28255 DRAINAGE REVIEW FILES
S P O K A Z-T E C O U N T Y
DnZSTCZ` CE EVGR*ZEE'.L~IG AND ROAD6 A DIVISION OF THE PUBLIC WORKS DEPARTMENT
°X1E[ia=A. Joh-ts, PE, countv Engineer
Januan- =7. 1 9,?9
Km GeibeL P.L. 2 '
DLvzd E-: ans & Assc~,~iates 11 W. Cataldo ~
spokane-Nva 99201 Re: Road & I?raina!ae Comments 1 for Valleyway Addition, P-1797 .
Km
Thz CoLmtc Esgineers hax-e performed a cursory review of the road and drainage plans for
th-6 proiect_ Tae folloxtiznLy items must be addressed prior to acceptance of the plans:
'V""* Ir aFoea.rs iom :he elevations shown on the topo map that small ditches should
pr&abh- Ez canscructei to direct water to Pond F from the east and west.
ot- that Dond F should be seeded with a dryland mixture, and that the other ponds
nzec to be seeded or sodded .vith a turf grass.
Y The aorth-south dimension on the Pond D easement is shown as 38.5' on the lot plan
and is 3 S.:5- on the road plan. Please coordinate. .-:~z oowe- Pole on Vallevway needs to be relocated 2' behind the back of the curb, as
mea-s-ure-d :o the 3-trzet-side face of the pole. o~,~, ~ a\-;~ment :alcul3tions need to be submitted for each roadway. . .
/
~ an :zspecaion a-creement and an inspection surety need to be submitted to the County. -
Y. Inst_ad ot 3 seP arate Dead End sian on the east side of Sonora, a Dead End Plaque
(NV=4-1P1 needs to be mounted on the street name pole. Also, note that two nine-light mar~ers (,%-16-I02_ red on red) need to be mounted on the Type III barricade.
P:;-a~e ca11 if s-ou haY e an\- questions.
:3^~ IA' 3rcad--2y Ave •Spokane, N:a 99260-0170' ~(509) 477-3600 FAX: (509) 324-3478 TDD: (509) 324-3766
Sincerely,
Spokane County Engineers
~
. ~
Doug Busko, P.E. -
c: Greenfield III Incoiporated
' P-1797 Project File ~ .
. , ~ ~
DRAINAGE REPORT
Valleyway Addition -
Spokane County, Washington
OFFICI~';L °UBLlC DOCl.rAtEN?'
Prepared For: SP04CANE COUNTY OFFICE
Greenfield. III Incorporated 0RU"INNA'd ~
N. 8500 Division PRp,}ECT 9~ .
Spokane, Washington 99208 SUBMiTTA1
MT1JBN f0 COUNi Y ENGINEER
RECEIVED
JAN 2 S 1999
GRNF0001 SROKANE COUNTY ENGINEER
.
. ~
y
.
January 21, 1999 l •
~NAL
EXPIRES
Valleyway Addition Design Report ~ C n
AIGRNF00011DRAINREP.doc
o • onals
O , . QLtality DAVID EVANS AND ASSOCIATES,
1
TABLE OF CONTENTS
INTRODUCTION .........................................................................................................................1
' THEORY ......................................................................................................................................1
Pre-development Basin 1
Post-deve/opment Basin 2
HYDROLOGY ..............................................................................................................................3
Pond Facflities 3
Conveyance Facilities 3
CONCLUSION .............................................................................................................................4
' APPENDICES
Appendix A- Site Location and Soils Information
Appendix B - Basin Map
Appendix C - Basin Calculations
Appendix D - Hydraulic Calculations
Appendix E- Supplemental Roadway Information
'
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Valleyway Addition Drainage Report i
A/GRNF0001/DRAINREP.doc 1/21/99
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INTRODUCTION
' This report contains the design calculations and stormwater analysis for the proposed Valleyvvay Addition
- subdivision in the Spokane Valley. The project site is more specifically located approximately 0.25 miles east of
Sullivan Road and abuts Valleyway on the south property line. The proposed 11-lot subdivision will include the
development of approximately 600 feet of Sonora Street and the widening of approaimately 200 feet of Valleyway.
Stormwater disposal will be handled in the conventional means of 208 ponds and drywells. This report is provided
in order to demonstrate how the proposed stormwater management facility can meet the requirements of the Spokane
' County Guidelines for Stormwater Management.
THEORY
Pre-development Basin
The proposed subdivision covers a little more than four acres «rith the addition of approximately two acre of off-site
area contributing to the stormwater facilities. Currently the site is undeveloped ground and covered with dryland
grasses. The site is generally flat v&rith less than 1.0% of fall across the entire site. A sma11 area north of the
property drains toward the projcct, however a earthen berm approYimately 2- 3 fcet high along the north property
line prevents any stormwater from entering the property. A similar berm runs along the east property line also
preventing any stormAvater from entering the property. As a result the only substantial off-site area that drains on-
site is the development to the west. Although topographic information was no acquired for this area, a field
observations shows that each lot slopes from the front of house out to the street and from the back of the house to
' the back property line and thereby onto the property. In addition to this off-site area, a sma.ll area at the southeast
corner of the project also drains into the stormwater facilities for this development. Both of these areas are included
~ in the stormwater calculations.
The soils on-site are classified as Garrison gravelly loam by the Soil Conservation Service and are typical of the
Spokane valley floor (Appendix A). This soil is characterized as a glacial outwash and is some«rhat excessively
drained. It has been approved by Spokane County as acceptable for drywell use without the need for addition
testing.
Valleyway Addition Orainage Report 1
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' Post-development Basin
For drainage analysis the project has been divided into four basins, A through D(Appendix B). With the exception
' of basin B. the stormwater facilities for each basins have been designed to accommodate the 50-year storm event due
to the off-site contributions to each basin. The stormwater facilities for basin B however are designed for the 10-
year storm event as is required by the stormwater guidelines.
' Runoff coefficients for each basin were determined using a combination of 0.9 for impervious surfaces and 0.1 for
all landscape and lawn areas. For design purposes, each lot is assumed to have 3,500 sq. ft. of impervious surface
to account for roofs, sidewalks, driveways, etc. The area breakdown for each basin can be found in Table 1.
Table 1
Basin Characteristics
;
•:.~::::.~:.~:.~.::.......•----._.....t~ • ~ •••n•~r:~x:•::•:t:•::.; . .
•
• .
:.;:.::•:•~r:-r:::':t::;'::;;::
~.ti , , . . _ .
. ; . •
..""._.........r•• . .
"...""•rr r • . ....::.;.;}?v$S$:ti:}SS: '
r.. r...x.............................~......... ...::~•'r'r}:;::v$•}r}XL;:::
• :.::r;r:r:.~..
..............x: ~v.~:.:::.:: ..:.~:r...:C?s: • vr:.ir:::::::: : ,
rT}
ry..... :w. ~ ~ . . . .
• . . r'P' ti:.; ~ v ~ • . . :
: Mx.......... ~ . . r..~. ~..:.::w::.•.-.-.-:.•.-::: . . • { i'"
......"""'......4 . . . ~ . . . . . :r : :w. ~ ~ }iii'r"'
• ....................:.~:.:;::::•:::•:.:l~t.t'e~,. R.tt~
~ . . -
..l...rtiYf.f........... . .................AVYJ..Y'}l......::.~:: _......:.........................'.•.:.-__...._.........J.'}::.f.............. - ......1.{`~•~'Y':::_•"_•'._...:.
._.........Y.. ...1 . . . ti.~.ti............._................................. .
. ..............1ti.~.L..L..L.........._...........................r. . . . . . ' •iJi:.:~:.: : 1:'f•:.•.•::::::::....
................l...1 l... .
x.{ ~i...... . . : -.:.~:.~.vr:v . : :~?:•::::~:fi...
..~5 . . . • . -
. . ........f......... :::':•::.~ii:i.~:~.:.~:'
, .
• -
. ti............. ' ' .•.9... ..1...... ~.::Y:::::::::: :'::.~:::.:i•:::i . a. : ~
.
...............r..ti....... . . , .
f..{... .~1. .f . .
.
. . .
'}4"''•}••~ J~....... .
. ........•f::::.V::l:. .
•
. . . • • ' . •
V.tiYlf.':. ~.:{•J:•.•: •.ti1{•• .
. . .
e
~a~~~~~~:
. . .........1.~1...:.~:.~:.~:.~:::: . .
. : . , .
Basin A 127$00 0.32
Asphalt & Curb 7,465 0.90
' Impervious Surfaces* 271,600 0.90
Lawns & Landscape 921435 0.10
Basin B 49,730 0.49
Asphalt & Curb 10,961 0.90
Impervious Surfaces* 13,285 0.90
. Lawns & Landscape 25,484 0.10
Basin C 49,150 0.39
Asphalt & Curb 102961 0.90
' Impervious Surfaces* 7,200 0.90
Lawns & Landscape 31,189 0.10
' Basin D 52,625 0.31
Asphalt & Curb 3,275 0.90
Impervious Surfaces* 10,500 0.90
LaNvns & Landscape 385850 0.10
* Includes sidewalks and 3,50 s9. ft per lot for roofs, drivewaYs, etc.
In each case, the front half of every lot is assumed to drain towards the street and the back half towards the back
property line. The objective of this drainage design is to collect, store and dispose of the post-developed stonnwater
runoffin accordance vvith stormwater guidelines for Spokane County.
Valleyway Addition Drainage Report 2
1/21/99
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HYDROLOGY
Pond Facilities ~
The proposed project is situated within the Aquifer Sensitive Area as designated by Spokane County. As a result, all
'
surface runoff from asphalt surfaces w111 be treated in «208" bio-filtration swales pnor to subsurface disposal. The
size of the ponds have been designed to accommodate the first one-half inch of runoff from the road and curb
surfaces. Ponding depth has been limited to 0.5 feet maximum before discharging to the subsurface. A .
combination Rational Method / Bowstring analysis was run for each basin using the appropriate storm event to
determine the peak discharge and necessary storage, the result of which can be found in Table 2. The depth of
ponding in swales with outflow structures was limited to one foot.
Table 2
~ Ponding Characteristics
. . .
. . . . : .
. . . . ,
. . . . . . . . . . ti.................. .
. . . .
.
. . • , t: .e:rr.
