27690 DRAINAGE REPORT
~
DRAINAGE TECHNICAL REPORT
. for the
TURTLE CREEK
SECOND ADDITION PLAT
SEPTEMBER 1998
W.O. No. 98389
Prepared for :
, DAHM DEVELOPMENT
12810 East Nora Avenue
Spokane, WA 99216
Prepared by:
' Inland Pacific Engineering Company
707 West 7'" Avenue Suite 200
Spokane, WA 99204
(509) 458-6840
'
'
DRAINAGE REPORT
for the
~
Turtle Creek Second Addition Plat
Spokane County, Washington
SEPTEMBER 1998
'
- d ign o e ~ts sho in th~isset of plans ~a`'nd calculaio s con~ o o
licable e~i~ ~ o s of th ;•po e Coun~ty Standards or Road and Sewer Co ~r ~fio, a. e ~ o e ou~n , u~i elines for,Stormwater Management. t~ esign e 'a ~ o h
. .,i;.:.~•.:
been aprove y,he Sokane ounty F~ngine.e,r: I appx~ove these pla~ns (ca ~u a'o s o
consruc~io ,t y x ~
~
This report has been prepared by Ann L. Winkler and Susan K. Murphy of Inland Pacific
~ Engineering Company under the direction of the undersigned professional engineer whose seal and
signature appear hereon.
. 0 WASic,r~~ If~
A. SL'
~
-~9 9 22916 s G/sTER
SIONALE
EXPIRES: I
~
Timothy A. Schwab, P.E.
Turtle Creek Second Addition
Drainage NarYative
'
GENERAL
;
~
Turtle Creek Second Addition is a 9.73 acre development of 28 single family residential lots
located west and south of Barker Road and Eighth Avenue in the Spokane Va11ey, within
Spokane County, Washington. The site is currently vacant with alfalfa as the predominant land
cover and vegetation. Single family residential development lies to the north, east and west. A
vicinity and location map have been included within the technical section of this document.
PURPOSE
The purpose of this report is to determine the extent of storm drainage facilities which will be
required to dispose of the increase in stormwater runoff created by the development of the Turtle
Creek Phase 2 plat. The storm draina e facilities on this project will be designed to dispose of
runoff from a ~ar ~ e~.s' required bY the S Wokane CountY Guidelines for
Y Stormwater Manag~ment. Calculations are included to vha he facilit~i~s also cont►ain t~he
50-y~a Pouiwi-nty aThis development is within the Aquifer Sensitive Area of
Spokane and is subject to '208' requirements. For this project, the 0- d 50-y~. va~~s
from the Spokane, Medical Lake, Reardon, Cheney and Rockford intensity curves w~r u~d as
well as the SCS iso-pluvial rainfall curves.
ANALYSIS METHODOLOGY
Per the Spokane County Guidelines for Stormwater Management, the Rational Method, which is
recommended for basins less than ten acres in size, will be used to determine the peak discharges
and runoff volumes for a11 basins.
PROJECT DESCRIPTION
~
The Turtle Creek Second Addition plat comprises 281ots of the approved 101 lots in the
, approved preliminary plat. Twenty-one lots were platted previously in the Turtle Creek First
Addition, for a total of 49 developed lots within the approved preliminary plat. The Turtle Creek
subdivision is located in the SE 1/4 of Section 19, T. 25 N., R. 45 E., W.M. within Spokane
~ County, Washington.
TOPOGRAPHY
The existing site naturally drains generally to the southwest, to Saltese Creek. The natural ditch
line, will allow the natural drainage route to remain in place from that oint west. The general
slopes within the Turtle Creek Second plat would be characterized as olN, from 1 to 13%. For
Inland Pacific Engineering Company D 1 Turtle Creek Second Addition Drainage Report
' .
development purposes, the natural slope was used for design and is mauitained as much as
possible throughout the project.
SOILS
As can be seen from the accompanying soils map from the Spokane County Soils Survey as
performed by the SCS, the site consists of three types of soils, two within the Class B type and
one within the Class A type. These soil types are described as follows.
GgA - Garrison gravelly loam, 0 to 5 percent slopes: Soils within this soil type aze some what
excessively drained soils formed in gravelly glacial outwash material from a variety of igneous
rock. Surface runoff is slow, and the hazard of erosion is slight. Spokane County Guidelines for
Stormwater Mana2ement indicate this to be a Soil Group Type B andi~~~
in~ alla~t~ion.
Hydrologic Soil Classification - B
' GmB - Garrison very gravelly loam, 0 to 8 percent slopes: Soils within this soil type are
some what excessively drained soils formed in gravelly glacial outwash material from a variety
of igneous rock. Surface runoff is slow, and the hazard of erosion is slight. GmB soils have a
thinner, more gravelly surface layer than GgA soils. Spokane County Guidelines for Stormwater
Manaaement indicate this to be a Soil Group Type B an~ re-a ~rov'e'~do~iv~.~~~ll ~ins ►alila_ io.
Hydrologic Soil Classification - B
MaC - Marble loamy sand, 0 to 30 percent slopes: Soils within this soil type are very deep,
excessively drained soils formed from sandy glaciofluvial material on dunelike, nearly level to
steep terraces and terrace breaks. Surface runoff is slow, and the hazard of erosion is slight.
Spokane County Guidelines for Stormwater Management indicate this to be a Soil Group Type A
an d c~~ 1' ~ s a a~voln
' Hydrologic Soil Classification - A
,
DRAINAGE NARRATIVE
' Offsile
Per Spokane County Stormwater Guidelines, a 50 year storm analysis has been done for Basins
A, B, C, E and F as required.
.
Inland Pacific Engineering Company DZ Turtle Creek Second Addition Drainage Report
~
Onsite
As this plat is within the aquifer sensitive area of Spokane County, all onsite and future drainage
will be collected and treated using the "208" runoff inethod as described in the Spokane County '
Guidelines for Stormwater Management. To facilitate this analysis, Turtle Creek Second
Addition was divided into 6 permanent sub-basins (A through F). Table 1 lists the basins and
pond for easy reference.
TABLE 1
oWNS l To al Street m . ~ ,tree We' ~h~ted
ea crea.ge ea ;1 ~pe'ous " "
rea
A 873,446 2.0075 73,223 0.1658 0.21
B 86,396 1.9834 113,714 0.2689 0.25
C 382232 0.8777 6,116 0.7373 0.27
D 252769 0.5916 6,151 0.1412 0.33
E 1629119 3.7217 28,627 0.6572 0.28
F 287,921 6.6098 47,781 1.0969 0.27
G 82552 0.1963 22436 0.0559 0.36
"208" Calculations
Within each basin the streets are divided into sub-basins by high and low roadway profiles.
' These facilities caPture uPstream stormwater runoff from the imPervious street surface and direct
the runoff into grassy '208' ponds. As shown on the '208' calculation worksheets included, the
, '208' storage volume provided is adequate to perform '208' treatment for the runoff created by the
first half inch of rainfall. .
' DRAINAGE CALCULATI0NS SUAI?IIARY
Calculations have been included for Drainage Basin considerations such as Peak Flow, Time of
Concentration, "208" sizing, drywell requirements, inlet sizing and curb inlets, as well as culverts
and pipe flows, some of which are summarized below with the remaining calculations included
in the appendix.
Inland Pacific Engineering Company D3 Turtle Creek Second Addition Drainage Report
Within the calculation section and where it has been determined necessary for clarity, several
sketches, as well as details from the plans have been incorporated to demonstrate assumptions
' and conclusions.
BASIN DESCRIPTIONS Basins A through F
Within this plat, and due to the general geographic features, a basic assumption was followed and
can be used to describe each basin; namely that ponds will be of the lot pond, or tract
, configuration.
Table No. 2- Pond and 208 Basin Summary
.
~
~ -08 o e 8 , , e~a !
A A 301 602 608 1-"B"
B B 488 976 1,012 1-"B"
C C 255 510 515 1-"A"
'
D D 256 512 544 1-"A"
E E 1,193 2,386 22500 2-"B"
F F 1,991 33,982 431240 2-"B"
G G 102 204 216 1-"B112
1- Type A is a Spokane Standazd Drywell - Single Depth, Capacity 0.3 cfs
1- Type B is a Spokane Standazd Drywell - Double Depth, Capacity 1.0 cfs
, 2- Installed as a part of Turtle Creek Phase 1
'
Inland Pacific Engineering Company D4 Turtle Creek Second Addition Drainage Report
; ' ' gAt tiy
- 6ALOWIK , r t w
y
STA 1AISS01"
0
j k C
- M1SS10N K~xwE~t ' ~
' W
Eti. t
oR,~ PtT RO w►sstaK s~~+zo
W
v 4 uxi SNARP
aCCa
~
:
, BaptiE D~s~Et
; •
L~7At4fl
- 800NE ~ g00l1E . •
.
oa ~ESUE1 ■ ~~~,~~t_ ao,a_ . _ _ -
""0 To SPO,Aft . ~ ~ E„E cat~,t ~
~ . • gROAOw~,~.~
svaiKGFIEL4 cc "
esra~,
9ROAOWAY ~~Kt ~ W CO'N~E't *eE~,a~~ ~ w~DO~h.
r • ~ ~
14~,LtiE'~
o 0 ~ Pt ♦V~ ' ~E~r fS ~at M1~~
[ SpRtI~GflE~ ~ A1.K~ uc i° Q0 v~~y 0 y 4 r~
~
0
z 0-
~°c• O 0 v YALI.EY w~~ Y G4•~~-~~ C, RiVERSIDE ~
~ o~
W ~
cr-
: -
N ~
o nsc~es ~ `
1 . r 1 Grce 1N4 .
