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26161 PE-1860 KEYSTONE MEADOWS - DRAINAGE RERC3RT (Revlsed 8130100) Keystone IMeadows Subdivisiaro spokane eounty, Washangrc~n &~Pq Poo RECEIVED ~AUG 3 1 2000 Preparedfor s~~~ ~NTY BcINEEP JTS Qe►►elopment 2,0(50i 4029 S Terra Verde Yeradale, Washingtan 99037 S ~ DEA Proj ect No. .ITSI]OOOO-0004 IEMFtEs 10109100 ~ T~E DESIGN 1MPR+C}VENiENTS SHQWN [N TH1S SET QF PLANS CC]NFC]RM TQ THE APPLICABLE E[]ITI[JNS OF THE SPOKANE CC][TNTY STANDARC?S FOR RC?AD AND 5EWER CGTISTRi.ICTION ANQ THE SP[JICANE COUNTy GUIpELiNES FOR 5TORM1&IATER N1ANAGEMENT ALL bESIGN DEViAT2ONS HAV'E BEEN APPROVEd BY THE SFOKANE CaLTiyTY ENGINEER I APPROVE THESE PLANS FOR CdN5TRUCT1ON AlalgUSt 30, 2000 . ~ DAVID EVANS AND A55tlCIA'i"E5, ~ i I~ ~ Ifl. CaNCLL7SIONS ~ The pr4posed irnprovements descnbed m fihis report and shown zn the plan set Nrill provide storrnvvater control ar►d Creatment in full compliancc raith Spakane County's Guidelrnes far StormwaterManagemerat r ~ I ~ i I ~ I_ [3rainage Repvrt ior Keystone Meadaws Subdivisivn 3 JrsNrarem DOC asre9roa DRAI[►IAGE CA,LCULATIOEd'S FOR KEYSTONE MEA'DpWS SRokane County, Washrrrgton (revised) Basin Ft1 A=--4,360 sq feet of ACP ~'iFA Volume Required =(4,360 sq ft)f24=1$2 cu ft Pond A A=63 sg ft, P=66 If VOILICTIe_(0 5')(53 5q ft )+(037J Cll ftIIf)(661f)=56GU ft PoY1d B A=1 X 9 Sq ft , F~228 1£ Volume =(0 5')(219 sq ft )+(U 375 cu ft fl f)(2281 f)= 195 cu ft Valume Prvvided = Pand A+ Pond B-251 cu ft >182 cu ft Basin R2 A=2,357 sq feet of ACP GPA Volume Required ={2,357 sq ft}124=98 cu ft Pand C A=146 sq ft, P=154 L f Valume =(Q 5')(146 sq ft )+(0 375 cu ft 1I f)(1541 f )=13 1 cu ft Basin A A=67, 16 Y sq ft =1 541$ acres ACP Area=7,740 sq ft , 24$ Volwne reguired=7,740 sq. ft 124=323 cu ft 208 Volume pravided =(1,225 sq ft )(Q 5')+(985 1 f)(0 375 cu ft Il E)=982 c f>323 cu ft Basin B A=65,227 sq ft =1 4974 acres ACP Area=6,150 sq ft 208 Volume requlred=6,154 sq ft 124=256 cu ft 208 Valume pravided =(1,635 sy ft )(0 5')+(735 1 f)(0 375 cu ft 11 f )=1,+Q93 cu ft >256 cu. ft Basin G A=59,754 sq ft =1 371$ acres ACP Area=7,5$0 sq ft 208 Volume required=7,5$0 sq ft C24=316 cu ft 248 Volurne proVided =(1,421 sq ft){4 5'}+(9901 f)(U 375 cu ft l1 f)-1,082 cu ft>316 cu ft Qrainage Report for Keystane Meadaws 5uhdivisian 1 UTSOOaMOwaINcaLC ooe 08134104 m DAVID EVANS AND ASSOCIATE5, ~ T R A N 5 M T T T A F. West rio Cat~kJo rO Ed Parry, P E 5pokmu, wasiu~ ggzos 5pakane County Engineers ~ 509327$697 411(, 'DA7E Augtt5t 31, 2000 l~~_ `~'~NIC4 FRQRA Doug ~uska, P ~ 4 F~ 50 9327 7345 ~ c~` PRVJECr Keystone Meadorrvs, P-1860 PRQJ # JTSDOQLIO-[}404 WI~rEM~coP~E~S~DmITIEi~oESCRiPTiaN 7 V 8130I00 Revised Road and Drainage Plans, Sheets 1-6 2 7 8130100 Revised []rainage Repnrt, with revised sheets fvr other repvrt you have 3 1 8131100 SUbmEttaI CheCI(EISt #2 4 2 8130100 fteuised Lot P4ans for all lots 5 1 8129100 Budinger soifs repart for gradativn analysis 5 9 8124J00 Asphalt taper calcufation 7 1 7121100 Red-Imed road and drainage plan set ~ AS YaU REQUE5TEC1 Z FCSR YOUR APPFipVAL ❑ RE'fUFtN FtEC]WE57E❑ ❑ DQCLfMENT CCIRITRQL Q FDR YC7UR INFORMATIC?N ~ F(7F2 YOL1R REVIEW ❑ COMMENTS BiIl, Attached are the revised road and drainage plans for this praject, along with the revised drainage repart, and other miscellanecaus documentation All items on your reView Fetter dated JuIy 28, 2000 have been addressed an these revisions lerry Stalp has rerrtewed tMese p1ans and will be sognmg the forthcattarng Mytar set Please review and coanment as necessary, and Eet me knvw if you have any addltzanal questions Thanks, Doug 8usko, P E orastwidifla . r s lengr'IjtsdQ0041wordltransmittaI to pazry doc F ~ ~ SUbmlttal CheCkllSt for Raad &Drainage Projects in Spokane Caunty - P1atsJShart P1ats T'hrs Submrltal Checklist is to he cosrapleted and srgned by the Spvnsor's Erzgrneer, and rncluded with each pIcm submrttal rnto 1he Spakane Caunty Engineers tJffice Xf thrs form as nat fudly cornpleted and srgned do not sutrmit pdans und calculatzorzs to Spok.arze Countyfor revrew and accepdartce Tncomplete ssrbmattals wadl he returned and wrl1 cause unnecessary dedays far yaur client P'xaject Narne Yk~FY•X71D.AJR5 ~i ~~~•c~~ Spokane Counky Praject Na - c' iDate • 0 E] ~'raject Engzneer '~~4 C', Phane• e~217' 9(09'~' Project SpQnsar 05"'o41sa Fhvne 4~5o)RJ~~~ 7C) A. Preliminary Process - Prior to Submittal of Aoad and Drainage Flans, the fallowzng events are to haue already accurred (By checkrng each rtem offshofvvrr belaw, yau are statrng dhat you hrave ver f ed tlzese evenlslatems have been compleFed) Adcrptian of a HearLng Exammer's Repart for thLS lang plat, or a Planning Repart for this short plat At least ane Pre-l3esign Meeting has been held wlth County staff' at the Eng9neers Office An "Agreement to Pay Fees" has been signed by the praject spansor, and submitted to the Count}+ Engineers QfFce fl A Channelization Plan (e g slgning and stripmg plan) of publzc roadway irnprovements, has been 11►11A coordinated and discussed with the County Engineers f3ffice S. Raad and Drainage P1an Submiktal The 9tems listed below are ta be pr❑aided as a minimum with a road and drainage plan submdttal Addifitonal mfarmation may be required tQ demonstrate that the plans meeC ali applicable standards (By checkrng "yes " for each rfsrn shown below, you are verifyrng dhat lhese rterrrs huve been campleled and are rncfuderl in j lhrs submatta! For rrny brx checked "nfa awritlerrJustaficatron rf crrry amrssrons cr1 ihe encf of this sectron rs reyurred ) 11 ltem T3escription EYyes Road and dramage pfans, two print sets {Certification statement on cover of plans} @'yes vi WIAX-Each Flan Sheet of record is signed and dated tay the project sponsor Vyes The raad and drainage design meets the requirements of State law, WAC 195-27 regarding "confornity with accepted standards", that is, the desrgn retlects the "state of the practice„ far the propcased concept C1Yyes The plans, Drainage Report, basin map(s), and any other calculations are stamped, signed and dated lay an engineer Iieensed in the 5tate of Washingtan &'yes 0 nla Drainage Report, tvvp sets Ta rnclude basin map(s), time of concentration routes in basin "I map, and Certificatinn statement on couer of report and basin map fiYyes 0 nla Geotechnicar Report, one set (Include all soil test pitlboring logs } Bll'yes 0 nla Structural Pavement Calcula#ions, one set E'yes 0 nl'a Cross-slope grade caiculairons for rQad widenirag prQjects 0 yes R'nla Maintenance Manual and Sin'king Fund calculattQns far drainage facilities locaTed autsede . ❑f County road right-of-waY B'yes 0 nla Written explanation of whnlwhat entity will be respansible fQr maintaintng dramage facilitzes which are lcacated outside of puhlic road right-of-way, and that the plan Zs acceptable ta the County Engmeers Oftice (e&J&-9AWpa 0&-ronc.',5r+1aU.4-r~ [lryes 0 nla Channelization Plan, or signmg and striping infonnation provided in the raad plans To be included in raad and drainage plan set Beyes 0 rrfa I har+e read the 1-fearing Examiner°s Report (lartg plat), ❑e Planntng Dept Findings and 1 Conditions (shQrt plat), for this project The design meets the cnnditions in the aeporC 0 yes Rnla CDpy of Approued Design I3eviations V'ye~s 0 nla Ffre DistriCt Apprvual, fpr private roads Eryes 0 nla Lot Plans Required for any lots wlth drainage easements and v►fhich front a puhlic rvad, ar ~ ffor lats which receive and treat runoff from a public right-af-way 0 yes rnla Any applicable SEate and Federal permits haVe been obiained (i e HPA, JAR.F'A, etc ) Fnr Permrts with canditacrns, a copy of the perinit and candrticrns are inciuded in the plan ~ submittal EYYyes 0 ra Inspecti6n Agreernent }aetween the sponsor and its engineer 0 yes iKrv'a For off-srte easements ta he granted to Spokane Gounty, the followmg items sha11 be included legal description, exhibit, and proofafownership 61"yes Q n1a Erosvan Gontrol Plan, required far "Major Land-Disturbing Activity " To be included in the road and drainage plan set Explanatian for any items listed ahove whicFr are nnt lncluded in this submittal (Tiote an onsufficient justification af w+hy an item was not mcluded m the suhmitted, or mcomplete cEoctrments, may result in the svhmittal beang retumed wathaut review vr withoui acceptance Provide attachments if nec+essarJ+ ) By signing belaw, the engineer is stating thaf the mforinatian pr❑aicted in the subznittal rs cornplete, that tlae irrfarmatian pro►eided in the Suhmratul Checklist is accurate, and the plans and calculafiians are m accordance wdth the Spokane Caunty Standards for Raad & Sewer C[7n5t1'71GttC]11' and the Gurdelanes for S1arinwater Nlrxnagerrzenl, except where an a raved Design Deviation allows otherwise Engineer's 5ggnature ~ Date -25 `a I - Cx:> Engineer's Name. Zo"&-Cs~'.s' 4d-p. (please print) ' .Tf there rn-e any questions ctboud thas form rar apprppraate prdcedures, please call Devedopment ,Servaces, S,pokune Courrt}a Pubdre Wcarks, at (509) 456-3600 For Spvkane Caunty [7se Only Submittal IVcr ~ Cvunty Piar► Reviewer ~~4 ,2^ Accepted 1n for Review,er- Genstrile! (~~l rvz sAymi. p Returned to the engineer rvithout review andlor aceeptance, See attached letter of explanation Processing £?ate ~ A:~p oo Submittal Ch,ecklist 2 Sgakane County Fuhlic Works, Apro129, 1998 08l23/2000 11'30 FA% 508 535 9589 Budiaser & Assoc ZOU2 ~ 3820 E. Broadway Spokane, Washingto 199202 budinger & a5sociafes, inC. gg eoteclhnical & material engir~~eers JefTy sWIP AU$um xi, zoaa JTS D"clopmenr 4M s~ Terra verde Veradale, WA 99037 Project rr,m,ber c00250 PRVIECT. New Housing Developmeni 4'h Avenuc and Mc'DQaald 5'aw 5p&cane, WA S[IHT£CT: Res►slts of Test p►t AdYancemenr Asfd Iaborstary Anatyses Dear NIr. S[olp, At yvus rcquw, we hare laggbd xtest pirs and conducpad 2 gradattans w suppnrt csf the pavement design. We understand that Doug Buska, PE, i?arsd Evam &Assmates wsll use this infvnmation to demgn the P'roposed residentW roadways in aceordance with the Spoicane Conty matnrc :nsth[cL F[r this peri9d rnur tnvodvarneot was limited to loggmg 2 test pits admeei by 1e►m1 F.acmvation etn AugLLSt " S, 2(W witla a Kobeica SKZOQ trackhae. Soils ve°e smpled by bu1k methnds aad oollected an " bj' excavating a wgd,grrs5ased am from the stde wal►s of the pas The test prt focatians wem dammed wiW Doti$ Busko, PE aad were rucamn-ed ►vft a ra1o4ape witb refemcc to suces 8Ad exivxig roadv►rays A descrspAlaA af'the 9amgitog locauans is pravided on t,he T'eSt P1t L.ogs (F'igires l(1 snd 2)} Saanples wem oblaueesd appmmatciy 6" to 12" belvw thc surfimp, wtuch hasi alre~dy bow a°~~pped o£ ~ vegetetion. 'I'he foAo►,rWg tesit wae arnducted cxi enh sample ui ,genffal acwrdance vviih the mtMvds listed 1_ MRf5Em cOIlnC1t A$TM D-2116 , 2. GTulabon ASTM D-422 8oils wcre shssified in accorctanoe ►nth the C,inEfied Soil Glassificatiau System [ASTM D-2497) RemIb ~ are prewatad on rhe attasbid Lr6aawary Swnffuuy, Tahle l Graphic rcmulis vf ths gredatiata are alsa prnvideci as Fsgum 2 (1 antl 2) It has bcea a plcasum to bc nf semse to yvu an t,tus ProjecL if yaru lrave anY yuestions, plcase call RmpmtfudlY Sabinimad a BUDfNGF.R & ASSUCIA CES, fNC °'~~~"t~ } r~~• . 7'nomas A. Points, ETi" Sta$'' Eugineer 7,4Yha7Addmum-i Dou$ 8p9kQ. PE. D:LVSd Evans dt 11n=aw - 1 Aundme= Iabongwcy Snmwtiry -Tsbk I, -,Cc% At Y.ap - fwrrm ((Paad 2),RmiIt4 OSL3radatvn - F,gunas 41 fiad Z} F.C. Budinger IPE Stephen D. BurcFt*t# PE ,l 5~-$~4i ohn E. Finnegan PE FAX (509) 535-96"9 Scott L. Waltcrs 08I23/2000 il 31 FAX 509 535 9589 Budinger & Assoe 0003 . ~e►~r I~si~ Q~r+relopm~ M[CDOMI[d Strcel 8t 4th Avenue pt*~ Numin.i GmI: iU 5pokeac, VVA TABLE Y ~ ~.~►B~]RA7'Ci~t~'' SUi~f~yARY ' IJP~lTS TEST PIT NUN~~ ~ 2 DEFT'H TOP ft 'J: °lz B07I'OM ft I 1 SAWLE TYFE $u!!c 8ulic Md15TURE ~a 42 45 [TNTTR CLASsEFICAT[(3N GP-GM GP-GM 6" ~ COBSLES 100 S~ ..~.r r _ . " `l•• _ - - - - - 1 71 S 1 °/'o ~ 1oo _ 62__ I r 97 54 ~ 314" {'iRA1EI, P 89 48 v ] 12° A "79 44 E JlCin .7 63 99 s €~1n ~ i 353^ 21~,~ I #16 N 2? 17 2 030 SANI] C 22 16 E #4f} 19 15 #Z00 13 13 r f I I ~ budinger & assvci$tes, inc. gWechnical & materiW erngmeers 08/2312000 li•ai F1lx 509 535 9589 Budinger & Assoc I6004 ' bud1ngL1` ~'t 7ss..,.jtes, 1nc. ~ari~~ Lcrg F~~e I{1; geotaeehnizal & ~natenal e~irieers Test Pic #1 I►+}~vd K~etco sx 200. rewel ~eav~an Prv)ar 9 000250 Prtojs+tt: Nnr Uovaing Durd I~ rrc~ ~ti~ ~a =.as ~a or ~ ' ~roo sT9i ] 4~s ~~e ~ +~th IL►~El~ dE fH[bomd Sbvei Lowcd 4y TAP ~ W~ F&+~tttc~, ivM Prsr~Aed Sarsfac- u1i m4gsrc1 ~~~a ,lP~afztmr C~+d+ltar Cra~r }Y~1~rur 7 ~~.a~,~ 5o¢Idrsenh. 5~ A?cr& l7+eoae lJk ~r~vn (S"] ►R ~al ~ ~'iAAVET. [CP-GM] ,Sp= rwd, -iil ssnpma mu, o=Pmu} cnMek pootyr 8rsd4 ftd~fw,ded mce qtpmem (,oM toa Z MDri[ Ikagt Sxr4m rrlGrsy' Alluaisl a 4-) 3 fiIdAV'a (CP-GM'f)Eetdl ae-u3l Wt, 7mAl16frsri= und Tt4pnR Deme 8tavrn rrlfizaY Al]unaE ,~ease~ eobb1tt pooelq Rmckd ajbraw&d d d+Ta irce PuwWwatsr vhaemd GR4'VEl. (GPI) sm -4 uUe s3lt, MauM9 eo6Mes und 5 ~ Doudde« poorbr gmdod. +uftsnmdcd ExCav-,~Irfla'fer►rpUted ac 4' • Cf 7 8 9 lD TT 12 U Ia 15 E8 17 18 19 20 21 22 , 23 24 m 26 37 ZS 29 30 budinger & associa#es, inc. geotechrncal & matenO erngineers 08/2312040 il 31 FAlL 509 535 9589 Bud1nger & Assae 16005 - ~ budinger & assaciates, inc. ~ig= 1 (2) ge0echnir,.al & materaaf en~~nem ~'~t Fit ~2 1uFetlcad 3fv~eb:o sr~ 209, ~ r~ti~ p,~,~ ~~~q ~1eir N~iai~~ ;~e.~~la~r 1~W Neu eeraerfinr sjd~ rwd I]a~; 818l0~ ~ ~ 4th A►rtdue 6rc iVleIIranaEd 5i~'e~t 13f~ 4tI~ wviceue E ~ by TAF -I84' imgh frcm centeuine vi4tb Spokaaty 'IYA Elevatim Nac Prornted 5wfas+x' $!t artd gra.+e! Aftravr ~vm~r~lprr L'alor Sr ~r~rre ~rulvr+ 1~e ssi(dtrposlF f ~p~~ - _ . $1 MeLn Iklu F2k $iVwn (5') lllSurt~1 Brown GRA16F2. (GP~)sanlj amamc smd. smstl mom Dtm Brorm wl{'iray A1fuvul vc- so+a! -1Mts. PowSY gradpl bubrwrrded frsu orpxqsa T ~ t;q~xk laP 411 3 GRAVEL (GP{3M'?) =sl1 -v= al; Prols mmmmt and, ! M~s.i! Lkave iirawa e~'aaar rt!l+rna! ~W-utat rabMm pnaaiy avded. =Nmuvdcd 4 GAAVE71 [GP~} ecfic spc~, tsacs Sdt vmwrenaT eahbkl aW g No Fea gtwindwuer ohwrve~{ ~ bmtfslerl. pcnii}' Araded. auF ed E-Avauam aammutd al .W a 7 8 4 10 II 12 f3 14 15 !b , 17 i& 19 20 xr ia 23 29 SS 26 27 28 ?4 34 budinger & associates, inc. geolechnrcal & materal engmem 08I23I2000 11 31 FAX 509 535 95$9 Budlnger &Assoc zpo$ , Afow Fiuwsfng Dere1opi, ; Ml~R~~1ECZ NU~~ER ~0 7~~~ • cDoM7oIc~ StrC9f & blri iavunue 5pvkane, VYA USCS GP-GM RESIJLTS OF GRADATION Ti~i Pff fl ~~aa~~ ~ ~E caSe~.E 5ANI7 StLT CLAY U.S. S7'ANDARQ SIEVE SPZES m ~ ~~aR x~ ~ p ~ o 0 -t- ; ~ ; ; , ~41 ,e,,.t4 ? I -4- 4-4- ='r-`i ~ 4 ~ ~ " ~"'°T' ~ _ ' ~ ' ~ ' ~ ~ ~.~T~- ` 1~ "J~F_ ~ . f ~ , ~r4 f e{ r i I , 4 r F117. w.a..-~.~ .f ~ . a _r. 61 Bo 4 ~ r z ' ~ ~ %1 ~ i ~ I ~rf T I'` ~ i' i I i ~ ~ ! 1 S e ~ ,~a~ ~ W 40 O ,j-~~"~r i• I I ~T ~--w--~-._, ti F ~,,,r_„~~ R I ' v ~ 1-.., a • ~ t '~~"~--~r , i'V," } . 'a`'~r ~ t 4~ ......r r ~ sT • j r i ~ ~ ~-,w„~~ ~ ~ _..1 1 { ' S 4 3 ~g i- I , i • ~r~ ~ , ~ ~ ~ ~ d GFi1tIM 01AMETER ~rrrrn) ~ budirager & assaciaies, lnc. Fi~ure 3 (1) ~ gevtoonical & matefti engmaa, s I 08I23/2000 11 52 FAX 509 535 9589 Budinger & Assoc F&07 • Now Fiausfng Qevelopi, PRaJECT NiJM9ER C;0 ]25Q " McFlonaid Straet ~ 4fh A►rertue Spokane, WA TJSCS GP=CM est , '~+~~z RESULl'S OF GRAD~ATION r WOSE FM ~ nRE COsBLE GRpvEL saND sILr CLaY U.S. $TnNaARo sIEvE s:ZEs . 100 ~ -4 ~ ~ ~ ~ fL r~~ 4• a"~'1 V ~ a ~ 1"~~ ~ 1 f E J-__.--.. . 'e..-.~.•~~.._ p I ~ I ~i'-'~'~' l~ ~i ~r~ 80 ~`i--}--- - .~l~ ~F A w r~ r ~ 9 ~ , ~ -~-~I - I ~ "11 'z..' 1 _ ~ • r9 ° ' ~---rt-----.. ~ - ' i ~ ' e"' i ; ~ ; Z i k s' E ~ L r LAJ 40 .1 t ~ r i~ '~~'T'i ~ 1•~ f t I__~ i f ~ ~ ~ p ~i E 20 U • ! i i 1 ~ r~~ f p J.s i~..~_ ! ' ? 'j'°~^'-~ 7J_ t j ~ -r~- 1 ~ ~ ~~S.r.Ls.~. ~~'^~1 -~~.."rs a O O ~ fl C! 4 IR ~`aRAlN ~IAI!!lETER (RR'am) v ~ ~ budinger & asscrciates, inc. F+gura 2 (2) 9eoeGhni001 & MaWa1 eNineeare 'A~` I 1 d - r-t- `z C>,47- ~ - - - _ ~ ~ _ _ _ - - l , - - - - - - - - - - - - _,~r ~-e e►~r-_L Ae ~ _ _ - - - - ~ ~ ~ ~ ~ s _ ` ^ ` s ~ ` G ` a k t~ ~-~•.4,~ Y' J~4.4~~ ~~~~i'e~l~' ~ DIRAINAGE REPORT - (Re+v►sed 8130100) Keystane Meadows Subd'ivision Spokcrne County, Washrngtr n cFFIciA.. ~UBtiC DOCL""r EC'~IVED s~()0N€ ~OUNTY EaaGINEUt~~ ~ 1 pno,*CT 0 ~ SpO~NF coUN~~ TO ~M ~GINE~ Prepared for JTS DeveIopment 4029 S Terra Verde Yeradale, Washzngtan 99037 A ~ 3m75 DEA PrvjeGt Na. JTSDQQpO-0004 ~EXPIREs 1OM1Cho ~ THE DESI[iN TIVfPROVEMENTS SHC]WN IN TI-YIS SET aF PLANS CONFORIVI TO THE APPLiCAE3LE E~ITIQNS OF THE SE'C?KANE COUNTY STANi]ARI3S FC7R RC]AU AND SE'WER CONSTR[lGTIf7N AND THE SPOK,hNE CQUNT1s GLI1rDEL1NES'FOR STl7RMWATER MANAGEN],EN'1' ALL DESIGN DEVIATl{)NS HA'N+E BEEN APPROVEa BY THE SPGKANE C(?