. ........:•.:.r
r:. x ~ Y ~
. . . . . :'r'~}5:~.:::}...
t~. ~ • - - .i;:r:>:•::
: -
. ~ • - - •
. ..v:.v r:.... . . , „ ~:rr:;•ri:•;r....:..:...:
. .
.
. ~T~t 1:~
~t:: .
. . ............r..r
. : .
. . . . . .
. . : . . . . . .v:::
. . ........,:..v:::: .
• . . . r...... . ; . . .
. • :~:x. .
. .
. . . .::•:>o-::•::•>:~ . .
• . ~ . ~ r~:::::: . ~ , : , ; ; : . . ~t.}~:::~::::::e~
. .
<•:<
•:•~i~~'
. ~r~:::
.
....:...............~r.~~~~::::.:.~>..........._......,.. r:r:::::~:.::... . . . .
...........T. ...~::::::::v:.tih.Y.;•:.. .
• .
....f•: •:r•: w: :v ...................r. v........:.:::: . ;:•:v •
M1
- . . .
. . . .4 . . • . .
.
...kNn.{....1 .
....n ~ h •:•::•v:::::::::::_::.~..~....:::::::::
~ . • . : . . -:r:::..... ?-•J-. . . . . . . : .
. ~ ~ ..ti . . . . .
h
. . J. ~::::l.•: :.L•.':•::..:.:•.S: •:.:t.~:.:'::.•:.ti{•::::.•
. . . ~ . • . . .
' JJ :lJ.. ` ' . .S•: J}f.{`}.Y.'..•M•Y..r~'~..~.C'•.L:~: J:::::.: N:. . . : . : .........J.Y.{f}:l •
............{.....L..... { . .
. . ...............1.. . ~ . ...._.............ti'J::::::::'. . . . .........~l.~
.........................lti.1Y~{'.. Y ._.'..............V.. .LV~.~................ . ~~!'~~:.~X' .....:..::::::::::::.~:lfh::•::::!!!••.
- -
. . r. . .
- -
~ .~.,,,_w~. . . - - . . . - ~
Basin A 7,465 •411 / 508 13,208 / 1,231 1.65
Basin B 105961r 4e/ 463 424 / 819 1.30
Basin C 102961 45Pf 460 554 / 748 1.47
Basin D 33,275 136 / 166 387 / 418 0.66
i
For basins B and C an analysis of the road only was also conducted to determine if a higher peak discharge occuned
' than for the entire basin. In both cases the peak discharge for the entire basin was greater and resulted in a greater
storage requirement. Detailed calculations can be found in Appendix C.
Conveyance Facilities
For basins B and C, stormwater is directed toward the street where it is routed to the drainage facilities via the
'
roadway gutter. Runoff enters the drainage s«►ales through curb drops that have been sized to accommodate the
peak discharge. At the low point in the basin, runoff ponds until the treatment requirement has been met. At this
point excess runoff either enters a concrete inlet a.nd is piped to a drywell in the street or enters a drywell directly.
Runoff from basins A and D is disposed of in a similar manner as that of basins B and C. However, the means in
which runoff enters the drainage swales in these basins is somewhat different then in basin B and C. Runoff in
basins A and D sheet flows down the back of the lots rather than being directed to the roadway surface. At the low
end of the basin, runoff generally enters the lot side of the swales. Once the runoff enters the swalcs, the same
Va/leyway Addition Drainage Repat 3
1/21/99
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' criteria are met before discharge excess stormwater. Design calculations for the inlets, pipes and grates can be
found in Appendix D.
CONCLUSION
' The stormwater facilities as designed for this project meet or exceed the requirements set forth in the Guidelines for
Stormwater Management for Spokanc County. Through a series of ponds, inlets and drywells, stormwater generated
' from the development of this property will be addressed on-site. As a result no adjacent property will be adversely
impacted.
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Val/eyway Addition Drainage Report 4
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Appendix A
Site Location and Soils Information
~cn
. , ► , • , ,
Outstatidifig Quality DAVID EVANS AND ASSOCIATES,
m m m m m m m m m m m m m m m m m ` m m
y~i uuniu 1 t x s s
' f •i D < nl 2 2 ~ < < D ~ ( ClIN10N I=
N m m p ,EllEA ~ ~ m x 0 TM .~j y g ~ ~
x Mc ~AeE ~wC c~eE ~ Cllr ~ > > McCAAE McCABE ~ ~ m m
~ ~ = a> s = m m m n `
~i ~
~ ~ BUKE AOAD
= BIAKE AD ~ m m m BIIEATHI AD
lp.,E
~ c C lN LAYHEq AI'HE m MAMER N MAMER AD m ~ z 9~ MAMER ROAD
< m ~~a MAMEf~m AD o o m= MA Eq ST .
AD oAVIS aDAVIS tR ~ ~o ~ o m ~
~
' C_ " EVERGAEEN = ROAD = EVERGAEEN m
" ROAD ;
~ AOUYAA W p e ~ - ~ ~ ~
1 9 B~~~VQI1
cT 9 ~
m c AD BOUVAA = BOIIV
BO VAA Aq BOIIVAR = z 8 0 IVA a m= A ~
dtt x z BANNEN BANNEN RD ~ LN ~ Lp AOU'AR r AA,NEN ^ O
O
L N n, c D ~ B A N N E D B A N N E N D A N N E NI m A i = v t
l Y D A W N p m~ B O L I VAA ~ BAMNEN g m LA 3
i)BR00K lN . ~ Oa~ ye ~ BAHNEN BES BEST BEST m N
B E S T R O 2 p BAHNEN 0~
c titi Ofi~q q~Y p~' m ; m -
A E E S ~ [ILREES B E S T A E S T A E E 9 AEEA z ~
CALYIN : R s r~ > z
C A L V I N R ~ 09 ~ CAIVIN CAIyVIN CAIVIN lN ~ m p LY~ _ ~ m ~ CALYIN m ~ - ~
~ WAAAEN WARAEN " r z
WARREN ~A AEN ~ e AAAEN D
~'3 " ADAMS ROAO ~ ~ ~ m
m = r ADAM$ •ROAD ' •'t~:~
MARCU .i~llfo+''`
.Y..C. ~ MARCU9 N (
~ ~ MAACU4
o~ N N CT = d M AIOOI ~-p ~ D ~o• i ~
eua'' z ~ oio.. r o ` BUANS AD T ~
N BUAN BUANS m BURNSt
~BU NS 3 s
4
-~i ;tO m N ~0 <i UANS
:SS = ~~~?a m ROA tm PAOGRESS ROAD►'"
N N - ~
.ES AD C ~ ST, C AlE9 z y m$
m z ST C >ALES AD.. T CMA IlE = a ~ WH
dURB CK 4 ~ S YpER D 9 a a 4u c
L~CENTURY Ew ER C 1 (NE EA ~ NEWER m S O M, p AD HEwE g ~
I N ~ Ix R D lN AY ENTU Y~ CE TURr ~ ~3 NE Eo Ar6NtU'
SULLIVAN ROAD m
PIONEEAIN PIONEEA CT PIONEERIIc ~
N > ~ 3
0 lN A ~
ti'yBEAIANE M AE lN q
o?ti = ~d'1d38W11~= = D y- , ~ ppK 2M0 S z
~
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0 1S ati ~ y~ p NOM~o ~ jy yc n
CANNEAY AD ~ t^ ~ :0
DA
CONKIIN ~ ~i; ~
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Ln IND, PAdL
.A . A
CAANINE Ci = ~ D 41H ST
CAANINE
ROCK . . > o
0 0 ~AM ~ ST
Q
NI1HNO3 ~ . m
~ y a
ON1 1 c SH AOCK LN -IND, P~,I ,
~ 8100EMON1 LN • ~ 6TH ST
► a ~ e i "4 .
StFFy STEEN AO = 1 o i
y 9e BLJEBE M!
n7 • PL
qD R 44 E ~ A9PEN x ~
~a M r y P FIORA RD
R 45 E A
c+ > r a c , ~
p ARC BEII O O •
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= 9
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~f'~ ~ ~ ~artcw' „~I '9!M lA ~ ~r~.~ ~ ~ ,y
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rwb,
~ ~ • w~ ,'{l'~ "p,~ I~.• ~~•~~w ~ • 1 1'1` ',,,~"y i ~ .
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!i -
SPOF:ANE COUNZ
iIIRVEY
they a,re eacelleait lnces for liunting migrltory wlterfowl. The surface color, rvhen moist, ranbes from very dlrk
' (Capability tuiit ZIIw-1; not ui a noodland group or brown to black. The t,estuiv of the surface layer is grav-
r t~,nge s i t e~ elly or very gravelly loam or silt louu. The subsoil rnnges
in c o l or f r o m d ar b b r o«- n t o ye l l owi s h U r own. C lay an d
lime have accuinulated on tlie bottoui of tlie pebbles in tlie
(xal•field Series lower subsoil. The depth to tlie gravel substratum ranges
The Glrfield series consists of Avell-drainecl, severe]~~ from 30 fio :i5 inches. 11s much as 10 percent of some a~re~.s
ei-oclecl soils tli:~t forined iii loess wicler, nrass a~id siiiall e.oltsists of Bong or Plioebe soils or of otlier G:trrison soils.
shrubs. 1'ltese soils occu )y ridaetops, kno~ =s, nnd the up- 2his soil is somewhat excessii•e1y drained and liu.s mod-
es of
er slopes on rollinn to hi.ly uplands. They hlve a surflce erFayer ately plants c.nie,a, aai ubilitse3~. . It It is etiholdssp to lbout ~r 5 or~ i:. nch I~,oots
of silty cl<iy To1ni and a subsoil of silr~• c11y tl►.tt is 111ter tliraat l~id l~er penetr~,te to the layer of s~nd, ~-~vel, ~nd cobblestones.
very lilyd, sticky, 1nc1 plastic. 1'lie :~iuiu.il in~eci~~it~.iti01i ~r~1e fertility is nlediwn. Sui•face runol} is slo~v, ItliC~ t~1C
is 1S to 2~ inclies, and the frost-free seasoii is al~out 1~0 h:~zardoferosionisslie*ht.
' a1;'s• About SO percent of the acreage is cultiv1ted; tlie rest is
rl►ese soils arc tised maiuly for gi.liii, alf<<lfu, aii(l ~r~ts.5. used for ~nazingA11C1 1s f~.rmste~lds or suburbl~i lots.
