HomeMy WebLinkAboutSUB201200071 Plan - Other (not approved) 2012-04-16Uls. Department of Agriculture
Natural Resources Conservation service
TR 55 Worksheet 2: Runoff Curve Number and Runoff
Project. Old Trail Development Creekside,111- Phase 11 Designed By. FGM, P
Location: C-r"kslde Subdivision Checked By: FGM, P
Cheek One: Present X Developed X
I- Runriff ramp Mimbpr WK11
FI. ENC21A
M/04-
Date: --!L/ �2012
Date'_ 4/1212011
Cover description
Drainage Area
Soil name and
(Cover type,. treatment, and hydrologic conrlition;,
Area
Pioduct of
CN (weighted)
-
Calculated
Description
hydr6logicgroup
percent impervious; unconnected/ connected
CN
(Acres)
CN xArea
total product/
'SValue
(Appeodix.A)
total area
impervious area ratio)
1110FILTER
8
I
Impervious Areas
98
2.64
25% 1
(Proposed)
Woods In Good Condition
55
1.59
87.5
70.6
4.16
Lawns in Good Condition (75%+ Groundcover)
61
4,93
3MIS
P,
lmpervjous Areas
98
0721
20.6
STR. 83 Ditch
Woods in Good Condition
55
0,07
3.9
6219
5.89
Lawns in Good Condition M%+ Groundcover)
61,
3,55
216,6
2. Runoff
2-Year Storm
10 Year5f0rm
DralnageArea Description
Frequency -years
Rainfall, P (24 hour)- inches
33
5.6
n/a
Runoff, Q- Inches.
1,17
2.55
B 10 FI LTER (Pro po,2d
Runoff, 0- Inches
0.76
1.90
STR, 83 & Ditch
Runoff, Q- inches
Runoff, Q- inches
Runoff,
-Q-11ndles
Runoff, Q- inches
Runoff ,o- inches
Runoff, Q.- inches
U.S. Departmoritof Agriculture
Natural 1168burces Conservatibn Service
TA55VVorksheet3*Time of Concentration (TJ or Travel Time (TI)
Project: Old Trail DevelopmentCreekside III- Phasell
Location: Creekside*Subdivislon
Check One: Present X Developed
Check One: T, x T,
Segment.11):
Sheet, Flow: (Applicable to T. only)
Designed By: ±r2M, PE
Checked By: FM, PE
Through Pllharea n1a
FL-ENG-21A
06/04
Date: 4/12/2012_
Date' 411,21L12.
.
BIOFILTER
R. 3 11itCh
{Proposed)
Woods- Light
I Surface description (Table 3-1) Underbrwh Dense,03riss
2 Manning's roughness.coeff., n (Table 3-1 0.4 0.24
3 Flow 11,ength, L (total L � 100) (ft) too Im
4*Tvofo-yeat-24-hour rainfall, P2(in,.) 347 17
5 L'a n d slope, s (ft/ft) U6 0101
6 Compute Tj- [0.007(n*L) U I P� P'S sops F 0.211 an
Shallow Conte ntrated Flow:
7 Surfacp description (paved or unpaved)
8 Flow Length, Lfft)
9 Watercourse slope, s (ft/ft)
10 Average velocity, V (Figure3-1) (ft/s)
11, Ti = L / 3600*V
Channel Flow:
12 Cross sectional flow area, a (fe)
13 Wetted perimeter, P, (ft)
14 Hydraulic0dius, r = a/P, (ft)
15 Channel Slope, s (ft/ft)
16 Manning's Roughness Coeff; n
17 V= (. 1.49r'13 s 0.5 ) / n
18 Flow length, L (it)
19 Tj= L / 36W*V
20 Watershed or subarea TorTt
(Add Tj in steps 6, 11 and 19)
U.S. Department of Agriculture
Natural Resources Conservation Service
Unpaved
550
0.033
2.9
Unpaved
400
0,04
LA
>
+,
Irof
0
C, v,
va
0
to
cu
Lr) >
rn C: 115
0,05
0
031
0.32
Project: Old Trail Devi lopmentCreekside fl]- Phase 11
Location: Creekside Subdivision
Check One: Present X Developed X
TR 55 Worksheet 4, Graphical Peak Discharge Method
Designed By. FGM, PE
Checked . By, FGM, PE
Supplemental Water Quality Information
(Above minimum required standards)
Short Version B MP Cornpiptflons.For Worksheq�s 2 -6
Albemarle Counly Water, P rpte"qfion Ordinancea,.Modified $11nipte Method.
Ptah: Old ,Trait -,CeaLksid6.tit ..Phase If Water Resources Area: Dewlop entArea
Pre .kt g__
Project Dralnage.Area Designation DALo4tijNto n,arefgntion basin
L. -storm plulant export Impounds, L=�JPJP
I.-'. :... � t . . Z.. . I j)R
RV mean runoff "coefficren, Rv=loim.t�o.wq(l)
P!
I percent lropeNousness.:
15 annual preibjpitatlon,'43lh.Albbi varfe
A project area in acres In subject drainage area,
t6nc - .1,
66t entration, trig/1 or ppm,fargetphosphonis
f 4016f gppli6d to RR.
