HomeMy WebLinkAboutPRELIMINARY DRAINAGE ANALYSIS36
0
3603
6
0
365
365
365355355
3
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345
350355345
350
355
ΔΔΔ
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Δ
Δ
Δ
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1.928 AC0.872 AC35
5
360
365
370
375
380
385
390
395
345
345350
350355
355
360
360360360365
365365365 365365370
370370370
375
375375375380
380380380385
385385
385
390
390Δ
Δ
Δ
EX FES-C1EX CI-C2
EX
S
D
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-
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1
EX CI-C3
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EX FES-C4
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AREA 1A40.484 ACRESAREA 1B5.139 ACRESAREA 2A6.469 ACRESAREA 2B1.673 ACRESJESS GRIFFIN, PE
5 KINGSTON DRIVE
LITTLE ROCK, AR 72227
TEL (501) 690-3456
JGGRIFFINPE@GMAIL.COM
SIENNA LAKE SUBDIVIONPHASE ISIENNA LAKE PARTNERS, LLCCITY OF LITTLE ROCK, PULASKI COUNTY, ARKANSASiiffrGG.ESS
E No.17170J nivGRAPHIC SCALE 1"=100'
C1 WEST LAKE LANE DRAINAGE MAPWEST LAKE LANE
SIENNA LAKE / D
E
T
E
N
T
I
O
N
P
O
N
D
ALTERNATE
DETENTION
POND
WEST_LAKE_LANE
TIME OF CONCENTRATION - FAA EQUATION
Tc = ((0.03 * (1.1 - C)) * ((L^0.5) * (S^-0.333))) * 60
C25yr= 0.55
PERIOD 25 YR 100 YR
C100yr= 0.62
(min)I (in/hr) I (in/hr)
L = 2526 5 8.50 10.00
z =120 6 8.20 9.80
S = 4.751 7 7.90 9.50
29.614 8 7.70 9.10
25.845 9 7.40 8.80
10 7.10 8.50
STORM RUNOFF - RATIONAL METHOD 15 6.00 7.40
Q=CIA 20 5.40 6.60
C25d= 0.55 30 4.50 5.50
C100d= 0.62 40 3.80 4.70
A = 40.484 50 3.40 4.20
I25= 4.50 60 3.10 3.70
I100= 6.10
100.198
153.110
TIME OF CONCENTRATION - FAA EQUATION
Tc = ((0.03 * (1.1 - C)) * ((L^0.5) * (S^-0.333))) * 60
C25yr= 0.55
C100yr= 0.62
L = 360
z =13
S = 3.611
12.249
10.690
STORM RUNOFF - RATIONAL METHOD
Q=CIA
C25d= 0.55
C100d= 0.62
A = 5.139
I25= 6.60
I100= 8.30
18.655
26.445
Natural Vegetation - Clay Soil - Steep 7%
area of the watershed (Acres)
assumed in inches per hour
assumed in inches per hour
Q=cfs 25yr
cfs 100yr
Natural Vegetation - Clay Soil - Steep 7%
maximum length of runoff for the area (ft)
change in elevation along L(ft)
% change in elevation along L divided by ∆z
Tc=min 25yr
min 100yr
assumed in inches per hour IDF VALUES FROM CITY OF LITTLE
ROCK DRAINAGE MANUALQ=cfs 25yr
cfs 100yr
BASIN: AREA 1B (EXISTING)
Tc=min 25yr
min 100yr
Natural Vegetation - Clay Soil - Steep 7%
area of the watershed (Acres)
assumed in inches per hour
BASIN: AREA 1A (EXISTING & PROPOSED)
Natural Vegetation - Clay Soil - Steep 7%
maximum length of runoff for the area (ft)
change in elevation along L(ft)
% change in elevation along L divided by ∆z
Page 1
WEST_LAKE_LANE
TIME OF CONCENTRATION - FAA EQUATION
Tc = ((0.03 * (1.1 - C)) * ((L^0.5) * (S^-0.333))) * 60
C25yr= 0.60
RETURN
PERIOD 25 YR 100 YR
C100yr= 0.70
Duration
(min)I (in/hr) I (in/hr)
L = 360 5 8.50 10.00
z =13 6 8.20 9.80
S = 3.611 7 7.90 9.50
11.135 8 7.70 9.10
8.908 9 7.40 8.80
10 7.10 8.50
STORM RUNOFF - RATIONAL METHOD 15 6.00 7.40
Q=CIA 20 5.40 6.60