' 4t {,~AIN ai~EaStOE~ K.S • a ~ 4~ t5
AVE
t'L . 4ZH
1 c°c oa ~ ~ v
~
' ~ N ~ ~K~ o~Rd uYi nacres
, -E ` ~ ~ 6~" Q ~ C~ee ~ten+ v cc . u~i
W o . ¢ .
y • .rn .c StK ~ . Q . • bjH_ 41 ~xa Hp z~~ J m tTH ` try ~
6TN !►VE ' •
tp AYE v ± ~
a c
. ~ • Tkti
•'%Z ~ ' txK ~'~-i-~ • . _ fTHAYE
~
lric " , t ,
' • I . •
~ Cet%tCot Ys1►er •
~ , • ' •
" s4tet ~ ~,m ~.VE W o
N
x F
~ w a d cs • . • ' ~ : to
~
~ ~ ()~A~.
< W y o' W c~° q,~v a
r z 11 ~`t1Fi h ~AVE ~ Q • ~ ' .
1~~ ~ ~ ~j • . ~ AV E
s 161 K .
O~ .
s ~ ~ 4` ?~c•y4 0
C,+
HTM L~
o
9 ak, a
~ y p ~ u o
"I i c 20T ~ ' C 2tN0 •
r
tisr l ~5~
~ w v ilapCr j1,yp 22kOtf ~~LC w 2la ~ .
~ Z ~ 2t
ZZ~ ~o 12)RO C?JR4 C! JRO Cf STEEN R
w O " d
w cc ' ui
AvE ' _ = p cr-
KT" ~ taTH i c,4WEp~ cr m.26oK m CT i ~ r+r ~►{'m~. Q ~ ~ ~ .
AV ~
.zcL CItEA~~'►9~'oy N • ~ 3~N~
~
• ~`s~
0
N sAlzNO aV=
~a LN RD 3 g x:
• J i
4
~ V
. ~
L
O
v
~ J .
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ w~ ~w ~ i rr~ ~ ~ ~
~
(Jo1ns §heQt 75)
~ : ~ _ I _ 'i:
'
~`a'r"' ~ng_'y~ JJ
r„~ • ` , . . I,~{ ~i~i , ~i~'h b' '•c. 'A , ~ ~ : ~i~, i
: i 4~ ~~~.,2~.~•
n r ~ 's'•yr_ ' ~°5°i~~,r~~ c~~* 4 C~ ~ s~ ' '
i,
~4)i~.r,"
il
~ "k II 11' ~
~ ru ~ a " I fn
Dd
L,
fp
(D , ~ i i , ~ h~# x.~ ~ ~ . ~ ~ , , i :p~ _„4~ I '•,~h ti `,sp~. ~
~ - - .a: r ~ ^
h~ 1 a ~ rf ~~r Y~~li~ ~u7y~ 4t 5 .a
Eg
:~rt e y r i } , ~ ' r • i , .
~ k - I ~ji~ . y~- '.~~„''~S'~." ~ ~ ,
~ q^ , _ r • ' .h ':S
r'~n ,~a ~ + •Ja ~a: ~ lar , ~ ' ~ , ;
~ t1 9 '!',.:~;~''r1~ F ; ' kT•. ~ 5 S ~ 'S ~`a• ~Sr~
. fF 'i~ S;
~,.j
i 1 ~ • x# ~ _ 1 ~,~w7~"°} ~
` • ~N 'F r' ~ 1 .~1's# ' I'~F; ' ~ ,a ~
70+x
~
~
~~✓~Sa `~~rL S' Ph. k _u m p ~~~r'~, f' y ~C¢~~' _ ~`Yf(3~ F+ ~
. e''!~..rS+i }r'•~"; , N~''~° P,., N fi{:, ~ ` ~I
~ey. Y 4 I
r~' ' , } ~ ' t•
~~kJ*•4
_~3
.I i
"Y !i
~L .
X C. ~
~ i b. ~ .
;!'YWiN`k~~~ ~
~ 0. •~~.~.(~l.ifl
t..
L h Slfeel 77)
~~~r~~
T 24 r~ . I T, 25 N. ~
0 ~h 1 Miae Q 5000 Feet
5cale l; 20 000 Range, t0wn5hip, and section corners shown nn this map are indefinite. •
0
i ~ 1 MiIc n
,
' Circular Channel Analysis & Design
Solved with Manning's Equation
, Open Channel - Uniform flow
Worksheet Name: TC 2nd Addition
Comment : Turtle Creek 2nd Addition - o►pp i eS ~Ou)01s I 11 ~
Solve For Actual Depth
Given Input Data:
~
Diameter.......... 1.00 ft4
Slope 0.0863 ft/ft
Manning's n....... 0.024
Discharge......... 2.71 cfs
Computed Results:
Depth 0.49 ft
Velocity.......... ~ 7.14 fps
Flow Area......... 0.38 sf
Critical Depth.... 0.71 ft
Critical Slope.... 0.0275 ft/ft
' Percent Full...... 48.70 0
Full Capacity..... 5.67 cfs
QMAX @.94D........ 6.10 Cfs
Froude Number..... 2.04 (flow is Supercritical)
'
1
1
1
Open Channel Flow Module, Version 3.41 (c) 1991
Haestad Methods, Inc. * 37 Brookside Rd * Waterbury, Ct 06708
Weighted Runoff Coefficient Calculation
~ Project: Turtle Creek 2nd
Basin: A IPE Job 98389
Total Area (acres): 2.0075 Designer: ALW
Imp. Area (acres): 0.1658 Date: 09/02
Grass Area (acres): 1.8417
Imp. Area "C": 0.90
G rass Area "C": 0.15
(Imp. Area)(Imp. "C")= 0.1492
(Grass Area)(Grass "C")= 0.2763
2.0075 0.4255
Weighted "C"= 0.4255 0.21
2.0075
~
'
Weighted Runo oe icient Calculation
Project: Turtle Creek 2nd
Basin: B IPE Job 98389
Total Area (acres): 1.9834 Designer: ALW
Imp. Area (acres): 0.2689 Date: 09/02
Grass Area (acres): 1.7145
Imp. Area "C": 0.90
Grass Area "C": 0.15
(Imp. Area)(imp. "C")= 0.2420
(Grass Area)(Grass "C")= 0.2572
1.9834 0.4992
Weighted "C"= 0.4992
0.25
1.9834
9
,
,
Weighted Runoff Coefficient Calculation
Project: Turtle Creek 2nd
Basin: D IPE Job 98389
Total Area (acres): 0.5916 Designer: ALW
' ImP. Area (acres): 0.1412 Date: 09/02
Grass Area (acres): 0.4504
Imp. Area "C": 0.90
Grass Area "C": 0.15
(Imp. Area)(Imp. "C")= 0.1271
(Grass Area)(Grass "C")= 0.0676
0.5916 0.1946
Weighted "C"= 0.1946
0.33
0.5916
~
'
,
,
Weighted Runoff Coefficient Calculation
Project: Turtie Creek 2nd
Basin: C IPE Job 98389
Total Area (acres): 0.8777 Designer: ALW
Imp. Area (acres): 0.1404 Date: 09/10
Grass Area (acres): 0.7373
imp. Area "C": 0.90
Grass Area "C": 0.15
(Imp. Area)(Imp. "C")= 0.1264
(Grass Area)(Grass "C")= 0.1106
0.8777 0.2370
Weighted "C"= 0.2370
0.27
0.8777
1
'
'
Weighted Runoff Coefficient Calculation
Project: Turtle Creek 2nd
Basin: E IPE Job 98389
Total Area (acres): 3.7217 Designer: ALW
Imp. Area (acres): 0.6572 Date: 09/02
Grass Area (acres): 3.0646
Imp. Area "C": 0.90
Grass Area "C": 0.15
(Imp. Area)(Imp. "C")= 0.5915
(Grass Area)(Grass "C")= 0.4597
3.7217 1.0512
Weighted "C"= 1.0512
0.28
3.7217
,
,
.
'
Weighted Runoff Coefficient Calculation
' Pro1'ect: Turtle Creek 2nd
Basin: F IPE Job 98389
Total Area (acres): 6.6098 Designer: ALW
~
Imp. Area (acres). 1.0969 Date: 09/02
Grass Area (acres): 5.5129
Imp. Area "C": 0.90
Grass Area "C": 0.15
(Imp. Area)(Imp. "C")= 0.9872
(Grass Area)(Grass "C")= 0.8269
6.6098 1.8141
Weighted "C"= 1.8141
0.27
6.6098
'
. '
1
'
,
Weighted Runoff Coefficient Calculation .
' ProJ'ect: Turtle Creek 2nd
Basin: G IPE Job 98389
, Total Area (acres): 0.1963 Designer: ALW
Imp. Area (acres). 0.0559 Date. 09/14
Grass Area (acres): 0.1404
, Imp. Area "C": 0.90
Grass Area "C": 0.15 .