Garfield silty clay loam, 0 to 30 percent slopes, severe- Tiost of tl eacre~~~e is irrigated. Irrigated lreas nre used
ly eroded (GaC3).-`r1iis soil occupies tlio narrow riclgetops for oi-clinrd f ruits and berries; C.'1vU1aE? COI1), cantaloup,
lnci uppec slopes oii loess.ll upl.iiicls in tlle souil►e,istecii cuctunbers' celer 1nd uasli•c ~rlie.ld oa and bnrle •
tt of rlie cotuicY• 11 fost slo 1~es a re l~et~~•ce~i S a~i<1 `~0 1~er- alfllf
< ~ y' ~•1~ for s~ed an l~as ure. l~rylaiid
1'
30 for ]i~,,y •~,iid
ca~it; :ti fc~v sm111.ire:LS hnve slol~es of ,no~~a iluun 1~ercciit, ~,i.eus ~.re used for ~~•hetit, blrley, and natire bunchbi:~ss.
:l-11C1 SOlllO 111rruw ridaetops L1ve slopes of less th.ui :i per- Thero is no dif1'iculty ui tlie use of machineiy, Uut tlie
cxait. Itepreseiit-itive profile: grn.vel is liai•d oii ti111;e iiuplemeiits. .111 crops e,.~cept
o to S tuchcs, d:trk-Lrow,,, tirm s[1tS elac loam; gcuuular struc- legumes respond to nitroden. Some crops respond to
turc; iieutral. sulftir, boroii,lnd pliospliortts. (CapabilitI, unit IIIs-2;
S to 43 iiiclies. dark-Lrowu, firm silts clus, yclloa•isli-Lrowii I.o1my 1a11~'(3 S1tC• not in n=oodlaiid ~'1'ou
s[ity clay louiu uelo~v u deptl~ of 23 inclies; brcaks into ~ ~ b n~
prisrns 1 iucli to 2 inclzes wide aud then into angular bloc:ks Garrison gravelly Ioam, 5 to 24 percent slopes (Gg6).-
' JA to % incli ttiiek; Cl:ty filtvs CoAt the prSSmS and nngulnr This soil has a surfnco layer 3 to 5 inches thinner thln rhlt
t,tock.s ; neutrnl. of Garrisoii nr1ve11y loam, 0 to 5 Percent slopes. IZunoff
43 ta 64 inclies cellowi.cli-Lrown, flrw Ueary silt loam ; lore:iks b
into prisws 1 to 2 inclies widc nnd then Into ungulur bluc;ks is meditim,lnd the erosion hazlyd is moder:►te.
% to Yi ii►eli tliick; neutrat. TLis soil is used in mucli tlie s.1me «-1y ns G.lrrison
' ~~crc.ent slopes. (Clpability uiiit
Tlio teituie of tlie upper subsoil is silty clay or cla3•. !1s fn-r.i.~-clly loam, 0 t-o 5 much ns 10 percent of some arens consists of Athena, Naff, INTe-r
~ ; Lotirny rn.nbo site; not in nicoodland group)
Nez Perc,e, or Pnlouse soils. Garrison oery gravelIy loam, 0 to 8 percent slopes
Tliis soil is «•el l draiued and slowly permeaUle. It liolds (GmB).-Tliis soil lia,s a thiivler, more grare11y surflce lnyer
9 or 10 inclies of water tlilt pllnts c1n use, Tt is sricl.v tllan G.lrrison gr1veUy loam, 0 to 5 Perceiit slopes, ancl
• niid Pl:tistic irhen «et; consequent13,, it can be cultii•ltecl liolds less thnn 5 inclie, of water thlt plants can use. The
only «•itliin rather n~,ribw r1u~e of moistui'C COI1tCllt. b•ave1 c.luses cxtreme wc.1r on tillabe machinery. !1s
Itoot Peiietrat.ion is very dee 1~lie fertility is ineditim. n11ich :~s 7~~crcent of some areas coiisists of otlier Garrisoii
Surface runoff is r~.picl, and t~le IlilZ11'd Of fliTtl1C1• erosion soils. (Caplbility unit I17'e-5; Sh111ow rlnbe sitQ; not
is severe. in :i woocll.incl broup)
Atore tliaii 95 Percent of f•he acreage is cultivltecl; tlic Garrison very stony loam, 0 to 20 percent slopes
irst is seeded to alfalfa or brass. Il'helt is the cliief ci•o]). (GnB;.-This soil holds less than 5 inclies of water that
Other crops bro«•n are barley anci dry fielcl peas. :111 p1<uits c:ui use, and it is too stony to be cultiv1ted. As
crops respond to nitrogen, sulfur, a-nd phosphorus. (C.1- I1111C11 1S IJ 1)CL•cent of some arens consists of otlier C,arrison
pnbility unit BTe-3; not vi a woodllnd group or r.ing,,,e site) soils, niid 1s mucli as 2 perceait is nlade up of brliiite
outcroPs.
(x1,1'1'1SOR Series This soil is use.d #or grizing. (Caplbility i»iit VIs-2;
' Slinllow i•ln(ro sitc; not in n ivoodlaiid aroup)
Tlio Garrison series is made up of someicliat exce;sivcly
drlined, grnvelly or stony soils thlt formed uncler ~r:~ss Glenrose Series
in binci~,l outwash miaed in the upper part witli volc.tinic
:tsh. These soils ~,re on ne~.rly lerel to moder:~tcly steep Tlie Clcnrose scries consists of ~~-ell-clrlinec~, mostly
terrnces. Tlie a~nnu~,l precipit~,tion is 18 to 2~ inclies, ~nd meclit~m-text~ured soils. Tliese soils formecl uncler brass
the frost-free se~.son is about 1"r0 cla3•s. lncl sclrtered pino trees in glacial till mised in the upper
Soils of tlie Garrison series are used for a rlriet~• ot 1)1rt ~~•ith lo~~s 1nd volcanic ash. Atan~~ areas nre brtivell3J
' crop s a,iid as f~.rmsteads ~,nd suburUan lots. or stoiiy. 1'l~ese soils are ne1r1~~ lerel to A'ery steep. Tlie
Garrison gravelIy loam, 0 to 5 percent slopes (GgA;.- 1nitttal preciPitltion is lbout 21 inches, and the frost-fcee
This is the dominant soil in the Spob~,ne V1lle~~ east of se~~son is about 135 days.
tlie city of Spok~,ne. 11Zost slopes 1re bet«-een 2~nd 5 Glenrose soils are used for grain,1~e1s, lE'11t1IS, j'e~etlbles,
percent. Repre,senta,tive profile: alfalfn, a,nd brass, and for gcazin;.
0 to 15 inches, black, very friable gracellp loAm ; grauular Glenrose silt loam, 5 to 20 percent slopes (GpB).-`rI11S
• structure; slightly acid. soil occurs on glaciated uplands in tlie e1lst-central part of
15 to 44 inches, dark-brawn, friaUle rerc grarellv lottm ; ueutraL
44 to 60 incbes multtcolored sand, gravel, and cobblestones.
Appendix 6
Basin Map
• , • Pi-ofessiolials
• • Quality DAVID EVANS AND ASSOCIATES,
Appendix C
Basin Calculations
~cn
. • , ,
• . • DAVID EVANS AND ASSOCIATES,
'
~cn
BASIN CALCULATIONS
Basin A
0 Tota1 Basin Area = 127,500sf (2.926 ac)
0 Land Use; - Runoff Coefficient `C';
Asphalt & curb = 7,465 sf 7,465 @ 0.9
Impervious surface = 27,600 sf 271600 @ 0.9
Landscape Area = 2,988 sf 2,988 @ 0.1 `C' = 0.32
0 Time of Concentration `Tc' =23.42 min. I(5o)= 1.77 in/hr.
0 Peak Discharge Q(so) _(0.32)(1.77)(2.962) = 1.65 cfs
0 "208" Requirements; - "208" Provided;
Volume Req'd =(7,465*0.5)/12 = 311 cf Volume Prov. = 1016*0.5 = 508 cf
0 Outflow Structure; 2-Type B Drywells mid area ~
0 Bowstring Storage required = 1208 cf. (see attached)
Basin B
0 Total Basin Area = 49,730 sf (1.142 ac)
0 Land Use; -Runoff Coefficient `C';
Asphalt & curb = 10,961 sf 1011961 @ 0.9
Impervious surface = 13,285 sf 13,285 @ 0.9
Landscape Area = 25,484 sf 25,484 @ 0.1 `C' = 0.49
0 Time of Concentration `Tc' = 9.61 min. I(,o) = 2.31 in/hr.
0 Peak Discharge Q,o> _(0.49)(2.31)(1.142) = 1.30 cfs
0 "208" Requirements; - "208" Providcd;
' Volume Req'd =(10,961*0.5)/12 = 463 cf Volume Prov. _(460+516)*0.5 = 488 cf
0 Outflow Structure; Type B Drywell mid area ~
' 0 Bowstring Storage required -424 cf (see attached)
0 Peak Discharge for road runoff only
'
Road Area - 10,961 sf
Runoff Coefficient = 0.90
Time of Concentration < 5.0 min.
Intensity = 3.18 Q,o) =0.72 cfs
. ~cn
1
, Basin C
0 Total Basin Area = 492150 sf (1.128 ac)
0 Land Use; - Runoff Coefficient `C
Asphalt & curb = 10,961 sf 10,961 ct 0.9
Impervious surface = 7,200 sf 72200 @ 0.9
Landscape Area = 31,189 sf 312189 @ 0.1 `C' = 0.39 ' 0 Time of Concentration `Tc' =9.47 min. =>~o = 3.35 in/hr.
k>
0 Peak Discharge Q(so) _(0.39)(3.35)(1.128) = 1.47 cfs
0 "208" Requirements; - "208" Provided;
Volume Req'd = (10,961 *0.5)/12 =457 cf Volume Prov. _(480 + 440)*0.5 = 460 cf
0 Outflow Structure; Type B Drywell mid area ~
0 Bowstring Storage required = 554 cf. (see attached)
0 Peak Discharge for road runoff only
Road Area = 102961 sf
Runoff Coefficient = 0.90
Time of Concentration < 5.0 min.