[]N"i`Y EiVGINEER 1APF'RC)VE THESE PLANS FQR CON5TRiJCT[c]N Au,guSt 30, 2000 r . DAVID EVANS ANI7 ASSOCIATE5, ~ ~ TABLE OF CON'TENTS i I. PRDJECT QESCRIPTI[3N . 1 A xn#roduction I i ~ IL HYDROLOGY ..........................................................................................................................1 I A Fre-Development Sasin 1 ~ B Post-;Develaprnent Basin 2 111. GDNGLUSIONS .............3 I~ ~ APPEN'DICES A~~endrx,4 Site Lacatian and Svils Tnfasmatian Apperedtx F3 Hydrologtc and Hydraulic Calculations _ Appendax C Post-Development Basin Map li I ~ ~ Orainage Report for Keystone Meadnws 5ubdivisrvn ~ ~ Spokane, Washingtan ~ I ~ I ~ i. PROJEcr oEScRIPTivN A. lntroductrvn KeysCnne Meadows subdivrs'vn Fs a hwenty-ane lot, single family develvpment lacated near the rntersection of F'ourth Avenue and McDonald Road in the 5pokane Valiey, cvvenng approximately four ' acres Roai improvements for the plat lnclude the widening of Fouc-kh Avenue and constructton of threa - new pnvate roads m the antenvr of the plat The project is in Section 22, Township 25 North, Fiange 44 ' cast, in the Spvkane County, Washmgton, and is located wrthin the bounds of the Rathdrum Aquifer -Sensi#ive Area (ASA) This report examines Che proposed stormwater cailcetion, tre.atment, and dispasal methoc3s that wi11 be employed in conjunGtion wtth this deueiopment ' IE. HYaRQLOGY I A. Pre-Develvprrrent Basin According to the 1968 5oi1 Survey of Spokane Cerunty, V4'ashington, prepared by the Soil ConserWatian 5ervsce, Che soil on-site is Garrison gravelly lvam This soil is found on slnpes of 1 tQ 5 percent and is - someKehat excessiuely drained Sp6kane County has pre-approved the use of dr}-we11s for soils in tus classification P1case refer to Appendix A for addiCiQnal soil information II Currently, ihe site is undevelaped-groundcoVer on the site cnnsists of dense weeds and brush The graund _siopes at approximately 0 5°/a-2%toyvard the middle of the site, and it does nvt appe-ar that the grade vn - the site has ever been appreciably altered Ftunaff currently stays on the site and secps inta the ground FpllpWing StOrm eVentS N0 CV1deriCe of erpSlpri L1P d1n7aglriP I"Uripff J]aCCEl115 15 7pp1fef1[ The old railroad nght of way, whach m the future wsll become a section of the Va1Zey Cauplet, lies on t.he plat's north boundary Fourth Avenue, on the plat's sauth boundary, does nat haVe curb and gutter at tlus i tame, currently, runofF sheei f]aws off of the rraadway and percolates into the adjacent vegetativn The lands east ar►d west of the plat appear to harre been used for orchards in the past, however, the land is naw coVered with lcaw grasses and weeds, and anay he used for pastureland There appear tQ be no other possible saurccs of offsite f]aw araund the site that need to be considered m this analysis i Drainage Report far Iteystane Meadows 5ubdi+vision ~ ~ Spokane, Washington B. Pas# Development Basins ' Fourth Avenue tis divided mto tw❑ post-deVeloped basins, Rl and R2 C'rassed Percolatian Ilreas A and B - I will treat the runQff fram the north half af 4th Avenue, west of Marrow Lane Crassed Peacolatiors Area C wi11 treati the run6fffrom 4th Avenue, east of Morraw Lane Pands A and B a.re linked with a 12" diameter culVert under the pruposed driveway af Lot 5, Black 3Spokane County Type 1 curb inle#s wlth 2' openAngs will be cvnstructed with a[1 three swales ta acd in conveying runoffofFoffthe road surface _ Type A drywells will be cQnstructed in Basins A, 8, and C to dispase of excess storm volume Storm runrrff from Basins A, thraugh C is treated in grassy ditches located along the entlre length of each i interior prLvate road The ditch secfiion is trapexrridal, with a2' wtde bQttom and 3 1 side slopes F3ecause the longitudinal slopes an all ditches is 0 5%, the swales are assumed to be flat (ref Pg 5-4 of the Gurdelrraes for Sdormwater Mnraugernerrt) The Iength af each swaie wial be limited to 100' lay constnaction ' of swa2e check dams Ten-inch diarneter CMP wil[ be mstalled under each driveway that crosses a ditch - sectron to allow cpnveyance of the flaw Type A dr,ywells will be constructed at the low gaints of each road to dispose of excess runoff ~ i The drywells for the project have been designed ta dispose uf runaff frQm not oniy the road areas, but also frorn the lot areas Fram Table 1of the ►aurdedrnes fnr Stormwater Managemerrt, the "C" factor for a i denstty Qf 4 77 DUfCiA (21 laCs14 4 acres) es D 40 Because the precise grading plan fmr the lnts is not known at this Cime, an apprQximate post deweloped basin schetne has been developed far the interior of the plat Thus, a"C" factur of 0 40, alang with the appraximate mterior basin areas, were used to perform ~I Bnwstnng calGUlataans Minar changes in the basin boundaries f4r the lats shrauld not have a significant impact on the dr}+well requirements - The grassed percolatton area for each basin was srzed ta treat the vnlume caf runoff fram a cane-haff ench - storm on the asphaltic surface withan the taasin 1]rywells and inlets for the proJecfi were sized using a tera- - year storm intensity The calculations for the swales and drywells are swmmarized 1n the table belaw _ 20$ IlQfume 208 Volume ~ Required PraVided I ~ 6a5in C F. C F. Orywell R1 1$2 251 1 Type A R2 98 131 1 Type A , A 323 982 1 Type A B 256 1,093 1 Type A C 316 1,082 1 Type A DraEnage Repart far Keystane Meadaws 5ubdiVision Z JTSD41drain dOC asrsatao I ~ ell. coNcLuSIaNs ' The proposed impraVements descnbad in this reporC and shvwn in the plan set will pravide starmwater control and ire.atment in full compliance wQth Spakane C+aunty's Gurdelrnes for S'tarrnwater 1Vlanagement i~ Ii _ Drainage Repart #ar FCeystvne Meadows SubdiVision 3 ' JTSD41dram DOC Q81311f10 Appendix A Site Location and Svils Informatinn ❑AVID EVANS AND AS50CIATES, ~ UNTY, WASHINGTON - SHEET NUMBER 75 44 E (Joins sheet 66) ' . 75 z N PROJECT LOCATI O N Y 1 } G ~ ~ _ ~ ~ ~ d m t M M C ~ 1 1 Mile 0 5000 Feet (Joins sheet 84) ~ Scale 1 20 000 r • + ~ ig sorr, svR«r occupy rolling to hilly uplands. They formed in layered thes are escellent pl~a~c~~es for hunting migratory wtiterfowl. loess under comferous forest. The annual precipita,tion is (Capability unit VIIIw-1; not ui a woodland group or ~ about 23 inches, und the frast-free season is alwut 125 dnys. range site) Freeman soils are used for grain, peas, clover, ulfalfa, and gmss, and as woodland. Garfield Series Freeman silt loam, 5 to ZO percent slopes (FaB).-This is the dominlnt soil on the silty upland north and east of The Gnrfield seizes consists of well-drnined, severely ; Rockford. 11Zost slopes are between 8 and 15 percent; a erodecl soils thnt formed in loess under grnss and smull Eew small nreas have sloPes of more than 30 percent, and slirubs. Tliese soils occupy ridgetops, I:nobs, and tlie up- , some of less tlian 5 percent. Slopes of more than 20 per- ~er slopes on rolling to hiily uplands. Tliey have a surfuce cent are short aaid ~are along the ed~s of the druinage~ca3•s. laj-er of silty cluy loum nud u subsoil of silty clfly that is • [tepresentative profile• rei~- h1rd, sticlc}•, nnd Pln,stic. The annunl precipitation 0 to 7 inches, very •dark grayish-brown, lrIuble stlt loAUi; is 18 to 22 inclies, and the frost-free senson is aUout 140 grauular structure; neutral dfiyS . 7 to 17 tnches, brmvn, friable silt loam, grayish brown at a 'rhese soils nie used maully forgrnin, nlffllfa, and brnss. QepW o! 12 inches, neutra~, Garfield silty clay loam, 0 to 30 percent slopes, severe- i 17 to 22 inches, grayishd>rocvn, Srm sllt loam that brnal:s into ly eroded (GoC3) -This soil occupies the narrow ridgetops 1- to 2-inch prisms ; neutrat d u~ slo loessll ulnnds ui the sout henstci n ~ to 72 inclies, dark-bro~vn, Srm silty clay loam, almost silt nn 1 Per Pes on P loam ; breuks into prisms 1 to 2 inches wlde, and then into pait of tlie connt3*. 11Zost slopes nre bet«een S niid 20 per- ' aagnlar btocbs l,y tnch to 1 tnch wtae, neutruL cent; a few smnll nrens have slopes of moie thun 30 percent, , The surface soil, when moist, rna b~►es from very dnrL and some nnrrow ridb tops hnve slopes of less thnn 5 per- grnsish Urown to dark bron n in color. The texture of the ceait. Representativo profile : , SUbSOII ranbes from heavy silt loam to silty clay loan~. 0 to S incl►es, dnrk-Lro~~n, flrw sitty clsy loa~n; granulnr struc- " As much ns 7 percent of some area,s consists of ~arkin, tuce; nentrnl. ; DClLryton, or severely eroded Freeanan soils. S W 48 ineLes, durk-bro«•n, 8rm silty clay, yellon-isU-broR-n This is n, moderAtely n-ell drained soil that has a very stlty clay loum below a deprh oP 23 inches; breaks into prisms 1 ineh to 2 inches wide und then into angular bloc}:s slowly permenble subsoil und is saturnted for short periods 14 to 'A incli thick; clay fllms coat the prLsms and angalflr ~ in spring. It holds a,Uout 5 to 7 inches of water that plunts t,tocks; neutrnl. cau use. It is easy to work egcept when snturated. Hoots 48 to 60 inches seilowisb-brown, firm lierivy sttt loam ; UreAkS i ' xAetTBte tit0 1ow0T lA ers ma.inly along ped faoes. ''l10 into prisms 1 to 2 tnches wide nnd then iato angular blocbs ' . ertility is medium. urface runoff is medium, and the % to % iuch tlilck; neutral Tlis tei-tui-e of the upper subsoil is silty cl~,y or c1~,3•. As liazu.rd of erosion is moderaxe. uch as 10 ercent of some ureas consists of Athena l~aff Diore thnn 95pe rcent of the acreage is cultivated; the m P > > rest is farm woodlots. Wheat is the chief cash crop. It Nez Peiroe, or Palouse soils. is $TOwn in rotation with peas and a gneen-manure crop This soil is well drAined and slowly permetible. It holds ,y or in awhea,t-fallow rotation. Other crops gro~an are peas 9 d or 10 inclastich ~es l ofien wet• water conthat tl plants it can can use. be It i cus lti stic~ntekd nnd bnrle • clover or alfalfa for hay or green manure; and nllp ~ ~uen9, grnss for se~ed, h1y, or pasture. All gram and 7rLs4ee crops onl~~ within r~,ther nnrro~v range of moisEui^e content. resnd to nitoen. respond to sulCapn- Root penetr~,tion is very deep. Tlie fertil~ty is inedium. bilty it IIIwoadndoup 5; not in site) Surfnce runoff is rapid, and tlie haza,rd of further erosion Fasilt loam 5 to 0 percent sloperely is se~-eie. eded (Fa)-Sran 50percent of the slayer ~IOl'g tllilll 95 1~ercent of the acre~.ge is cultirated; the of this soil h1s been removed by erosion. Fertility is me- l-est is seeded to alfalfa or grtiss. Wheat is the cliief crop dium to low. Surface runoff is ra.pid, and the hazard of Otlier crops grown are barley ~,nd dry field peas 411 crops respond to nitrogen, sulfur, and phospliorus. (C1- erosion is severe. As much as 10 percent of some nrens ptilillity unit Ne-3; not ul a~voodland group or rnnge site) consists of uneroded Freeman soils ` . The same crops are grown as on Frceman silt loam, 5 to 20 percent slopes, but yields are lower. (Capability iuiit Ga11iSOn Series IVe-3; woodla.nd group 5; not in a razge site) The Garrison series is mlda up of someArhat eacessively Freeman silt loam, 20 to 30 percent slopes, severely di-1ined, giavelly or stony soils thnt formed under grass eroded (FaC3).-DSore tha.n 50 Percent of tlie surface layer 111 alacial outwash miaed in the upper part R-ith ~-olc~~.nic of this soil has been removed by erosion. Surfnce runoff asli These sods are on nearly level to modei-ately steep is rapid, n,nd the erosion ha.zard is severe. Tncluded in {errnces The annual precipitation is 18 to 22 inches, anci mappug were a few areas of Dea.ryton soils. the frost-free se:LSOn is about 170 days. The same cropsare grown as on Freeman silt lolm? 5 Soils of the Garrison series are used for avuriety of to 20~percent slopes, but yields are lower. (Cupabilrty crop s and ns f~,rmstefi,ds a,nd suburban lots. unit IVe-3; ~coodland group 5; not in range site) Garrison gravelly Ioam, 0 to 5 percent slopes (GgA).- This is the dommant soil in the Spoknne Vnlley east of Fresh Water Marsh tlie city of Spokane. Most slopes are between 2 and 5 Fresh water marsh (Fm) consists of shallow, swampy Percent. Representa,tive profile: ponds and of fringes around lakes that have a fluctuating = o to 15 tnches, btack, very friable graveRy ioam ; granuiar water level. The v tation consists of tules reeds and structnre ; slightly aCtd ~ > > 15 to 44 inches, dark-brmvn, friable very gravelly loam, neutral rushes. These areas are of little value for grazing, but 44 to 60 inches mnltrcolored sand, gravel, and cobblestones ST'OKANE CUX3NTY, WASF3INC`,TU~T 19 he Lmmrface coIar, when tnvist, ranges ft~om very dark tTis county, 11iost slopes are between 6 and 15 percenL L wn to black °Tha testnre of the surface Ia~er ~,~rav- ~presenr,atire profi]e; e„~ or rerp g;r~.velly laam. or ~tt lvum. Tlie su soil ranges oto a~~~hes, black, ver9 frtaulQ suc loaun; gran,lar srractUre, an color fzam dark brawia to yellawisli brrrtvai Clay and neut.fial 1 s)iave ar.cumulated on the battom of the pe.blales an t1ae 13 to a~ ~nches, aIIrk-brown, arm roam r.nat ureaxs into linsins l er subsoi3. Tlie deptli tir tlie gravel subsUaturn ranges 1 to 2 inches tvfde, sftbtts aela. f az.m30 #0 55 inc].res. As much as 14 percent af &ome ni en.s 62 to 72 clarli-brown, frLnble lvaw , slightly acid. ~~i er is verry dar& brozan. Zt is 10 s~ts of Bang or Phoe~ sails ar af ot}.~er C`irarrisau ~a1.~. xn ~la~ #he surf~e laY nis soil is somew]iat e.~c,essively draiiied azad lius iiiad- to 1G inclies tliick. The t~xture vf tlre subsoil rranges from c ely raptd perineabrlaty. It haTds abaut 5 inches of silt laniii to ligltt siPty cla;p laam Frotn 5 to 25 percent of «-ILLer that plants =i rase- Itis easy to work. Root.s the lorrer snbsoil is r.amposed af gravel and stones. A.s ~netrate to the Iayer o# s~.nd, gra.vel, and eobblestan~s. lnuch au 5 peccQrct af some ureus c:Ansists of T3ernlaill, ' fsatili~ is n~edium. Surfaoe ruilvfT is slow, tuiid t1le I3ear~rtvnp or Larkin soils. 1 Lrd af erosion is sl~lht Tiizs soil is ~rell draijied aiad mocierntely permeable rt ~b~aut 80 per~nt a the aerert;'e is cuItavated; tlxe iest is kiolds 9 to 11 zticlies of Nvater that plants can use. Tt is Iised far pwii;g, and as farrnsteA,ds or subnrban lots. e-isy to irork. Root penetratian is very (lee . Tile fBr- ! st of the ~.cre~.ge is arrigra~ted.. Trrigated ar~s are used trl~lty is Iiigli. Surfaccs i-►uio~ is madium, an~ tlae hazard t orehard fruits and berries; cahba„7e, torn, cantalaup, of erosian xs anoderat.e. cu..ambers, c:elexya and squash; wheat, aats, aiid bai ley; llfflre tlEan 90 )ereeiit of the acre.-ige is cultivated y tlle alfalfa for hy; and gr•ass for seed and p:~sture. ~7ryln~id x~est is glazed. i`']ie~tit is #I~e cliief ciap It is grawi in aLs are used. for r~•l~ea.t, barleya and natave buizeligr~,ss lotatian zritli barley, raafs, peas, lentils, alfaifa, or gr1ss. ~ ina is nn diffieulty in the usa a# macllinery, but tlie A11 grnss naad gmin craps respand to nitra&en; lea?nles *.vel is hard vu tillage amplements. All crogs escept xwpona ta sulfier. (Capu}aility unit IIIe-2; Laaniy range le-o,umes respand to nttsagen. Some craps respoizd to site, nvt in a rcoadlaud rnup) s ur, l~c~rnn, and p~aos~phorus. {Oa~sability unit ZIIs-2; Gtenrose silt 1oam,~ t0 5 percent slnpes fGpAI: This I mp unge site; xiat in awoodIand group} sail has a surface layer 2 to 4 inches thicker than thnt o# .,arrrsan grave11p Ioam, 5 to 20 pereent slopes [GgB1- GIenruse silt loa.nn, 5to 20 psment slopes. Surfa.m runofl `I hf5 SQil h1ts & S11I'fACSB itLyeT 3 to 5 1S1CalC5 Cl1 iilll0r tIlari tlitl t 15 SIOw, Alid tllB CI USlf31l haZI4Y'd l3 5I}tt. Included 'aiinaap- a irar~san gravelly 1nam, D to 5~ner~nt sla~3es. I3,unoff P'lliff srere sma11 ai~n.s af LTiilig a~ Dearytvn'sails. i, e-diurn, arzd the erosion liazard is naoderlte. ie same cra ~s aa~e gro~vn as on Glenrase silt loam, 5 ~his saxT is used in ~nuch the same ~ray €r~s Garrison to 24 ~erce;Yt s~v~es; in a~3ditaon, veaa.bles are grre~►ii. m~.Ve1~,y laarny Q to 5 percent slope.s. {Gapability unit (CaP ility uiiit lre--2; Laamy rangre site; z3at in a ivcrod- 1 -5; Loaxnq range site; not an a Zrcaodlztind group) laaid group} mLrrisoa rrerp gravelly 1nam, 0 to 8 percent slapes Glenrasa siit loam, 24 ta 30 percent slvpes [GpCI: This {u„d}: This soi3has a thiiiner, more grnvelly surfnce laper soik has a surface 1ayer 3 to 5mches thina►er than t,hat af l1aii Gttrris7ix gTavelly lvattl' 0 ta 5 percmt slopes, njid Glenrose silt inauY, 5 to 20 perc,ent slupes. Surfaoe ruwaiff i, Ls less tlLan 5 inehes of rvaf.er that PlAnfs can tLse. The is ra.pad, and tlze erosian hazard is senexe. Abont 5peroent } rel cause,s extzvine trear on tillage mnchanery. As of some areas cansists af Bern1ai11 and Deasty#on soils. rztuvh as 7 peareerit of some nrezis consists uf otlier Gara ison The snine crops nie giarrn a.s on Glenrase silt lorun, 5 to ;aals, {Capability unit xVe,S; Shailow range site; not 20 percent slope.s, but mare of th$ acreage is in gmss and nwoodlmndYgraup} Iegumes. {Capabllity unit ]Lne--2; Laamy ranba site; arrisvn very stony laam, 0 to 20 percent slopes no~ in a wondland grouP) 16,ar. T'his sail halds less than b incIies af lva#ar that G1enrose silt laam, 34 to 55 percent sIapes (GpD),-Tlias Iilnnts can use, aiid 'at is tnv ststny to be cultivated. As sail lias a srarface litper 3 to 5 inclies thuner tlzan that of uh as 15 permit of same areas can.sists of other Garrisan Gleni-ose s31t loaiu, 5 to 20 percent slape& Surfnce ruiL- ~ xnrl as mual-x as 2 parcent is m.ade up vf grnnate off is rrapid, and t1►e erasion hazard is severe. About 3 GuWrops, percent of saine tireas cansists af Beruhill or Dearvton TIifs s+niT is used for graz'rng (Gnpability unit VIs-2; se'rts. Tlaas sai1 is used only fvr gra.zing. {Capabil't w llncv t~ange site; aiot in a~vaodl~uid graup} ianit Vra-1; I~ortli E sposnre i~,nge site; iiot zn a zvoo land graup) (xieluose Sekies Glenrose gravelly silt loam, 5 to 20 percent slopes [GB}.