'
(Imp. Area)(fmp. "C")= 0.0503
(Grass Area)(Grass "C")= 0.0211
0.1963 0.0714
Weighted "C"= 0.0714
0.36 _
0.1963
' -
'
~
,
BOWSTRING METHOD PROJECT: Turtle Creek 2nd
PEAK FLOW CALCULATION PROJECT Turtle Creek 2nd DETENTION BASIN DESIGN BASIN: A
BASIN.: A 10-Year Design Storm DESIGNER: ALW
Tot. Area 2.01 Acres DATE: 09103
Imp. Area 7223.0000 SF
C = 0.21
Time Increment (min) 5.0
CASE 1 , Tme of Conc, (min)
Outflow (cfs) 1
50 ft. Overland Flow ,.='~-~•r Design Year Flow 10
;Area (acres) 2.0075
Ct = 0.15 . Impervious Area (sq ft) 7223
L= 50 ft. C Factor 0.21
n = 0.40 '208' Volume Provided
S= 0.020 Area' C 0.422
Tc 2.93 min., by Equation 3-2 of Guidelines
Time Time Inc. Intens. Q Devei. Vol.ln Vol.Out Storage
160 ft. Gutter flow (min) (sec) (inmr) (cfs) (cu ft) (cu ft) (cu ft)
Z1 = 50.0 For Z2 5.00 300 3.18 1.34 539 300 239
Z2 = 3.5 ~ Type B =1.0
n= 0.016 ~ Rolled = 3.5 5 300 3.18 1.34 539 300 239
S= 0.011 10 600 2.24 0.94 663 600 63
15 900 1.77 0.75 748 900 -152
d= 0.165 ft. , 20 1200 1.45 0.61 796 1200 -004
25 1500 1.21 0.51 817 1500 -683
A R Q Tc Tc total I Qc 30 1800 1.04 0.44 834 1800 -966
35 2100 0.91 0.38 845 2100 -1255 ,
0.73 0.08 1.34 1.44 5.00 3.18 1.34 40 2400 0.82 0.35 865 2400 -1535
45 2100 0.74 0.31 874 2700 -1826
Qpeak for Case 1= 1.34 cfs 50 3000 0,68 0,29 889 3000 -2111
55 3300 0.64 0.27 918 3300 -2382
60 3600 0.61 0.26 952 3600 -2648
CASE 2 65 3900 0.60 0.25 1012 3900 -2888
10 4200 0.58 0.24 1052 4200 -3148
Case 2 assumes a Time of Concentration less than 5 minutes so that the 75 4500 0.56 0.24 1086 4500 -3414
peak flow =.90(3.18)(Imp. Area) = 0.47 cfs 80 4800 0.53 0.22 1095 4800 -3705
85 5100 0.52 0.22 1140 5100 -3960
90 5400 0.50 0.21 1160 5400 -4240
So, the Peak flow for the Basin is the greater of the two flows, 95 5700 0.49 0.21 1199 5100 -4501
1.34 cfs 100 6000 0.48 0.20 1235 6000 -4165
' 208' DRAINAGE POND CALCULATIONS • Required'208' Storage Volume
Impervious Area x.5 in 112 inlft 301 cu ft
, • ~ ~ ~ 208' Storage Volume Provided 3 04 cu ft
DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM
Maximum Storage Required by Bowstring 239 cu ft
_
~°~Number and Type of Drywells Required 0 Single
1 Double
m m m m m m m m m m m m m m m m m m m
BOWSTRING METHOD PROJECT: Turtle Creek 2nd
PEAK FLOW CALCULATION PROJECT TuRle Creek 2nd DETENTION BASIN DESIGN BASIN: B
BASIN: B 10-Year Design Storm DESIGNER: ALW
Tot. Area 1,98 Acres . DATE: 09109
Imp. Area 11714 SF '
C = 025
Time Increment (min) 5
CASE 1 Time of Conc. (min) 5.16
Outflow (cfs) 1
50 ft. Overland Flow " 'Design Year Flow 10
f Area (acres) 1.9834
Ct = 0.15 - Impervious Area (sq ft) 11714
L= 50 ft. 'C Factor 0.25
L
n = 0.40 '208' Volume Provided
S= 0.020 r Y""Area' C 0.496
,.ac~,a •:~~e
~ - Tc = 2.93 min., by Equation 3-2 of Guidelines Time Time Inc. Intens. Q Devel, Vol.ln Vol.Out Storage
350 ft. Gutter flow (min) (sec) (iNhr) (cfs) (cu ft) (cu ft) (cu ft)
- •
Z1= 50.0 ✓ For Z2 5.16 310 3,14 1.56 646 310 336
Z2= 3.5 Type6=1.0 .
n= 0.016 Rolled = 3.5 5 300 3,18 1.58 634 300 334
S= 0.025 ' 10 600 2.24 1.11 783 600 183
15 900 1,77 0.88 882 900 -18
d= 0,150 ft. 20 1200 1.45 0.72 939 1200 -261
25 1500 1,21 0.60 963 1500 -537
A R Q Tc Tc total I Qc 30 1800 1.04 0,52 983 1800 -817
- - 35 2100 0.91 0.45 995 2100 -1105
0.60 0.07 1.56 2.24 5.16 3,14 1.56 40 2400 0.82 0.41 1019 2400 -1381
45 2700 0.74 0,37 1029 2700 -1671
Qpeak for Case 1= 1.56 cfs ' 50 3000 0.68 0.34 1047 3000 -1953
' 55 3300 0.64 0,32 1081 3300 -2219
• 60 3600 0.61 0.30 1121 3600 -2479
CASE 2 ' 65 3900 0.60 0.30 1192 3900 -2706
70 4200 0.58 0.29 1238 4200 -2962
Case 2 assumes a Time of Concentration less than 5 minutes so that the 75 4500 0.56 0.28 1279 4500 -3221
peak flow =.90(3.18)(Imp. Area) = 0,77 cfs SO 4800 0.53 0.26 1289 4800 -3511
4 85 5100 0.52 0.26 1342 5100 -3758
. 90 5400 0.50 0.25 1365 5400 -4035
So, the Peak flow for the Basin is the greater of the two flovus, : 95 5700 0.49 0.24 1411 5700 -4289
1.56 cfs 100 6000 0.48 0.24 1453 6000 -4547
- , ~
208' DRAINAGE POND CALCULATIONS
Required'208' Storage Volume
= Imperoious Area x.5 in I 12 inlft 486 cu ft
;
208' Storage Volume Provided SQ ~cu ft
N•
_ DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM
Maximum Storage Required by Bowstring 336 cu ft
Number and Type of Drywells Required 0 Single
1 Double
m m m m m m m m m m m m m m m m m m m
BOWSTRING METHOD PROJECT: Turtle Creek 2nd
PEAK FLOW CALCULATION PROJECT Turtle Creek 2nd DETENTION BASIN DESIGN BASIN: C
BASIN; C 10-Year Design Storm DESIGNER: ALW
Tot. Area 0.88 Acres DATE: 09110
Imp. Area 6116 SF
C = 0.27
Time Increment (min) 5
CASE 1 Time of Conc. (min) 5.00
Outflow (cfs) 0.3
50 ft. Overland Flow Design Year Flow 10
Area (acres) 0.8177
Ct = 0.15 Impervious Area (sq ft) 6116
L= 50 ft. 'C' Factor 0.27
n= 0.40 '208' Volume Provided 257.5
S= 0.020 Area * C 0.237
Tc = 2.93 min,, by Equation 3-2 of Guidelines
Time Time Inc. Intens, Q Devel, Vol.ln Vol.Out Storage
180 ft, Gutter flow (min) (sec) (inlhr) (cfs) (cu ft) (cu ft) (cu ft)
Z1= 50.0 For Z2 5.00 300 3.18 0.75 303 90 213
Z2= 3.5 Type6=1.0
n= 0.016 Rolled = 3.5 5 300 3.18 0,75 303 90 213
S= 0.015 10 600 2.24 0.53 373 180 193
15 900 1.77 0.42 420 270 150
d= 0.125 ft. 20 1200 1.45 0.34 447 360 87
25 1500 1.21 0.29 459 450 9
A R Q Tc Tc total I Qc 30 1800 1.04 0.25 469 540 -11
- - 35 2100 0.91 0,22 415 630 -155
0.42 0.06 0.75 1.67 5.00 3.18 0.75 40 2400 0.82 0.19 486 720 -234
45 2700 0.74 0.18 491 810 -319
Qpeak for Case 1= 0.75 cfs 50 3000 0.68 0,16 500 900 400
55 3300 0.64 0.15 516 990 -474
60 3600 0.61 0,14 535 1080 -545
CASE 2 65 3900 0.60 0,14 569 1170 -641
10 4200 0.58 0.14 591 1260 -669
Case 2 assumes a Time of Concentration less than 5 minutes so that the 75 4500 0.56 0,13 611 1350 -739
peak flow =.90(3.18)(Imp. Area) = 0,40 cfs 80 4800 0.53 0.13 616 1440 -824
85 5100 0.52 0.12 641 1530 -889
90 5400 0.50 0.12 652 1620 -968
So, the Peak flow for the Basin is the greater of the two flows, 95 5700 0.49 0.12 674 1710 -1036
0,75 cfs 100 6000 0.48 0,11 694 1800 -1106
208' DRAINAGE POND CALCULATIONS
Required'208' Storage Volume
,
= Impervious Area x.5 in I 12 iNR 255 cu ft
208' Storage Volume Provided 257.5 cu ft
ORYWELL REQUIREMENTS -10 YEAR DESIGN STORM
Maximum Storage Required by Bowstring 213 cu ft
Number and Type of Drywells Required 1 Single
0 Double
m m m m m m m m m m - m m m m m m m m
BOWSTRING METHOD PROJECT: Turtle Creek 2nd
PEAK FLOW CALCULATION PROJECT Turtle Creek 2nd DETENTION BASIN DESIGN BASIN: D
BASIN: D 10-Year Design Storm DESIGNER: ALW
Tot. Area 0.59 Acres DATE: 09103
Imp. Area 6151.0000 SF
C = 0.33
' Time Increment (min) 5
CASE 1 Time of Conc. (min) 5.00
Outflow (cfs) 0.3
•rr...■•
60 ft. Overland Flow Design Year Flow 10
Area (acres) 0.5916
Ct = 0.15 impervious Area (sq ft) 6151
L= 60 ft. 'C Factor 0.33
n = 0.40 ~'208' Volume Provided
S= 0.020 ~ Area * C 0.195
Tc = 3.27 min., by Equation 3-2 of Guidelines .