Intensity = 4.58 Q(so) =1. 03 cfs
Basin D
0 Tota1 Basin Area = 52,625 sf (1.208 ac)
0 Land Use; -Runoff Coefficient `C';
Asphalt & curb = 3,275 sf 35275 @ 0.9
Impervious surface = 10,500 sf 10,500 @ 0.9
' Landscape Area = 38,850 sf 38,850 @ 0.1 `C' = 0.31
0 Time of Concentration `Tc' =23.56 min. I(-%) = 1.76 un/hr.
' 0 "208" Requirements; - "208" Provided; .
Volume Req'd =(3,275*0.5)/12 =136 cf Volume Prov. = 332*0.5 = 166 cf
0 Outflow Structure; Type B Drywell mid area ~
0 Bowstring Storage required = 387 c£ (see attached)
DAVID EVANS AND ASSOCIATES
BOWSTRING METHOD (FIFTY YEAR STORM DESIGN) PROJECT: GRNF0001
' DETENTION BASIN DESIGN BASIN: BASIN A
DESIGNER: KMG
NUMBER OF DRYWELLS PROPOSED DATE: 1/6/99
' 0 Single (type A) 2 Double (type B)
Total Area (calc.) (see H l) 2.93
Time of Conc. (calc.) (see H 1) 23.42
Composite "C" (calc.) (see Hl) 0.32
Time of Conc. (min) 23.42
Area (Acres) 2.93
C' Factor 0.32
Impervious Area (sq. ft.) 7465
Volume Provided 208: 508 storm: 1231
Outflow (cfs) 2
Area * C" Factor 0.94
#l #2 #3 #4 #5 #6 #7
. Time Time Intensity Q dev. V in V out Storage
Inc. Inc.
(min.) (sec.) (in.lhr.) (cfs) (cu. ft.) (cu. ft.) (cu. ft.)
(#1 *60) (A*C*#3) (Outf.*#2) (9546)
23.42 1405.33 1.77 1.65 3115 2811 305
1
5 300 4.58 4.29 1723 600 1123
10 600 3.20 2.99 2408 1200 1208
15 900 2.47 2.31 2788 1800 988
20 1200 1.98 1.85 2979 2400 579
25 1500 1.67 1.56 3091 3000 91
30 1800 1.46 1.37 3112 3600 -488
35 2100 1.30 1.22 3136 4200 -1064
40 2400 1.18 1.10 3178 4800 -1622
45 2700 1.07 1.00 3182 5400 -2218
50 3000 1.00 0.94 3255 6000 -2745
55 3300 0.92 0.86 3252 6600 -3348
60 3600 0.87 0.81 3320 7200 - 3 8 8 0
' 65 3900 0.82 0.77 3359 7800 -4441
70 4200 0.80 0.75 3502 8400 -4898
75 4500 0.77 0.72 3587 9000 -5413
80 4800 0.75 0.70 3704 9600 -5896
! • 85 5100 0.72 0.67 3758 10200 -6442
90 5400 0.70 0.66 3850 10800 -6950
95 5700 0.69 0.65 3989 11400 -7411
' 100 6000 0.67 0.63 4061 12000 -7939
DRAINAGE POND CALCULATIONS
Required grassy swale pond storaole volume
= Impervious Area x.5 in./ 12 in./ft. = 311 cu. fr.
provided: 508 cu. ft.
DRYWEI,L REQUIREMENTS - 50 YEAR DESIGN STORM
Maximum storage required by Bowstring = 1208 cu. ft.
provided: 1231 cu. ft.
Number and type of Drywells Required = 0 Single
2 Double
,
' DAVID EVANS AND ASSOCIATES
TIME OF CONCENTRATION (minutes) BASIN: BAS1N A PROJECT: GRNF0001
Tc (overland) Tc (gutter) Areas "C"
, Ct = 0.15 L2 = 0 0.60 0.90
Z 1= 0 0.20 0.90
L 1(A) = 620 Z2 = 0 2.12 0.10
N(A) = 0.4 B= 0 0.00 0.00
S(A) = 0.003 n= 0 0.00 0.00
s = 0 4.00 0.00
Tc (A) = 23.42 d= 0 0.00 0.00
Total A Comp "C"
L 1(B) = 0 Tc (gu) = 0.00 2.93 0.32
N(B) = 0 Tc(A+B) = 23.42
S(B) = 0 Q=C*I*A= 1.65
Tc(tot.) = 23.42 Q(est.) = 0.00
Tc (B) = 0.00 lntensiry = 1.77
A= 0
WP = #DIV/O!
R = #DIV/O!
V = #DIV/O!
Tc (total) = Tc (overland) + Tc (gutter) Tc(gu) _ #DIV/O!
Tc (overland) = Ct*(LI *N/S^0.5)1\0.6) Q(est) _ #DIV/O!
Ct = 0.15
L 1= Length of Overland Flow Holding = 0.00
N= friction factor of overland flow (.4 for average grass cover)
S= average slope of overland flow
Tc (gutter) = Length (ft.)Nelocity (ft./sec.)/60
B= Bottom width of gutter or ditch
Z1 = inverse of cross slope one of ditch
Z2 = inverse of cross slope two of ditch
d= depth of flow in gutter (estimate, check estimate with Flow)
Area = d*B+d^2/2*(Zl+Z2)
Wetter perimeter = B*d+(1/sin(atn(1/Zl))+l/sin(atn(1/Z2)))
Hydraylic Radius = R= Area/Wetted Perimeter
Velocity= 1.486/n*R^.667*s^.5
' Flow = Velocity*Area
n = 0.016 for asphalt
s= longitudinal slope of gutter
'
' DAVID EVANS AND ASSOCIATES
BOWSTRING M ETHOD (TEN YEAR STORM DESIGN) PROJECT: GRNFOOOI
DETENTION BASIN DESIGN BASIN: BASIN B
DESIGNER: KMG
' NUMBER OF DRY WELLS PROPOSED DATE: 19-Jan-99
0 Single (rype A) 1 Double (type B)
Total Area (calc.) (see H 1) 1.14
Time of Conc. (calc.) (see H 1) 9.61
Composite "C" (calc.) (see H 1) 0.49
Time of Conc. (min) 9.61
Area (Acres) 1.142
C' Factor 0.49
Impervious Area (sq. ft.) 10961
Volume Provided 208: 488 storm: 819
Outflow (cfs) 1
Area * C" Factor 0.56
#1 #2 #3 #4 #5 #6 #7
Time Time Intensity Q dev. V in V out Storage
Inc. [nc. (min.) (sec.) (in.lhr.) (cfs) (cu. ft.) (cu. ft.) (cu. ft.)
1 *60) (A*C*#3) (Outf.*#2) (#5-#6)
9.61 576.43 2.31 1.30 1001 576.43 424
5 300 3.18 1.78 716 300 416
10 600 2.24 1.25 998 600 398
15 900 1.77 0.99 1086 900 186
' 20 1200 1.45 0.81 1133 1200 -67
25 1500 1.21 0.68 1149 1500 -351
30 1800 1.04 0.58 1162 1800 -638
35 2100 0.91 0.5l 1170 2100 -930
40 2400 0.82 0.46 1192 2400 -1208
45 2700 0.74 0.41 1200 2700 -1500
50 3000 0.68 0.38 1217 3000 -1783
55 3300 0.64 0.36 1253 3300 -2047
60 3600 0.61 0.34 1296 3600 -2304
65 3900 0.60 0.34 1376 3900 -2524
' 70 4200 0.58 0.32 1427 4200 -2773
75 4500 0.56 0.31 1472 4500 -3028
80 4800 0.53 0.30 1482 4800 -3318
85 5100 0.52 0.29 1542 5100 -3558
~ 90 5400 0.50 0.28 1566 5400 . -3834
95 5700 0.49 0.27 1617 5700 -4083
100 6000 0.48 0.27 1665 6000 -4335
DRAINAGE POND CALCULATIONS
Required grassy swale pond storage volume
= Impervious Area x.5 in./ 12 in./ft. = 457 cu. ft.
provided: 488 cu. ft. OK!
DRYWELL REQUIREMENTS - 10 YEAR DESIGN STORM
Maximum storage required by Bowstring = 424 cu. ft.
provided: 819 cu. ft. OK!
DAVID EVANS AND ASSOCIA,TES
' TIME OF CONCENTRATION (minutes) BASIN: BASIN B PROJECT: GRNF0001
Tc (overland) Tc (gutter) Areas "C"
Ct = 0.15 L2 = 365 0.24 0.90
Z 1= 50 0.32 0.90
L l(A) = 60 Z2 = 3 0.59 0.10
N(A) = 0.4 B= 0 0.00 0.00
S(A) = 0.004 n= 0.016 0.00 0.00
s = 0.0055 0.00 0.00
' Tc (A) = 5.29 d= 0.186 0.00 0.00
Total A Comp "C"
L 1(B) = 0 Tc (gu) = 4.32 1.14 0.49
N(B) = 0 Tc(A+B) = 5.29
S(B) = 0 Q=C*I*A= 1.30
Tc(tot.) = 9.61 Q(est.) = 1.29
Tc (B) = 0.0 Intensity = 2.31 .