-Tliis sail lialds from 7 to S inches of Erftter that lie Glenrose sesies cnirsists nf -well-draiiied, mgstly plant.s alai izse. Sxnall area,s of Bernhill and I]eA,zqtrvn ?j iuin-textured soais. Thesci sails formed under grr►ss satis n eie iticluded in inap~xr~. s-,.~ scltteaed ~Sitie ti'ees ri~ glncinI till mised in tl~e u]aper T1ais soil is u-ed in rriuc i the same trap as Glelimse sifG IM i twitFh loess nud valcnnic ush. 1VIany areas are gnavellya IO:tYda) 5 to 910 percent slopes, but yields are Iess. (Capa- i+ aixy . Tlzes$ sniLs are nea.rly 1ene1 to very steep. ~'lie uility aiuit I~"e-4, Toamy range site; not ii~ awoc~dlnnd t .~a1 precipit~tian is ~.baut 21 inclie5, and tl~e irost-aftee ~~o«P) st,V~n is ~ut 135 days Glenrase graveTTy silt Ioarn, 20 to 55 percent slapes [``arlenrose saiis ate used for grain, peas, lentaLS, vegetflbles, (GrQ}.-Thzs sail 1ioIds 7 to 3 inrhes af lvater that plants ~ Ifa., and gi ass, anti for gi azLng. can use. Surface runvff is rapid' and the erosian hazard lentose silt Zaam, 5 to 20 percent sFopes IG,pB1.-This as severe Tncluded in mapping were areas of T3ernhill OCC'llls OXl glnC1fLt0d u[]li4.17dS lIl thC eil5t-C,eiltTaI paPt Of silt laatn, 30 to 55 perceiit slopes. , ~ + 3^s[ sM ~4 C.PZ'. ~c+.r~5e7'p3~~.7✓~'za"~"' "s~`~'t -t- • ~ r , • . ` y 74 5o1z SURVVEF TABLE 6.-Bf'8E+f &Sa'ipti09Z8 Uf SOi& cG7Ld ' G'LasssScation Dept7h _ Map Soil name Descriptaon af sod n.nd sibe frvm symbol surfaca UST]A textuse DsC DragGon stoay 83itioam, 0 to 3fl peroent Similur to ❑ragaon sJt ioeun, 0 to 30 pemnt stopes sloges, extept thaG the surfaw leyer is stany. DsD Drngoon stony silt loaas, 80 to 55 per- eent slope,s Dr[] Uragaon uQSy racky coenglcu, 20 to 55 Dragnaii part similar to 1)rngonn s7t loum, 0 to gcscenC slopcs 30 pe rcent alopu5, csocpt thAt dcp&ts to taed- rac4, raaiges from 10 to 20 uiches. RocK au, - ~ crop uicluded in this compicc. Ek8 T:ioik,nsilt Ioa,m, ❑ to 20 perecnt siopcs II'lediki rn-te.ettcrtd, t% cll-dramcrisatl farmed frcain 0 t0 24 Sdt 1oam-----°----- glaciul Lill caiitauusig a lurgu amoiinG of 101- r,xuiic Ash in the surfucc Iaycr; undcrlain by 24 to 44 Graveily lvam_-_--_, grsvri nt depth of 30 to 60 inches, occup4rs 44 to 53 Vc,ry grnvelly sandy. uudtilnteiig, morliiicitikc topography lonm. ~ 53 to 64 GrASCI------------ EIC Elarl.a very stony ailt 1oam, Ln 30per- Similar to Eiai€:a siit lanm, to 20 peracnt $lopes, cxait slvpcs. cxcept theL ilacy Are very sWny thraughsaut. EID Elaikn very sto:iy silt loam, 30 +Fa 55 , pcrcent slapes. Em L'nidcnt silt laam A'IcdLum-te-xLured, samcEVhat poorly draancd, U to ?ti Silt loam_ slknliiie sail inrmed in a]lurmim from Wcur- catits silt, volca.nic n5h, mztid diatonit,Q; depth 26 to 41 Very 6ne sandi• to ssster tnbls Reecttiates from near t,he surfa* lanm. to abvut s rcct. 41 to e0 Sandy clny loam._. FaS Frecma,n sslt lvaen, 5 to 20 pcrmit Vcry clccp, tnvdcrutcls t►v11 drauzcd uplaild sotls 0 to 22 Silt loam-------- - elopes with medium-texturrd stidace lnyer vtd mcdi- F483 Freeman sdt 1oarn, 5 to 20 pcrcmit tim 4r taicxlerntcip Sne textAired aulsoil; formed 22 in 72 SikLy cLy loam__. ~ slapcs, sevexely t.rvded. froui sflt osi ralling to hiUg uplanda. FaC3 Frcematt sdt lo$m, 20 La 80 pcsoaAt slopes, scNcrely croclad Fm Fmh Qrat,er rnarsh Shullow, snaznp►•, iiytcrtrattciit ponds s~nd LMUges nroiuid'lal.es that Yuene zt liitotuaf.ing nmtcr t,abie_ Engineering dnta is nat g7von, ns land 0. pe is toa %-anahle GaC3 Garfie]d siltp clstiy lriam, 0 ttia 34 paresiit t'erp dr.ep, ❑ell-dnaanecl smil devdaped in aocm 4 to 8 sdtv cl:sv loatuni siapes, se►crely erndea3 on ridgetops RIld k190U6 Uli the tallijig to hdlg $ to 23 Siit}• elns•_.__---- uplands 4n thc Pnlausc scail :►rcu. 23 to GU Sil63 el.ir laam-. C;gA Gzerrisvn grudelly Fvaan, 0 to 5 pcrr,cnt GravOly, mccieiiin-textured, samewhut caces- Q to 15 Graveilr loam__- , slopes siveiy dnlttied soilg fmrmed in grnvcil►+ gincta1 15 bv 44 I''erY grii% rlly T G,g$ GarnSan gravellv 1oam, 5 to 24 perceitt eatxvnsh inatenal frrrm m vnreety af acid, 44 to fiU Snnd, gra., cl, and slopcs_ igneaiis garinE rock, aii ne.7riv !cvel to mad- cabbIesLaiies. crately riopuig terrntit~cs, dapl,h to znixt~irc aF ` winai, gr;1t e1, and oDbblesWn[x rAnges ftOm 2% to 5 feCt f'ams {;arrisvn verv gnitrelly ln:uYe, U to 8 Sinjtil tir to C.tirnson gr,s►el[c lrram, cxcept that U to 15 Very graveliv 1 percent slbpes flae storf irc lai er ts %crr gruti•elly 15 to 44 t'ery grnvcllu 1 44 to 6Q $axid, grnvd, snd cobblcst,ones GnB Garrisnn very staiiy loani, D to 20 Sunilar t4 C:arrGSVii gr,a%cllc lonm, ekcept ttuit percent slopes thc surfac*e larer ts t cry staiiy. GpA Glenrasc siltloam, U to 5 pcrccntsIopes Vcr, decp, mrciium-te~sf.ured, x4e11-draaned suils Q to 72 Siit lnam_----- Gp8 Glenroseailtloam,5tsv20pcrcezitslQpes 1Fvreuesi frocu aod igucous gtsc~al tsll, surface GpC Glenrosc silt loam, 20 to 30 pcrcent la±~~er iii[iueiiced l3r lves.s asid volcanic ash, on slapc.s gcnEly ralling fa -tenp tipiands GpI7 Glenrese silt loam, 30 to 55 pereeiit stopcs ~ ' ^ - • =~I • . ✓ • v~ ~ - ~ ~ 1( FI Ij $P6SANE ODUNTI', '4YJlSEING7`UN 75 st; ad physica2 ccnd chmicaal praperliesY-Cantinued ;lawficataon-Caufzuued Pcreeutege passEng srta~e- Ar•aalable ~ PermtahilYty vt ater T;eaction I]ispersiou $hrink-swc91 Rv 4 ~a. 10 h'a 200 Capacils (p:a dilution) teenGial _ rfied AASHL7 .(3 7 mai~ )(2 0 inm) (0074 ~ inm ) fu ptr kr !p pa he o/ rarf p1! ~ '1-4 8310 4)5 $ia to 41 i GU [o iU $ to 2 5 0 17 ta (120 6 i 1o Ii > fligh ---r--- I,aw to mod- er.itv S1f__.----- A"4 7) to 40in $[1 ,i i R.a 30 0 $ to 2 a 0 12 [o 0 14 G t ia fi b f lagfi l,ow p _ A`2------ .iA to G[i 20 to 3f1 5 to i 5 5 Q l0 1[I [i 0 4kI to fl. [pE G] to a 3 Iligh»_ T,Qw A-I to3.a 101020 [1 6a a >lU fl 09 fa ff (gi ti 6 to 71 llrgh------- I,au. a1T,JCL A-4------ 95 to 100 134) to 100 90 to Ory ❑ 8 to 15 0 1 e lo O 20 7Slo 11i{;1i T.n►v 1,cs ma(i- cnit.e_ A-4------ 4 ) 1 to 14H1 901oiOn 60(o :r) (1 8 dn 2 1 n. 17 to 0 20 7 a rn s4 Alodc•r,dtL--- 7.a►ti•. C--------- A"6------ `•ls to 100 00 to J:a $v d.v'JO U? to 0 80 17 i4 [l ?i) G fi 1oi3 I.otir------- h3odcrat,e tI M_.__ A-4------ 95 to li!(} 94 to 100 $o to go 0 2 to 11 8 q 17 lc, U?il fi G to 7 3 MUclrriete___ I,otr I.fl tnqd. ( r.itr C i a--6 95 to 101) W to ioa sa to 90 < o (ri u ir Wn?rr c G to 7.3 T.Uw Aindrrntc. `1 A-Fi------ 95 to Fn[1 3[! tv 100 9tlta 95 2 to f} S il 17 to Q 16 G G to i 3 T,a~v------- 1hfadcrnLc eA--7------ 95td 1 Oq 90 to 1(9) 90 to 95 d! 05 to 0 2 U 14 to (Y ] 7 Sr l3 ([r 7 3 iow _ v__ Diigf~ ~L A-6------ 95 to 100 JU to lUU Jii Ca 95 0 2 to 2,5 0 17 to 0 ?U fr G to 7 3Lnn------- 11Sac3crate ;a A-4 65 ia 85 90 to 754 3r) to rn Q R to 2.5 , 0 12 to 0 14 G G!o i 3 Aioclcrntc A Sow A-2 45 to GS 3[1 to 60 5 fa 15 2 5 to 5[] l} i1ti to 0 d[I G. Q to 7 3 Atndcratc--- Low ~l A°1_.---- 25 tv 33 IIQ to 20 0 to a' ]10 0 04 to 006 fi G tv 73 I°T,gh------- L,o.v '1t-------- A-2------ 30 #p 60 20 W 5O 8 to 15 2 5 La 50 a ns to n ao G 1 to G G Modernfie___ X,o►v lu_ _ p_Z__---- 45 to 65 30 to 80 5 to 15 2 5 to 50 ❑ Q5 wo 10 G G to i 3 ATvdei-ate--- Ln►v A-1 25 in 35 1(} to 20 b to a" >10 0 04 to Q UG G G tv 7$ ldigti------- I,ow. A-9------ $0 to 95 75 to 95 60 to 85 fY 8 to 2. a 0 IT to 0 20 G. i to 7 3 A3aderate__ Latv to ~ maderate ~ ~ i 92 sOa. SUxtvEY X F TASL'E 7.-I7l.tE1pYdatwR af 8ng77t, ~ Suitahiltty ns souree vf - Sod featum affecting- Sqil scries or type, Fatraa paa and annp symbala _ Topsoi[ Sand' Gravel' Itvad 51l I3ighsray locat3on Dikes or Ie►*ecs ReSCi'191C E ~ Drngoon (DrC, Govd to Nat suit- hrot sutt,- Fair to Mvdci-aLe to very high I.ativ stabaiity, Mnderate ia ~ bsC. DsD, ponr. able. ahle gocad suscegtihiiaty to semspervious to madcratc ; ❑rD) frasL actiota; mod- zmpcrnipus rapid pcr+ ~ erut,e to moderatel►• r►FLea cram- ahilitk rApid germeabEl:t3, puctrd; low to 19n to inodcratC inodrrilte shrinR-s%tiell s}tritik-r,i%e1I i pntenf.is] g3otenLinl Eloikn (EkB, E1C, Fair_----- Notsuit- Suatnfale nt Goad____. Mceclernte ia high sus- Lo►s• Aabdity, I4Toderate tc EIf3) able. depLik ceptibifi4►• iq frast Rcuupsrvvmus to rapid pcr, ~ greater actiQii; moderntc to imprrviotw abali#y. thatn Ga verv a-aprd permc- n lieri compact- i»ciir, stbiliLp lan La moe'.- ed; Iqw to niod- eratc shrink-s%e$1 craW Oriuk- pvlcnteal sue!! 130YviiLin1 ~ LS"SlldL'[IL 81IL Zf)IilI7 Fai.r__-___ Natsuitst- 11'at suifi,u- F'vor_____ Verv 1ii,gti susceptibil- Law stahArty, uui- . Mudernfe t, ~ (Em). ble hle. ity W fmst aciion, perviotes ►visen modernas? mo3crute W mod- cotnpact.ei; lau sPo►~ per•r " crate3y slpu^ pernic- to moderaW abklitr ~ ubilits• lox LQ i[tod- sI]rl3il.-miCll ' erntc slviak-snelt pof,entiel paiefitial; saturatcd + sn wonf.cr and spnrig Freerman (FaB, Fa.ir to Nat sitita- Nat swta- Paor_____ Moriera,te to sery liagti blodcrn#.e sfabf1- Moderat.e1■ FaB3. FaC3). pcor. , ble. bie. sur,mptibditp to aty ;¢m~rsagus to ~•ery ~l frosE a~rrn; a~uder- n~hen cornprcct- permenbi, ately rAo►r to verv sd, lvw to moc!- slrnAs permeabil6, crat,e siarfnk- loiti to mvderaCe m% e!1 pofcntisl; ' shnttk-sm elk paten- soiTs crack s% hen ' tial, sttturated in dr5 " spriiig Gsr&e3d (GaC3)--_ Faar to Not sutiGa- Not suita- Poor----- Moderate to vicry high Moderaf.c sf.slsil- Modernfe tc ; I Baad ble bTe suscxptzbdity to frcst ity; zrnpernious slow pern ~ sctsvn; msderute to ►vtien campaat- a4i11ty , slan per:ncabditi-, ezi; moderake to i innderate to htgh high shrinle- r s3irmk-s%% e11 poten- s►s e11 potent,ial tiR! Garnsan (G A, T`air----- TJot auiw Gc~od 4~e1on Exeellent_ Si~zfit to no sus~pti- Maderate st.~bsl- A'~oderate tc ~GgB. Gm~, able surfsce biliLy to fmst aetion, ity , pervfous , ery rapi, Gn8) iayer_ tnodcrste to Vcry whra coin- peraneshil rapid permcabiliEy, yact.ed, Pow low shnnk-s%s cll shrink-swe11 pvt[;aitisl yot,cnLisl I See ivotante at end af table. I • " t' ~ SPUSANE +C0UNTX, WA$1MNCxTON 93 bpertie~ of so~.s~ontinued F. - Soil fcntures affecting-Cantiuucd Fnnn pnncls- I;goneinued Agncultural Tcrmees and &Erage disposal ~ f dmznage Imgsiivix dnersYOns RTat,enrays fidds TraffiaahzLty ~ ,CetabanA mcnt dy lov gIseas ?I'[aderatc i,o Aioderate an- T.rnw resistsnce Lom resistanc:c to ?1toderate to Vary low shcnr ~ strongthr ceml- modnrut,ely La1,e r1tc, to craosxnn, erostali; rnod- snoderutcTy stxength; low pwrioste to lm- rupid pxsme- modernte znvdcrate to orntc ►.ater- rnpid pcrnxc- lvrxcf-carrymg iwApua n-hen abjiity na►tcr-liolding maderAteIy l:olding cnp.lo- nhilitp, li1Qd- CAjJACILyi ,,cialpacted, me- cnpaadty rnp:d pcrme- itv , o•cgvlatz10u rr;~te to ir orl- mvderaxte to dnim cainpr~s- nl»l3ty difficitl6 to crnt.~ly rnpid rnoderats]y iln7Etv. loiti es01.11sh e--,cept tcatcr-hoiding rapid perme- - alnbalit, ioii l7ragnon capactty. abzlity si!'t lottm vr s~r sLrengthf Alocicrnte La A4orlcmEc: to ~1~odrrate resist- ~Siaclemtr sm~E,t- 1Todcr;►te t~cs ~o►v she;~¢~ ~~~Frmipervxous to very tapicl itncldrrat,ely ,aiicc to erv- aitcr Lo crosialr, r~ry ru~~si strc~~g43~• mvd- inpervevua i~cu perincabiiiCv rapfd iutake stvii; moc~er- mvdrrnte n•alCr- ~rmc.n iLLv, crnte ta ~ygh corni~ctecl, slight rn,te+ rnodrr- ntc to t°sn liQldrng ca- :nodrmte 1oadr.sirrying i. sampressi6iistr, atc wrktet- r.tiy3tci periii4'- ]3aeit► y vrgcta- n ntr,r-Itnlding cupnctty; moti. Evnr sfi.AbxIttv holding ca- nbflrGy divn cii~i'icult to c.lpacrty. cntc to ►sery ~ pqcit} est.nbIisli cxccpt rnpid porme- 91f ElpCI.9 SdL abdity, ~ ~C}.9f1] ~ ey 1n►% 5111•.13 Modernte to fiTodcrafi,e to Aladerate resi3t- 1forlcrnte resyst• .lfodrrntc to Vcrq lnw slicar 1 4.reugEh; 3siiper- mvdcrately anoderutely anee tca erv- n«cc to crostoai, inorlc•rntch &trCngth, mad. ~ iiiiatts w€scn cnm- slan pcrme- slalr ints►ke sisii, znodcr- vxr,• higli n ater- slou pernig3- erate to low paded, modernte uhdity; satu- rafe, vorv utc' tO lii[1dCC- t1p2(I111g C.irl.'lc- SLbIIICyYV['tS` !ou!d-carrying to bigh 4ompress• rntcrl aFi ts in- ln~h u:~tcr- at~•ly ~4k~' AL;4', cscrp#. Fvr Iug1B nacrl~d- eap~s~city, mad- ~~litv, u~eraEe Ler aud ha ding en- pert2rcnbiZitr, sali-toTew.tart Ing c.apacity; crnte to tnat!- stnbg ty , cmeks spriiig pacitp. spccirs, va~cta- s.ntumt.eci i~i erntcly slo~v rrbtcn dry. trvn difricuTt to t+iiiter it:u! permenbilrty cststbIisli spritzg ery low slacar Moderafely 1Vlodemtely 11Sodcrtetc resist- Madcr•ute remst- Moderntely Very law shear dtengt,li, unper• siow to very sIan* to $low ances to era- ance to croslon, alow to ►rerry stmngth mvd- vlpus wheu com- stow perme- intake rat[s; eioit, rnaier- very ltigh vratce- elain Petme- `vrute lnsd- x pe#ail; tnelium abeLtv, anku- vcry high Atrly s1o~~ to Zxn9ciing ra,~ac- ~bility, , verp cnrrying ca- tm t~ilitv rs►ted in n•ater-holding vcr3 slow pt:r- itv, vegetntion hzgix crntCr- pacity ; mpd- maileraite stAtid- sgntig cagacity. mc;ruility. fnirir casp to haldjng ea_ ceatfily sTow to F ikp; eaila crack estnbiish pacity, satu- very siow ~ Irlam di"y'• rated in permcubillty. sgintig nF loa• shc•zr INIadQrn#,c to Slotir sutal.c 11'xodvraGc resist- A4vderutc resest- I4iotlerate to Vcry lnw shear ftnmzti, iniper- slan• permc- rat,e, very anm to Cro- naIce Ea crost0si, slow perme• strength; mod- ~ r1~►s Kiag u com• abifiSy high wAter- s:on, inoder- very hig2i ahdrty, very erwteload- :t~sKi~sun ~ hnlding caa atc to slon Ivutcr•tsoldiitg h~ h vs~uter- eat~rying ca- ~oorn~r4~ bfT- p a c aty. pe r m e a b i t i E y. c ap~. e r t v. h r sci in g c a- p a c l t yr m o d- (~p' ~~rate vegetateoii p.tirity. eeate to slnw ! ~tiy• ~oll ta1rlv eAsy to permeabaity. eract~e s~~aCt] l1CV. L`SG.4t]Ii8h lth+hftrstrciigth, A'foderntc to Rspi[£ lntn,ke Modera#e i•csist- Maderatc restst- ~liodera~te to Iixgh shear Perviaue K Iien ti•er3• r:Epic9 rn,te, moder- nnce to ero- ai:ce to crosiott, wery ra id sLrength, high ~ QO"~~, slight perztieubility. afi,e to 4a~v slort, moder- modernt,e to lrr~u pcrm~s~ilety, load-carrying aom{rr~Rsdnl1~.y, ~z~ater-hnlding ste to very ti►•ater-holdEng moderate to capacitY, ~dcrnGc xt i- c.apacity rnpid perme- czLpnc►Ly' , vego- law water- moderatc to ~4ily. abi[2fy Lnteali ditifculC hoZding ca- very rapid to rst.ablmsh oea pacxty permesbility ~ 7'~P&F,o'!1y ]4Rl13, f~.1r1,r• ca.sy on otlicr sails P i S• ~ Appendix B Hydrologic and Hydraulic Calculations m DAVID EVANS AND ASSOCIATES, ~ ~ ORAaNAGE CALGIJLATIONS FOR KEYSTONE MEADOWS Spokane Counfy, Washingfon _ {revased} I Basin R7 A=4,360 sq. feet of ACP ; i GPA Volume Required =(4,36[l sq ft }124=1S2cu ft - Porrd A , A=53 sq ft, P=651 f Volurr►e =(0 5')(53 sq ft}+(p 375 cu ft Il f)(661 f)=56 cu ft : I pond B A=219 sq ft , P=2281 f Volume =(4 5'){219 sq ft}+(U 375 cu ft Il f)(2281 f)=195 cu ft Valume Provided = P4nd A+ Fond B=251 cu ft > 1$2 eu ft Basin R2 A=2,357 sq feet of ACP GPA Volume Required =(2,357 sq ft)f24=98 cu ft Pond C A=146 sq ft, P=154 1 f Volume =(f] 5')(146 sq ft)+(0 375 cu ft 11 f )(1541 f)=13I cu ft ' Basin A _ A=67,161 sq ft =i 5418 acres ACF Area=7,740 sq ft 208 Volume requsred=7,740 sq ft f24=323 cu ft 20$ Valume provided =(1,225 sq ft)(D 5')+(9$5 1 f)(d 375 cu ft Il f)=982 c f>323 cu ft I Basin B A=65,227 sq ft=1 4974 acres ~ ACF Area-6,150 sq ft ' 208 Volume required=6,1 S[] sq ft 124=256 cu ft 208 Volume provided =(1,635 sq ft)([15')+(735 1 f)({] 375 eu ft il f)=1,493 cu ft >256 cu ft Basin C A=59,754 sq ft =1 3718 acres ACP Area=7,5$0 sq ft 208 Valutne required=7,580 sq ft 124=316 cu ft ~ 208 Volume Pravided = (],421 sq ft )(Q 5')+(990 1 f )(U 375 cu ft 11 f 1 y082 cu ft>31d cu ft Orainage Rsport for Keystane Alfeadows Subdivision