„ Time Time Inc. Intens. Q Devel. Vol.ln Vol.Out Storage
150 ft. Gutter flow ' (min) (sec) (inlhr) (cfs) (cu ft) (cu ft) (cu ft)
Z1= 50.0 For Z2 5.00 300 3.18 0.62 250 90 160
Z2 = 3.5 Type B =1.0 - n= 0.016 Rolled = 3.5 .5 300 3.18 0.62 250 90 160
S= 0,011 10 600 2.24 0.44 307 180 121
15 900 1.77 0.35 346 270 76
d= 0,124 ft. 20 1200 1.45 0.28 369 360 9
25 1500 1.21 0.24 378 450 -72
A R Q Tc Tc total I Qc _ :..30 1800 1.04 0.20 388 540 -154
35 2100 0.91 0.18 391 630 -239
0.41 0.06 0.62 1.64 5,00 3.18 0.62 40 2400 0.82 0.16 401 720 -319
45 2700 0.74 0.14 405 810 -405
Qpeak for Case 1= 0.62 cfs 50 3000 0.68 0.13 412 900 -488
' 55 3300 0.64 0.12 425 990 -565
60 3600 0.61 0.12 441 1080 -639
CASE 2 65 3900 0.60 0.12 469 1170 -701
70 4200 0.58 0.11 487 1260 -713
Case 2 assumes a Time of Concentration less than 5 minutes so that the . 75 4500 0.56 0.11 503 1350 -847
peak flow =.90(3.18)(Imp. Area) = 0.40 cfs : 80 4800 0.53 0.10 507 1440 -933
-85 5100 0.52 0.10 528 1530 -1002
90 5400 0.50 0.10 537 1620 -1083
So, the Peak flow for the Basin is the greater of the two flows, 95 5700 0.49 0.10 555 1710 -1155
0.62 cfs --100 6000 0.48 0.09 572 1800 -1228
208' DRAINAGE PONO CALCULATIONS
, - . Required'208' Storage Volume ~
Impervious Area x.5 in I 12 inlft 256 cu ft
208' Storage Volume Provided Lcu ft
DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM .
r'•, Maximum Storage Required by Bowstring 160 cu ft
tJ - .
Number and Type of Drywells Required 1 Single
0 Double
BOWSTRING METHOD PROJECT: Turtle Creek 2nd
PEAK FLOW CALCULATION PROJECT Turtle Creek 2nd DETENTION BASIN DESIGN BASIN: E
BASIN: E 10-Year Design Storm DESIGNER; ALW
Tot. Area 3.72 Acres DATE: 09110
Imp. Area 28621 SF
C = 0.28
Time Increment (min) 5
CASE 1 Time of Conc. (min) 15.53
Outflow (cfs) 2
50 ft. Overland Flow TM Design Year Flow 10
Area (acres) 3.7217
M 4wJr. ~
Ct = 0,15 Impervious Area (sq ft) 28627
L= 50 ft. C Factor 0.28
n= 0.40 :,'208' Volume Provided 1250
S= 0.020 Area ` C 1.042
Tc = 2.93 min., by Equation 3-2 of Guidelines
. . Time Time Inc. Intens. Q Devel, Vol.ln Vol.Out Storage
1150 ft. Gutter flow ' (min) (sec) (infhr) (cfs) (cu R) (cu ft) (cu ft)
`
Z1 = 50.0 For Z2 15.53 932 1.74 1.81 2261 1864 397
Z2= 3.5 TypeB=1.0
n= 0.016 Rolled = 3.5 S 300 3.18 3.31 1332 600 732
S= 0.005 10 600 2.24 2.33 1877 1200 671
15 900 1.77 1.84 2224 1800 424
d= 0.223 ft. 20 1200 1.45 1.51 2292 2400 -108
25 1500 1.21 1.26 2291 3000 -709
A R Q Tc Tc total I Qc 30 1800 1.04 1.08 2294 3600 -1306
35 2100 0.91 0.95 2292 4200 -1908
1.32 0.11 2.01 12.61 15.53 1.74 1.81 40 2400 0.82 0.85 2322 4800 -2478
45 2700 0.74 0.77 2326 5400 -3014
Qpeak for Case 1= 1.81 cfs 50 3000 0.68 0.71 2350 6000 -3650
55 3300 0.64 0.67 2412 6600 -4188
• 60 3600 0.61 0.64 2490 7200 -4710
CASE 2 65 3900 0.60 0.63 2637 7800 -5163
70 4200 0.58 0.60 2730 8400 -5670
Case 2 assumes a Time of Concentration less than 5 minutes so that the 75 4500 0.56 0.58 2811 9000 -6189
peak flow =.90(3.18)(Imp. Area) = 1,88 cfs 80 4800 0.53 0.55 2826 9600 -6774
85 5100 0.52 0,54 2935 10200 -7265
90 5400 0.50 0.52 2979 10800 -7821
So, the Peak flow for the Basin is the greater of the two flows, 95 5700 0.49 0,51 3072 11400 -8328
1.88 cfs 100 6000 0.48 0.50 3160 12000 -8840
- 208' DRAINAGE POND CALCULATIONS
Required'208' Storage Volume
Imperoious Area x.5 in 112 inlft 1193 cu ft
,~,a7.~*;~.i~;•
208' Storage Volume Provided 1250 cu ft
DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM
A~
Maximum Storage Required by Bowstring 732 cu ft
Number and Type of Drywells Required 0 Single
, 2 Double
m m m m m m m m m m m m m m m m m m m
BOWSTRING METHOD PROJECT; Turtle Creek 2nd
PEAK FLOW CALCULATION PROJECT Turtle Creek 2nd DETENTION BASIN DESIGN BASIN: F
BASIN; F 10-Year Design Storm DESIGNER: ALW
Tot. Area 6.61 Acres DATE: 09110
Imp. Area 47781 SF
C = 0.27
• Time Increment (min) 5
CASE 1 Time of Conc. (min) 10.90
Outflow (cfs) 2
50 ft. Overland Flow Design Year Flow 10
~LL~~•~- Area (acres) 6.6098
Ct = 0.15 Impervious Area (sq ft) 47781
L= 50 ft. 'C' Factor 0.27
n= 0.40 -.'208' Volume Provided 2120
S= 0.020 Area * C 1.785
Tc = 2.93 min,, by Equation 3-2 of Guidelines
Time Time Inc. Intens. Q Devel, Vol.ln Vol.Out Storage
1310 ft, Gutter flow (min) (sec) (iNhr) (cfs) (cu ft) (cu ft) (cu ft)
Z1= 50.0 For Z2 10.90 654 2.14 3,82 3347 1308 2039
Z2 = 3.5 Type B =1.0
n= 0.016 Rolled = 3.5 5 300 3.18 5.68 2281 600 1681
S= 0.014 10 600 2.24 4.00 3214 1200 2014
15 900 1.77 3.16 3545 1800 1745
d= 0.245 ft. 20 1200 1.45 2.59 3681 2400 1281
25 1500 1.21 2.16 3719 3000 719
A R Q Tc Tc total I Qc 30 1800 1.04 1.86 3754 3600 154
35 2100 0.91 1.62 3772 4200 -428
1.60 0,12 4.38 7.97 10.90 2.14 3.82 40 2400 0.82 1.46 3838 4800 -962
45 2700 0.74 1.32 3859 5400 -1541
Qpeak for Case 1= 3.82 cfs 50 3000. 0.68 1.21 3911 6000 -2089
55 3300 0.64 1.14 4023 6600 -2577
.60 3600 0.61 1.09 4161 7200 -3039
CASE 2 65 3900 0.60 1.07 4414 7800 -3386
70 4200 0.58 1.04 4578 8400 -3822
Case 2 assumes a Time of Concentration less than 5 minutes so that the 75 4500 0.56 1.00 4720 9000 -4280
peak flow =.90(3.18)(Imp. Area) = 3.14 cfs 80 4800 0.53 0.95 4750 9600 -4850
85 5100 0.52 0.93 4939 10200 -5261
90 5400 0.50 0.89 5017 10800 -5783
So, the Peak flow for the Basin is the greater of the two flows, 95 5700 0.49 0.87 5179 11400 -6221
3.82 cfs .100 6000 0.48 0.86 5330 12000 -6670
. 208' DRAINAGE POND CALCULATIONS
Required '208' Storage Volume
' - = ImpeNious Area x.5 in 112 in/ft 1991 cu ft
208i Storage Volume Provided 2120 cu ft
9•r~ DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM
Maximum Storage Required by Bowstring 2039 cu ft
,
Number and Type of Drywells Required 0 Single
2 Double
BOWSTRING METHOD PROJECT: Turtle Creek 2nd
PEAK FLOW CALCULATION PROJECT Turtle Creek 2nd DETENTION BASIN DESIGN BASIN: G
BASIN: G 10-Year Design Storm DESIGNER: ALW
Tot. Area 0.20 Acres DATE: 09h4
Imp. Area 2436 SF
C = 0.36
Time Increment (min) 5
CASE 1 Time of Conc. (min) 5.00
Outflow (cfs) 1
0 ft. Overland Flow Design Year Flow 10
