1800 .64 ' e�. ) 40 C/ 2400 1.06 s 1 I {: 3600 1.06 s :, 20 4800 1.77 a 6000 1.77 7200 2.47 7 0 .35 .71 1.06 1.41 1.77 2.12 2.41 2.83 3.18 3.53 5 s„ .18 .53 .8$ 1.24 1.59 1.94 2.3 2.65 3 3.35 �+ s Mears 19$4 to 1993 Flow Rate cfs H oirly rainfall- flow c a tut e 6 To:3MM997344 Fras:Rinksr Materials Fax:Rinkr Material■ TgtLL at:JLN-09-2003-1):15 Dnr:544 Pps:007 NMXTEOkMVj Hydro Conduit Dh4sion April 9, 2002 JB Engineering Consultants,Inc. Attn:Jim Bottem 9465 Provost Road NW, Suite 202 Silverdale, WA 9838.3 Re: Stotmceptor Removal Rates Dear Jim: Stormceptor has conducted several field studies to evaluate the removal rates of various pollutants. When our units have been sized based on 80%annual'I'SS removal,field monitoring has shown that we have been able to achieve removal rates in the ranges indicated below. 90-99% Total Petroleum Hydrocarbons(TPH) 10-30% Total Phosphorus (TP) 40-60% Total Kjeldahl Nitrogen(TKN) 40-50% Lead(Pb) 35-40% 7jno(Zn) 15-25% Biochemical Oxygen Demand (BOD) This letter should not be taken as a guarantee of performance,but as an indication to what level our units have been proven to be able to perform. If you have any questions,please call me at 1-800-909-7763. Thank you. Sincerely, Hydro Conduit Division Rinker Materlids Peter Van Tilburg --t To:3606987344 Fram:Rinkr Materials Fax:Rinker Materials TQ➢tALL at:JUN-09-2003-17:15 Doc:544 Page:002 StormceptorTM Sizing Program Version 3.0.0 Selected Rainfall Station Particle Size Distribution State NASHINLTrON Dian. (um) Percent (% Vel. (tt/s) Name SEATTLE TACOMA INTL AP IO 9 747) 20 20 0.0013 Slay. (ft) 400 Latitude N 47 deg 27 min 60 20 0.0D51 Longitude N 122 deg 18 min 150 20 0.0154 400 20 0.2123 Site Parameters 2000 20 0.9417 Total Area (ac) .5/ Imperviousness (t) 41. Impervious Area (ac) .22 Stormceptor Sizing Table Stormcoptor Model 1 Runoff Treated 1 TSS Removal STC 4501 99.7 80.5 97C 900 100.0 88.3 STC 1200 100.0 $9.3 STC 1600 100.0 90.5 STC 2400 100.0 92.9 STC 3600 100.0 93.9 STC 4600 100.0 95.4 STC 6000 100.0 95.6 STC 7200 100.0 96.6 OTC 11000 100.0 97.7 STC 13000 100.0 97.9 STC 15000 100.0 98.3 Comments i xDOZ thresholds are typically so% annual TSS removal and 911 of the annual floe tisated. The FTC exceeds both those standards and appears optimal for your site. Additionally, 60.5 ISO removal will be obtained at 100-200 mg/L influsnt utilizing a STC 4501. For concentrations less than 1D0 mg/L, the S7C 4501 will achieve an effluent of leas than or equal to 20mg/L. Project. Naumann Orthodontics, Silverdale, NA Designer, JE Engineering Consultants