Appendrx 8 i KIJTSQ60041DRAINCALC 0 QC 08/30i00 X3A,'V'TI3 EVANS AND ASSD+CIATES B[3WSTRING METHOp (TEM YEAR STQRM DESIGN) PROJECT ItEYSTOiVE MEADOWS DETENTIORI BA51fV DE51GN PRaJECT NQ JTSQO004 BASIN R1 NUMBER OF DRYWELLS pROPOSED DESI{3NER aavG susKo, P E 1 Singfe {type A} 0[]aubie (tyPe B) aATE July 20, 2000 Tatal Area (calc ) [see H1) 0 10 Time of Conc (cale) (see H l) 5 00 Composite "C" {cafc y (see H1) 090 Tirote af Conc (rnm) 500 Area (Acres) 01001 C' Factor 090 Impervious Area (sq ft) 4360356 Volume Pravided 208 251 storm 334 t3utflow {cfs} 03 Area * G" Factvr 009 #1 #2 #3 #4 #5 #5 #7 7ime Teme 9ntensi#y Q dev V rn V out 5torage InC Inc [mm } (sec ) (in thr ) (c#s) (cu ft ) {cu fE ) (cu ft ) (#7''60) {A#C"#3} (C]ut# *#2) {#5-#6) 500 30000 318 0 29 115 9000 25 5 300 318 029 915 90 25 90 600 2 24 020 142 180 -38 15 900 1 77 016 160 270 -110 20 1200 1 45 013 170 360 -190 25 1500 121 0 19 175 45(] -275 30 1840 104 009 178 540 -362 35 210(} 091 008 181 630 -049 40 24(]0 082 0 07 185 720 -535 45 2700 0 74 4 07 987 810 -623 50 300[] 068 006 390 900 -710 55 3300 064 008 196 990 -794 60 3600 061 005 203 1080 -877 65 3900 060 005 278 1170 -954 70 4200 058 0 05 225 1260 -1435 75 4500 0 56 045 232 1350 -119 8 80 4800 053 005 234 7440 -1206 85 5100 052 005 244 1530 -1286 90 5400 0 50 005 248 1620 -1372 , 95 5700 049 004 256 1710 -1454 900 6000 0 48 004 264 1800 -`i 53fi QFt,AINAGE PC}Nd CALGULATlONS Grassy swa1Q'208' pond storage volume = Impervious Area x 5 in 1 12 En Ift = required 182 cu ft provided: 251 eu. ft vK! DRYWELL REQUfftEMENTS -10 YEAR DE51CN STORM Maximum storage by 8owstnng = required 25 cu ft pravided: 334 cu. ft ❑K! Number and type of drywel[s reqwired = 1 SIAIGLE 0 D❑UBLE DAVIII EVANS AND ASSOCxA'FES PRCIJECT KEY5TC3NE MEr4DDWS DESiGNER DDtlG BIJSKD, P E PROJEGT NO JTSDO(]04 OATE July 20, 2000 BAS1N R1 TiAllE QF CONCEAlTRATION (min) SurFace Areas "C" Tc (oVerland) Tc (gutter) Descnpfian (acres) Ct= 0 15 L2 = 5000 ACP 01001 090 Z1 ~ 5000 drivesisidewalks 00000 000 L1(A) ~ 000 Z2 = 017 lawnlfandsr.ap~ 00000 000 N(A) = 0 00 B= 1 50 earthen ditches 00000 000 S(A) = 0O n= 002 parkslplaygrnunds 00000 000 s= 0(]1 fforestlwgadland 000[30 000 TC (A)= 000 d (ft) = 009 meadcswlpasture 00000 000 ' d {in) = 1 az Total A comP „C„ 01001 090 L1(B) = 004 Tc (gu) = 090 N(B) = 0 00 7c(A+B) = 000 Q=C"`I"F1- 029 S(B) _ 000 fl{e5t 029 TC(tot 500 Tc (B)= 00 IntensEty = 318 A= 0308739 WP = 58371 R= 00529 V = 092 Tc (#ratal) ~ Tc (overland) + Tc (gutter) Tc(gu) = 090 Tc {crverland} =Ct"(L1"N15"4 5)^0 6) Q(est) = 029 Ct= 0 15 L4 = Lcngth o€ t3veriand FEaw Hording = 094 N= fnebon factor of overland flow ( 4 for average grass cvver) S = average slupe of orrerland flaw Tc (gufter) = Length (ft )Nelocaty (ft Isec )!BD B= 8ottom width of gutter or ditch ZI = inverse of cross slope one of ditch Z2 = rnverse of cross s1ope twv af d+tch d! dspth af fl4w in gutter (estimaie, Gheck estirnate with Flow) Area = d`B+cf"212'(Z1+Z2) Wetted perimeter= B`d+{l Isin{atn(11Z1)}+ 1lsin(atn(11Z2))) Hydraufic Radius = R = AreaMletted Penme#er Velacity = 7 486In'R" 667"S" 5 Ffow R Velactty'"Area n _ 016 for asphal# s= longitudinal sfope of gutter DAVTD EVANS AND ASSaCIA'I'ES BOWSTRING METEfOD (TEN YEAR 5Tt7RM DESICaN) PRO.lECT KEYSTQNE MEADOWS [)ETEIVTIC]hf BAS]N DESiGN PROJECT NC] JTSDDQD4 BA51N R2 Nl1M8ER OF DRYVlIELLS PRC}P(J5E❑ ❑ESIGNER bC}UU BUSKO, P E 9 Single (tYpe A) Q Dauble {tYpe B} DATE ,luly 20, 2000 Tvta6 Area (calc ) (see H1) 005 TErne of Cor►c (caIc ) (see Hl) 500 Compnsite "C° (catc ) (see H1) 090 Yirtae of Conc (min) 5 00 Rrea (Acres) 00547 C' Factar 090 Impervious Area {sq ft} 2356 596 1,dolume !Provided 208 131 storm 174 Outflflw {cfs} 03 Area * C" Factor 005 #1 #2 #3 #4 #5 #6 #7 Time Tirtze intensity Q dev V tn V out 5torage Cnc Inc {rnin y (sec ) (in ehr ) (cfs) (cu ft ~ (cu ft ) (cu ft } 1 *60) 4A-c-#33 (ourf *#z) (~5-#6) 500 30000 318 015 62 sa aa -28 5 soo 318 015 62 ga -zs 10 600 224 Q 1'1 77 980 -103 15 900 1 77 009 86 270 -1841 za 1200 145 007 92 360 -268 25 1500 121 006 94 450 -356 30 1800 1 04 005 96 540 -344 35 2100 091 0 D4 98 630 -532 ao 2400 082 004 100 720 -620 45 2700 074 004 141 810 -709 50 3000 068 043 103 900 -797 55 3340 064 003 706 990 -884 60 3500 4 61 003 110 1080 -970 65 3900 BO 003 117 1170 -1053 70 420(} 4 58 003 129 1260 -1139 75 4500 0 56 003 725 1350 -1225 80 480[} 053 003 126 1440 -1314 85 5100 0 52 003 132 1530 -9398 9{] 5400 050 002 134 1620 -7486 95 5700 049 002 138 9770 -1572 100 6000 4$ 002 143 1800 -1657 DRAINAGE P4ND CALCULATIDEdS Grassy swaie'208' pond storage volume = Im,psrvious Area x 5 m 112 m Ift = requiced 98 cu ft provided: 131 cv. ft OKI DRYV+JEL!L REQl9{REMENYS - 90 YEAR ❑E51GN STORM o Maxemum st+orge 6y BowsirEng = r+equired -28 cu ft pravided: 974 cu. if. DKl' Number and type ot dryvvells required ~ 7 SINGLE 0 oouBLE DA'VII] EVANS AND A55OCYA"TES PRQJECT KEYST+ONE'MEAat3WS DE51GNER OC]lJG 6USKD, P E PROJECT Na JTSd7O004 DATE July 20, 2000 6ASf{V RZ TIME OF COfVCENTR4'FIUN (min) 5urface Areas "'C' Tc (overland) Tc (gutter) Descnptivn (acres) Ct = 015 L2 = 50 00 ACP 00541 090 Zl = 5000 dnveslsidewalks 00000 000 L1(A) _ 000 7-2 = 017 lawnlfandsr-ape 00000 000 IV{A} _ 000 B= 1 50 earthen ditches 00000 000 S(A) _ 000 n = 002 parkslplaygrounds 00000 000 s= 001 fQrestlwoodland 00000 000 Tc(A)= 000 d(ft) = 006 rneadowlpasture 00000 0(]0 d (in) = 0.74 Tota1 A Camp "G" 00541 090 L1(8) _ 000 Tc (gu) = 1 OS N(B) = 0 00 Tc[A+B) = 00(] Q=C'`I*A= 0.15 S~~} = 000 Q(est ) ~ 015 Tc[tot } = 500 Tc(B)= 00 fntensaty = 318 A= 0189427 WP = 46635 R = 00406 1!= 078 Tc (tata1) = Tc {ouedand} + Tc (gutter) Tc(gu) = 1 OB Tc (oV$iland) = Cif*(LI "~/SnQ 3)^0 6) ❑($St) = 015 Gt= 0 15 L`S = Lcngih af Overland Flow Haldmg = 094 N=frictiarr factor of overland flaw ( 4for average grass cover) 5= average slcape mf overland flaw Tc (gutter) = Length (ft )lVelocity (ft Jsec )ISD B= Bottom width flf gut#er ar ditch Z1 = rnVerse of cross slape orae af ditch c 2= inderse a# cross slope twn of ditch d = depth of flaw in gutter {estrmate, eheek estimate with FPow} ►4rea = d*B+d ^212*(Z1+72) Wetted perimeter = B*d+(1lsin(atn{11Z1 )}+11sirt(atn{1fZ2})} Hydraulic Radius = R = RteaMJetted Penmeter 4'elvcity = 1 4861n`R" 667`s" 5 Flow = Velocity'Area n= 0 016 for asphali 5 = Iongitudmal siape of gutter i TAAVID E'ifANS AlYD ASSOCIATES Bt]WSTRING METHOC] (TEN YEEIR aTORM DESIGN) PROJEGT KEYSTQIVE MEADUINS ❑ETENTIC3N BpSIN DESIGN PROJECT NO JTSd0004 BASIN ►4 NUM6ER OF DRYWELLS PRUPDSE❑ ❑ESIGNER dO1JG E3LJSKQ, P E I Singfe {rype ►4} Q Double {type B} DATE Jufy 20, 2000 7crta! Area (calc ) (See H 1) 154 Time of Gonc (ca€c ) (see H'! ) 500 Composrte "C" (calc ) (see 1-11 ) 040 Time af Conc (min) 500 Area (Acres) 9 54 18 C'Factor 040 Imperviraus Area (sq ft) 67160808 Wo1ume Pravided 208 1505 storrrl 2305 Outfilovsr (cfs) 03 Area " C" Factor 062 #1 #2 #3 #4 #5 #5 #7 7ime Time lsntensity Q dev Uin V csut Storage Inc Ine {min 7 (sec ) (in Itrr ) {cft} (cu ft) {cu ft y [cu ft } (#9 "80) (A'C"#3) (Outf *#2) (#5-*6) 500 30000 3 18 196 788 9000 698 5 300 318 196 788 90 698 10 600 2 24 1 38 970 18[] 790 15 900 1 77 109 1094 270 824 20 1200 1 45 089 1164 360 804 25 15[]0 1 21 075 1995 450 745 30 1800 1 04 064 1220 540 680 35 2100 091 056 1236 630 sos 40 2400 082 0 51 1265 720 545 45 2700 074 046 1279 810 469 50 30(}0 068 042 1301 900 401 55 3300 064 039 1343 990 353 50 3E40 fi1 038 1393 1084 313 65 3940 060 0 37 1481 1170 311 70 4200 ❑ 58 036 9539 1260 279 75 4500 056 4 35 3589 1350 239 80 4800 53 033 1602 1440 162 85 5100 0 52 032 1668 1530 138 90 54470 4] 50 1] 31 1697 1620 TT 95 5700 0 49 030 1753 1710 43 100 6000 048 030 1806 1800 B pRAINAGE PONfl CALCQ1LATIaNS Grassy swale'208' pond storage volume = lmpenraaus Area x 5 rn 112 m ift = required 323 cu ft provided: 10& cu ft b.,,,58 OKI DRY►JVELL REQIJIREMENTS - 10 YEAR DESIGN STC3RM , C3 SL). Maximum storage by 6rswstring = required 824 eu ft pravided: 2305 cu. tt. OK! Number and type of dryvveCfs required = 1 SlNGLE 0 DOllBLE DAVT13 EVANS AND ASSDCIATES PROJECT ICEYSTCINE MEADOWS 0E51GNER DC7UC, BUSKQ, P E PRC3JECT NO ,lTSDO044 DATE July 20, 200(] BA51 N ►4 TVME OF COfVCEIdTRATION (min) SurFace Areas "G" 1`c (averland) Tc (gutter) pescrrpbnn (acres) Ct = 015 C.2 = 3620I3 overall basin 1 541 8 040 , Z1 = 0 33 dnveslsidewalks 00000 000 L1(A) = 000 Z2 ~ 033 lawMandseape 00000 000 N(A) = 000 B= 200 earther+ ditches 00000 000 5(►q) _ 000 n= 003 parkslpEaygrounds 40000 000 5 = 001 foresUwaodland 00000 000 Tc (A)_ 000 d(ft) = 0 53 meadowlpasture 00000 000 d(in) ° 636 Tataf AComp "C" 15418 040 L9(8} _ 000 Tc (gu) = 3 57 N(B) = 000 Tc(A+B) = 000 o=c•i*A- 1 ss S(B) = 000 Q(est ) = 195 Tc{tot } - 500 T'c(B)= 00 Intensrty = 318 A= 1 152697 , V1IP = 3 1 t62 R = 03699 V = 169 Tc 4totafy = Tc (averland) +Tc (gufter) Tc(gu) = 3 57 Tc (overland) = ct*(Ll•NIs^a 5)^o 67 Q(est) = 195 Ct=0 75 L1 = Length af Overland Flow Halding = 6 30 N = frrction factflr of averland flavu ( 4 for average grass coVer) S= average slope af overiand tlow Tc cgu#ery = Lengtr, {i# }/VelQcity (ft eseC )/st] B = Battom width af gutter or ditch ZI = enverse of cross slope one of ditch Z2 = inverse af cross sfope iwa af ditch d= depth of flvw in gutter {estirroate, check estimate wi#h Flow} Area = d`8+d"2/2*(Z1+Z2) Wetted perameter= B*d+('Clsin(a#n(11Z1))+l/sin(atn(1lZ2))7 Hydrau!« Radius = R = ArealWe#ted Penmeter Velocity = 1 4861n*R^ fifiT+S" 5 Flouv = Velocrty"'Rrea n = 0 015 fcar asphaPt s= IDngitudinal sla,pe of gutter i)AeVID EVANS ANl7 ASSflCTA1"ES B[7WSTRftiG METHOED (TEN YEAR 51'+ORilll DESIGN) PRQJECT KEYSTflNE ME4DOW5 ❑ETEAITION BASIA1 aE5lGN PROJECT NO JTSDO004 BAS1 N B NUMBER C]F DRYWELL5 PROAQSED C]ESfGNER DDUG BL15KD, R E 9 5ingle (tyPe A) a Double (type B) C]ATE July 20, 2000 Tfltal Area (Galc ) (see H1) 150 Time vf Conc [calc ) 4see HI} 500 Composite "C" (calc ) (see H 1) 040 fiirne of Ganc (mira) 500 P,rea (Acres) 14974 C' Factor 040 IfT1pefVIQGS IgfEa (5q ft) 65226744 VC11Ufi1e Prf]Wided 1348 StOff1'1 2064 QfJtflC1W (CfS) 03 ' Area " C" Factor 060 #1 #2 #3 #4 #5 #6 47 Tirr7e 7rme Intensity Q dev V in V Qut Starage Inc Inc (min ] (sec } (in Ihc ) (c€s) {cv ft ~ (cu ft] (cu ft ) (#1 -60) (A*c*#3) (outf '#z) (#5-#6) 500 3000a 318 1 90 766 9000 676 5 300 318 1 so 766 90 676 10 640 224 9 34 942 180 762 15 9[}0 1 77 1 06 1062 270 792 20 9200 1 45 087 1131 360 771 25 1500 1 21 0 72 1161 450 711 30 1800 1 04 062 1185 540 645 35 2100 91 0 55 9200 630 570 40 2400 082 049 1229 720 5(]9 45 2700 074 044 1242 810 432 50 3000 068 041 1263 900 383 55 3300 064 038 1304 990 314 60 3600 061 37 1353 1080 273 65 3900 050 0 36 1438 1170 268 70 4200 058 035 1495 1260 235 75 4500 0 56 034 1544 1350 194 80 4800 0 53 032 1555 1440 116 85 5100 4 52 0 31 1620 1530 90 94 5400 050 030 1648 1620 28 95 5700 049 029 1703 1710 -7 10(] 6000 048 029 1754 1800 -46 ---------__~~__________________.~.._...~.~..___-----____ee~____e~_e~_~t___---- ------------a ❑RAENACE PDIVD CALCULATIDNS Grassy swale`208' porrd sforage volume r lmperviaus Area x 5 in 112 in Ift = required 256 cu ft pr4dided: l348-cu. ft.j>.e-sg~ OK! DRYWELL FtEG2l9IREMEIJTS - iQ YE4R DESIGId STORM it v 99 Maxrmum 5torage by Bowstring ~ required 792 cu ft prorrided: 2064 cu. f#. QK! Nurriber and type af dryvs►ells required = I 5[NGLE - 0 DDUBLE ~ nAVin EvANs AvD AssocIATEs PROJECT KEY5TQR1E MERDOWS aESIGNER DOiUG 8U51tC7, P E PRC}JEGT NC3 JTSDQ004 QATE JG1y 20, 2000 BASfN B TIME C3F CDRfCENTRATIVN (mm) Surface Areas "c" Tc (overland) Tc (gu#ter) Descriptifln {acres} Ct = 015 L2 = 44600 averall 6asin 14974 040 , Z7 = 0 33 driveslsEdewalks 00000 000 L"d(A) = 000 7-2 = 0 33 lawnllandscape 0(]000 000 N(A) = 000 B= 200 earthen ditches 00000 000 5(A) _ 000 n= 03 parkslplaygrounds 00000 000 - S = 001 forestNuoadland 00000 000 Tc (A)= 000 ti (ft) = 052 meadonrJpas#ure 00000 000 d(in) = 8.24 Total A Cornp "C° 1 4974 0 40 L1(8) _ 000 Tc (gu) = 4 44 N(B) _ 00 Tc(A+B) _ 00 Q=C'i*A= 7.90 5(B) = 000 Q(est 1 89 Tc(tflt } = 500 - Tc (B)W 00 Intert5ity = 318 A= 1 129232 ~ WP = 30952 R = 03648 V= 168 Tc (tatal) = Tc (averland} + Tc (gutter) 7c{gu} = 4 44 Tc (overland) = Ct"(L1"NIS"0 5)40 6) Q(est) = 189 Ct=015 L1 = Length af OverEand Flow HoEding = 7 76 N= friction factor af overland flaw { 4 for average grass cover} S= average slope af overQand flaw Tc (gutter) = Length (ft )IVePocity (ft fsec )160 B=Bottam width of gutter or ditch Z1 = inverse of crass slope vne of ditch 7-2 = Enverse of cross sEape two of ditch d= depth of flow in gutteE (esdrrtate, check estimate with Ffow) Area = d'B+d "Zf2'{Z1 +Z2} Wetted penmeter = 8`d+{11sin(atn{iiZ1 )}+11sin(atn(IIZ2))) HydrauitG Radius = R= AreaAWetted Perimeter Velociry = I 486fn'R" 657*5" 5 Flow = Velociry"Area n = 0 016 for asphalt s= loragitudrraal sl❑pe ot gutter DA'VID EVANS AND A,S5[3CIATES BQWSTRING METHOd (TEN YEAR STORM DESiGN) PRdJECT ISEYSTONE MEAE]OW5 DETEIVTE[7N BASIry flESfGry PRC]JECT IVD .iTSOD004 BASIPI c N4JMBER OF DRYWELLS PRQPQSEQ DESIGNER a❑EJG BLJSKO, PE 1Stngle (type A) 0 boubGe (tyPe B) DATE July 2[], 2000 Tota! Area (cafc ) [see Fi1) 1 37 Time of Corae (ca[c } (see H1) 500 Compvsite "G„ (calc ) (see HI) 040 7ime of Conc (min) 5 00 Area (Acres) 13718 G' Fac#or 040 ' 1rnpervious Area (sq ft ) 59755608 - Valume Provided 208 1820 storm 2787 Outflaw (cfs) 03 Area " C° Factor 055 #1 #2 #3 #4 #5 #6 #7 Time Time lntensity Q dev V in V out Storage !nc Inc {min ) (sec y (rn !hr ) (cfs) (cu ft ) {eu ft y {cu ft ~ (#i "60) (A""C'"#3) (Oui#'#2) (#5-#6) 500 30000 318 1 74 701 9000 611 5 300 318 974 709 90 691 10 600 2 24 123 863 180 683 15 900 1 77 0 97 973 270 703 20 12(]0 1 45 080 1036 360 576 25 1500 121 066 1064 450 614 30 1800 1 04 057 1085 540 545 35 2100 091 4 50 1900 630 470 40 2400 0 82 046 1126 720 406 45 2700 074 041 1138 810 328 50 3000 068 037 9157 900 257 55 3300 064 035 1195 990 205 fiQ 3604 061 033 1239 1080 159 65 3940 060 033 1318 1974 148 ' 70 4200 0 58 0 32 1369 1260 149 75 4504 056 031 9414 1350 54 80 4800 053 0.29 9426 1440 -14 85 5100 0 52 0 29 1484 1534 46 90 5400 050 027 1510 1624 -910 95 5740 049 0 27 1560 1710 -1 SD 100 6000 048 026 1607 1800 -193 DRAINAGE POND CALCLILRTIONS Grassy swafe'2D8' pond storage valume = Imperviaus Area x 5 m 112 in 1#t = required 316 cu Fk pGUvided cu, fEQ.,,:~,3 Ult! DRYWELL REQUIREMENTS - 10 YEAR pESfGN STL3RM , l MaximGm stcarage by Bowstring = reqGired 703 cu f# pravided: 2787 cu. ft. QK! Number and type af drywefls required = 1 SfNGLE 0 DOUgLE , DAVID E'VANS AND ASS[3CIATES PROJECY KEYS`~ONE MEADQWa DESIGNER DDUG BCJ ;Kp, P E PRQJEC7 NO JTSD0004 DATE Jufy 20, 2000 BA51 N G TVME OF CaNCENTRATlQN [min] SurFace Areas °C° Tc (ovecland) Tc (gutter) DescnptEan {acres} Ct = 0 45 L2 = 360{lp overall basin 1 3718 440 Z1 = 0 33 dnveslsrdewalks 00000 000 L1(A) _ 000 72 = 033 lawnllandscape 00000 000 _ N(A) = 000 B= 200 earthen ditches 00000 000 ' S(A) _ 000 n= 003 parkslplaygraunds L10e(l 000 s= 001 fforesthvoodland 0000(} 000 7c (A) = 0(}0 d (ft) _ 049 meadcrwlpasture 00000 0 00 d (in) - 5.88 Tatal A Comp "C„ 13718 040 L9(B) = 000 Tc (gu) = 3 69 N(B) = 000 Tc(A+g) = 000 [1=C*I*A= 1.74 S(B) = 000 Q(esc ) _ 172 rc(tot ) = 500 Tc (B)= 00 rntensrty = 318 A= 9059233 'I1VP = 30320 - - F2 = 03494 U = 163 7c (tfltal) = Tc (overlarrd) + Tc (gutfer) Tc(gu) = 369 Tc (vr►erland) = Ct"(L1 *N!S"0 5)110 fi) Q(es#) _ 1 72 Ct=d15 Ll = Length of C3verland Flnw Holding = 6 26 N= friction factor of overland flaw {4 for average grass oover} 5 = a+rerage slope of ovedand flow Tc (gultter) = Length (ft )IVelQCit~ (ftIsee )160 8 =$ottorn width af gut#er or drtch Z1 rnverse of crQSS slfl,pe vne flf drtch Z2 = inverse of cross slope turo of ditch d= depth of ftow m gutfer (estimate, check estimate ►rvith Flow) Area = d'B}d4212*(29+?'2) wettea ~~nmeter = e#d+(l Isfn (~tn(l rZl))+I rsin(atn(l rr.2))) Hydraulec Radius = R _ Areal'Wekted Penrneter Velocrty = 1 486fn`R" 667's" 5 Flcsw = Velacq'Area n= D 046 for asphalt s = lartgitudinal siope of gutter Appendix C Post-Developed Basin Map otitstapidipig , , Otitstatiditig • DAV1D EVANS AND ASSOCIATES, ~ , DRAINAGE REPC]RT Keystone Meada►rvs Su~~~~~ ,,T Spokane County, Washangton SPOKANE GauNT't ENGIs~EER`s OFFlM ~R~~1NAL , Ec~ P~ ~ ~UBM,TTAL # RECEIv~~ Au~ ~ ~ ~~~O FE-~~ ~O COUNW ENGINEM RECE~~~~ SpOMNE COUNTY E~~N EER Prepcrred far JUL z 1 2000 JTS Deuelvpment sROKANFCOUNTY ENGINEER 4029 S Terra Verde veradale, Washirrgtorr 99037 ~ w D ~ 4 DEg Projecr No JTSDOqaO-0004 ~ DEP! ~1 e~o `i`HE I3ESIGN IMPRQVEMENTS SHClWN IN 7'HIS SET OP PLANS CONFC}RM TO THE Al'PL1GA8LE EDITIDNS iJF'TITE SPOKANE GQUNT'1' STANDARDS Ff7k ROAD AND SEWER CONSTRUCTIDN AM] THE SPOKANE CDUNTY GUIIfELINES F[]R STC3RMWA'TER MAWAGEMENT ALL DESIGN DEVIATIC]Pd5 MAVE BEEA1 APPROVED BY THE SPOKANE CflUNTY ENGINEER I APPRaVE THESE PLANS FQR CQNST'RUCTIQN Jtily 20, 2000 m I3AVID EVANS AND ASSdCIATE5, ~ I. ~ S P O K A N E ~ C O U N T Y DIVISION OF ENCINEERING AND ROADS A DMSIQN OF THE PUBLIC WORKS DEPARTMENT Wi1Lam A Johns, P E, County Engmeer July 28, 2000 Doug Busko, P E David Evans & Associates 101 W Cataldo Spokane, WA 99201 SUBJECT: - Keystone Meadows 15' Submittal Gentlemen: We have conducted a cursory review of your July 20, 2000 submittal of Design Documents for this project, and we have found that the submittal generally does not conform to the requirements of the Spokane County Standards for Road and Sewer Constructton or the Guidelines for Stormwater Management. We are, therefore, unable to accept your submittal for review at this time The attached comment list contains the items of concern wtuch we discovered, and rt is not to be construed as being comprehensive. If you have any questions about this review, please contact Ed Parry at 477-3600. Thank you. Smcerely, William A. Johns, P. E. Spokane County Engineer a, waz J. , P.E. Plan Review Engineer encl - Design Documents - plans Comments (1 page) cc project file reviewer (comments onty) Sponsor Gerald Stolp, JTS Development, Inc , 4029 S Terra Verde, Veradale, WA 99037 1026 W Broadway Ave o Spokane, WA 99260-0170 •(509) 477-3600 FAX (509) 477-7655 (2nd Floot) 477-7478 (3rd Floor) • TDD (509) 477-7133 [ ~ i ~ Doug Busko, P.E. P1860 - Keystone Meadows 1" Submittel July 28, 2000 Page 2 of 2 Items needed: 1) Developer signature should be included on future submittals 2) 4`hAvenue a) Need to provide CL station & offset callouts for drywells b) Need to provide CL station & o$'set callouts for culvert c) Inbound tapers aze typically 10:1, 100' minimum d) Does the outbound taper meet AASHTO requirements for a"shoulder taper"? 