Area (acres) 0,1963
Ct = 0.15 Impervious Area (sq ft) 2436
L= 0 ft. 'C' Factor 0.36
n= 0.02 '208' Volume Provided 108
S= 0.020 Area' C 0.071
Tc = 0.00 min., by Equation 3-2 of Guidelines
Time Time Inc. Intens. Q Devel. Vol.ln Vol,Out Storage
150 ft. Gutter flow (min) (sec) (inlhr) (cfs) (cu ft) (cu ft) (cu ft)
Z1= 50.0 For Z2 5.00 300 3.18 0.22 90 300 -210
Z2= 3.5 Type6=1.0
n= 0.016 Rolled = 3.5 5 300 3.18 0.22 90 300 -210
S= 0.030 10 600 2.24 0.16 111 600 -489
15 900 1.77 0,13 125 900 -775
d= 0.070 ft. 20 1200 1.45 0.10 133 1200 -1067
25 1500 1.21 0.09 137 1500 -1363
A R Q Tc Tc totai I Qc 30 1800 1.04 0,07 140 1800 -1660
- 35 2100 0.91 0.06 142 2100 -1958
-
0.13 0.03 0.22 1.46 5.00 3.18 0.22 40 2400 0.82 0.06 145 2400 -2255
45 2700 0.74 0.05 147 2700 -2553
Qpeak for Case 1= 0.22 cfs 50 3000 0.68 0.05 149 3000 -2851
55 3300 0.64 0.05 154 3300 -3146
60 3600 0.61 0.04 160 3600 -3440
CASE 2 65 3900 , 0.60 0.04 170 3900 -3730
70 4200 0.58 0.04 176 4200 -4024
Case 2 assumes a Time of Concentration less than 5 minutes so that the 75 4500 0.56 0.04 182 4500 -4318
peak flow =.90(3.18)(Imp. Area) = 0.16 cfs 80 4800 0.53 0.04 184 4800 -4616
85 5100 0.52 0.04 191 5100 -0909
90 5400 0.50 0,04 194 5400 -5206
So, the Peak flow for the Basin is the greater of the two flows, 95 5700 0.49 0.03 201 5700 -5499
0.22 cfs 100 6000 0.48 0.03 207 6000 -5793
208' DRAINAGE POND CALCULATIONS
, Required'208' Starage Volume
= Impervious Area x.5 in ! 12 inlft 102 cu ft
208' Storage Volume Provided 108 cu ft
DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM
Maximum Storage Required by Bowstring -210 cu ft
Number and Type of Drywells Required 0 Single
1 Double
m m m m m m m m m m m m m m m m m m m
50-year STORM BOWSTRING METHOD PROJECT; Turtle Creek 2nd
PEAK FLOW CALCULATION PROJEC Turtle Creek 2nd ~ DETENTION BASIN DESIGN BASIN: A
BASIN A DESIGNER: ALW
Tot. Area 2.01 Acres DATE: 09l03
Imp. Area 7223 SF
C = 0.21
~ Time Increment (min) 5
CASE 1 #Time of Conc. (min) 5.00
Oufflow (cfs) 1
50 ft. Overland Flow Design Year Flow 50
1' R.MlA1l1c?M
Area (acres) 2.0075
L.
Ct = 0.15 Imperoious Area (sq ft) , 7223
L= 50 ft. ,-,'C Factor 0.21
n = 0.40 ' '208' Volume Provided
S= 0.020 Area * C 0.422
Tc = 2.93 min., by Equation 3-2 of Guidelines
Time Time Inc. Intens. Q Devel. Vol.ln Vol.Out Storage
160 ft. Gutter flow (min) (sec) (in/hr) (cfs) (cu ft) (cu ft) (cu ft)
Z1= 50.0 5.00 300 4.58 1.93 776 300 476
Z2 = 3.5
n= 0.016 5 300 4.58 1.93 776 300 476
S= 0.011 10 600 3.20 1.35 947 600 347
15 900 2.45 1.03 1035 900 135
d= 0.189 ft, 20 1200 1.95 0.82 1070 1200 -130
25 1500 1.62 0.68 1094 1500 -406
A R Q Tc Tc total I Qc 30 1800 1.56 0.66 1251 1800 -549
35 2100 128 0.54 1188 2100 -912
0.96 0.09 1.93 1.32 5,00 4.58 1.93 40 2400 1.19 0.50 1250 2400 -1150
45 2700 1.06 0.46 1276 2700 -1424
Qpeak for Case 1= 1.93 cfs 50 3000 0.99 0,42 1295 3000 -1705
55 3300 0.92 0.39 1319 3300 -1981
60 3600 0.87 0.31 1358 3600 -2242
CASE 2 65 3900 0.82 0.35 1383 3900 -2517
70 4200 0.80 0.34 1451 4200 -2749
Case 2 assumes a Time of Concentration less than 5 minutes sa that the 75 4500 0.77 0.32 1494 4500 -3006
peak flow =.90(4.58)(Imp. Area) = 0,68 cfs 80 4800 0.75 0.32 1550 4800 -3250
, 85 5100 0.72 0.30 1579 5100 -3521
90 5400 0.71 0.30 1647 5400 -3753
So, the Peak flow for the Basin is the greater of the two flows, 95 5700 0.69 0.29 1688 5700 4012
1.93 cfs 100 6000 0.67 0.28 1724 6000 -0276
206' DRAINAGE POND CALCULATIONS h~ e a e~ D 2sq.St.
Required'208' Storage Volume
= Impervious Area x.5 in 112 inlft 301 cu ft ~
° 50 year Volume Provided 541 cuft UQj`q m4~.i^P
DRYWELL REQUIREMENTS - 50 YEAR DESIGN STORM 5~ 1'~~'dt
- Maximum Storage Required by Bowstring 476 cu ft
C)
Number and TYpe of Drywells Required 0 Sin9le l~> y
~ 1 Double I
4 UM~ 5 ad < ;k9CP
INLAND PACIFIC ENGINEERING
m m - m m m m m m m m m m m m m m m m
50-year STORM BOWSTRING METHOD PROJECT: Turtle Creek 2nd
PEAK FLOW CALCULATION PROJECT Turtle Creek 2nd DETENTION BASIN DESIGN BASIN: B
BASIN B DESIGNER: ALW
Tot. Area 1.98 Acres DATE: 09109
Imp. Area 11714 SF
C = 0.25
Time Increment (min) 5
CASE 1 Time of Conc. (min) 5.00
Outflow (cfs) 1
50 ft. Overland Flow Design Year Fiow 50
Area (acres) 1.9834
Ct = 0.15 Impervious Area (sq ft) 11714
L= 50 ft. : „'C Factor 0.25
n = 0.40 . ~ 208' Volume Provided
S= 0.020 : Area' C 0.496
Tc = 2.93 min., by Equation 3-2 of Guidelines Time Time Inc. Intens. Q Devel. Vol.ln Vol.Out Storage
350 ft. Gutter flow (min) (sec) (iNhr) (cfs) (cu ft) (cu ft) (cu ft)
'
Z1= 50.0 ' 5.00 300 4.58 227 913 300 613
Z2 = 3,5
n= 0.016 5 300 4.58 2.27 913 300 613
S= 0.025 10 600 320 1.59 1114 600 514
15 900 2.45 1.21 1217 900 317
d= 0.172 ft. , 20 1200 1.95 0,97 1259 1200 59
' 25 1500 1.62 0,80 1287 1500 -213
A R Q Tc Tc total I Qc 30 1800 1.56 0.77 1471 1800 -329
35 2100 1.28 0,63 1398 2100 -702
0.79 0.09 2.27 2,04 5,00 4.58 2.27 40 2400 1.19 0.59 1470 2400 -930
45 2700 1.08 0.54 1501 2700 -1199
Qpeak for Case 1= 2,27 cfs 50 3000 0.99 0.49 1523 3000 -1477
55 3300 0.92 0,46 1552 3300 -1748
60 3600 0.87 0.43 1597 3600 -2003
CASE 2 65 3900 0.82 0.41 1627 3900 -2273
70 4200 0.80 0.40 1707 4200 -2493
Case 2 assumes a Time of ConcentraGon less than 5 minutes so fhat the 75 4500 0.77 0.38 1757 4500 -2743
peak flow =.90(4.58)(Imp. Area) = 1,11 cfs 80 4800 0.75 0.37 1823 4800 -2977
85 5100 0.72 0.36 1657 5100 -3243
90 5400 0.71 0.35 1937 5400 -3463
So, the Peak flow for the Basin is the greater of the two flows, 95 5700 0.69 0.34 1985 5700 -3715
2.27 cfs 100 6000 0.67 0,33 2027 6000 -3973
.
. , 208' DRAINAGE POND CALCULATIONS .~1
Required'208' Storage Volume n Q p~ o~, ~ SU,~ = Imperoious Area x,5 in 112 iNft 488 cu ft
,
50 year Volume Provided q ~ 0 cu ft~~
ORYWELL REQUIREMENTS - 50 YEAR DESIGN STORM
Maximum Starage Required by Bowstring 613 cu ft
wl'n;7;-:,y..,
°~Number and Type of Drywells Required 0 Single
1 Double ~
INLAND PACIFIC ENGINEERING
50-year STORM BOWSTRING METHOD PROJECT: Turtle Creek 2nd
PEAK FLOW CALCULATION PROJEC Turtle Creek 2nd DETENTION BASIN DESIGN BASIN: C .