A = 0.916794
WP = 9.8900
R = 0.0927
' V = 1.41
Tc (total) = Tc (overland) + Tc (gutter) Tc(gu) = 4.32
Tc (overland) = Ct*(L1 *N/S^0.5)^0.6) Q(est) = 1.29
Ct = 0.15
L1 = Length of Overland Ftow Holding = 13.00
N= friction factor of overland flow (.4 for average grass cover)
S= average slope of overland flow
Tc (gutter) = Length (ft.)Nelocity (ft./sec.)/60
B= Bottom width of gutter or ditch
Zl = inverse of cross slope one of ditch
Z2 = inverse of cross slope two of ditch
d= depth of flow in gutter (estimate, check estimate with Flow)
Area = d*B+d^2/2*(Zl+Z2)
Wetted perimeter= B*d+(1/sin(atn(1/Zl))+l/sin(atn(1/Z2)))
' Hydraulic Radius = R= Area/Wetted Perimeter
Velocity - 1.486/n*R^.667*s^.5
Flow = Velocity*Area
n = 0.016 for asphalt
' s= longitudinal slope of gutter
. ,
1
'
' DAVID EVANS AND ASSOCIATES
' TIME OF CONCENTRATION (minutes) BASIN: B(Road) PROJECT: GRNF0001
Tc (overland) Tc (gutter) Areas "C"
Ct = 0.15 L2 = 365 0.25 0.90
Z 1= 50 0.00 0.00
L 1(A) = 0 Z2 = 3 0.00 0.00
N(A) = 0 B= 0 0.00 0.00
S(A) = 0 n= 0.016 0.00 0.00
s = 0.0055 0.00 0.00
' Tc (A) = 0.00 d= 0.149 0.00 0.00
Total A Comp "C"
L 1(B) = 0 Tc (gu) = 5.00 0.25 0.90
N(B) = 0 Tc(A+B) = 0.00
S(B) = 0 Q=C*I*A= 0.72
Tc(tot.) = 5.00 Q(est.) = 0.72
Tc (B) = 0.0 Intensiry = 3.18
A = 0.5883265
WP = 7.9227
R = 0.0743
' V = 1.22
Tc (totat) = Tc (overland) + Tc (gutter) Tc(gu) = 5.00
Tc (overland) = Ct*(Ll*N/S^0.5)^0.6) Q(est) = 0.72
Ct = 0.15
L 1= Length of Overland Flow Holding = 13.00
N= friction factor of overland flow (.4 for average grass cover)
S= average slope of overland flow
Tc (gutter) = Length (ft.)Nelocity (ft./sec.)/60
B= Bottom width of gutter or ditch
Z 1= inverse of cross slope one of ditch
Z2 = inverse of cross slope two of ditch
d= depth of flow in gutter (estimate, check estimate with Flow)
Area = d*B+d^2/2*(Z1+Z2)
Wetted perimeter = B*d+(1/sin(atn(1/Z1))+1/sin(atn(1/Z2)))
Hydraulic Radius = R= Area/Wetted Perimeter
Velocity = 1.486/n*R^.667*s^.5
Flow = Velocity*Area
n = 0.016 for asphalt
' s= longitudinal slope of gutter
'
'
, DAVID EVANS AND ASSOCIATES
BOWSTRING METHOD (FIFTY YEAR STORM DESIGN) PROJECT: GRNF0001 1
DETENTION BASIN DESIGN BASIN: BASIN C
DESIGNER: KMG
NUMBER OF DRYWELLS PROPOSED DATE: 1/19/99
0 Single (type A) 1 Double (type B)
' Total Area (calc.) (see H 1) 1.13
Time of Conc. (catc.) (see H 1) 9.47
Composite "C" (calc.) (see Hl) 0.39
Time of Conc. (min) 9.47
Area (Acres) 1.13
C' Factor 0.39
Impervious Area (sq. ft.) 10961
Volume Provided 208: 460 storm: 748
Outflow (cfs) 1
Area * C" Factor 0.44
#1 #2 #3 #4 #5 #6 #7
Time Time Intensity Q dev. V in V out Storage
Inc. Inc. (min.) (sec.) (in./hr.) (cfs) (cu. ft.) (cu. ft.) (cu. ft.)
' (#1 *60) (A*C*#3) (Outf.*#2) (#5-#6)
9.47 568.40 3.35 1.47 1123 568 554
S 300 4.58 2.02 811 300 511
10 600 3.20 1.41 1118 600 518
15 900 2.47 1.09 1190 900 290
20 1200 1.98 0.87 1215 1200 15
25 1500 1.67 0.74 1246 1500 -254
30 1800 1.46 0.64 1282 1800 -518
35 2100 1.30 0.57 1314 2100 -786
40 2400 1.18 0.52 1348 2400 -1052
45 2700 1.07 0.47 1364 2700 -1336
50 3000 1.00 .0.44 1407 3000 -1593
55 3300 0.92 0.41 1416 3300 -1884
60 3600 0.87 0.38 1454 3600 -2146
65 3900 0.82 0.36 1479 3900 -2421
, 70 4200 0.80 0.35 1549 4200 -2651
75 4500 0.77 0.34 1592 4500 -2908
80 4800 0.75 0.33 1650 4800 -3150
' 85 5100 0.72 0.32 1679. 5100 -3421
90 5400 0.70 0.31 1725 5400 -3675
95 5700 0.69 0.30 1792 5700 -3908
' 100 6000 0.67 0.30 1828 6000 -4172
DRAINAGE POND CALCULATIONS
. Required grassy swale pond storage volume
=lmpervious Area x.5 in./ 12 in./ft. = 457 cu. ft.
provided: 460 cu. ft.
DRYWELL REQUIREMENTS - 50 YEAR DESIGN STORM
Maximum storage required by Bowstring = 554 cu. ft.
provided: 748 cu. ft.
Number and type of Drywells Required = 0 Single
1 Double
DAVID EVANS AND ASSOCIATES
TIME OF CONCENTRATION (minutes) BASIN: BASIN C PROJECT: GRNF0001 '
' Tc (overland) Tc (gutter) Areas "C"
Ct = 0.15 L2 = 365 0.16 0.90
' Z1 = 50 0.25 0.90
L 1(A) = 60 Z2 = 3 0.72 0.10
N(A) = 0.4 B= 0 0.00 0.00
S(A) = 0.004 n= 0.016 0.00 0.00
s = 0.0055 0.00 0.00
Tc (A) = 5.29 d= 0.195 0.00 0.00
Total A Comp "C"
L 1(B) = 0 Tc (gu) = 4.18 1.13 0.39
N(B) = 0 Tc(A+B) = 5.29
S(B) = 0 Q=C#I*A= 1.47
Tc(tot.) = 9.47 Q(est.) = 1.47
Tc (B) = 0.00 Intensity = 3.35
A = 1.0076625
WP = 10.3686
R = 0.0972
V = - 1.45
Tc (total) - Tc (overland) + Tc (gutter) Tc(gu) 4.18
Tc (overland) = Ct*(L i*N/S"0.5)^0.6) Q(est) = 1.47
' Ct = 0.15
L1 = Length of Overland Flow Holding = 13.00
N= friction factor of overland flow (.4 for average grass cover)
S= average slope of overland flow
Tc (gutter) = Length (ft.)Nelocity (ft./sec.)/60 _
B= Bottom width of gutter or ditch
Z 1= inverse of cross slope one of ditch "
Z2 = inverse of cross slope two of ditch
d= depth of flow in gutter (estimate, check estimate with Flow)
Area = d*B+d^2/2*(Z1+Z2) .
' Wetter perimeter = B*d+(1 /sin(atn(1 /Z 1))+ 1 /sin(atn(1 /Z2))) Hydraylic Radius = R= Area/Wetted Perimeter
Velocity = 1.486/n*R^.667*s^.5
Flow = Velocity"'Area
' n = 0.016 for asphalt
s =longitudinal slope of gutter
1
'
'
' DAVID EVANS AND ASSOCIATES
TIME OF CONCENTRATION (minutes) BASIN: C(Road) PROJECT: GRNF0001 ' verl .
Tc (o and) Tc (gutter) Areas "C"
' Ct = 0.15 L2 = 365 0.25 0.90
Z 1= 50 0.00 0.00
L 1(A) = 0 Z2 = 3 0.00 0.00
N(A) = 0 B= 0 0.00 0.00
S(A) = 0 n= 0.016 0.00 0.00
s = 0.0055 0.00 0.00
Tc (A) = 0.00 d= 0.171 0.00 0.00
'
Total A Comp C
L1(B) = 0 Tc (gu) = 4.56 0.25 0.90
, N(B) = 0 Tc(A+B) = 0.00
S(B) = 0 Q=C*I*A= 1.03
Tc(tot.) = 5.00 Q(est.) = 1.03
Tc (B) = 0.00 Intensity = 4.58
A = 0.7748865
WP = 9.0925
R = 0.0852
V = 1.33
Tc (total) = Tc (overland) + Tc (gutter) Tc(gu) = 4.56
Tc (overland) = Ct*(L 1*N/S^0.5)^0.6) Q(est) = 1.03
Ct=0.15
L1 = Length of Overland Flow Holding = 13.04
N= friction factor of overland flow (.4 for average grass cover)
S= average slope of overland flow
Tc (gutter) = Length (ft.)Nelocity (ft./sec.)/60
B= Bottom width of gutter or ditch
Z 1= inverse of cross slope one of ditch
Z2 = inverse of cross slope two of ditch
d= depth of flow in gutter (estimate, check estimate with Flow)
Area = d*B+d^2/2*(Z1+Z2)
Wetter perimeter = B*d+(1/sin(am(1/Z1))+1/sin(am(1/Z2)))
Hydraylic Radius = R= Area/Wetted Perimeter
Velocity = 1.486/n*R^.667*s^.5
Flow = Velocity*Area
' n = 0.016 for asphalt
s =longitudinal slope of gutter
' DAVID EVANS AND ASSOCIATES
BOWSTRING METHOD (FIFTY YEAR STORM DESIGN) PROJECT: GRNF0001 J
' DETENTION BASIN DESIGN BASIN: BASIN D
DESIGNER: KMG
NUMBER OF DRYWELLS PROPOSED DATE: 1/6/99
0 Single (type A) 1 Double (type B)
Total Area (calc.) (see H 1) 1.21
Time of Conc. (calc.) (see H 1) 23.56
Composite "C" (calc.) (see H 1) 0.31
Time of Conc. (min) 23.56
Area (Acres) 1.21
C' Factor 031
Impervious Area (sq. ft.) 3275
Volume Provided 208: 166 storm: 418
Outflow (cfs) 1
Area * C" Factor 0.37
#1 #2 #3 #4 #5 #6 #7
Time Time Intensity Q dev. V in V out Storage
Inc. Inc. .
(min.) (sec.) (in./hr.) (cfs) (cu. ft.) (cu. ft.) (cu. ft.)