1995 Collector in Flat Tenain Design Speed ("S") = 40 mph e) New location for ex. Sign at 7+60 should be shown on plans fl Sawcut line and ACP to be replaced needs to be coordinated with the road detail 3) Private roads: a) Need to show swale floor Limits, as for 4`bAvenue b) Will need check dams to develop 208 Volume. Swales are considered "flaY" if both the length is less than 100 ft and the slope is less than 1% c) Need to provide CL station & offset callouts for drywells d) Need to provide CL station & offset callouts for culverts e) Culvert at 3`dLane sta. 11+15 should be indicated in profile. Is the cover over this CMP adequate for not only the normal passenger car traffic, but aiso the expected construction traffic? CMP typically requires 2 to 3 feet of cover, depending on the bedding classification fl Floor elevations should be provided at drywells g) Sgot etevations should be provided at selected points on the edge of pavement & in the roadside swale (e.g., drainage break point at 2`dLane sta. 12+19 RT) 4) Road Details a) 4t° Avenue • i) How was the M, value determined for the pavement section design? AASHTO design method requires that actual samples be taken for some sort of testing. Data from samples taken should be included with the next submittal u) Sawcut line needs to be coordinated with the road plan 5) Drainage Calculations a) Swale volume for 208 treatment (along pnvate roads) needs to be adjusted due to the length of the swale. It may be that this can aL,o be resolved with a detail for the dnveways along the private roads 6) 208 Lot Plans: A section detail is needed for each Lot's Plan ' ~~bmittal Check1iSt far Road & Drainage Projects in Spnkane Cvunty -Platsl5bort P1a#s This ,Su6mrrtal Checklrst is tQ be eompleled unrl sigrted b,y dhe Spartsar's Lnganeer, and ancludea' wath each p1an ,su$matlal rntv the Spvkune Couraty Engrneers Office If thrs forrn rs not fully cQmp[eled and srgned, do not sub►nrt pdans arrd ccrdculateans to Spokmre Counry for revrew crnd acceptance Incampdete submrlluls wrll he returned and tivrll cause unnecessary deluys for your clrenl Praject Name Spvkane County Prnjeci No ~tp -o - `3 1B Date 7-~c - CuD Project Engineer- 73L^~S KAD. P. C-=: . Phone .?2 - &!,o `l 7 Project Spansor ST-41It. -1=1 Fhone .92 4-Z-z4~9 A. Preliminary I'rocess Przor to Submittal of Road and I3rainage Plans, the fall❑wing events are to have aiready gccurred (By checkrng ersch rlem vff shawn belon; ycru rlre staterrg 1hat you hwe verafeed these eventslrtems have beQn completed) ~ ~Adoptaan of a Hearing Examiner's Report for this long plat, or a Planning Report for this short plat S' ~ At ieast one Fre-Design Meeting has been held wsth Caunty staff at the Engrneers Qffice An "Agreement to Pay Fees" has been signed by the project spansflr, and submitted ta the Gounty Engineer5 Dffice As ChanneEixation Plan {e g sign9ng and striping plan} of public roadway improvements, has been ,,sIIA,, coordinated and discussed with the Cnunty Engineers Office B. Raad and Drainage Plan Subxnittal The items listed bela►a aee ta be provided as a mincmum with a road and drainage plan submittal Additsanal informatian may be required to demonstrate that the plans meet all apglicabTe staRdards (By checking ` yes " far Each rdem sFrnwn beTow, yau crre verifyrng that these adems have beera cornp[eted cr,nd are rneduded rn thr.s submrtza! For arry box checked "rrJa a wrttterr Jus1 fcation af aray vmrssron.s at the end of th►s sectran rs requrred) Item ]Desrription vyes Road and drainage plans, two print sets (Certificatzon staCement on coaer of plans) 0 yes +aN M'rLAX Each Plan Sheet of recard is sagned and dated by thc praject sponsor gll-yes Ths raad and drainage design meets the requirements of State law, WAC 196-27 regarding "conformity witih accepted standards", that is, the design reflects the "state of the practice" for the proposed concept Vyes The plans, ❑rainage ReporC, basm map(s), and any ather calcuiatians are stacr►ped, signed and dated by an engineer licensed en the State of Washington R"°y+es 0 nla I3rainage Report, twa sets To inctude: basin rraap(s), time of concentration routes en basin map, and Certification statement on couer of repcsrt and basin map Q yes EKnla Geotechnical R,epart, nne set (include a11 sail test pxtlbnring ings } 9'yes 0 r/a Siructural Pavement Caiculatiaras, ane set R'yes Q nla Cross-slope grade calcu2a#ians for rolid widening projecfis 0 yes 5rnJa Maintenance Manual and 5inking Fund calculations fot drainage facilitzes located outsade ~ ~ . of County road nght-of-way 6'yes 0 n/a Written explanation of who/what entiry will be responsible for maintainmg drainage facilities which are located outside of public road right-of-way, and that the plan is acceptable to the County Engineers Office /k Aac3--c.. Ar 7;,•e,-_ ,V p%.,a--. B'yes 0 n/a Channelization Plan, or signing and striping information provided m the road plans. To be included in road and drainage plan set Vyes 0 n/a 1 have read the Hearmg Examiner's Report (long plat), or Planning Dept Findings and Conditions (short plat), for this proJect. The design meets the conditions in the report 0 yes Vn/a Copy of Approved Design Deviations 9ryes 0 n/a Fire District Approval, for pnvate roads 6Kyes 0 n/a Lot Plans Required for any lots with drainage easements and which front a public road, or ~ for lots which receive and treat runoff from a public nght-of-way 0 yes fYn/a Any applicable State and Federal perm►ts have been obtained (i e HPA, JARPA, etc ) For Permits with conditions, a copy of the permit and conditions are included m the plan submittal 9ryes 0 n/a Inspection Agreement between the sponsor and its engineer /N Sc.opts oF _<gazvVc+ess ~ 0 yes B~n/a For off-site easements to be granted to Spokane County, the following items shall be included legal description, exhibit, and proof of ownership U yes B'n/a Erosion Contro) Plan, required for "MaJor Land-Disturbing Activiry " To be included in the road and drainage plan set Explanation for any ►tems listed above which are not included in this submitta) (Note an insufficient justification of why an item was not included m the submitted, or mcomplete documents, may result m the submittal being returned without review or without acceptance Provide attachments if necessary ) By signing below, the engineer is stating that the information provided in the submittal is complete, that the tnformation provided in the Submittal Checklrst is accurate, and the plans and calculations are in accordance with the Spokane County Standards jor Road & Sewer Constructron, and the Gurdelines for Stormwater Management, except where approved Design Deviation allows otherwise Engineer's Signature ~-z,&:, Date _ 7.?o - ao Engineer's Name 6_ (ptease print) IJ there are any questions about this form or approprrate procedures, please call Development Services, Spokane County Public Works, at (509) 456-3600 For Spokane County Use Only Submittal No ~ County Plan Reviewer Accepted in for Review e ~ Returned to the engineer without , See attached letter of explanation. Processmg Date: Submittal Checklist 2 Spokane Counry Public Works, Apri129, 1998 DRAINACE REPORT Keystone Meadvws Subdir►ision Spokcme Courtty, LYashrngton p (tlo 0 I"API RECEIVED Prepcra ed for Jul 71 ?~~o~~ JTS Development ~~OKANE CouNT~ ENG, =[R 4029 S Terra Verde Yercxdale, Washrngton 99037 ~ 7- DEA Project No JTST]D444-4404 I "W'=0V THE DESIGN iMPRC3VEMEN'TS SHOWN IN THIS SET QF PLANS GDNFORM Ti] TTiE APPLICABLE EDITIONS OF THE SPOKANE COUNTY S`1'ANDt1RD5 FQR ROAD AND SEWER CQNS'FRUCTIdN AND TCIE SPC3KANE COUNTY GiJIDELIAIES FOR STORMWA'TER MANAGEMENT AI.L DESIGN DEVIATIONS HAVE HEEN APPRC]VED BY THE SPQKANE CdUNTY ENGINEER I APPROVE THESE PLANS FQR GDNSTALTCTFdN Jtikly 20, 2040 [ • UAVII] EVANS ANI] A55OCIATES, ~ s ` p Kane uaurrry rngineers Project eys ormeacfvw5, 07-M ' W 1428 Broadway Hve 477-3600 Joh Plv JTSpO004 Spokane, IiVA 59280 E7isc No File Name JTSC74 Curh Grade TYPICAL SEC710N DATA 26-Jran-40 Rvadway half wadth ENTER-a 145 02 21 pM Road Name ENTER- 4th Avenue Left or Rfght ENTER- LeR Curh Type B Stativn Cnterval ENTER--s Varies Curb EL Curb EL Edge Pave GENTER °!n 5LIJPE EDGE D157 % SCC3PE EpGE B18T FRDM (45°/0 ° (-2 /o #u C;utter LIlJE GEN TER- PAAIEMENT CIL T[? C!L TQ PAVEMENT EL7GE F'l/Mi' fram E1P + FROM E/P + SELECTECI Clesign Top Curb StATIaN IELEIAA7IDN L1NE ELEVATfQIV EIP EL1GE PAIAIE °k 5L[3PE TOGIRTER FACE C[JRS HGT} CURB HGT] ELEV 56 GlaADE % Grade 50093 836 527 10 8 29 -027 814 600 -250 3110 8 50 8 14 836 8 31 -2 53 552 71 8 29 000 8 13 600 -267 -0 D4 8 50 813 9 35 8 18 -394 -0 51 577 70 8 30 004 812 6 00 -3 0Q -0 f)4 850 8 12 8 34 8 31 -2 29 052 603 07 8 32 006 812 600 -3 33 -0D2 8 50 812 83.4 $ 18 -3 82 -051 628 82 834 008 8 47 600 -283 019 8 58 817 8 39 834 -2 53 0 62 654 15 836 008 8 20 600 -267 012 8 50 8 24 8 42 8 21 -3 4 t -051 878 80 841 0 20 824 600 -2 88 016 8 50 824 846 8 44 -2 fi 8 093 703 88 842 004 8 29 600 -2 17 020 8 50 8 29 8 51 8 31 -4 29 -052 73107 846 [7 95 8 33 600 -2 17 013 850 8 33 8 55 $ 51 -2 41 074 756 44 8 42 -09 6 8 32 600 -1 67 -004 850 8 32 8 54 8 37 -3 94 -4 $5 781 89 8 45 012 8 33 600 -2 00 004 8 50 8 33 8 55 8 52 -2 29 0 59 807 ifi 8 48 4 12 8 36 600 -3 04 -0 12 8 50 8 30 8 52 9 35 -3 94 -067 832 12 843 -0 Zf7 8 27 fi va -2 6T -012 8 50 827 849 8 48 -206 0 52 85633 8 37 -025 8 24 6 DO -2 9T -412 8 50 824 846 8 38 -3 12 -050 88082 840 012 8 23 600 -2 83 -0(34 8 54 8 23 8 45 823 453 -053 OFF1C1A1. P1J8LiC DQCUWENT ` SPOK;NE CC3UINTl' EAiGhiEER`S OFFi~~ 0 rr-i'l ~~~AL RECEIVED PRcJb cT# ~ ~ J I~ ~ ~ s(~~. I~,~~. # RETU -FN TO C7UNTY ENG!NEEW SPOME COUNrr ~ i FEexible PaVernenf Design 4th Avenue Improvements Keys#one Meadaws Subdivision, P-1860 ESA'L Factor ESAL Va[ue Reliahdity, R- 90 AaT 15601 000081 456 ESA1. Value =(ADT)(ESAL Facfor)(365 days) Std Devaat[on, S= 045 Trucks (°h) 1 51 0421 3,587 ESAL Value =(A[3T}(ESAL Factar)(% vf traffic){385 days} Resdsent Modulus, M= 10,000 Schaol Bus(°!o) 0751 287 8,044 ESAL VaPue r(ADT)(ESAL Factar)[% af traific](180 days) Init3al 5errr (psi), po 4 2 5TA Bus (°fa) 4l 257 QESpL Value _(AaT)(ESAL Factar)(°/o of traffie)(365 days) Termina15ervv (psi), pt= 25 Refuse Truck 0 131 1 431 536 ESAL Value =(ADT){ESAL Factar)(% af traffic)(260 days) Design SCTV . Po Pt= 17 Grow'th Rate g= 3 0 Annual ESALI 10,6231 Design Year, t= 20 Design ESALI 285,4321 Design ESA L-j[(1+9)'-1]1g]fAnnual ESRLl Required StV=1 2 51 5ee atfachednorrragraph a1= 042 ACP Depth (in). D 'f = 4 0 Design SN=~ 251 Design SN=a I *D f ta a'Da`m 2 +a9'D3"fra3 a2= 0 14 C57C aepth (in), D2= 60 23= U CSBC Depfh (in), D3= 00 m2= 095 ~ C: m ~ rn3= Q p ~ ~ ~ M rn M p~ C) 5~ ° ~ m rr,~ ~ m C=> m ~ m Pn David Errans and Associates, lnc ~ S lengrljtsdQb04lF'vmt_design xls Spokane, Washington 6RI00 ~ w ~ NOVDGtAM SOWES: A PSI 1~ 4.~ - 1.5 ~~].0 18 = Z g*Sfl+ 9.3s*io410(~1) - o.ZO + 1~~ - + 2.32*loqYO~t - 8.07 105r4 0.40 f 5.19 cs~+iti TL ~ n TL E []esign 5erviCenbrlity LDSS, ❑P5i 2 g ~fl a v p~ 40 I I I ~ Y (I3 s ~ .02 $O ` - - - . v~ ry D A V1 ~ I a Js *~a ~Q Z 10 QQ a 3 { - 0° n ~',I.!'; ~ I 1 ~ I ~ 1 I I_ cc ~ w y ~ I ~A f I I a 90 6 05 W ~ - - - 80 Hi 70 r -60 Exompla t x o I ~ 50 WIlt 5 x 90$ 9 s x s s r 3 '2 y ' R 95 n/o Desrpn 5tructura! Numb r, 5N ~ ~ 5O=035 ~ M~ = 5000 psj ppSi - 19 ~ Sotutian: 5N = 50 ~ n Figure 3.1. Design Chart f+or Flexible Pavements Based on Using Mean Values far Each Ingut ~ y c~ R ~ !v-~~- ~so t ~ .~~~,.4 ~-~~,~•r ~'~'.~~YY~r.~~ ~~.r~~~ ~ DAVIr~ ~~ANs AxD ASsOcIATEs, T R A, N S M I T T A L Wat 310 Cautuo ~ rO BiIl Hemmings, P E VSD sp&am Washmgw 99207 ~ Spokane County Engmesrs spa~~~ ~outvr TcL 509327 $697 F- 509327732i5 0,4TE ,July 21, 2000 FRoM Doug '8usko, P E PROJECT Keystone Meadows, P-1860 RRoJ # .lTSDOOQa-0004 ITEM C.f}P.IE5 I]'A`TEx RaF~Til~N 1 2 7121100 Road and arainage Plans, and Dramage Repart 2 1 7121100 Subrnitfia4 Checkl3st, Pvrnt Calcs, Curb Calcs, Fa Approval, Insp Agreement ~ AS YOl3 REQUESTED E FOR YDUR APPROIIAL ❑ RETURN REQLlESTED Ej mOCLJMENT CON7ROL ~ FOR YCIUR INFt3RMATION E FOR YOUR REVIEW Q GC]MMENTS Bill, Attached are the rgad and dramage pians fQr this project, along with the drainage report anr] the necessary paperwoe'k Please review and comrnent as necessary, and lei me know ifyou have any quesfiions Thanks, doug Buska, P E . ■ Qiiality 5lengrtjtsd40G41wortlltransmittal tn hemmmgs doc m ~ TABLE OF CONTENTS ' I. PROJECT DESCRIPTION .......................................................................................................1 A Introduction 1 II. HYDROLOGY ..........................................................................................................................1 A Pre-Development Basin 1 i B Post-Development Basin 2 III. CONCLUSIONS .....................................................................................................................3 APPENDICES Appendix A Srte Locatwn and Soils Information Appendrx B Hydrologic and Hydraulic Calculations Appetrdrx C Post-Development Basin Map Drainage Report for Keystone Meadows Subdivision , Spokane, Washington ~ ` I. PRQJECT ❑ESCRIPTIDN ~ A. Jntrvducfron ~ - ICeystane Meadaevs subdiuisian is a twenty-vne lot, smgle family develnpment locatcd near thc intersection af Fnurth Avenue and McDanald Raad in the Spokane Valley, covenng approximatcly four acres Road irnprovements for the plat include the wadening af Fourth Avenue and construction of three new pnvate roads m the mtcnor of the plat The project is in Section 22, Tawnship 25 Nnrth, Range 44 east, m the Spokane County, Washmgtnn, and is located within the hounds of the Rathdrum Aquifer 5ensitive Area (ASA) 'Fhis repart exammes the proposed sCarmwater collec#ion, treatment, and dispasal methods that will be employed in conaunction with this develvpment ~ 11. HYaROLOGY A. Pre-Develvprnent Basin According to the 1968 5oi15urvey of Spokane County, Washington, prepared by the Soil Cvnservakion 5ervice, the soil un-spte is Garrison graveEly loam This soil is found on slopes of 1 to S percenC and is snmewhat excessively drained 5pokane County has pre-appraved the use of drywells for soils m thps , classificacion Please refer ta AppendQx A for ad$itional smzl mfvrrnation Gurrently, the site is undeveloped-groundcouer on the site consists of dcnse wceds ar►d brush The ground slopes at apprnximately 0 5%-2°/d toward the middIe af the srte, ar►d it does nat appear that the grade on the srte has ever been appreciabiy altered Runoff currently stays on the site and seeps into the grvund followmg storm events No evidence aferosion or damaging runo£f patterns is apparcnt The oId railroad rip,ht af way, which m the future wnll become a seetion of the Va11ey CoUplci, iics vn thc plat's north bowndary Fourth Avenue, on the plat's south baundary, docs not haVe curb and gutter at [his time, currentiy, runoff sheet flows aff of the roadway and percalates into the adjaccnt vcgctation The lands east and west af the plat appear ta have been