BASIN C DESIGNER: ALW
Tot. Area 0.88 Acres DATE: 09110
Imp. Area 6116 SF
C = 0.27
Time Increment (min) 5
CASE 1 Time of Conc. (min) 5.00
Outflow (cfs) 0.3
50 ft. Overland Flow Design Year Flow 50
Area (acres) 0.8777
Ct = 0.15 ' Impervious Area (sq ft) 6116 '
L= 50 ft. 'C' Factor 0.27
n = 0.40 '208' Volume Provided
S= 0.020 , Area " C 0.237
Tc = 2.93 min., by Equation 3-2 of Guidelines
Time Time Inc. Intens. Q,Devel. Vol.ln Vol.Out Storage
180 ft. Gutter flow (min) (sec) (inlhr) (cfs) (cu ft) (cu ft) (cu ft)
Z1= 50.0 5.00 300 4.58 1.09 436 90 346
Z2 = 3.5
n= 0.016 5 300 4.58 1.09 436 90 346
S= 0.015 10 600 3.20 0.76 532 180 352
15 900 2.45 0.58 582 270 312
d= 0.144 ft. 20 1200 1.95 0.46 602 360 242
25 1500 1.62 0.38 615 450 165
A R Q Tc Tc total I Qc 30 1800 1.56 0.37 703 540 163
35 2100 1.28 0.30 668 630 38
0.55 0.07 1.09 1.52 5.00 4.58 1.09 40 2400 1.19 0.28 703 720 -17
45 2700 1.08 0.26 717 810 -93
Qpeak for Case 1= 1.09 cfs 50 3000 0.99 0.23 728 900 -172
55 3300 0.92 0Z2 742 990 -248
60 3600 0.87 0.21 763 1080 -317
CASE 2 65 3900 0.82 0.19 778 1170 -392
70 4200 0.80 0.19 816 1260 -444
Case 2 assumes a Time of Concentration less than 5 minutes so that the 75 4500 0.77 0.18 840 1350 -510
peak flow =.90(4.58)(Imp. Area) = 0.58 cfs 80 4800 0.75 0.18 871 1440 -569
85 5100 0.72 0.17 888 1530 -642
90 5400 0.71 0.11 926 1620 -694
So, the Peak flow for the Basin is the greater of the lwo flows, 95 5700 0.69 0.16 949 1710 -761
1.09 cfs 100 6000 0.67 0.16 969 1800 -831
208' DRAINAGE POND CALCULATIONS
Required'208' Storage Volume n Q eU ?r,~ ~c~ 5 c;,
= Impervious Area x.5 in I 12 inlft 255 cu ftp r ov eA
50 year Volume Provided 406,5 9 cu ft
V13 ~urn2
DRYWELL REQUIREMENTS - 50 YEAR DESIGN STORM ~Cj
,
Maximum Storage Required by Bowstring 352 cu ft
Number and Type of Drywells Required 1 Single `1 ~O 3>~ 5 j
0 Double `
v o 1~l m~; ~.k' ~
INLAND PACIFIC ENGINEERING
m m m m m m m m m m m m m m m m m m m
50-year STORM BOWSTRING METHOD PROJECT: Turtle Creek 2nd
PEAK FLOW CALCULATION PROJECT Turtle Creek 2nd DETENTION BASIN DESIGN BASIN: D
BASIN D DESIGNER: ALW
Tot. Area 0.59 Acres DATE: 09103
Imp. Area 6151 SF
C = 0.33 a~''~+•.
Time Increment (min) 5
CASE 1 Time of Conc. (min) 5.00
Outflow (cfs) 0.3
60 ft, Overland Flow • Design Year Flow 50
' Area (acres) 0.5916
Ct = 0,15 Impervious Area (sq ft) 6151
L= 60 ft. 'C' Factor 0.33
n = 0.40 '208' Volume Provided
S= 0.020 Area' C 0.195
Tc = 3.27 min., by Equation 3-2 of Guidelines
Time Time Inc. Intens. Q Devel. Vol.ln Vol.Out Storage
150 ft. Gutter flow (min) (sec) (inlhr) (cfs) (cu ft) (cu ft) (cu ft)
Z1 = 50.0 5.00 300 4.58 0.89 359 90 269
Z2 = 3.5
n= 0.016 5 300 4.58 0.89 359 90 269
S= 0.011 10 600 3.20 0.62 439 180 259
15 900 2.45 0.46 479 270 209
d= 0.142 ft. 20 1200 1.95 0.38 496 360 136
25 1500 1.62 ' 0.32 507 450 57
A R Q Tc Tc total I Qc 30 1800 1.56 0.30 579 540 39
35 2100 1.28 0.25 550 630 -80
0.54 0.07 0.89 1.50 5.00 4.58 0,89 40 2400 1.19 0,23 579 720 -141 .
45 2700 1.08 0.21 591 810 -219
Qpeak for Case 1= 0.89 cfs 50 3000 0.99 0.19 600 900 -300
55 3300 0.92 0.18 611 990 -379
60 3600 0.81 0.17 629 1080 -451
CASE 2 65 3900 0.82 0.16 641 1170 -529
70 4200 0.80 0.16 672 1260 -588
Case 2 assumes a Time of Cancentration less than 5 minutes so that the 75 4500 0.77 0.15 692 1350 -658
peak flow =,90(4.58)(Imp. Area) = 0.56 cfs 80 4800 0.75 0.15 718 1440 -722
85 5100 0.72 0.14 731 1530 -799
90 5400 0.71 0.14 763 1620 -851
So, the Peak flow for the Basin is the greater of the lwo flows, 95 5700 0.69 0.13 782 1710 -928
0.89 cfs 100 6000 0.67 0.13 798 1800 -1002
208' DRAINAGE POND CALCULATIONS
Required'208' Storage Volume .
= Impervious Area x.5 in ! 12 inlft 256 cu ft~ r~~J'
~ 1 $G
50 year Volume Provided 4~Q cu ft
DRYWELL REQUIREMEN T S - 50 Y E A R D E S I G N S T O R M
Maximum Storage Required by Bowstring 269 cu ft
Number and Type of Drywells Required 1 Single
. , 0 Double iq> 9
vOIvrm ~ S Qd ~
INLAND PACIFIC ENGINEERING ~
m m m m m m m m m m m r ~ ■ ~ ~
50-year STORM ' ".~BOWSTRING METHOD PROJECT: Tu e reek n
PEAK FLOW CALCULATION PROJECT Turtle Creek 2nd . ~:DETENTION BASIN DESIGN BASIN: E
BASIN E • DESIGNER: ALW
Tot. Area 3.72 Acres DATE; 09103
Imp, Area 28627 SF ~';Y ~ _ C= 0.28 •=k~ Tme Increment (min) 5
CASE 1 Time of Conc. (min) 14.81
Outflow (cfs) 2
50 ft. Overland Flow Design Year Flow 50
Area (acres) 3.7217
Ct = 0.15 Imperoious Area (sq ft) 28627
L= 50 ft. 'C' Factor 0.26
n = 0.40 '208' Volume Provided
S= 0.020 Area " C 1.042
Tc = 2.93 min., by Equation 3-2 of Guidelines
Time Time Inc. Intens. Q Devel. Vol.ln Vol.Out Storage
1150 ft. Gutter flow (min) (sec) (inlhr) (cfs) (cu ft) (cu ft) (cu ft)
Z1= 50.0 14.81 889 2.45 2.55 3038 1778 1260
Z2 = 3.5 .