(41*60) (A*C*#3) (Outf:*#2) (#5-#6)
23.56 1413.49 1.76 0.66 1244 1413 -169
S 300 4.58 1.71 687 300 387
10 600 3.20 1.19 961 600 361
15 900 2.47 0.92 1112 900 212
20 1200 1.98 0.74 1189 1200 -11
25 1500 1.67 0.62 1235 1500 -265
30 1800 1.46 0.55 1243 1800 -557
' 35 2100 1.30 0.49 1253 2100 -847
40 2400 1.18 0.44 1269 2400 -1 l 3 l
45 • 2700 1.07 0.40 1271 2700 -1429
50 3000 1.00 0.37 1300 3000 -1700
55 3300 0.92 0.34 1299 3300 -2001
60 3600 0.87 0.32 1326 3600 -2274
' 65 3900 0.82 0.31 1341 3900 -2559
70 4200 0.80 0.30 1398 4200 -2802
75 4500 0.77 0.29 1432 4500 -3068
80 4800 0.75 0.28 1479 4800 -3321
85 5100 0.72 0.27 1500 5100 -3600
90 5400 0.70 0.26 1537 5400 -3863
95 5700 0.69 0.26 1592 5700 -4108
100 6000 0.67 0.25 1621 6000 -4379
DRAINAGE POND CALCULATIONS
Required grassy swale pond stora~e volume
= Impervious Area x.5 in./ 12 in./ft. = 136 cu. ft.
provided: 166 cu. ft.
DRYWELL REQUIREMENTS - 50 YEAR DESIGN STORM
Maximum storage required by Bowstring = 387 cu. ft.
provided: 418 cu. ft.
Number and type of Drywells Required = 0 Single
1 Double
' DAVID EVANS AND ASSOCIATES
TIME OF CONCENTRATION (minutes) BASIN: BASIN D PROJECT: GRNF0001
'
Tc (overland) Tc (gutter) Areas itCol
Ct = 0.15 L2 = 70 0.24 0.90
Z 1= 3 0.08 0.90
L 1(A) = 650 Z2 = 3 0.89 0.10
N(A) = 0.4 B= 0 0.00 0.00
S(A) = 0.0036 n= 0.03 0.00 0.00
s = 0.01 0.00 0.00
Tc (A) = 22.81 d= 0.375 0.00 0.00
1
Total A Comp "C"
L 1(B) = 0 Tc (gu) = 0.75 1.21 0.31
N(B) = 0 Tc(A+B) = 22.81
S(B) = 0 Q=C*I*A= 0.66
Tc(tot.) = 23.56 Q(est.) = 0.66
Tc (B) = 0.00 Intensity = 1.76
A = 0.421875
WP = 2.3717
R = 0.1779
V = 1.57
Tc (total) - Tc (overland) + Tc (gutter) Tc(gu) = 0.75
Tc (overland) = Ct*(L1 *N/S^0.5)^0.6) Q(est) = 0.66
Ct=0.15
L 1= Length af Overland Flow Holding = 2.49
N= friction factor of overland flow (.4 for average grass cover)
S= average slope of overland flow
Tc (gutter) = Length (ft.)Nelocity (ft./sec.)/60
B= Bottom width of gutter or ditch
Z 1= inverse of cross slope one of ditch
Z2 = inverse of cross slope two of ditch
d= depth of flow in gutter (estimate, check estimate with Flow) Area = d*B+d^2/2*(Zl+Z2)
' Wetter perimeter _B*d+(1/sin(am(1/Z1))+l/sin(atn(1/Z2)))
Hydraylic Radius R- Area/Wetted Perimeter
Velocity = 1.486/n*R^.667*s^.5
Flow = Velocity*Area
, n = 0.016 for asphalt
s= longitudinal slope of gutter
' '
Appendix D
Hydraulic Calculations
. , , . , , a .
DAVID EVANS AND ASS4CIATE ,
O ,
~cn
1
' CURB INLET CALCULATIONS
Pond A
0 Inlet - 14+50.0 Valleyway ; sump condition Q= 3.OLH^3/2
Q(m~.) = 1.65 cfs (Basin A total discharge)
L= 4.0 feet Hq'd = 0.26 ft.
with a 2" depression, resulting ponding depth above normal gutter flowline equals 0.10 ft.
' Cross slope at 14+50 = 4.05% Ponding sPread of 2.5 ft.
0 Inlet - 15+72.0 Valleyway ; sump condition Q= 3.OLH^3/2
The contributing area to this inlet consists of approximately 100 feet of Valle}way and 125 feet of Sonora
Street. The resulting peak discharge is considerably less than the discharge for the entire basin. Therefore the
necessary head is less that calculated for the inlet at 14+50.
Pond B
~ 0 Inlet - 12+75 .0 Sonora; sump condition Q= 3.OLH^3/2
Q(m.) = 1.30 cfs (Basin B tota.l discharge)
L= 4.0 feet H«Q•a = 0.22 ft.
with a 2" depression, resulting ponding depth above normal gutter flowl'ule equals 0.05 ft.
Cross slope at 12+75 = 2.13% ponding spread of 2.5 ft.
' Pond C
0 Inlet - 14+64.42 Sonora ; continuous grade
, The contributing area to this inlet results in a Peak discharge (Qa) of 0.61 -cfs and a flow depth (Y) of 0.14 feet
(see attach Basin B1 calc.) Using figure 16 (attached) of the Spokane County Stormwater Guidelines and a
gutter depression (a) of 2" the following information is obtained;
QalLre = 0.09 Le = 6.78 feet.
L(a„a;,) = 4.0 ft L/La = 0.59 using a/y = 1.19 Q/QA = 0.71 Q= 0.43 cfs
Qp.) = 0.18 cfs to neYt inlet
0 Inlet - 14+52.42 Sonora ; continuous grade
'
Wrth a Q. _ 0. 18 cfs Nvhich = QP for mlet 14+64.42 the flow depth based on fgure 18 (attnched) of the Spokane
'
. ~cn
County Stormvvater Guidelines equals 0.085 ft. Again using figure 16 (attached) and a gutter depression (a) of
2" the following information is obtained;
' QJLa = 0.0575 L. = 3.13 feet < L(e,.o) = 4.0 ft
Qp'") = 0.0
Pond D -
0 Inlet - 12+75.0 Sonora ; sump condition Q= 3.OLH^3/2
Q(m~) = 1.47 cfs (Basin C total discharge)
' L=4.Ofeet H,,,q'd =0.24 ft.
with a 2" depression, resulting ponding depth above normal gutter flowline equals 0.07 ft.
Cross slope at 12+75 = 2.13% ponding spread of 3.5 ft.
Pond E
0 Inlet - 14+45.03 Sonora ; continuous grade
The contributing area to this inlet results in a peak discharge (Qa) of 0.57 cfs and a flow depth (y) of 0.137 feet
(see attach Basin C1 calc.) Using figure 16 (attached) and a gutter depression (a) of 2" the following
' information is obtained;
Qe/Le = 0.09 L. = 6.78 feet.
L(a,,a;,) = 4.0 ft L/La = 0.59 using a/y = 1.19 Q/Qa = 0.71 Q= 0.40 cfs
Q(,S) = 0.17 cfs to nett inlet
'
Inlet - 14+33.03 Sonora ; continuous grade
' = 0. 17 = for inlet 14+45.03 the flow n f re 18 (attached) of the Spok
With a Qa cfs which QP depth based o gu ane
County Stormwater Guidelines equals 0.085 ft. Again using figure 16 (attcrched) and a gutter depression (a) of 2"
' the following information is obtainEd;
QEJLfl = 0.0575 L~ = 2.95 feet < Lwa;,) = 4.0 ft
QcrM> = 0.0
'
DAVID EVANS AND ASSOCIATES
'
TIME OF CONCENTRATION (minutes) BASIN: B1 (Total) PROJECT: GRNF0001
Tc (overland) Tc (gutter) Areas "C"
'
Ct = 0.15 L2 = 177.4 0.15 0.90
Z 1= 50 0.08 0.90
, L 1(A) _ 60 Z2 = 3 0.22 0.10
N(A) - 0.4 B= 0 0.00 0.00
S(A) = 0.004 n= 0.016 0.00 0.00
s = 0.0055 0.00 0.00
Tc (A) = 5.29 d= 0.14 0.00 0.00
Total A Comp "C"
L 1(B) = 0 Tc (gu) = 2.54 0.45 0.51
N(B) = 0 Tc(A+B) = 5.29
S(B) = 0 Q=C*I*A= 0.61
Tc(tot.) = 7.83 Q(est.) = 0.61
Tc (B) = 0.0 Intensity = 2.65
. A = 0.5194
WP = 7.4441
R = 0.0698
' V = 1.17
Tc (total) = Tc (overland) + Tc (gutter) Tc(gu) = 2.54
Tc (overland) = Ct*(LI *N/S^0.5)^0.6) Q(est) = 0.61
Ct=0.15
L1 = Length of Overland Flow Holding = 6.32
N= friction factor of overland flow (.4 for average grass cover)
S= average slope of overland flow
Tc (gutter) = Length (ft.)Nelocity (ft./sec.)/60 .
B= Bottom width of gutter or ditch
Z 1= inverse of cross slope one of ditch
Z2 = inverse of cross slope two of ditch
d= depth of flow in gutter (estimate, check estimate with Flow)
Area = d * B+d^2/2 * (Z l +Z2)
Wetted perimeter = B*d+(1/sin(atn(1/Zl))+l/sin(am(1/Z2)))
Hydraulic Radius = R= Area/Wetted Perimeter
Velocity = 1.486/n*R^.667*s^.5
Flow = Velocity*Area
' n = 0.016 for asphalt
s= longitudinal slope of gutter
' '
' DAVID EVANS AND ASSOCIATES
TIME OF CONCENTRATION (minutes) BASIN: C1 (Total) PROJECT: GRNF0001
Tc (overland) Tc (gutter) Areas "C"
1 - -
Ct - 0.15 L2 - 196.8 0.13 0.90
Z I= 50 0.08 0.90
L l(A) = 60 Z2 = 3 0.28 0.10
N(A) = 0.4 B= 0 0.00 0.00
S(A) = 0.004 n= 0.016 0.00 0.00
s = 0.0055 0.00 0.00
Tc (A) = 5.29 d= 0.137 0.00 0.00
Total A Comp "C"
L 1(B) = 0 Tc (gu) = 2.85 0.50 0.44
N(B) = 0 Tc(A+B) = 5.29
S(B) = 0 Q=C*I*A= 0.57
Tc(tot.) = 8.14 Q(est.) = 0.57
Tc (B) = 0.0 Intensity = 2.59
A = 0.4973785
WP = 7.2846
R = 0.0683
V = 1.15
Tc (total) = Tc (overland) + Tc (gutter) Tc(gu) = 2.85
Tc (overland) = Ct*(L 1*N/S^0.5)"0.6) Q(est) = 0.57
Ct = 0.15
L 1= Length of Overland Flow Holding = 7.01
N= friction factor of overland flow (.4 for average grass cover)
S= average slope of overland flow
Tc (gutter) = Length (ft.)Nelociry (ft./sec.)/60
B= Bottom width of gutter or ditch
Z 1= inverse of cross slope one of ditch
Z2 = inverse of cross slope two of ditch
d= depth of flow in gutter (estimate, check estimate with Flow)
Area = d*B+d^2/2*(Zl+Z2)
Wetted perimeter = B*d+(1 /sin(atn(1 /Z l))+ 1/sin(atn( l/Z2)))
Hydraulic Radius = R= Area/Wetted Perimeter
Velocity = 1.486/n*R^.667*s^.5 Flow = Velocity*Area
n = 0.016 for asphalt
' s= longitudinal slope of gutter
'
OEPTH OF' FLOW - y- FEET ~
•OI .02 .03 .04 .OS .06 .08 .10 .2 ,3 .4 .S .6 .T .8 .9 1.0
. I + ~ ( 1.0
1-t
I r I ~I I I I i ~ ~ ~
.s
-T- -4- 7- .s
-
i i ~ 1~ - l-r+-T ! ~ r -~-1- j ~ 4--4
~ .4
A
.3
'.2
L I I I i IL I I ' Qa
VIA, L
a
10
~
~.oe
.oe
r ~
~ ' ~ ~ I 1 • .os
~
.oa
1
.