V required 1treatment volume In cy, 0,5" mar ImperW area A(1)4m�o
RR r6quirddr0ioval , L(, 0 t� , st) 7 (X L(pie)
11/aRR removal elftlency, 14R1001(ppsf)
Routina Method: storaae-indication
2-year SCS 24-hour Storm
inflow (cfs) 7.364.at 12.04(hrs)
discharge (cfs) 5.000 at 12.18(hrs)
FL-ENG-2.Ir water level (ft) 701.583 at 12.18 (hrs)
06/04 storage (cy) 352.297
io-year SCS 24-hour Storm
inflow (cfs) 16.028 at 12-04 (hrs)
discharge (cfs) 8.83.1 at 12.20(hrs)
water level (ft) 702.541at 12.20(hrs)
Date: 4/12/2012 storage (cy) 619.592
Date,, 4/11/2012 too -year SCS 24-hour Storm
inflow (cfs) 34.631 at 12.04 (hrs)
discharge (cfs) 15.198 at 12.26 (hrs)
water level (ft) 704.537at 12.26(hrs)
storage (cy) 1319.257
1. Data
Drainage Area
Description
Drainage Area
Description
Drainage Area
Description
Drainage Area
'Description
Drainage Area
Description
Drainage Area
bescription
Drainage Area
Description
Drainage Area
De'scriptIon
BIOFILTER
(Proposed)
STR. 83 & Ditch
Drainage Area (Am) in miles
0,0143
0,0060
Runoffcurve number CN=
70,6
62,9
Time of concentration (Tc)=
0.31
0.32
Rainfall distribution ty, I e,=
11
11
Pond and swamp areas spread
throughout the watershed
3.8
0
I
I
I
I
I
I S : I 7fiXf 19. Ifinf'.
2. Frequeh =years
2 10
2 10
3, Rainfall, P (24 hour)- inches
3.7 5.6
3.7 516
4. Initial Abstraction, Ia- inches
U31 *0.831
1.179 1. 179
5., Computeja/P
0.22 0,15
0.32 0.21
6. Unit peak discharge, Qu- csm/ip
600 650
550 625
7. Runoff, Qfrom Worksheet, 2- inches
1,17 155
0,76 1190
8, Pond and Swamp adlystmei
0,74 V4
1I
9, Peak Discharge, Op- cfs
where QP=Qu Aw.
Routed through
SWM Facility
2,49 7,09
Basin Input Data
6 ContourAreas
Elevation(ft) Area(sf) Computed Vol, (cy)
700-00 49S4.00 0.0
701.00 6336.00 208.5
702-00 7451.00 463.6
704-00 10104.00 1111.3
7o6.00 3.2915.00 1962.7
707.SO 15126.00 2739.8
Start-Elevation(ft) 700-00 VOI.(cY) 0.00
3 Outlet Structures
Outlet structure o
Culvert
name: Barrel
multiple 3.
discharge out of riser
D (in) i.S.000
h (in) 0.000
Length (ft) 63.5oo
Slope 0,0050
Manning's n 0.0110
Inlet coeff. Ke 0.500
Equation constant set 3
Invert (ft) 694.000
Outlet structure i
Curve
name: 24" ADS Standard Grate Inlet Stage -Discharge Curve
multiple I
Invert (ft) 701.100
discharge into riser
file: twenty -four -ADS Grate Inlet.txt
Outlet structure 2
Culvert
name: Emergency Spillway
multiple 4
discharge through dam
D(n) 15,000
h (in) o.000
Length (ft) 20.000
Slope 0.010
Manning's n 0.013
Inlet coeff, Ke 0.500
Equation constant set 3
Invert (ft) 704.750
Inflow Hvdroarar)hs
3 Inflow Hydrographs
Hydrograph
o
SCS
name: 2-year SCS
24-hour Storm
Area (acres)
9.16o
CN 70.600
Type
2
rainfall, P (in)
3,700
time of conc. (hrs)
0.3100
time increment (hrs)
o.o2oo
time limit (hrs)
30-000
fudge factor
0.74
routed
true
peak flow (cfs)
7.374
peak time (hrs)
12.039
volume (cy)
1o64,328
Hydrograph
i
SCS
name: to -year SCS 24-hour Storm
Area (acres)
9.16o
CN 70.600
Type
2
rainfall, P (in)
5,600
time of conc. (hrs)
0.3100
time increment (hrs)
0.0200
time limit (hrs)
30-000
fudge factor
0.74
routed
true
peak flow (cfs)
16.oSo
peak time (hrs)
12.039
volume (cy)
2316.420
Hydrograph
2
scs
name::ioo-year SCS 24-hour Storm
Area (acres)
9.3.6o
CN
70.600
Type
2
rainfall, P (in)
9.100
time of conc. (hrs)
0-3100
time increment (hrs)
0.0200
time limit (hrs)
30-000
fudge factor
0.74
routed
true
peak flow (cfs)
34.678
peak time (hrs)
12.039
volume (cy)
SooS.iol]i
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