used for orchards in the past, hawever, the land is now covered wrth low grasses and weeds, and may be used for pastureIand There appear to he na other possible sources of offsiCe flaw around Che site Chat need ta be considcrcd in this analysis i I drainage Repnrt for F(eystane Meadows 5ubdivisian ~ Spokane, Vllashington 1 ~ B. Post E?evelapment 6asins i Fourth Avenue is divrded into two post-deueloped hasins, R1 and R2 Grassad Percolation Areas A and B will treat the runof#' frnm the north haif of 4"hAvenue, ►vest of Morrow La.ne Grassed PcreoIation Aa-ea C will ireat the runoff frvm 4"' Avenue, east of Morrow Lane Ponds Aand S are linked with a 12" diameter culvert under the proposed dnveway of Lot 5, Block 3 Spokane County Typc 1 curb inlets Lvith 2' openings will be canstructed with all three swales to aud in convoying runoff aff of the road surface A ~ Type A drywell wnll be constructed m swales B and C to dispose of excess starrn volumc Starm runoff frQm Basins A thrvugh G as treated an grassy ditches located alnng the entire length of each intcnor privatc raael The ditch section is trapezoidal, wxth a 2' wide hvttvm and 31 side slapes Because the iangitudinal slopes on all ditches is 0 5°/0, the swales are assumed to bc flat (ref Pg 5-4 of the Gurdedrnes for 5tarrnwater Management) Ten-inch dianaeter CMP wtll be insTalied under each dnveNvay that crosses a ditch section ta alIorv canveyance of the flow An allo%vance has heen made in the swale calculations for the grassy dttch area deleted due ta construction of a dnveway to each hvmcsite Type A cPrywells will be cnnstructed at the low points of each rcjaad to dispose of excess runoff The drywells for Che pro3ect have been designed to dispvsc of runoff from nat only the road areas, but also £rom the lat areas Fram Table 1 of the Gurdelrnes for Stormwater Management, the "C" factQrs for a density of 4 77 DLTIGA {21 lotsl4 4 acres} is 0 40 Bccause the precise grading pla.ri £or the lmts ts nat Icnown at this time, an approximate post deveioped baszn scheme has been devclapcd for the intcrior of fi.hc plat Thus, a` C" factar of Q 40, along with the approximate interior basin areas, Nvere used ta per#'orm Bowstring calculatians Minor changcs m the basin boundanes for the lvts should not have a significanx impact an the drywell requirements i Drainage Report for Keystone Meadows 5ubdivision 2 Spakane, Washangton ~ The grassed percolativn area far each basin wa.s sized to treat the valumc of runn€f fram a nne-half inch storm on the asphaltic surface wixhin the basin Dtywells and mlets far the peoject were sized using ten- year storm intensity The calculations for the swales and drywells are summanaed in the table below BASIN 208 VQLUME 208 VOLUMIE DRYWELL REQIIIRED, C.F. PROVIDED, C.F. R1 ] $2 251 1 Type A R2 98 131 1 Type A - ' A 323 I,545 1 Type A a 256 1,348 1 Type A C 316 1,820 l Type A III. CQNCLUSIONS The proposed amprovements dcscribed m this repQrt arad shown in the plan set wi1P provide storrnwater - controi and tt'eatment in fuli compliance with Spokane County's Guidelrraes for Stormwater Mcrnagement I I i Drarnage Repcrt far Keystone Meadows Subdivisian 3 5pokane, Washington Appendix A Site Location and Soils Information ~cn Outstanding , , , • . g Qiitilitl, DAVID EVANS AND ASSOCIATES, ~ NTl(, VIIASFIING7ON - SHEET N11MBER 75 44 E (lains sh2et 66) , 75 N PR[3JECT LOCATI ON ~ ~ - . ~ ~ ~ h N ~ •O ~ ~r 1 Mile Scate 1 aa 000 ° . , , SODO Feet (lotns sheet 84) ~ t 18 SOIL SIIRA'EY occupy rolling to hilly uplands. They formed in layered they are eacellent pltticce~~s for hunting migratory wlterfowl. ~ lcess under coniferous forest. The annuul precipita.tion is (Capability unit VIIIw-1; not ui n, woodland group or ~ about 23 inches, and the frost-free season is about 125 days. range site) "Freeman soils are used for grain, peas, clover, alfalfa, and gmss, and as woodland. Gai-field Series Freeman silt loam, 5 to 20 percent slopes (Fae).-Tlus is the dominant soil on the silty upland north and east of The Garfield seizes consists of well-dinined, severely ; Rockford. 1ltost slopes are betR'een 8 and 15 percent; a, erodecl soils thnt formed in loess under gi-nss and small few small nreas liave slopes of more than 30 percent, and shruUs. These soils occupy ridgetops, 1.-nobs, and the up- some of less than 5 percen~. Slopes of moro than 20 per- per slopes on rolling to hilly uplands. Tliey have a surfuce cent are short and are along the eces of the drainage~~a3•s. 11yer of silty cluy loum and a subsoil of silty clny that is Representative profile• ~-ei~• hard, stick~~, and plnstic. The annual precipitation • o to 7 inches, very •dark graytsh-brown, friuble sttt toam; is 18 to 22 mclies, and the frost-free season is about 140 ' grannlnr structnre; neutraL dflyS. 7 to 17 inches, brown, friable silt loam, graytsh brown at a 'I'hese soils nre used mnuily for grnin,llfalfn, and grnss. depth oP 12 inches ; neutrai. Garfield silty clay loam, 0 to 30 percent slopes, severe- , i7 to 22 inciies, grayish-brown, 8rm sllt loam that breafis into ly eroded (GaC3).-This soil occupies the nlrrow ridgetops 1-to2-inchprisms;neutraL d u slo loessnl ullnds ui tlie soutlie~lstecn 22 to 72 inches, dark-brmvn, Srm sllty Clay loam, slmost sitt fln Pper Pes on P ioam ; breaks into prisms 1 to 2 incbes wide, and then into pait of tlie countS. 11Zost slopes 1i-e between S n~id 20 per- - angular btocbs % inch to 1 incb wtae ; neutrat. cent; fe~~• smnll nretis ha~=e slopes of more than 30 percent, The surfnce soil, when moist, rniigw from very ditrk and some nnrroxi, ridgetops have slopes of less tlilti 5 per- grnSish bro«n to dark brown in color. The texture of tlie ceut. Representative profile: subsoil rnnbes from hen,vy silt loam to silty clay loam. o to s tnctiea, dark-Lro«n, srm sitts day toam; granular strac- ' As much ns 7 percent of some areas consists of larkin, tuce; neutrut : Dearyton, or severely eroded Freeman soiLs. S to 48 tncves, aur1:-brown, flrm s,tty clay, ye1toR-ish-brown ; This is n. moderatel well drnined soil that has a very sncs ciay ioam below a depth of 23 incbes; brea6s ivto y prlsms 1 inch to 2 inches wide and then tnto angular blocl:s ° slo«ly permenble subsoil and is sltum,ted for short periods 14 tp % inch thick; clay fllms coat the prisms and angulur in spring. It holds aUout 5 to 7 inches of water that plants btocks; neutrnt. can use. It is easy to work eaceptwhen saturated. Roots 48 to 60 inches sellowish-bromn, firm heuvy silt loam; I1L'eII64 ' eneLrnte the lower lay ers mainly along ped fn,ces. The into prisms 1 to 2 inches n•ide and then into angular Llocls . ~ to ~ lnch tbick; neutral. ertility is medium. Surface runoff is medium, and tlie Tlie tes-ture of the upper suUsoil is silty cl~,y or cl~,y. As httizn,rd of erosion is moderate. 1liore than 95pe rcent of the acreage is cultivated; the much 1ercent of some ureas consists of Athena, l~aff, rest is farm woodlots. Whea.t is the chief cash crop. It T as 10 ~ez Peirz, or Palouse soils. is grown in rotution with peas and a green-manure crop This soil is well drA.ined and slowly permeable. It holds or i whea,t-fallow rotation. Other crops grown are peas 9 or 10 inclies of water tliat plants cuu usa It is stickv and barle clover or alfalfa for hay or green manure; and nnd plastic ~vlien ivet; consequently, it caai be culti~•ated grnss for s~ eed, h1y, or asture. All grum and grn,ss crops °lll~~ ~ritlun a, r~,ther naribw range of moisture content. res nd to nitrogen. es respond to sulfur. (Cap~.- Root peuetration is very deep. The fertility is medium. Surfnce runoff is rapid, and tlis hazard of fui~tlier erosion Uility' urut IIIe-3; ~ood and group 5; not in ~ rnnge site) Freeman silt loam, 5 to 20 percent slopes, severely is se~•eie. eroded (Fae31.-Diore than 50percent of the surface layer "Nfoi-e tlinn 95 percent of the acreage is cultix-ated; the of this soil hns been removed by erosion. Fertility is me- l-est is seeded to alfalfa or grn.ss. Wheat is the chief crop dium to low. Surface runoff is ra,pid, and the liazlyd of 4ther crops grown are barleq and dry field peas. ?111 erosion is severe. As much as 10 percent of some are.ns crops respond to nitrogen, sulfur, and phosphorus (Ca- ` consists of imeroded Freeman soils. ptibility unit Ne-3; not m awoodland group or ia nge site) The same crops are grown as on Freeman silt loam, 5 to 20 percent slopes, but yields are lower. (Capability unit Garrison Series Ne4; woodla.nd group 5; not in a range site) The Garrison series is made up of somewhxt eacessively Freeman silt loam, 20 to 30 percent slopes, severely dInined, gmvelly or stony soils thnt formed iuider gmss eroded (FoC3).-11Zore tha,n 50 percent of the surface l~,yer in gllcial outwash miaed in the upper part R-ith ~-olcanic of this soil has been removed by erosion. Surft~ce runoff ~h. Thesa soils are on nearly le~~el to moderately steep is r~pid, ~,nd the erosion hazard is severe. Included in telrlces. Tlie annual precipitation is 18 to 22 uiches, ancl mappug n-ere a few Areas of Dearyton soils. the frost-free se.tison is about 170 days. The same cro 1)s are grown as on Freeman silt lo1m, 5 Soils of tlie Ga.rrison series are used for a~-ariety of to 20 percent slopes, but yields are lower. (Cu.pability crop s and as farmsteads and suburbttn lots. unit IVe-3; wood]and group 5; not in range site) Garrison gravellp loam, 0 to 5 percent slopes (GgA).- This is tlis dominant soil in the Spokane Vtilley east of Fresh Water Marsh the city of Spokane. Most slopes are between 2 and 5 Fresh water marsh (Fm) consists of shallow, swampy Percent. Representative Profile: ponds and of fringes around lakes that have a fluctuating ` 0 to 15 inches, black, very friable gravelly loam ; granular water level. The vegetation consists of tules> reeds> and structure ; slightl9 actd. 15 to 44 inches, dark-brasvn, frinble very grnvelly loam ; nentral rushes. These areas are of little value for grazing, but 44 to 60 tncbes mnlticolored sand, gravet, and cobntestonea $POKANE CO[I1VTYy WAaHIiCGTA1 19 he rurfacae colvr, 'when moist, xarrge.s from very dark ths county. 3fost slapes are ~ween B and 15 pereenL b vn ta b'Lwk. The texture af the surface la~er is ~v- R.epnesen~ive profile : e.l,~, or ~grRvelly loaan ar silt loarxi. ~`lie su soil ranges 0 ta 13 Inehgs, blach, very frTable silt luam; granulac strncture ; an color fram dark brown to yellowisla bresn*n. CIay and neutraal. h , ]iave accumulttfed an the beft,tom of the pebble.s in Lhe .13 xn~~es ~ ae s~~~ aloam thut breaks inta ~►rts,ns i~ r sutasoil. The depth ta the grave1 substratum ranges 62 to 72 dark-brown, trTnbte soam; slighti,yv acid. fr.v~a 3o tv 55 inr.hes. A.s mucli as 30 pement of soine areas ~ Paces thc surfar~e laye r ~s t~edA.rk ~rotsn. X~ is I4 ~nsis~ of Ban.g or Phoebe seils or af ot,~ier ~r~son soils. F his soil is some`rliat eacessively dra.iiied and 1tas nzod- to 16 incl►es t]►ick. The texture, of tl►e subsoil ranges frrom e B1y tapid perineability. It lanlds abaut 5 inches of silt loltn to Iiglit siity clay lvam From 5 to 25 pescent of N1 V,01! that piants caii use- It as easy to wa& Raat.s tFla loirer subsail is ccampcased of gravel and stones. As etmte to the ]a er of saiad, gravel, and cohblesst,ones. znucll As 5 pement of some ureas r.ansists of Bernliill, r fertility is me~ium Surfa.~ ru~~ofF is slosv, and tlze A~'~~i~, 4r ~ar-in scrils~ li drd of erasion is slight. T~~is sotl is►i e11 dt~rzied and moderntely permeable. It ~,bout 80 perreiit of the acreuga is culti►rated; the i-est zs ltnlds J to 11 iiiclies of water thnt plants can use. It is liscd far graaing: and as farmst,eads or suburhan Int.s. ensy to icoxl~, Root ~aastra~tian is very dee .°~he fer- A t o# the acrea.ge is irrigat,ed Irrrigated :~zeas art~ used tllity is l~xgli. Surfaee i-uno~ is inedium, an~ tize h~rd f orcliasr~1 fruzts axid berries; cabbage, corn, c.antaloup, of erosian is inoderate. cuutimbers, ce1eiy, niid squash; tvheat, oats, aaad baxley; Aloi`~ than 94 peacent of the acie~~ge. is cultivate•d; tlie aifalfa fvr ht~y; and grn~ss for seecl and Z~:rstura Llryl~.ii~1 i'~t is gi-nze. l'4~he.~t is ttte c}lief crop It is a own in a s a~ t~s~ far ~rlieat, ]aarTey, and na,tive Uunahbrass. iatativn itiitli blriey, oats, peas, 1entiLs, al#a.lfa, ar grass. 7 re is nv d'zf&culty zn tiie use of macliiiiery, hut t1ie All gcass ajxd grnua crops respond to nitzagen; legumes frd-T.rel rs hnr+d nn tilla~e implem~~. Ail crops except i~pond to sulfur. (Ct~pak~ility uiiit I~e-2; ~amy range l~wne.s resp~and fo n~r ogen. Some cr+aps respond ta sxtB; nat in 'L wcodland graup) -;i ur, barou, and p1wsphorus. (C:a,pabllity unit ~~Is-2; Gienrose silt 1oam, Ut0 5 percent slapes (G,pA): Thi~ I afty rauge site; nat in awnadiand. grQUp~ soil 1~~ a surfaoe l~.yer 2tra 4 inches tlucker t~ian that of .,~a~n graveTly, loam, 5 to 20 percent s Qpes (Gg6}.- Grlenrose silt loaan, 5to 24 percent slopes. Surfa.ce runcrff TlLis soil has a surfuce lAyer 3 t0 5 inclies tliiiii3er than tlint Is slaw, aiid tlie eiYasian ltazard is sli~ht. Included i~i map- n ~arriso~i gra~aeli~+ laain, 4 to 5 perc~ait sltspes Runaf~ Pl ~-ere smn11 n~~s af X3ialig an 77earytvn wils. ediumz and #,T~e ervsinn haz€~r~d ~ madernte. ~ie sa.me eraps aiv gro`vn €4s on Glenrnse silt flaam, 5 ~dus soil is used in muc1Y tlie same R-ay zzs f`xnrrisan to 20 1)ercent slo 1)es; in additaon, veg.bles are gro«•n. -mvellp lvam, o to 5percent slo~ses. (Gapab1lity unit (Car at~ility unit Il~er2; Lou.mq ra.nge szte; jiot ~n a~vo+~d- I ~n~ay xanga site; not in a Srs~~,I;~nd gasoup) land group} . irrin verp grarellp loarm, 0 ta 8 percent $lapes GIenrose szlt ioam, 20 ta 30 pe"ent slopes [GpCy.--Tlais f C3rnd).-This soilliKs a#.hinnar' snore grnvellg surface Iaper soil has a surfaoe layer 3t0 5 iaaches tYunner tlian thu.t of t 1uan Guzrisan gravelly laagn, 0 to 5 percent slapes, and Glenrose silt 1a1m, 5 ta 20 pazeent slopes. Surfam runnff 1t, $less thaI1 5 lIIC1iP5 of wAtCI tl11fa plRIIfS CA.ili 11m The is tapid, nnd the erasian hazard is severa Abant 5 t el causes extreme ZTet~r nn tillage naachinery As of same a~r,s cansists vf ]3ernhilT and I3earyt,on na„quil as 7perQent of same ni•eas cansists of otlier Garresoii The sanae crolss nre grawn as an C'xlenrase silt loain, 5 to ;orls ((;r+~sability unit XV~S; Shallarv ran~ site; nvt ?4 ~~rcent slape,s but mare of the aereaga is in grass and n►raadlandgraup} leg-ttrnm (Cagabality uuit Me--2; Uamy range sEte; trrisaa Yery stony Zvam, 0t0 20 percent slapes rlQt rn it waadland gi-oup) (G,oi: 7`his soil holds 1ess than 5 anclies of water tlkat Glenrose silt loam, 30 xo 55 percent slopes (Gp[]).---Tlixs ~~l;~nts et~n use, Ai~d it as too ston;y to ~a cultivated ~.s sant lias a surfaee la~yer 3 ta 5~ch~ ~.liuiuer tlian tY~at of u 1i as 15 perrent of snme a,reas cansists of otlier Garrison Glenrnse silt loaui, 5 to 20 percent sIones. Surface ruii- , azid as mucli as 2 perceut is made up of gmnite vff is ml3id, and t,lis emsion ltazard is seveta. About 3 can c ereent of soziie areas car~ists of ~ierrz~hiil ar Dea.r~pton, I~ Tliis soil is used for grazing. {+Capabilaty unit V'Is-2; sails. Tliis soil is ased only fvr ~ing• (G,aPabilit3' S 11azv arange site; iiot nn awovdgand grotip) tilut VTe-1; I~o~~tl~ Esposure ra.r►ge site; nflt ai~ a tivaQd- land group) Gletuase Series Glenrase gravellp silt laam, 5 ta 24 pexcent sTopes (Grg).-Tliis soal liolcis frorn 7 tv 9 inches of wtiter that le Glenrose series cansists of rvell-draiiisd, mostly ptants caia use. Smnl1 areas of SernhalI nnd Deaxytron 11, iuin-textuted snils. These soils formed under grnss so11s were aticittded an mapin~ tsL.t scatte~~ed piiie ta~ees i~i glaci~.l till rnFxed ui tlie upper Tl1is soil i.s u~d in muc~i the saine way as Glezlrose sil~ i0t t tritli Toess and valcainzc ash lllany areas u.re gr-weliy loatn, 5 to 20 perr.ent slopes, Uut yieids are 1ess (Capa- 1E+ oray. These svils are nearly level to very steep. The bllity unit rVe-4; Laamy rangs site; not ui a tvaodland ii inI y ~er.ipit~.tian is about 21 incltes, Aild tl~e tr~rst-fiee b11011P) Sc.~~a is a'~aut 135 days. Glenrose graveYly silt loarn, 20 to 55 percent sl+npes Glenrose sails are used f4r gra.in, peas, lentrIs, vegetables, [GrM-'Thi., snil lLatds 7 ta 9 inches of ivater tlant plants til #,z, and grass, aiid far grazing. can use 5urfnce rutioff is ra.pid, and the erosian 1iazard enrose si1t loatn, 5 t$ 20 percent slages (GpB}.-This is ssvere Xncluded an mapping wexe areas of Bernhill 4;011 nccuts on glflciafed uplands in the east-central p1rt of silt leaaiii, 30 t0 55 13erceiit siopes ' . {-~t, cn 'W--g:=- ..,`t . , . .::`:':s 74 soIL svavEY TABLE 6.