°3
I ~ ~ ~ I ~j ' ~ ' I l II ~
, I I i I I I I I I
.02
.oi
1.0
000011- .e
DISCHARGE PER FOOT OF
LENGTH OF CURB OPENING ' .6
INLETS WHEN INTERCEPTING
+ .s
' 100 % OF GUTTER FLOW - - - ~ - - - + 1- 1
.a
oo,
~ -l-
1 I I ( 1 Q
b) PARTIAL INTERCEPTION ~-3 Qa
RATIO FOR INLETS OF -1-- - ~ -~----~--•-+--t- -J--~-1-
LENGTN LESS THAN La
i / ~ -t- - -.2
i ~
. ~ ~ti° ~ fi--L--t•~--rt i
-7. 10
~ . , .1o
.OS .06 .08 .10 .2 .3 .4 .s .6 .8 1.0
L/LQ -
CAPACITY OF CURB OPENING INLETS
_ ON CONTINUOUS GRADE
6-39 FIGURE 16
'
' ~ 2.0 ' .
r~
a
couAtlo.. o- 0.66 (A) s* 4*'%
10000 , n 49 111OW0111Clt COtrvlGKMt 4• 411411rr4r0 .'O
9000 FoRMuL• ..ll'oko.ilur[ ro Ol•tteuL tr
8000 •orror of c«AN■cL
7000 tts •cupaoeK or cOoss awrc .08 • 1.0
6000 QcrcOc.u ~ M. O. 0. rGoucoIrGs .07
5000 ' F"i ho, [OYATIOM (N! .06 .80
4000 EXAMPLE (scc o•s■co ures) ~ .O~ .TO
3000 sl.c, s s • 0.03 too ~ .60
, . ,o
~
I , so 04
~ . .o~ • ~
LUAL ~ . I-Z .so
2000 0.:= V io U. ti
.iso, 0. :.o crs __----.03 a .40
ro Z
1000 3 Z .30
900 .02
800 W ~
C 700 ` 600 = a
Q s ~ .20
soo 3
0 soo W Z
INSTRUCTIONS ~
Q 300 ~ .o? W .01 p
1 GO"CCf vIe1 •At►0 w/TM f10O[ (f) Q .Oa ~
~i.
41,1110 COmt[CT OriGMaetc t0) rf■ _ .03 Z QQg
200 OepfM (d1 fM(s( ♦f0 l1M(f "Wf
NttRSteT •r ruQry.a ~44111 FoR (f) .O! Q .007 .10 •
cwKCri soLurIo.. ~ .01 V .006 W -
--1• .003 W 1.08
~ loQ Y.iM&►t0 CM41111"l ~ LL. w •07
-80 90 •s s«osIll wt wroa+ia►« O a .06
To .ir« . • ; ~.004
W a
60 Q,. ~ ,p5
SO s 10 OCtCRY149 T ~d ~ O 1.003 M
ast«seat o~ Ir d . • W
s0 CC .04
ro•rror a w•.rtL _
30 •~vwc ~~o.M 4"-'-~~ V
04114614c ocoto d •oR rorAL asc■.qsc O. .002
11o( ICCTIM 1N90 Yse NOYON1400" TO ~ •Q`;
, 20 ot*c..~.c o~ stct~o. .•o~ ot•rM Q-
••.•-(i)
r'' _
ro otic•stac asw•444
a .02
M con►osirc stcrar. - d . ' ~ .
110 •oLLo. I.sr-SucTIo. S. f W '
To oeral• oIscwARu In .001 Q.
.
ucrIor . •r •SsurCe • 8.4d -4'1
0[ITM 1; OOf&l• 0. IOIt . .
flOf( •ATIO i,, 460 OtPTN 1'. T111s O, ~ O0
L.ol
NOMOGRAPH FOR FLOW
. IN TRIANGULAR CHANNELS
6-42
. FtGURE 18
'
~cn
' PIPE CALCULATIONS
Outflow from Basins A and B first enters a catch basin in thc respECtive pond for each basin and then is conveyed to
the drywells through a 12" PVC storm pipe. The pipe for each basin was designed to handle at a minimum the
design capacity of the drywells for each basin. Hydraulic calculations were done using Haestad's Flo,"'rnaster
program. The design capacity for Basin A is 2.0 cfs for the two type B drywells. With a pipe slope of 2.09% the resulting
flow depth in the pipe is 0.38 ft. This is Nvell below the desired 70% maaimum flow depth.
The design capacity for Basin B it is 1.0 cfs for a single type B dry,%vell. With a pipe slope of 2.09% the resulting
flow depth in the pipe is 0.26 ft. This again is well below the desired 70% maximum flow depth
The flow calculations for both basins are attached at the end of this section.
GRATE CALCULATIONS
There are rivo types of grates utilized in the design of thc stormwater facilities for this project. In the ponds that
utilize catch basins a type 2 grates are used while type 4 are used when outflow enters-the drywell directly. In each
case the available head is 0.5'. The capacity of each grate is based on tlie equation; Q/P = 3.0 H^3/2, where;
Q= design or ma.ximum inta.ke
P= perimeter of grate openings
' H= design or maaimum head available
For a type 2 grate, the perimeter (P) is equal to 6.13' and for a type 4 it is Equal to 6.28'. Therefore the maximum
, grate capacities are;
Type 2
Q = 6.13*3.0*(0.5^3/2) = 6.5 cfs
,
Type 4
Q = 6.28*3.0*(0.5^3/2) =6.66 cfs '
Since there are no means to prevent clogging of the grate within the "208" ponds, the maximum capacity of the grate
is reduced by a factor of safety of 2. Considering the maximum capacity for the designed drywells is 2.0 cfs for
basin A, the available capacity of the grates is sufficient.
'
Basin A outflow pipe
Worksheet for Circular Channel
' Project Description
Project File d:\worlclgrnf00011grnf0001.fm2
Worksheet Catch basin to drywell connection pipe
Flow Element Circular Channei
Method Manning's Formula
Solve For Discharqe
Input Data
Mannings Coefficient 0.010
Channel Slope 0.020900 ft/ft
Depth 0.38 ft
' Diameter 12.00 in
Results
Discharge 2.00 cfs
Flow Area 0.27 ft2
Wetted Perimeter 1.32 ft
Top Width 0.97 ft
Critical Depth 0.60 ft
Percent Full 37.50
Critical Slope 0.004061 ft/ft Velocity 7.45 ft/s
Velocity Head 0.86 ft
Specific Energy 1.24 ft
Froude Number 2.49
Maximum Discharge 7.20 cfs
Full Flow Capacity 6.70 cfs
Full Flow Slope 0.001871 ft/ft
Flow is supercritical.
'
01/21/99 David Evans & Associates FlowMaster v5.08
08:55:44 AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 Page 1 of 1
' •
Basin B outflow pipe
Worksheet for Circular Channel
Project Description
Project File d:\worklgrnf00011grnf0001.fm2
Worksheet Catch basin to drywell connection pipe
Flow Element Circular Channel
Method - Manning's Formula
Solve For Discharge
Input Data
Mannings Coefficient 0.010
Channel Slope 0.020900 ft/ft
Depth 0.26 ft
Diameter 12.00 in
Results
Discharge 1.00 cfs
Flow Area 0.16 ft2
Wetted Perimeter 1.07 ft
Top Width 0.88 ft
Critical0epth 0.42 ft
Percent Full 26.10
Critical Slope 0.003437 ft/ft
Velocity 6.12 ft/s
Velocity Head 0.58 ft
Specific Energy 0.84 ft
Froude Number 2.50
Maximum Discharge 7.20 cfs
Full Flow Capacity 6.70 cfs
Full Flow Slope 0.000465 ft/ft
Flow is supercritical.