n= 0.016 5 300 4.58 4.77 1919 600 1319
S= 0.005 10 600 3.20 3.33 2681 1200 1481
15 900 2,45 2.55 3069 1800 1269
d= 0243 ft. 20 1200 1.95 2.03 3053 2400 653
25 1500 1.62 1.69 3042 3000 42
A R Q Tc Tc total I Qc 30 1800 1.56 1.63 3417 3600 -183
35 2100 1.28 1.33 3204 4200 -996
1.58 0.12 2.55 11,89 14.81 2.45 2.55 40 2400 1.19 1.23 3337 4800 -1463
45 2700 1.08 1.13 3319 5400 -2021
Qpeak for Case 1= 2.55 cfs 50 3000 0.99 1.03 3407 6000 -2593
55 3300 0.92 0.96 3453 6600 -3147
60 3600 0,87 0.91 3538 7200 -3662
CASE 2 65 3900 0.82 0.85 3591 7800 -4209
70 4200 0.80 0.83 3753 8400 -4647
Case 2 assumes a Time of Concentration less than 5 minutes so that the 75 4500 0.77 0.80 3853 9000 -5141
peak flow =.90(4.58)(Imp. Area) = 2.71 cfs 80 4800 0.75 0.78 3988 9600 -5612
85 5100 0,72 0.75 4053 10200 -6147
90 5400 0,71 0.74 4219 10800 -6581
So, the Peak flow for the Basin is the greater of the hnro flows, 95 5700 0.69 0.72 4316 11400 -7084
2.71 cfs 100 6000 0.67 0.70 4400 12000 -7600
208' DRAINAGE POND CALCULATIONS I I
Required '208' Storage Volume e? U. °~1 = 2 36~
= Impervious Area x.5 in I 12 inlft 1193 cu ft
P-O,J . ~ ry
~,,,,~,-~,~0 ~
50 year Volume Provided 2250 cu ft '
DRYWELL REQUIREMENTS - 50 YEAR DESIGN STORM
Maximum Storage Required by Bowstring 1481 cu ft = 2Z 5 Qt(A.Q,
Number and Type of Drywells Required 0 Single
2 Double 114 ~
y
INLANO PACIFIC ENGINEERING
m m m m m m m m m m m m m m m m m m m
50-year STORM ' qra BOWSTRING METHOD PROJECT: Turtle Creek 2nd
PEAK FLOW CALCULATION PROJECT Turtle Creek 2nd DETENTION BASIN DESIGN BASIN: F
BASIN F DESIGNER: ALW
Tot. Area 6.61 Acres DATE: 09103
Imp. Area 41781 SF
C = 0.27
Time Increment (min) 5
CASE 1 . Time of Conc. (min) 10.49
Outflow (cfs) 2
50 ft. Overland Flow Design Year Flow 50
,Area (ac.res) 6.6098
Ct = 0.15 ' Impervious Area (sq ft) 47781
L= 50 ft. ''C' Factor 0.27
n = 0,40 '208' Volume Provided
S= 0.020 Area' C 1.785
Tc = 2.93 min., by Equation 3-2 of Guidelines
Time Time Inc. Intens. Q Devel. Vol.ln Vol.Out Storage
1310 ft. Gutter flow (min) (sec) (inlhr) (cfs) (cu ft) (cu ft) (cu ft)
Z1= 50.0 10.49 630 3.12 5.57 4702 1259 3443
Z2 = 3.5
n= 0.016 5 300 4.58 8.17 3286 600 2686
S= 0.014 10 600 3.20 5.71 4592 1200 3392
15 900 2.45 4.37 4871 1800 3071
d= 0.269 ft. 20 1200 1.95 3.48 4921 2400 2521
25 1500 1.62 2.89 4956 3000 1956
A R Q Tc Tc total I Qc 30 1800 1.56 2.78 5601 3600 2007
35 2100 128 228 5286 4200 1086
1.93 0.13 5.57 7.57 10.49 3.12 5.57 40 2400 1.19 2.11 5528 4800 728
45 2700 1.08 1.93 5617 5400 217
Qpeak for Case 1= 5.57 cfs 50 3000 0,99 1.77 5679 6000 -321
55 3300 0.92 1.64 5770 6600 -830
60 3600 0.87 1.55 5922 7200 -1278
CASE 2 65 3900 0.82 1.46 6021 7800 -1779
70 4200 0.80 1.43 6302 8400 -2098
Case 2 assumes a Time of Concentration less than 5 minutes so that the 75 4500 0.77 1.37 6478 9000 -2522
peak flow =.90(4.58)(Imp. Area) = 4.52 cfs 80 4800 0.75 1.34 6711 9600 -2889
85 5100 0.72 128 6828 10200 -3372
90 5400 0.71 127 7114 10800 -3686
So, the Peak flow for the Basin is the greater of the two flows, 95 5700 0.69 1.23 7283 11400 4117
5,57 cfs 100 6000 0.67 1.20 7430 12000 -4570
• 208' DRAINAGE POND CALCULATIONS 1 I ~
Required'208' Storage Volume h ~ ~ <1 ~;i : ;Cl `•b ' ~ ,
= Impervious Area x.5 in ! 12 inlft 1991 cu ft r tp LI
50 year Volume Provided 3% ( Z.cu ft ~
'1CV.%;"e -
i
DRYWELL REQUIREMENTS - 50 YEAR DESIGN STORM
Maximum Storage Required by Bowstring 3443 cu ft Cu 4 1' ,
Number and Type of Drywells Required 0 Single
' 2 Double
,
INLAND PACIFIC ENGINEERING ~
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ " M M ~
50-year STORM BOWSTRING METHOD ROJECT: Turtle reek 2n
PEAK FLOW CALCULATION PROJEC Turtle Creek 2nd DETENTION BASIN DESIGN BASIN: G
BASIN G DESIGNER; ALW
Tot, Area 0.20 Acres DATE: 09114 ,
Imp. Area 2436 SF
C = 0,36
Time Increment (min) 5
CASE 1 Time of Conc. (min) 5.00
Outflow (cfs) 1
0 ft. Overland Flow Design Year Flow 50
Area (acres) 0,1963
Ct = 0.15 Impervious Area (sq ft) 2436
L= 0 ft. 'C Factor 0.36
n = 0.40 '208' Volume Provided
S= 0.020 Area * C 0.071
Tc = 0.00 min., by Equation 3-2 of Guidelines
Time Time Inc. Intens. Q Devel. Vol,ln Vol.Out Storage
150 ft. Gutter flow (min) (sec) (inlhr) (cfs) (cu ft) (cu ft) (cu ft)
Z1= 50.0 5.00 300 4.58 0.32 130 300 -170
Z2 = 3.5 n= 0.016 5 300 4.58 0.32 130 300 -170
S= 0.030 10 600 3.20 0.23 159 600 -441
15 900 2.45 0.17 173 900 -727
d= 0.080 ft. 20 1200 1.95 0.14 179 1200 -1021
25 .1500 1.62 0.11 183 1500 -1317
A R Q Tc Tc total I Qc 30 1800 1.56 0.11 210 1800 -1590
___35 2100 1.26 0.09 199 2100 -1901 •
0.17 0.04 0.32 1.33 5.00 4.58 0.32 - 40 2400 1.19 0.08 210 2400 -2190
45 2700 1.08 0.08 214 2700 -2486
Qpeak for Case 1= 0.32 cfs 50 3000 0.99 0.07 217 3000 -2763
- 55 3300 0.92 0.07 221 3300 -3079
60 3600 0.87 0.06 228 3600 -3372
CASE 2 65 3900 0.82 0.06 232 3900 -3668
70 4200 0.80 0.06 243 4200 -3957
Case 2 assumes a Time of Concentration less than 5 minutes so that the 75 4500 0.77 0.05 250 4500 -4250
peak flow =.90(4.58)(Imp. Area) = 023 cfs 80 4800 0.75 0.05 260 4800 -4540
85 5100 0.72 0.05 265 5100 -4835
90 5400 0.71 0.05 276 5400 -5124
So, the Peak flow for the Basin is the greater of the iwo flows, 95 5700 0.69 0.05 283 5700 -5417
0.32 cfs 100 6000 0.67 0.05 289 6000 -5711
208' DRAINAGE POND CALCULATIONS 2
Required'208' Storage Volume hted -eA 0 4 5
q= Impenrious Area x.5 in f 12 inlft 102 cu ft(P r Q) V N21 ~ S~.~
.
50 year Volume Provided 0 cu ft U~,
ORYWELL REQUIREMENTS - 50 YEAR DESIGN STORM 4,Lf ~U .
Maximum Storage Required by Bowstring -170 cu ft
Number and Type of Drywells Required 0 Single
1 Double
v6 Li,y~(
~
INLANO PACIFIC ENGINEERING
.
-Dl~<_) - l`r ~e~~/~ r- - 7iZ~~b
SPokane Count3' Staff Review Checklist
-
for
-.D4E~~/~'re-`lle ~jneeitn_j-:~~_*_f
Project Name: ec, c-- - A,- Project Nurnber: p- leo:3 g c
~
Project Sponsor: /P/.4n0
Sponsor's Engineer: .
Design
Firm: Engineer:
~ -
Meeting Date: i12~ Meeting Time: -3; "7''
~
County Staff Present at Meeting: ,
Other Meeting Attendees:
a4 • /~7` %'L ~Z.
narseirepr~senting ~ name/representing
zame/representing name/representing
The Following Items need to be Discussed w/ the Design Engineer
General Items
la. List certain special requirements listed in the Conditions of Approval, EIS, or MDNS. Trus is
not an all-inclusive list. The Engineer and Sponsor is responsible for adhering to all Conditions and
design criteria.
4-,
description reference
~4W
description reference
2(~
K9,0A,~-_,c- , -S!9
description OK)
E 2- L S 1 etz. ~ _ ~ . W Z7
description reference
(C"A~-~~t/~
~
. 1 b. Does the Engineer have a copy of the Examiner's/Staff Conditions of Approval? VE..S
f--C~ Z)7)_~ . S ~~R• ~ 3~~
4 t5 7 Q a . er-Qc-.D_ - a3~v
.
Pre-Design Meeting Notes for Pro,ject: Page: 2
Spokane County Public Works ~
2. Include Standard Plan notes in the Road and Drainage Plans.
Road Plans
1. Road Classifications and Desi Criteria. _
i #1 #2 ~ #3 #4
Street Name ~ 4
Classification .nn
Roadway wiath, .6
' :t
Minimum right-of-way width
. •
. • •
. ~
. •
see note (1)
Min. Horiz. Curve w/ super
c .
..........................i................
Min. Horiz. Curve w/o super ~
~ :
General Land SlopelTerra.in _,z q
E. ;E .
3
. .
Design Speed, mph
Curb Type & Clear Zone
.
(see Sec. 3.15) ~t
f,
Sidewalk required? (yeslno)
Note (1) Additional right-of-way may be given by the Sponsor.
Discussion:
2. According to the Design Engineer, at is the maximum number of units which will have
access from a single roadway? S.,) . What is the max. allowed per Sec.1.03? 16 ~v,
3. Minimum intersection spacing is 300' for along a Principal or Minor Arterial (per Sec. 3.04),
and 150' for a Collector or Local Access street. What spacing is provided for this project?