-BTiCf d2SCTL17t'lOliB Of 807U d77d }~LCjt Clsssificstion Depth Map Soil namc Desctiption of soil and site from sSmbol surface USDA texture , la. DsC Dragoon stony silt loam, 0 to 30 percent Stmilur to Dragoon sdt laun, 0 to 30 pcrxnt slopes. slopes, except that the surface lsycr is stony. DsD Drngoon stony silt loam, 30 to 55 pcr- cent slopes. DvD Dragoon very rocky complcx, 20 to 55 Aragoon patt simdtu to llrngoon sitt lonm, 0 to percent slopcs. 30pe rcent slopo, axocpt thut depth to bed- rock rnuges from 10 to 20 iuclics Rock ou, - ~ crop tucluded m ihis complcr. Ek6 L•'ioikt►silt lonm, 0 to 20 percent slopes. 1licdnim-tcxtured, ncil-draincd soil tormed frocu U to 24 Silt loam__________. glaciul till contuiuiitg n largc nmount ot vol- cwuc nsh in thc sur[ncc laycr, tmdcrlnin by 24 to 44 Grarclly loam_______ gruvcl nt depth of 30 to Gll inches; occupics 44 to 53 Vcry gruvclly sandp, wtdulnt►ug, moratnrld.c topograpUy. lonm. % 53 to 60 Gravcl____________~ EIC Eloika very stony silt lonm, 0 to 30 pcr- Similt►r to Eloil.a sitf, loam, 0 to 20 pcroent slones, cent stopes. cacepc that thcy nre vcry stony tAroughout. EID Lloikn very stony silC loam, 30 to 55 pcrcent slopes. Em L•'wdciit silt lonm Medium-tcxturcd, somcwhat poorly drained, U to3G Silt Ioam_______.__, ulkoline soli tormed in alluvium trom calcar- cous silt, volcnnic 3sh, and diatonite; depth 26 to 41 Vcry finc sandv Lo nntcr tablc flucGiutes iro►n ncar thc surtace lonm to about 6 lect. 41 to 60 Sandy CIAy IOA[D.:. Fa8 Frecrosui silt loam, 5 to 20 pcrcent Vcry <lecp, inodcratclr wcU drained uplnnd soils 0 to 22 Silt loam________ - slopes. with meduim-tcxtuird surfacc Inyer and medi- fa83 Freeman silt loam, 5 to 20 perceut um or moderatelv 6ne te.ettired subsoil; formed 22 to 72 Silty clay loam ~ siopes, sevcrely croded. fmm silt ou mlluig to hfflq uplsods. ~ faC3 Ftceman silt loam, 20 to 30 peroent slopcs, sevcrcly croded Fm Frah wntcr marsh. Slwllow, sxrampv, intcnmttcut ponds und tnnges arouwd lakes tlu►t hlve n fluctuating ivnter tablc Enguieermg dnta is not given, As 11nd t% pc is too vanable GaC3 Gar6cld silty clay loam, 0 to 30 pcrceut \'cry dcep, nell-clrnined soii devdoped in locss U to 8 Silty cl:►v lonm__ slopes, sevcrely erodcd. on ndgctops and lnolu on thc rolll„g to hilly 8 to 23 Stltr cinc•______-- uplands in thc Palonsc soil 1rca. 23 to 60 Siltj• cl.i}• lo1m--- • GgA GAmson grAVClly loam, 0 to 5 pcrcent Grnvelly, mcdium-tcstured, somcwhnt exces- 0 to 15 Cravcllv lOam___ , slopes. siacly drniueci soils formed in grnvell,y gincial 15 to 44 l'cry gr.i% cliy 1 Gg8 GarrtsOn grAVelly loam, 5 to 20 percetit outAvnsh mltcrial from a vnnety of ncid, 44 to 60 Snnd, gra%el, and slopes igPicous p-irent rocl:; on neariv lcvcl to mod- cobblestones. crntcly flopiug temces, depLh to mubirc of ' &-ind, gr.i,~cl, and cobblestones mnges from 2;4 to Zi fect Gm8 Cnrrison vciy grnvelly lonm, 0 to 8 Similhr to Carr►son gravcil}• loiim, cacept that 0 to IS 'v~ery grnvelly i percent slopc:s. the sui Gice ln~er ts % cry gravdly. 15 to 44 Yerv grnvellv 1 44 to 60 Sand, grnvcl, and cobblcstone6. Gn6 Carr►son vcry stony lonm, 0 to 20 Sunil.ir to G:►rrisou gra%cll%• lonm, cacept that percent slopes. thc surface laycr is %cry stany. GpA Clenrosc silt loam, 0 to 5 pcrcentslopcs Veq% dcep, iucd►um-tc\turcd, well-drained soils 0 to 72 Siit loam__---- Gp8 Gleurosc siit Ioam, 5 to 20 percentslopes formed from acid iieous glacial Wl; surfacc GpC Glenrose silt loam, 20 to 30 pcrcent la~~er inHuenced bv ~ocss and rolcamc ash, on slopes gently rolling to stccp upiands GpD Glenrosc silt loam, 34 to 55 pcrcent slopcs ~ .SPOKANE C[]UNTYr WASEEENGTDN 75 sts aed physac¢l anrl chhemicu.l prnpert?es~ontinued ',Ea,gScs#aoA-Coi3tiuued Petoenfsge p,assing s3exe- Ax ailakalc ' T'crmeabihty natcr Ii.euctaon 1)tspersion Shaink-svvell Na 4 N0 10 hTv 200 capacst} (1 5 dElut[on) pQtentiaE „ i6ed AASH{9 i tntii.) (2 U mtn } (0074 :nm ) Ira per hs lrt ptr rre cJ soel ,p11 4-4 ly 95 8fl WI,i GU to 70 0.8 to ?,i 0 ] i lo 20 V I tv [1 i IEigh_.---__ I,atv to invd- <•r:it~~ 51i-------- A°4 7) lo $i 40tss80 .ia tv:zil U 8 fa 2's Il 12 lof] l-! G 1 fn Ci G llagls------- Lgu _ A-2...... 30 to {i[l 20io 5U 5 to 1.5 a Q l0 10 19 Q(me fo 0 01i fi 1 I+o i i 9 ~ igh-- - I,o,,► A-1_..___ 21, 1a i i 10 lo?q il f.o 5 >10 0 (I4 to [a !Hs 4) [i 10 7 3 Iligfi------- d.nu 11IrCL_A-4_°_--- 93 to 100 9il Lo lUQ 90 to 9:5 4 S to 2. :i il 17 to 41 ?fl 7 fi to 90 lligla Low Lv anpcl- cratitt~ A-4------ o5 10 1SI() q[! to 1[1o G[1 ta 7[1 [l $ Ln .i 0 17 to 0 21} 7 4 to $4 AfoIrrjstc___ X.o►v. Cr.---.,---- A-GG------ 95 to 100 !1f} to Ji $5 44) 9U 0 2 iv 0 8 U 17 to q?ii G fs tu r 3 IA►►_______ - AIDdCYAt.C. ]l :L.... A-4------ Q5 to 100 90 t0 I00 $4 La 90 0 2 to El 8 Cl 17 1n 0 20 G G l0 73 '_linrlr3.i14-___ I.aL; iai mod- c•~ n~,e G] A-6 9510100 00 to I[30 80 to gU [U ~1:., ❑ lr to Q 20 G G ia i.i I Y.o►%1!todernte A"'6-.____ 45 to 100 90 to 100 90 to 95 0_ 2 to 0 fi U iT W a 16 6 61rs 7 3 I.aw------- 34ladef-nte A-?------ J5 to 100 q(l to I[30 90 to 95 [I qJ to [I 2 14 to 0 17 CL G to i 3 Lvw Y€igii *L A-6 95 to I00 90 to I00 JO to 93 0 2 to 25 0 17 d,n I] 20 Q G 1u : 3 Low A4odcrnte d) p-4 65toS5 40 to 80 35 to Pi{3 0. N to 15 012 to i! 34 [i G (a 7 3 Ainclci:tfe Lotn . A--2------ 43 ta 05 30 to 60 5 to 15 2r) to 5 0 0 08 to 0 10 G G to i 3 113ntls;rate_-- IAw il-------- A`1--..__ ?a to 35 10 fA 20 0 to :i ]TA 0 04 to 0 UG 6 G to 7 3 liigli T,aiv A-2------ 30 to 60 24 fa 50 5 to 15 2 5 to 50 fJ 04 to 0 10 G T to G Fi Modcrate___ Low A-2------ 45 to 65 3[1 bo 80 5 fa 15 2 5 ra S C] Ll US Y.a D 10 fi G to 7 3 A4vr3cinte___ T.atv A-I------ 25 to 35 10W20 0 to S ]10 0 04 to U OG G G io : 3 H Egh------- T.ow 41 ~ L---- A--4 86 to 95 75 to 95 60 to 85 0$ to 2 a a 17 to 020 G 1 to 7 3 Moderate__ Low to moderate ~ ~ a~ r ~ 92 soIEL svRvEY TASLz 7.-Interpretuiz.on Df engarit Sustability us source af- SQit fratarns affc.ctSng- Soil &erics crr type, Far1u pna IInsi rnup symbals Topsail Sand s Gravr.l ' 1toad fiil Highway lsrcatian Dikes Qr lcvees Resen o1r ~ ~ I)rttgooa (OrC, Gaod fa Nat suit- Not suit- Fuir to Modcrate to Very high Y,ow stghiiity; Modernte ai ' DsC, DsD, poar, aule able gnod snsceptib=lit,y to semiperVious to madez•at(- ~ ❑vp) frast aetioti; mod- imp-erviaus rapid pr.r= j erute to rnnderateh ri Ptcn com- alaiLte- T'fLp!d j1CPTISi.'AbIIIF.S e pncterl, lpn Ya lo►r to tnodcratc :nodenitc shruil.-s►ee11 stirisik-ms;ll pot.ent[al rOtePiL1.1I D-laika (EkB, E[C, Fair_Nnt suit- Sudtnble at GOOd...-e_ MOdCTA(C L9 llEgli $LLS- T.fItL' s.tlibiIiLti ; MoIer2teYc ~ EI[]) able dcpth CL'pI.1L1fLlty to frast rciiiincrviou5 1n sapid pcr~ greater ncLoptt, inoderntc to inincr►•ioiis abil:t% thari 60 very rapid perine- niien compact- iuclee,i. alsiiiGy ivti► to nirx'.- cd; Zox to mad- ~ craLe shrrtik-snell cratc shraeik- ~rsfentmit! snel! [)otcEELiaI J Enrdciit silt loAm Fatr_---__ Nat suitsr,- ~TOt $[ilYil- PQflP-..--' AFeCy Zllgii R4ESCeIItth11- LOIY ,£t.4tlillty1; Ittd- MadCiAYi tr ~ (Em) hie bte. ity to frost activ», pervioiis whefi rnoderatc] modcraf.e to mr,d- cvmpacterd, IaN► SIt3i► gxr,i crafcl► Plo3r pernic- to:noderatr a1~iht3 uGilita loa to mod- slirink-sncli ernte shrink-swc11 I]pCCII{.IaI p6t(.'liL1RI, sat+jr-ited s 1Il 111Rti'T Aiid $pT111g Freeman (FaB, Fais Ea Not sixsta- Not suit,a- Povr----- Modcrate to %eir► bagh Molerute stahil- Moderatelti FaB3, FaC3). goar. ble. ble asisceptibilLty to =ty , imperFious to ver3• =1 trwt action; mnder- 11 hen oompnet- permsabi ' afkly s!o►v to very ed; In'sv W mod- sEaw permeabflit► , eratc stirink- 1u►A to anoderatc snell pot.ential; stiriiik-sn el9 pnt-cis- sails crack n•hciti ttinl, sntmated itz dry_ spricig ~ Garfietd (CaC3)___ Fsir to Nat autCa- Not suits- Poor_____ Modcrate #,o +•cry liigh Moderatc sf.alSTi- 1Viodera#e &c ~ I goud. Ule bYe suscepYibihLy !o frest aty•, irrapervious sln~v pern $ctivEi; rnaderate to n•lien eompactr abiliky. " slon• permeahiliti , ed; mnderaf,e to j~ tT10d@P&tE..' {A h1gFY high shrink- ~ $hrink-s~~e1! poten- va cll potent3si tial iGarnson {~g A, Fsur_ 1~iot sui~ l~~d below Exeellant_ S1~g1~t ~ no Buscepti- Maderate stabik- Moderate t( Gg6. GmB, ebTe. surfare bilety to frv5t action, itp , pervraus %cry rap3, ' GnB) layer moderatc to very when catn- prrineabi1 rapid perme.ability, pscted, low lo,.F rhrznk-sncii ShrEnk-swell potetitial poLent3al 1 t~ $ee fpotnnte at end a[ tahle. ~ . I ~ T ' r $PQXANE COUl4i'I`g, WAMMOMN $3 Vp6tj,r,a of soils-Coatinued ~ Soii Leatures a9fecYang-Cvntinued ymn Pouds— Coatinu[xl AgnGSdturaRl Terra.ccs nnd Sev~ge disposul drninage Irrigatxan diversions WaCermays fields Trafficabihty 1 I j-tl"Fsat& ment 4.' crp low shr.ar ATodcrnte to Aiacleratc in- 7,aw resLstaiiee Low resistance to Moderuto to VOry lonr $hemr ~gu"gth, semi- modcrately i.al.e rate, to crosyon; rrosivn, mod- moderut.eely etcength; low p&•ioiIS to im- rnpid permc- moderALe tsioderate to erate natcr- Pap:d pcrmi- ltsnd-currytng pwsivus whan abality. xC'yitCT-}S4IdII1Fj moderAtely iivlduig cuYrac- nbdttg ; mod- enpncity: c+ompacted, me- enpaciLy. snpirl pcrme- ltr, lL'gPtFiL3oi1 rr.itc to xx ori- moieratc to dEilm aenipress- :ikiilety, di~i'icult to cratcly rrepid moderntely a4iitttv; 1ou csta1.ltsh e.kecp6 vatcr-liold»>g rapid perme- ' ginbilLtR on l7ragnoii cap.iclty nl2ilii'y. sdt 1oam .,pw simr etreiigth; hfvderntc I.v Mrxlerate to Aiodir.ztc resist- Iliadcrntr regist- .liodcrale to Low stienr {toemipcrvw¢s to vcrp rapirl mslt4rr:~telW atir:c to rro- nnec~ to emsaon, ~•ery rapid aLreiigt,h mod- a im~rvfoua tvhcsi ~r~nc:~bihGv raptd siil,t►E.c sion; madcr- nzadcentc wnter• penmemlsility, erAte La high ~ tompactc[!,slight raLc, modrr- ate to vcrr lialdtsig ca- modcraLc laad-caerying oomprcsmhkhLv, ntc nuter- taptd pemiie- pncitt, V(.gcta- ►tnter-haZdeng capacity; naod- l6ar stahBity hotding ca- nbelitv 1,ioii ciificult to cspaczky crafc to vcry p.tcity. csUlslIsh euccpt rnpid perme- oii EIaIk:t si1t abiIitX. } 14atT1 ~ t ery 10n siit al Mocler.ite to A'Iodcrnte to iliadernte trsist- \fodcrate resist- lfodcrntc to L'crg Tow sticar j atrengtb; imper- moderately siinc8cmtely ancc to rro• nnee to crosion, inasierntch• stretigLh mad= ~ ADUs w1ien cam- slow pt:r[nC- 51~~4 intai:c sicrn, rnasicr- very* lugli uatcr- do►r pernic- era,tc to iow pnr.lad; moderAte abiZatv, sa.tu- rate, verti* afA• to mocter- fiolditig c.nlaao- AUIGy;vrry iand-carrying lab3gh comprnss- rnfeil iti `%in- iii hv►nter- af,cly clvtr ib~ , s~xcrp~t for lug1innter-laald- cnpucity, :nrul- re BEty; mgdarate t.er attid ho dirsg cn- pcrmcabditv. Wit-tulen►nt M capACdty, crnte to mosi- ~ '~t~ cracks 9pT111g paeiLn spi:etrs, vc•geta- s.tturnt.eci in eratr.ly slozv tion ciifTtcalY to n znGer ansi permcability a cstablish spenyg ~ "y law si:eae Moderatcly Mvderntr•1y ModerAF,e remst• Afodcrnte resist- RiDdemtely VCry 1ow ah6ar SUength:2naper- 4aloic to dety slaw w slow anao to era- unce #A arasivn, SIow to veryy strength• mod- ~wkm +rhsrn com- sionr perme- inLal:e rato; inon; mvder- very lughnratcr- stow peme- ernte laad- rt gWed,; tned[tam ahility; sntu- vcry high atrty slon to hvtding capac. fibiFity; vcry cnrrying cs- ~msprembtlitv~ r~.ted an ~ater-holding racr~- slon- pcr- ~tRr, r~egeCat9o~i ,~igh trnter- gacstp mpti- t~craLe s~hi - sprixig ~pncity. mc:~Uility fnirl~• easy to hoCditig ca- erat~ly slow to 1 #ty ;so& ernck csG.nblish paei~y , s3tu- very $lvw 1 rrko dry. rated in permeubilxty. spiang M9Ioar Ow-ir ilfodernt,e to Slon intake Madcr:etc resist• 1"(uderate resist- Aivclerut.e to Vcry low shear dreaglli, imper- sloes pcrmc- rate, very ance to cro- Inoe to croseoii, sla►v petme- sLren h; mod - ~ ~ e►lu,u aom• nbility. hrghwAter- asaii; madcr- very, higEi abality; very eratelload- , snc eiiuEU to haldang ca- r~tc to sion ti~ater-holding high renLer- carrying es h ertln[arC~Sibrl- paaity. yaermeahilaty capaatt* ha7ding ea- pttc~6y, mod- ~3r' m~nrlrrrit , c vegetat►oii pn,city. erate to slow ~~~Y' soii tarrly easy to ~r perme.~cbility, k eracs en dry est,l~Lsh ~slwarsLrcngth, MQdernte to Rsgid intuke Mnderate resist- A4odcmt,e rrsest- ?livdermte f,a Iiigh shear Per[ane nFien ti ery rapid tate, moder- ance ka era- aisee to erostaii, very rap:d strength, high ~ LMgactcvl, s1ight periaieability. ate Ln low saan, moder moclcratee to low pcrmeabdity, Ioad-catrytng '~3►~ d~il~Ly, naCer-hvIsiing at,e to very water-haIdgn9 moderate to eapaeity; zxpacity rsspid perin~ cnp~ciLy , ve- 1.a►v water- :aodeaate to ~ility. abdify tatiati d~H'irax~t halding cu.- very rapxd to est.abiish on pacity permeabrlity vec y stvny lawn, ~ fAtr13, euy on , otllcr soils st{ ya ~ Appendix B Hydrologic and Hydraulic Calculations ~cn Outstanding , , , • d • Qtia DAVID EVANS AND ASSOCIATES, ~ 1 ~ ~ DRAIA1AGE CALCULATIONS FC]R FCEYST[)NE MEADC]WS Spokane Gounty, Washrngfon QASIN R1 A= 4,350 sq feet of ACP +GrP,A Vorume Required =(4,36a sq ft )124 = 1$2 eu. ft Porzd A A=63sq ft,P=561f Vtalurne =(4} 5')(63 sq ft.) +(0.375 cu ft fl £)(6fi i f56 cu ft Porrd B A=219sq ft,P= 2281.f Valrarrie = (0 5)(219 sq ft.) +(0 375 cu ft I11)(228 1 f) = 195 cu ft Vvlwme Provided =Pond A+ Pand B~ 251 cu ft > 182 cu ft BASIN R2 A= 2,357 sq feet of ACP GPA Vvlume ltequired =(2,357 sq_ ft)124 = 98 eu. ft. Aand C A=146sq ft,P=15411 Volume =(0 5')t146 sq, ft )+(0 375 cu. ft.ll.f )(1541.f 131 cu. ft BASIN A A = 67,161 sq. ft. = 15418 acres ACP Area = 7,740 sq. ft. 208 Va1une required = 7,740 sq. ft !24 = 323 eu. ft. 24$ Voluane provided = 550 if caf frontage-(6 lats)(20 L f❑f dnvewayllvt) = 4301 fof grassy ditch Volurne m grassy ditch _(430 1 f)(2' wnde)(1.75 cu ft Il.f.) = 1,505 cu. ft >323 cu ft BASIN 8 A=65,227 sq ft. = 14974 acres ACF Area = 6,150 sq ft 208 Valume required = 6,150 sq ft.124 =256 eu ft ,J Drainage Calculahons by Qoug Buskv, P E DAVID ETANS AND ASSOCTATES, INC. July 20, 2000 208 Volume provided = 5251 f❑f fCOntage-(71ots)(20 k f vf dn.~ewayllat) = 385 l.f of grassy ditch Volume in gassy ditch = (3851 f )(2' wxde)(1.75 cu. ft 1I f}= 1,348 cu. ft>25b cu ft BASIN C A = 59,754 sq ft =13718 acres ACP Area = 7,5$0 sq. ft 20$ Volume required = 7,5$4 sq ftJ24 = 316 cu ft 208 Volume pravided - 650 1 f. of frvntage -(71nts)(2[l l f. Qf drivewayllat} = 520 1.f of grassy ditch Volume in grassy ditch =(5241S )(2' wade)(1.75 cu ft Il f} = 1,820 cu. ft,>316 cu. ft. ❑rainage Calcutations by Doug eusko, PE DAVIi]I EVANS Alll'D ASSOCIA,TES, INC. Ju1y 20, 2000 DAVZD EvANs AvD AssOcIATEs B(DWSTRIIVfi, METH(7D {T'EN YEAR SFC]RNC DEStGN) PRc]JEC7 KEYSTQIVE MEpE3tJVV: DETENTiCJN SASIN pESfGN PF2U,lECT NC} JTSDO004 BASIl1'I Ri NUMBER OF pRYWELLS PF2OP[75Ep DESiGhlER DOUG BU5KC3, PE 1 5mgle (type A) 0 Dauble (tyPe B} ❑ATE July 20, 2000 Tatal Area (ca!c ) (see H1) 010 Time at Conc (raic )(see 1-111 ) 500 Com,pvsite „G" (calc ) (see 1-111 ) 090 Yime af Conc (mm) 500 Area (Acres) 01001 C' Factar 0 90 Impervious Area (sq ft ) 4360 356 VoIume Provrded 208 251 stcrrrn 334 Out#low (cts) 03 Area " C" Fac#or 009 #1 #2 #3 #4 #5 #6 #7 Time Ticne Intensi#y Q dev Vin V out Storage Inc lnc (min ~ (sec ) tin Ihr y (cfs) {cu ft } [cu tt y {cu ft ~ (#1 "60) tA*C'`#3) (Outf ""#2) [#5-#6) 500 30000 318 029 115 9000 25 5 300 318 0 25 115 90 25 10 600 2 24 020 142 980 -38 15 900 1 77 016 160 270 -110 20 1200 145 013 170 360 -19(] 25 9500 429 i} 91 175 4,0 -275 30 9800 1(]4 009 178 540 -362 35 2100 099 008 189 630 -449 40 2400 082 007 185 720 -535 45 270(} 074 007 987 840 -623 50 3000 068 006 190 soa -71o 55 3300 064 006 196 990 -794 6{] 3600 061 0 45 203 1080 -877 65 3900 060 005 216 1170 -954 70 4200 058 005 225 1260 -9035 75 4500 056 005 232 9350 -1118 80 48043 053 005 234 1440 -1 2a6 85 5100 52 0 05 244 153(] -1285 9(} 5400 050 005 248 9620 -1372 95 5700 049 004 256 9710 -1454 100 6000 048 004 264 1800 -1536 DRAENAGE POND CALCLJd.ATIOIVS Graasy swale'208' pond st❑rage valume = Frnpennous Area x 5 rn 112 m Idt = required 182 cu ft prar►ided: 251 cu ft. ❑K! DRYWELL RLQl9EREMENTa - 10 YEAR DESiGN 5TC3RM , Maxamurn starage by Bawstnng = req~ired 25 cu #t pTVvided: 334 cu. ft. ❑K! Numher and type of drywefls required = 1 SfNGLE 0 aDUBEE DAVZI) EV'ANS AND ASS[3CiATES PR(7JECfi KEYSTC]NE MEADDWS ❑ESIGNER DvUG BIJSFCO, P E PROJEC7 NC] J7SDD004 DATE July 20, 24(]0 BAS[N R1 71ME QF CONCENTRA7ION (mkn) 5urface preas "C" Tc (aveefand) Tc (gut#er) D85C6SptIOI7 (acres) Ct = 015 L2 = 5000 ACP 01001 090 Z'6 = 5000 dn►►eslsidewaf'ks 00004 000 Ll (A) = 000 Z2 = 017 1awKStlandsrape 00000 000 N(A) = 0 00 B= 1 50 earthen ditches 00000 000 5(A) = 000 n= 0 02 parkslpfaygrounds 40000 000 5= 0 01 fvrestlwaadland 00000 000 Tc {A} = f}fB d (ft) = 009 rrseadcawlpasture 00000 000 d (in) = 1.02 Total A Comp "C" 01001 090 L1(6) _ 000 Tc{gu} = 0 90 N(B) = 000 Tc(A+B) = 0 00 Q=C"I"A= 0.29 5(B) = 0[}0 Q(est ) = 0 29 Tc(tot 500 Tc (B) = 00 Intensify = 3 78 A= 0308739 WP = 5$371 R = 00529 lA = 092 Tc (totaf) ~ Tc (over9and) + Tc (gut#er) Tc(gu) = 090 Tc (ouerland) = Ct*(L'f'NIS"Q 5)^0 6} Q(est) = 0 29 Ct= 0 15 Li - Length of {3verland Flow Haldirag = 0 94 N=~ctian factor of ovedand ftow ( 4 for average grass rouer) S= aderage slope of nvedand flow Tc (gufter) _ Leng#h (ft )Nefocity (ft Isec )160 B = Bottom width of gutter or ditch Zl = rrtveese of cross s9vpe vne of ditch Z2 = Anverse of crass siape fwro of ditch d= depth of ftow in gutter (estimate, check esticnate with Flow) Area = d"F3+d"2!2'(Z1 +Z2) Wetted penmeter= B'd+(alscn(atn(1IZ1))+ilsin(atn(11Z2))) Fiydraulic Radius = R = ArealliPVefted Penmeter Velocaty = 1 4$61n*R " 667 *S^ 5 Flow = Velocity"Area n = 0 016 for aspnalt s' longitudina8 slope of gutfer DA,VID EVANS AND ASSOCIATES 60WSTRiNG METHflD (TEH YEAR STDRM DESI GN) PROJECT KEYSTC?R9E iViEADOWS DETEIVTION BA51N DESBGid PRDJEC7 NO J7SDO004 BAS I N R2 NUMBER OF ❑RYWELLS PRQPC]5ED pESIGNER DDUG BUSKQ, P E 1 SingEe (tyPe A) 4 Double (tyPe B) DATE ,luly 20, 2000 Total Area (calc ) (see H 1) 005 Ttme of Conc (cafc ) (see H1) 5 00 Composite "C„ (calc ) (see H 1) 090 Time of Conc (enin) 5 00 Area (Acres) 00541 C' Factor 0 90 Impervious Area (sq ft ) 2356596 Volume Provided ~ 208 131 stgrm 174 C3utflow (cfs) 03 Area C" Factor 005 #1 #2 #3 #4 #5 #6 #7 Trme Time Interssity Q dev V in V out Stvrage Inc lnc (min ) (sec ) (in Ihr ) (cfs) {cu ft} [cu ft) [cu ft } (#l -60) (A-C-#3) {outf *#2) (#5-#B) 500 300 00 318 015 62 9000 -28 5 300 318 015 62 90 -28 10 600 2 24 D 11 77 180 -143 15 900 1 77 009 86 270 -184 20 1200 1 45 007 92 360 -268 25 1500 1 21 0{}6 84 450 -356 30 9800 1 04 005 96 540 -444 35 2100 099 004 98 630 -532 40 2400 0 82 004 100 724 -620 45 2700 074 004 141 810 -709 50 30[]0 0 68 0 03 143 900 -797 55 3300 064 003 106 990 -884 64 3600 061 003 110 1080 -970 65 3900 0 60 0 03 117 1170 -9 053 70 4200 058 003 121 1260 -19 39 75 4500 056 003 125 1350 -9225 80 4800 053 0 43 126 1440 -1314 85 5100 052 003 9 32 1534 -1398 90 5400 050 002 134 9620 -148+6 95 5700 049 002 138 1710 -1572 100 60(30 0 48 002 943 180{] -1657 _~~e_~,~~~_~r------------------------------------------------~_W_~.