~
01/21/99 David Evans 8 Associates FlowMaster v5.08
08:55:12 AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 Page 1 of 1
Appendix E
Supplemental Roadway Information
~cn
. , , • Pi-ofessionals
• C . g Quality DAVID EVANS AND ASSOCIATES,
Spokane County Engineers Project: GREENFIELD III
W.1026 Broadway Ave 456-3600 Job No.: GRNF0001
Spokane, WA 99260 Disc.No.:
File Name: VWCURB
TYPICAL SECTION DATA 08-Jan-99
Roadway half witlth ENTER--> 20 11:16 AM
Road Name ENTER--> Valley Way
Left or Right ENTER--> Left
Curb Type INTEGRAL CURB & GUTTER
Station Interval ENTER--> 25
MINIMUM MAXIMUM
Curb EL. Curb EL. Edge Pave,
CENTER % SLOPE EDGE DIST. % SLOPE EDGE D1ST FROM (-4.5°l0 (-2% to Gutter
LINE CENTER- PAVEMENT CJL TO CIL TO PAVEMENT EDGE PVMT. from FJP + FROM E/P + SELECT- Design Top Curb
STATION ELEVATION LINE ELEVA710N EIP EDGE PAVE % SLOPE 70 CURB CURB HGT) CURB HGT) ED ELEV % GRApE % Grade
1425.00 2029.04 2028.80 7,50 -3.20 0.00 12.50 2028.69 2028.97 2028.75 -4.00
1450,00 2028.93 -0.44 2028.68 7.50 -3.33 -0.48 12.50 2028.57 2028.85 2028.62 •4,05 -0.50
1475.00 2028.87 -0.24 2028.75 7,50 -1.60 028 12.50 2028.64 2028,92 2028.75 -3.55 0.50
1500.00 2028.82 •0.20 2028.75 1.50 -0.93 0.00 12.50 2028.64 2028.92 2028.87 -2.41 0.50
1525.00 2028,80 -0.08 2028.70 7,50 -1.33 -0.20 12.50 2028.59 2028,87 2028.75 -3.09 -0.50
1550.00 2028.82 0.08 2028.65 7.50 -2,27 -020 12.50 2028.54 2028.82 2028.62 -3.77 -0.50
1575.00 2028,54 0.08 2028,59 7.50 -3.33 -024 12.50 2028.48 2028.76 2028.50 -4,36 -0,50
i 1
82.76'
I I
I I
20' BUILDING SETBACK
~
j. I I
~o ~
340
GjSTE~'
SIONAL ~
~ EXPIRES: AUG. 2000
cn i v, I
w ~
~ N
~
.
NORTH ~ I
SCALE 1 M = zo'
~ 14.0' I
36' BUfLDING SETBACK
-----------4-
BOTTO M . . 20 ' 4'
EL=2028.42 NP.
6ERM -
EL=2029.5 • o
' °M° UTIUTY EASEMENT
DRAINAGE I o +
0
EASEMENT IBORDER EASEMENT
0
82_79=
14+52.42 14+64.42 S ON 0 R A S T.
4' CUR6 DRQP 4' CURB OROP
I E= 2028. 75 I E= 2028.80
SIDEWALK INLET SIDEWALK INLET
IE=2028.56 IE=2028.61
JANUARY 21,1999 J
~ LOT 2, BLOCK 1 1
♦ J ` VALLEYWAY ADDITION J
,
/ - - ~ - - - - ~
82.76
f I
I I
20' BUILDING SETBACK
~ f
I I
~
w I cnl
rn w
. ~
~ 14.0' ~
36' 6UILDING SETBACK
BOTTOM 20' 4'
EL=2028.42 - ~-TYP.
BERM
EL=2029.5 ~ .
UTILITY EASEMENT
DRAINAGE
+ ~f BORDER EASEMENT EASEMENT
~ ~
~
~ 82.790 _1. 1--
~
s o N oRA S T. 44 CURB 2 DROP 44 2
CURBDR0P
tE=2028.75 IE=2028.80
SIDEWALK INLET SIDEWALK INLET
z IE=2028.56 IE=2428.61
~
3UMI JANUARY 21 1999
CISTE~' ~ ~
sIONAL
NoRTM LOT 3, BLOCK 1
IEXPIRES: AUG. 1, 2000 ~ SCALE 1~ = 20° yA .T.FyWAY ADDITION
82.7[J'
L
- - - - - -
~ ~ 20' BUILDING SETBACK
~ ~o~ wA a°t
l'z
34M 1 ww
GIST
Sj~NAL E~
~EXPIRES: AUG. 1, 2000
~
c,i +
cn
~
_ 0,
N OR TH I I
SCALE 1" = 20'
12+90.0, 35.0' LT.
CONC. INLET W/
TYPE 2 GRATE
EL=2027.50 ~ I
IE=2025.50
___36' BUILDING SETDACK
10.0'
- f BOTTOM
~P f - . . . . ~ EL=2027.00
t 1 o BERM
~ EL=2028.20 UTILITY EASEMENT
I
~ . I
' . . + r DRAINAGE o
.30 o
EASEMENT
80RDER EASEMENT
I ~ ~ o o, ~
82.79'
12+75.00
4' CURB DRQP 12+90.0, 13.5' LT. S o nr o R A .S T.
IE=2027.99 TYPE "B" DW ~
SIDEWALK INLET W/ TYPE 4 SOLID
IE=2027.80 COVER.
IE=2025.05
JAN UARY 21,1999 J
~
.
~ LOT 4, BLQCK 1 ~
` _ _ ~ VALLEYWAY ADDITI_ J
82.76'
I I
I I
`24' BUILDING SET6ACK - ^ - V - - - - ^ - ^ - !
Cn cp
W ~
~,4
N
1 ~
12+90.0, 35.0' LT.
CONC. INLET W/
- TYPE 2 GRATE
~ f EL=2027.50
36' BUILOING SETBACK IE=2025.50
~
- - - .0~ - r. - _
DRAINAGE 28 - -
EASEMENT BOTTOM
r EL=2027.00
4' TYP. t--- BERM
UTIUTY EASEMENT ' EL=2028.20
o -
.30'
o . .
BORDER EASEMENT ~ • I ,
~ 82.799 I
L N O R A s r. 1?+75.00
CURB
5 LT.
WAS E
TYPE ~ 6" DW
SIDEWALK 1NLET W/ TYPE 4 SOLtD
0 IE=2027.80 COVER.
IE=2025.05
~
JANUARY 21,1999 ~
~
s'sJONAL E~
NoRTH LOT 5, BLOCK 1
IEXPIRES: AUG. 1. 2000 i SCALE 1 p= 20' VALLEYWAY ADDITION
~ ~
~ L 12.5' i 12.0' ~
I' -
^
-
14+50.00 104.51 '
4' CURB DROP 6,
IE=2027.95
SIDEWALK INLET
IE=2027.76 I . ~ . '
0
+ o r- - 20' BUILDING SETBACK
K I
~ m ~
~ . ~
~4 II o ~ I
15+08.0 Im: o: Z I
38.5' LT. CONC. ~
INLET W/ TYPE D-°' D ~
2 GRATE. ~ ~ c~n m I
EL=2027.45
IE=2025.45 ~ W =a : o
Ico
15+08.0 rJV ~ c lc
17.0' LT. TYPE ~ I (-4 '4BSOL 0 OVER E „ I . ~
IE=2025.45 12 PVC D IV) W
~ P m ~ ~ ~
cn
~ . . Z I > v
N I
D }
~ i
I ~
r ~ ~ I
II ~
15+48.0 °
17.0' LT. TYPE 36' BUfLDING SETBACK
DW W/ TYPE ~ o
4 SOLID COVER
IE=2025.45 ~
15+72.00 UTILITY EASEMENT
4' CURB DROP
IE=2027.85 o
SIDEWALK f NLET BORDER EASEMENT I
IE=2027.66 84.23' -
WM.
soNORA srEEr
'`V1 4~)
o w~ JANUARY 21,1999
~ ,
~ ~ISTE~
sSIoNAL
NoRrH LOT 7, BLOCK 1
EXPIRES: AUG. 1, 2000 ~ SCALE 1„ = ZO' yAT.T.FWAY ADDITION
1 ~
14+33.03 14+45.03
4' CURB DROP 4' CURB DROP
IE=2028.65 IE=2028.71 S ON O R A S 7.
DRAINAGE 99.64'
40 - EASEMENT
TYP. -
• ~ ~ 4-o- 10' UTILITY EASEMENT
• N I • r: BOTTOM (
r' EL=2028.32
20, 1 BERM I
. . EL=2029.1
14 _ 0'
36' BUILDING SETBACK! I
~
~
W
LP
o,
W~ ~
ol ~
L
I ~
I ~
20' BUILDING SETBACKJ
99.64'
~ _ - - - - - - r
YIAS
wo`
~
4;;) <v JANUARY 21.1999
GISTE~
`s f0NAL E~ ~
NoR~ LOT 2, BLOCK 2
~EXPIRES: AiJG. 1, 20M ~ SCALE 1„ = 20' VALLEYWAY ADDITIQN
` ~ `
J
14+33.03 14+45.03
S 0 N Q R A S T. 4' CURB DROP 4' CURB DROP
IE=2028.65 IE=2028.71
i
99.64' pRAINAGE 4'
EASEMENT ~ TYP
10' UTILITY
EASEMENT BOTTOM ~ .N , .
~ EL=2028.32
~ BERM +
EL=2029.1 20'. . .
14.0'
( 36' BUILDING SETBACK I
~
W
Ln
°1 wl
_ Ln
I ol
~
I I
~ I
_20' BUILDING SETBACK
99.64'
- - - - - - - -
~
JANUARY 21.1999
SJ~NAL
NoRTH LOT 3, BLOCK 2
~EXPIR£S: AUG. 1. 2000 ~ SCALE 1~= 20' VALLEYWAY ADDITION
, m .
i ~
12+47.0, 23.0' RT.
TYPE "B" DW 12+75.00
W/ TYPE 4 GRATE 4' CURB DROP S O N O R A S T.
ELEV.=2027.50 IE=2027.99
- - - - - -
~ 31.3' _ 99.64'
0
~
00
BOTTOM 10' UTILITY EASEMENT
EL=2427.00
BERM DRAINAGE
EL=2028.20 ~ 38.5' 4, E,qSEMENT ~
36' BUILDING SETBACK
~
W
~ cn
c~n
0
-AI I
I I
I I
20' BUILDING SETBACK
~ ~
99.64'
~~F' ~ wAS~
.
~ 3`2''1
w
ISTE JANUARY 21,1999 J
Sj~NAL
NoRTH LOT 4, BLOCK 2
1EXPIRES: AUG. 1, 2000 ~ SCALE 1n = 20' VALLEYTWAY ADDITIQN
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L L- L ~ CLC Associates, Inc.
~acu+e, WA - DENVER, co ~o~ w~g, ~ch • s~a~ 200 (509) 458-6840 DATE: 11 /01 /99
Spokana, WA 99204 FAX: (Sfl8) 458-6814
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CLC As iat Inc. ~ ~ soc es,
Planning • Engineering • land Surv~~ng ~
Architecture ~ landsca e Architecture - P 701 West 7th • Suite 200 (509) 458-6840 N07 TO SCALE
Spokane, WA 99204 FAX: (509) 458-6844
~ ~ , _ ~ . .