~ ~1- PV,I7'
v
Pre-Design Meeting Notes for Project: Page: 3
Spokane County Public Works ,
4. Are any off-site slope easements needed, or off-site right-of-way acquisitions needed? If so,
describe. -
5. What type of turn-arounds are needed? (i.e. cul-de-sac, hammerhead, etc.)
- - ~ - - - ~
Street Name Turn-around Type Location
4,
...~.~...................r..................... `
~(5vnz=~Z>
"
6. Road Surfacing Requiremenls (Sec. 3.16)
a) What method in determining road surfacing requirements does the Design Engineer propose
to use (ii&:;;. eAASHTO Design Method, County thickness table, or other)?
P>- df:~ /c../ x . .
b) Provide the Design Engr. a copy of the Soil Sample Procedures, Design Report Format &
Alternate Pavement Design Table.
7. Does the Engineer plan on applying for any Design Deviations? If so, briefly describe below.
Please note that approval of all Design Deviation's must be obtained prior to construction
plan submittal.
v '
Storm Drainage
1. Basin Map
.
a) Did the Design Engineer bring to the meeting a basin map? ~S . If so, does the basin
map show topography and sufficient information to be useful? .
b) Does the basin map depict any contributing off-site runoff flowing onto the property?
Does it appear to be correct? . If not, explain. 74 D
c) Is a site visrt needed to venfy the basin luruts? Schedule for: .
{Note: Concurrence with County Engineer's on basin limits is requ.ired prior to plan submittal. }
2. Is the site located within the Aquifer Sensitive Area (ASA)? /T/O . What type of water
quality treatment is proposed by the Design Engineer?
.
Pre-Design Meeting Notes for Project: Page: 4
Spokane County Public Works ,
3. What subsurface investigations, if any, are needed with this project to make sure the
proposed disposal process will function as planned.
4. Are there downstream conditions which wi11 affect the design of drainage facilities. If so
describe possible mitigative measures.
~j ,f~~` ~~C E~ ~~1 J • ~r ~'T - ~ /~b,~
1
5. Is maintenance access provided to each GPA swale or drainage pond? If there is something
unusual, what requirements were given to the Design Engr.?
6. What daes the Developer/Engr. propose for providing for perpetual maintenance of the
dra.inage facilities? Please briefly describe proposed mechanism, and what is needed to
accompiisn this.
7a. What Design Storm(s) should be used in the course of analysis (i.e. 10-yr, 50-yr, etc.).
7b. Is a Detention or Retention system proposed? Please describe.
8. Are Erosion Control Measures required with this project? If so, briefly describe applicable
requirements.
c,,..
r
9. Is a second Pre-Design Meeting needed? /t,0 .
.i
r
Pre-Design Meeting Notes for Project: Page: 5
Spokane County Public Works
List of Documents Provided to the Sponsor's Engineer:
a)
b)
c)
d) •
e)
Any easements needed outside of the plat boundary, for drainage or other, are to be acqrcired prior
to road and drainage plan submittal. The Sponsor or Sponsor's Engineer shald provide separately
a legal description and Title Commitment (or similar proof of ownership) of the affected parcel(s)
for proposed easements.
The Submittal Checklist, completed and signed by the Sponsor's Engineer, shall be provided with
each plan submittal.
Note: P~ovide a copy of this completed document to the Design Engineer at the end of the pre-
design meenng.
filename: PreDesign meeting
} RECEIVED
INLAND PACIFIC ENGINEERING - TRANSMITTAL MAR 2 Z 1999
'
707 W. lth Avenue, Suite 200 Spokane, WA (509)458-6840 Fax: (509)458-6844 SPOKqNE COUNTl' ENGINEt
.
:'9." .
TO• ~ SPOKANE COUNTY ENGINEERS ~
~E. . .
P P~~ ~~~E 4
ATTENTION: D
ou9 Busko °
::r:::::::
.
P. ' K~i~: ~AN;::::::: :
~Ad~~~~~~
Description: PE-1753A _
0 Xerox Prints 0 Copy of Letter a
0 Original Drawing O Contract Documents ❑
0 Plat Certificate ❑ Declaration of Cov. 0
No. Copies Description
1 Maq and Findinas
Purpose
■ Information 0 Review & Comments ❑ Per Your Request
0 Written Approval ❑ Signature & Return ❑
Remarks
Doug - Enclosed please find a copy of the approved Preliminary Plat on
the above referenced project which shows the original Phase I(a total of
56 lots). We received approval to finalize Phase I in more then one plat.
Turtle Creek 2nd will one create a total of 48 Lots. Vl/e should not have to
place a 10% cost to the traffic signal at this time. Please check with Pat
Harper regarding as he had some involvement with the original approval.
If you have any additional question, please do not hesitate to contact this
office.
Signed:
'Wie Jo Sparling
~
~
and shall be binding upon the owner(s), their heirs, successors or assigns,
includ.ing the obligation to participate in the maintenance of the private road as provided herein."
29. The proposed subdivision shall be improved to the standards set forth in Spokane
County Board of Commissioners Resolution No. 80-1592, as amended, which
resolution establishes regulations for roads, approaches, drainage and fees in new
construction.
30. The County Engineer has examined this development proposal and has determined
that the impact of this proposal upon the existing county road system warrants the
dedication of additional right-of-way and the roadway improvements herein
specified.
31. The following statement shall be placed in the final plat dedication: "The private
road as shown hereon is an easement which provides a means of ingress and egress
for those lots within the subdivision.having frontage thereon." .
32. The County Arterial Road Plan identifies Barker Road as a Principal Arterial. The
existing right-of-way width of 60 feet is not consistent with that specified in the
Plan. In order to implement the Arterial Road Plan, in addition to the required
right-of-way dedication, a s(rip of property 18 feet in width along the Barker Road .
frontage shall be set aside in reserve. This property may be acquired by Spokane
County at the rime when arterial improvements are made to Barker Road.
33. There may exist utilities, either underground or overhead, affecting the subject
property, including property to be dedicated or set aside for future acquisition.
Spokane County assumes no financial obligarion for adjustments or relocation
regarding these utilities. Applicant(s) should check with the applicable utility
purveyor and the Spokane County Engineer to deternune whether applicant(s) or
the utility is responsible for adjustment or relocation costs and to make
arrangements for any necessary work.
R 4? s '
34. Based on the~ ffic analysiS provided by the applicant the following conditions of Z
approval were accepted-by the applicant through a Mitigated Detemvnation of
Nonsignificance and would be complied with prior to finalization of the applicable
phase: T't~aev cr. !9T Apt% - zi lors ,
Znu r - Lo-j-S ~
Phase I FIF-57' 56 zT
4 tg l.ocs
NPE The applicant shall pave Long Road and build the pedestrian walkway in Phase
I of the proposal as delineated in the Preliminary plat of record.
Phase II 1jE k-f Z(o 40"t" S
The applicant shall install a new traffic signal at Barker Road and the
Eastbound (south) I-90 ramps. The applicant shall be responsible for design,
funding, and construction of the traffic signal along with improvements
associated with the traffic signal. The traffic signal and improvements shall
meet WSDOT standards. ,
HEC Order for PE-1753-94 Page 11
~
~
~
The applicant shall place 10 pereent of the cost to upgrade the traffic signal at
Barker Road atzd AppIeway in an escrow account managed by Spokane
Count}+ for future upgrades to the signal at this intersectivn.
Phase III ~ 11 Z-oT,'S* - -
The applicant sha11 submit plans for review and approval b}r the County
Engineer for the impravernent of Barker Road fram Eighth Averiue to
Appleway to 32 feet.
35. The applicant shall provide grading and erosian control plans prior to finalization of any
phase of the proposed development. .
36. The private raads as shown on the preliminary plat are not acceptahle ta the County
Engirieer. Redesign of a private road wanld be required parior to approval of any final
glat for zhis proposal. -
SPOKANE COUNTY DIVISY~~ OF UTILYTIES -
I . Any v9rater service for this praject shali be provided in accordance with the
Caordinated Water System Pian for Spokane County, as amended. 2. Sewerage facilities are not affected by this proposal therefare na re~ommendatian.
3. The awner(s) or successor(s) in interest agree to authorize the County ta place their
name(s) on a petition for the fvrmacion of ULID by petition method pursuant to
RC'W 36.94, which getition includes the owner(s)' property; and further not to
object by the signing of a protest petition against the formation of aULTD by
resalution methvd pursuaflt to RCW Chapter 36,94 which includes the owner(s)'
properiy. PkOVII3ED, this canditian shall not prohibit the ovvner(s) or
successor(s) frorn +objecting to any assessment(s) on the property as a result nf
improvements called for in conjunction with the forrriativn of aULID by either
petition or resolution under RCW Chapter 36.94. .
4. Applicant shall make cantaection ta Pub1ic Sewer S}rstem. Sewer Connection
- Perrnic is required.
5. Plans and specifieatians for the gublic facilities cannection are ta be -reviewed and
apprvved by the Utilities 13epartment. Spokane County plan submietal requirements
aPpIY•
6. Security shall be deposiEed with the Utilities. Dep anme n t for const~ruction of public
facilities connection.
5POKANE COUNTY HEALTH DISTRYC7' -
1. The final plat sha11 be designed as indicated an the preliminatry plat of record antilor
any attache.d sheets as noted. y
BEC Order for PE-l7 5 3 -34 Page 12