~.____~_ QRAlNAGE PC)ND CALCI]L4T9ON5 Grassy swale `208" pand stvrage vale,me = Impervtous Area x 5 in 112 irr Ift = required 98 cu ft prnvided: 131 cu. ft. ❑KI flRYWELL, REQLJIREMENTS - 9(] YE►4R aES1GlV ST+DRM . IVlaximum storage hy Bowstrrng = required -28 cw ff provided: 174 cu. ft. OK! Number arrd type of drywells requireci = I SINGLE 0 aaUBLE DAVITD EVANS AND ASSOCIA'TES PFdflJEGT KEYSTONE MEADt7V!!5 DE5IGNER QOUG 6LJ5K0, PE PRQJECT NC] JTSDD004 C}ATE July 20, 2000 BA51 N R2 T1ME OF GQlVCENTRATI[]N, (mEn) Surface Areas "C„ Tc (oVerland) Tc (gutter) Descriptian (acres) Ct ~ 015 L~ ~ 5000 acP 00541 090 Z'! = 5000 dnueslsidewaiks 00000 000 L1(A) = 0 f1a Z2 = 017 lawnflandscape 00000 000 N(A) = 000 B= 1 50 earthen ditches 00000 000 S(A) = 000 n= 002 parkslplaygrounds 00[]00 000 s = 01 foresttwwaodland 00000 000 Tc (A) = 000 d(ft) = 0 06 rrseadowlpasture 00000 000 d (in) = 0.74 Tatal A Comp "C" 00541 090 L1($) = 000 Tc (gu)= 108 N(B) = 000 Tc(A+B) = 000 Q= G"i*A= 0.15 S(B) = 000 Q(est ) = Q 15 Tc{tat y = 500 Tc(B)= 00 VntensEty = 3 18 A= 0189427 Wp = 46635 R = 00406 V = 078 Tc (total) = Tc (overland) + Tc (gutter) Te(gu) = 108 TC (vverland) = {Gt"(L1'ry!5"D 5)1*0 5] Q(est) = 015 Ct=O 95 L1 = LengtFa of C}verland Flow H4lding = 094 N= fncbon faetoe o# overland Bow ( 4 far average grass cover) 5 = average slope of overland flow Tc (gutter) = Length (ft )lVelocity (ft lsec )I60 8 = Boftom width of gutter or ditch Z1 -invErse of cross slo,pe ane af ditch Z2 =[nver5e of cross 51ope twv of dttch d = depth of flow in gutter (esbmate, check estimate wifh Flow) Area = d"B+ti"2I2*(Z1+Z2) Wetted perimeter = B*d+(1lsin{atn('iPZl)}+1lsEn(atn(l1Z2)l) Hydraufic Radius = R = AreallNetteti Perimeter Velocity = 1 485in*R " 667*s" 5 Fivw = Velvciry*Area n = Q 0 16 for asphalt s = ilongitudina0 slope nf guner DAVII1 EVANS AND ASSOCIATES BQWSTRING METH00 (TEM YEAR STORM DESIGN) PRDJECT KEY5TC3NE IVIEADOWS DETENTIC3N BASIN QESl~`,N PRO,IECT N0 JTSD0004 BASIN A NUMBER QF DRINVELLS RROPOSECD QESiGNER DC3UG BUSKO, P E 1 Single (tYpe A) 0 Dauble (t1'Pe 8) DATE Jufy 20, 2000 TotaP Area (r.a1c ) {see 1-17} 154 Tfme of Gonc (calc ) [see 1-11 ) 500 C'Qmpo$it$ rrp.~a ('~1~. ) ($ee Fll ) ~1W0 lr Trme of Ganc (min) 5 00 Are~ (ACCes) 15418 +G' Factor 040 Impervious Area (sq ft) 67160808 Vcalume Provided 208 1505 starrn 2305 Outflow (cfs) 03 Area ` C" Factor Q 62 __~--------------------~__-----_~___~._.~~.P_-------------------------------- #1 #2 #3 #4 #5 #a6 #7 Time Time Intensitjr Q dev V in V out Storage Inc !ne (rrun ) (sec ) {in fhr } (efs) (cu ft ) {cu ft ) (cu ft ) [#1'60) (A*C-#3) (autf'#2) (#5-#6) ---------_..~_..a__.~~,..-----------------------~_---___-_~-__~_.~~.~~,.~__-------- 500 30000 318 1 96 78$ 9000 698 5 300 318 196 788 90 69$ 10 600 224 1 38 970 180 790 9 5 900 1 77 1 09 1094 270 824 20 1200 145 089 1154 3641 804 25 1500 1 21 0 75 1195 450 745 3[] 1800 1 04 0 64 9 220 54{] 680 35 2100 091 056 9236 630 605 40 24(]0 082 051 9265 720 545 45 2700 074 046 3279 810 469 50 3000 068 042 1301 900 401 55 3300 0 64 039 1343 990 353 60 3600 061 038 1393 1080 313 65 3900 060 0 37 1481 1170 311 70 4200 058 0 36 1539 1260 279 75 4500 056 035 1589 1350 239 80 48(]0 053 033 1602 144(} 162 85 5100 052 032 1668 7530 138 90 5400 050 4 31 1697 1620 77 95 5740 049 030 1753 1770 43 10(] 6000 048 030 18{]6 1800 5 ___....-----------------------v_~.o__.~~~~~---_---___..........------------------- DRAINAGE PC3ND CALCULATIC3NS Grassy swafe '208' pond storage volume = lmpervious Area x 5 in 112 ira Ift. = required 323 eu ft provided: 1505 cu. ft C7Ks C3R1rWELL REQLJIREMENTS -14 YEAR DESIGN SYORM , Maxirraum stocage by BowstrEng = required 824 cu ft pro►►ided: 2305 cu. ft. OiCf Number and type of drywefls required = I 51NGCE 0 DOUBLE DAVTD EV,ANS A,ND ASSUCIATE5 PROJEC7 KEYSfiONE MEADC3WS DESIGNER DC7llG 6EJSKC), P E PROJECT ND JTS❑[]004 DATE July 20, 2000 BA51 N A TtME +OF CdNCEN7RATIUN (mrn) SurFace Areas °C" Yc (overland) Tc (gutter) oescnptrorr {acres} CE _ 15 L2= 36200 averalB basin 1541$ 040 Z1 = 033 drrveslsidewafks 00000 0 00 LI{A} = il i}4l Z2 = 433 fawMandsr-.ape 00000 fl Oa N(A) = 000 13 = 200 earthen dEtches 00(]00 000 S(A) = 000 n= 0 03 parkslp9aygrounds 00000 f]0 s= 001 #orestlwoodland 00000 0 00 Tc {A} = 000 d(ft) = 053 meadowlpasture 00000 000 d(in) = 636 Total A Comp "C" 1 5418 040 L1(8) = 000 Tc [gu] = 3 57 IV(B) = 000 Tc(A+B) = 000 Q=C*I*A= 196 S(B) = 000 ct(est 1 95 Tc(tot y = 500 Tc (B) = 00 Intensiry = 3 18 A= 9 952597 VIIP = 31162 R = 03699 V = 1 69 Tc (tatal) = Tc (overtand) + Tc (gvtter) 'Fc(gu) = 357 TC (preerland) _Ct*{L1 "NIS"0 5)"0 6) Q(est) = 1 95 Ct=0 15 L9 = Length of DVedand Flow Holding = 630 N= frrcticrn factor of overlarad flouv { 4 for average grass caver} S= average slope of oVedand flaw Tc (gutter) = Length (ft )Nelocity (f# Isec )160 B= Bottom widfh of gutter or dFtch Z1 = inverse o€ cross sfope one of ditch Z2 = inverse of ceoss sfope two of ditch d= depth of flow in gutter (estrmate, check estimate with Flow) Area = d`B+d"2J2*(Z1+Z2) Wetted penmetsr= B"`d+(91sin(atn(1lZ9))+91sin(atrr(I IZ2))) Hycfrauhc Radius = R= ArealVlletted Penmeter Velocity = 1 4861n"R" 667`s" 5 Flow = Ve[DCity*Area n= 0 016 for asphalt s= iongitudinal slope of gutter DAVID EVANS AIV'U ASSUCIATE5 BOWSTRING METHOD (TEN YEA'R STDRM DESlGAi) PROJEC T KEYSTONE MEAD4WS DETENTIaN BASIN C]ESIGN PROJECT N(7 JTSDD004 8A5IN B NUMBER OF DRYWELL5 PRaPOSED ❑ESIGNEFt DC}UG BU5KO, PE 9 Single (h+pe R) 0 Double (tyPe 8) DATE Juiy 20, 2000 Totai Area (ca[c ) (see 1-11) 1 50 Tirne of Conc (calc ) {see 1-19} 500 Camposite "C" (calc ) (see 1-11 ) 040 Trme of Cvnc (mm) 500 Area (Acres) 14974 C' Fac#car 0 40 frnpervious Area (sq fk ) 65226744 Vo[ume Provided 208 1348 storm 2064 C]utfiow (cfs) 3 Area ' C" Fac#ar 060 #1 #2 #3 #4 #5 #6 #7 Tirne Time Intensity Q dev V in V aut Storage Inc lnc (min ) (sec) {in Ihr } (cfs) (cu ft } {cu ft ~ {cu Tt ) (#1*60) (R"C*#3) (Dutf "#2) [#5-#6) 500 30000 318 190 766 9000 676 5 300 318 190 766 90 676 10 600 2 24 1 34 942 180 ► 62 15 900 1 77 1106 1062 270 792 2[] 1200 1 45 087 1131 360 771 25 1500 1 21 072 1161 454 711 30 1800 1 04 062 1185 540 645 35 2100 091 0 55 1200 1530 570 40 2400 082 049 1229 720 509 45 2700 074 044 1242 810 432 50 3000 068 0 41 1263 900 363 55 3300 064 038 1304 990 314 60 3500 061 0 37 1353 1080 273 65 390[] 060 036 1438 1170 268 70 4240 058 035 1495 1260 235 75 4500 056 034 1544 1350 194 $D 4800 053 032 1555 1440 116 85 5100 052 039 162(] 1530 90 90 5400 050 030, 1648 1620 28 95 5700 0 49 029 1703 1710 -7 140 6000 048 029 1754 1800 -46 ❑RAINAGE PC)N0 CALCLJI_A,T1QNS Grassy swaPe'208' pond storage volume = Imperviaus Area x5 in ! 12 ira Ifit = required 256 cu ft pravided: 1348 cu ft. OK! ORYVIIELL REQUiREMEfdTS - 10 YEAR DESIGN STC)RM . Maximum sforage by Bowstring = requirsd 792 cu ft provided. 2064 cu. ft, [}K! Number and type of drywells required = 1 51NGLE 0 D(]UBLE DAVI'iD EVANS ANY3 A,5SUCIATES PRCJJEGT KEYSTONE MEADC3WS DESIGNER DC]UG BUSKQ, P E RRC}JECT ND .]TSDO004 C1A7E July 20, 2000 BFISIN B TIME dF CC]NCENTRATIC)N (min) Surface Areas "G" Tc (overland) Yc (gutter) Ciescnptaon (acres) Ct = 015 L2 = 44600 vVerall 6asin 14974 040 Z1 = Q 33 dnveslsidewalks 00000 000 L9(A) ~ (30 Z2 a 033 EawMandscape 00000 000 N(A) = 900 8= 200 earthen dttehes 00000 000 S(R) = 000 n = 003 parkslpraygrounds 00000 d[]0 s= 0 01 forestlwoodland 00000 000 7c (A)_ 000 d[ft] _ 052 meadowlpasture 00000 000 d(in) = 6.24 7atal A C❑rrap °C„ 14974 040 LI(8) = 000 7c (gu) = 4 44 N (B) = 0(]0 Tc(A+B) _ 000 Q=C'I*A= 1.90 S(B) = 000 Q(e$t y = 1 ss Tc(tvt ) = 500 TC{B} _ 00 Intensity = 318 F1= 1 129232 WP = 30952 R = 03648 V = 1 68 Tc (tntal) ~ Tc (overland) + Tc (gutter) Tc(gu) = 444 Tc {overland} = Ct"(L1"NiS^O 5)"0 fi} Q(est) = 1 89 Ct= [l1a L1 = Length of averfand Fimw Halding = 776 IV = fraction factar of averland flauv ( 4 for average grass cover) S= average slope of ovedand flow 7c (gutter) = Length (ft)Nelocrty (ft Isec )I80 B= Bottom widdh of gutter or dEtch 21 = Enderse of cross slope one of ditch Z2 _inderse of cross slope tw❑ of drtch d= depth of flvw m gutter (estimate, chsck esbmate with FEvrna) Area = d"B+d"212*(Z1+Z2) Wetted peruneter = 8"d+(11sin(atn(11Z4))+11san(atn(91Z2))y Hydraulic Ftadius = R = AreaMfetted Penmeter Ve9acity = 1 4861n`R " 667"s" 5 Flaw = Velocity*Area n = 0 016 fQr asphalt s= fvngitudiraal slape of gutter I)AVID EVANS AND A,SSCI~~ATE5 gO1N5TRIIVC METHUD {TEN YEAR STi]RM DESRCN) PRC]JECT KEYSTONE ME4DOWS DETENTIOlV BA51tV DESEGN F'ROJEC7 hlO .DT5D0004 BASIN C NL9MBER C7F DRYWELLS PRQPOSE[7 DESI{'aluER ❑QLfG BLJS}{D, P E I Srngle (iyPe A) []ouble (tyPe B) DATE July 24, 2090 Totai Rrea (ralc )(see H 1) 1 37 lirne of Canc (calc ) (see hl1 ) 500 ~Cnmposae „C" (CaIC ) (5ee H 1) 040 Trvte of Conc (mrrr) 500 Area (ACres) 13718 G' Fac#or 040 Irnpervious Area (sq ft ) 59755608 VaEume Proaided 208 1$20 storrn 27$7 gui°f!❑w (cfs) 03 Area * C" Factor 055 #9 #2 #3 #4 #5 #5 #7 Trme Tiraie fnterasity Q dev Vin 1J aut Starage !nc Inc {min } (sec ) (m Ihr ) (cfs) (eu #t ~ (cu St } (eu ft) (#1 *60) {s-C-#3) (ouff *#2) (~5-#6) 5 00 300(l0 3 18 1 74 701 9000 611 5 300 318 174 701 90 611 10 600 2 24 1 23 863 980 683 15 900 177 097 973 270 703 20 1200 145 080 1036 360 676 25 1500 129 066 1064 450 614 30 1800 1 []4 0 57 1085 540 545 35 2100 091 0 50 9100 630 470 40 2400 082 045 9126 720 406 45 2700 074 041 1138 810 328 50 3000 068 037 9157 900 257 55 3300 064 035 9995 990 205 60 3600 061 033 1239 1084 159 65 3900 060 033 1318 1170 148 70 4200 D 58 032 1369 1260 109 75 4500 056 031 1414 1354 64 80 4800 053 029 1426 1440 -14 85 5100 052 029 14E34 1534 -46 90 5400 4 50 027 9510 16241 -1 1(l 95 5700 049 027 1560 1710 -9 5Q 100 6000 048 026 1607 1800 -193 ORAINACE Pf]ND Cr4LCULATEC3IVS Grassy swale '208' pand storage volurne ~ Pmpervious Area x 5ira 112 m Ift = eequired 315 cu ft provided• 1820 cu. ft OK! DRYNELL REQCJiFtEMEMTS - 10 YEAR DE51GN 5TOfiNl , Maximum storags by Barvstnng ~ required 703 cu ft pravided: 2787 cu. ft flK! Number and tyrpe of drywells required = I S1NGLE 0 DULIBLE DA~ID EVANS AN'li7 ASSOCIATES PRoJEcY KEVSroNE MEAoowwS QE5IGNEFt DOUc BusKO, P E PRQ.9ECT ND JTi 5DOO[;4 T3ATE ,1u1y 20, 2000 BA51N C YIME OF CQNGENTRpTfON (min) Surface Areas "C" Tc (overiand) Tc (gutter) Descnption (acres) ct = 015 L2 _ 36000 ~~eran easin 13718 040 Z1 = 0 33 8nveslsidewa[!cs 00000 000 E.l {A} _ 000 ?2 = 033 IawMandscape 00000 000 N(A) _ 000 B= 200 earthen ditches 00[}{]0 aoD $(A) = 4 00 n= 003 parksJplaygrnunds 00000 000 s~ 0 01 farestlwaodland 00000 000 - Tc {A} = 040 d(ft) = 49 meadewfpasture 00000 0 00 d (in) = 5.88 Total A Cornp °C" 1 3718 040 LI(B) = 000 Tc [gu] = 3 69 N(B) _ 000 Tc(A+B) = 000 q-C*f*A= 174 S(B) = 000 Q[est ] = 1 72 Yc(tot 500 Tc (B)= 00 Intensity = 3 18 A= 1 059233 WF' ~ 30320 R = Q 3494 V = 9 63 Tc {tqtai} = Tc {ovedand} + 7c (gutter) 7c(gu) = 3 69 Tc (vveriand) = Ct*(L1 "IdIS"0 5)1,06) Q(es#) = 1 72 Ct=0 15 L°f = Length of OVerland Flow Holdirog = 626 N= frictiora factor of overland flow { 4for aVerage grass cover} 5= average slope of oVe~and flow 7c (gutter) = Length (ft )Nelocity (fLIsec )160 B =Bottom width of guttee or ditch Z1 = inverse of cross s1npe one of ditch Z2 = rnverse of cross sfope tvvo o# ditch d= depth of flvw in gutter (estimate, check estimate with Flow) Area = d'8+d"Z12"(Z1 +Z2) Wetted penmetec= 8*d+(11sin(atn(1lZl)}+I Issn(atro{1IZ2})} Flydraufic Radrus = R = Area/Wetted Renrneter Velocaty = 1 48SIn*R " fi$?'s" 5 FVvw = VePocity'Rrea n ~ 0 018 far asphalt s= longitudtnal slope of gutter - Appendtx C Post-DeveEoped 6asin Map DAV'li3 EVANS ANU A55OCIATES, ~ W ~ Z • i i Y I LL. ~ ( 4 ~ l~ ~ ~ F E • +N ~ - I c0 r ~ v CCAAA P,&747 ~ i . ~C J~ R..,' : ~ r„y"` j !o w _ 1 ~ I _ ' 4 ~ •sy' p ~ 1i • ~ ~ • y S.+Vr. ~ 44,b Y7 ~ ~ ~ i y_--• . _T_~ ~ ~ ~ r]t~ ~ ~ ~ aNO B N OTTOM AREA=219 SQ. FT. i oo POND C ~ ~`o ~ I aTTOM EL,-2006.6$ BOTTONC AREA=146 SQ. FT. ' ~1 flU~P• RAMPS AND BaTTOM EL.-2006.85 YF'E A DW, R9M EL-2007.18 ~ ~WARNINGCONSZRUCT STRIPS PER NAN~ICAP SPOK. C0. STD, a-~--z , RYWELL: STA. 6+92.14e 25.96 LT.--- 90 N~ TYPE A DW, R!M ELT2007,35 ' ~ ~ F DRYhNEL STR. 7+$7.50, 26. II ~ i ~ 4~1Y~ ~ n . ' , 02' LT. ~ti~, ~ I ~ ° I • ~ n '~a, t • ~ w i e r t " 4 , ti e 'r ' `x ~ ~ r ~ , r.r ~ Ir I I . . . . • ~.~P-; , ~ ~ • r - - y ± ~ f • 1 , ~ ` , t l . 200 STA. 9+02.43, END Ta~'Eft 76 ~,~/~I ~ l. \ l!~~ ~ _ _ _ _ _ ~ ~~S ~ . _ .,w ~ i • ! ~"li n qrPr FT- ,'.w^\ LOCATE EX. SIGN ----I_ EXISTING EDGE E PLA7ES PER SPDKANE C0. STD. BEHiND C11R8, 7+88.40 I~ QF AGP 5r C' 7+00 - ~ t_. ~ ~ ~B+OQ a' 9+00 . 1 AV~NUE N$9•46'00°E ' ~ _ ~r ► o ( SAINCUT LINE ` ~ ~ - - - ~ _ . _ . STA. 7+40.48 4TFI A1fE.= Ex. CL STRlP~ MONUMENT LINE STA. 10+00 MORROW LANE , _____.___.,___i~~i'____~w. _._~___..._._...W_•-.~__..._ M___L_..._..~;,r~^_._ __._._,'f[`,,...__..____,... i ~ ~ a 10 20 40 I~ 5 x I I"=LO' ~ ~ w LLi DEVELOPER'S ,APPROVAI,, Z ~ ~ z F. ~ ~ I I . ~ i ~ ~ ~ , KEYSTONE MEADOWS SUBDIVISION , ROAD AND DRAINAGE PLANO SPOKANE COUNTY, WASHINGTON P-1860-98 ~ ~ ~...-~~,.-.,yw . ~~.r .r= p'~.~e.v,...-~~~~~.,..:..~,..M.~R~',~.~.~°,r,~ r • aTOLIVE 2 I~LI1f~ ~ f~ ~ QLIYE~I p3 a'~ ~ zI ui: w~ 0 $ u, .,.e.-.J... flLIVE mJ ~ z : ~ I YALLEY ~ ca ~ w W . . ~~k . ~ ~.-Q,~ ~ O°,~~„ Q t D~ ~ ? x ~ x a~, . VAILEY ~ ~AY , , . ~ w 3~ . ; WT a. ~ WIXO N~{ W I4 NIXOFi @IIXON ~1 NIXQN.: LU ~ g hI ~ IXQN m i ~ h f ~ ~ ~,t~FAYwFR TlH MAIR mAIE MAIh a y~,..~E c3~' MAIN AVE .,._._~,w.,ryNAI~I MAIN 31 ~ . .w.. a ~ ^2,. Q . RIYERSIQE AI1N ` IY~FISIDEt ~........r~ A! r v~ I a ~ A14ER519E RlVEAS~E 3 ~ ~I ~ ~IV Q AIYER510E ~ a~ os } • ~ ~~~E 21 ak rI Project Locat1~arI : SPRAGUE L r~ t ` 'o' w;2ND 1ST ,ry,. ~ $ A d$ 2N0 m 6ased o; m~ cn J Educetlan 3A1) ~Ris! 3AD 3RD AV6 J g 0 ~i ~i -,„3RD AVE [X 31~p AVE 4TH AVE 4TH AVE x wa m~ SRD:CT ~n- tt _ ~ Y..~.... ~ C4 j r ~Ke stanei1~ STHAVE S.~H.~STH_.~ > ~„~SiM ~ 5if4 CT~ ~i m~ p v! z6TH ~ .r4 lig m ~ 6TH ~R Ws ~ 6THa ~'~.,...6TM _ 6TH.~R,_ AVE ~DTH ~.w...,....~~.~ N,- 7TM k...,.,..v~.. , AV~ w»-~ra.,.. I ~ t Z ~ O I 7TH AVE W Y' ~ $ ~ ¢ I ~H _ kYE, u, ~ TTiI lx~ W a: J1., o: M s~ o L ~ pC~ , c~~ wu , a s€ } , 8rH AVE Lu e v to~ 1 i ff' m~ s 9 ~ ~e 9Tli AVE _ ~ F~.9TH mj AYE = i... .,2 ~s r9TH1.. AV~ ~ Q, ~ ~ 9TH y~, y; a 1..91H nr~. ~ ~ ~9TH AVE ~ ~ z~ q~ 1~TH ~n AVE w~ =,10TH 9TH CT~ !DT a ~ ' ~ OTH g T ..A. ~~,y 11T~! u~ ° 11TH . AVE ~Fx 'Irr~ C ~ ~ ~ r ~ R - , ' J. di QpPnr[u ary v 0. 4;~ d. 12TH AVE EI~. 3=12TH AVE: ' . ~ ,~,r • . ~ . __e, . . ,..w._...~ a,~.~~~~,,..~.Y.,~~.,, ~ ^ w.~~....,~,~.~ F s.~. . y-=lry.~~,.~ ..~<u I ~ w, _ _1a~TN a u E 137H , AYE, O~ x ~ 13TH f _ #C27 C ~ ~.t a 14TH 14TH 14TH AVE~ VICINITY MAP NOF TO SCALE