C25d= 0.60 30 4.50 5.50
C100d= 0.70 40 3.80 4.70
A = 5.139 50 3.40 4.20
I25= 6.90 60 3.10 3.70
I100= 8.80
21.275
31.656
TIME OF CONCENTRATION - FAA EQUATION
Tc = ((0.03 * (1.1 - C)) * ((L^0.5) * (S^-0.333))) * 60
C25yr= 0.56
C100yr= 0.64
L = 986
z =77
S = 7.809
15.394
13.114
STORM RUNOFF - RATIONAL METHOD
Q=CIA
C25d= 0.56
C100d= 0.64
A = 6.469
I25= 6.00
I100= 8.00
21.736
33.121
20% Residential - Single Family
80% Natural Vegetation - Clay Soil - Steep 7%
area of the watershed (Acres)
assumed in inches per hour
assumed in inches per hour
Q=cfs 25yr
cfs 100yr
20% Residential - Single Family
80% Natural Vegetation - Clay Soil - Steep 7%
maximum length of runoff for the area (ft)
change in elevation along L(ft)
% change in elevation along L divided by ∆z
Tc=min 25yr
min 100yr
assumed in inches per hour IDF VALUES FROM CITY OF LITTLE
ROCK DRAINAGE MANUALQ=cfs 25yr
cfs 100yr
BASIN: AREA 2A (EXISTING & PROPOSED)
Tc=min 25yr
min 100yr
Residential - Single Family
area of the watershed (Acres)
assumed in inches per hour
BASIN: AREA 1B (PROPOSED)
Residential - Single Family
maximum length of runoff for the area (ft)
change in elevation along L(ft)
% change in elevation along L divided by ∆z
Page 2
WEST_LAKE_LANE
TIME OF CONCENTRATION - FAA EQUATION
Tc = ((0.03 * (1.1 - C)) * ((L^0.5) * (S^-0.333))) * 60
C25yr= 0.55
RETURN
PERIOD 25 YR 100 YR
C100yr= 0.62
Duration
(min)I (in/hr) I (in/hr)
L = 136 5 8.50 10.00
z =7 6 8.20 9.80
S = 5.147 7 7.90 9.50
6.690 8 7.70 9.10
5.839 9 7.40 8.80
10 7.10 8.50
STORM RUNOFF - RATIONAL METHOD 15 6.00 7.40
Q=CIA 20 5.40 6.60
C25d= 0.55 30 4.50 5.50
C100d= 0.62 40 3.80 4.70
A = 1.673 50 3.40 4.20
I25= 8.00 60 3.10 3.70
I100= 9.80
7.361
10.165
TIME OF CONCENTRATION - FAA EQUATION
Tc = ((0.03 * (1.1 - C)) * ((L^0.5) * (S^-0.333))) * 60
C25yr= 0.60
C100yr= 0.70
L = 136
z =7
S = 5.147
6.082
4.866
STORM RUNOFF - RATIONAL METHOD
Q=CIA
C25d= 0.60
C100d= 0.70
A = 1.673
I25= 8.20
I100= 10.00
8.231
11.711
Residential - Single Family
area of the watershed (Acres)
assumed in inches per hour
assumed in inches per hour
Q=cfs 25yr
cfs 100yr
Residential - Single Family
maximum length of runoff for the area (ft)
change in elevation along L(ft)
% change in elevation along L divided by ∆z
Tc=min 25yr
min 100yr
assumed in inches per hour IDF VALUES FROM CITY OF LITTLE
ROCK DRAINAGE MANUALQ=cfs 25yr
cfs 100yr
BASIN: AREA 2B (PROPOSED)
Tc=min 25yr
min 100yr
Natural Vegetation - Clay Soil - Steep 7%
area of the watershed (Acres)
assumed in inches per hour
BASIN: AREA 2B (EXISTING)
Natural Vegetation - Clay Soil - Steep 7%
maximum length of runoff for the area (ft)
change in elevation along L(ft)
% change in elevation along L divided by ∆z
Page 3
WEST_LAKE_LANE
CU FT
R= 0.06493
A= 53.765 AC
Tc= 42 MIN
0.06493
Rd = 2.81671 151.440 divided by 53.765
Ru = 2.75178 147.950 divided by 53.765
147.950 151.440 53.765
V=R x A x Tc x 60 = 8,797
R= Rd - Ru =
AREA 2A 21.736 21.736 6.469
AREA 2B 7.361 8.231 1.673
AREA 1A 100.198 100.198 40.484
AREA 1B 18.655 21.275 5.139
BASIN EXISTING PROPOSED AREA
CFS CFS ACRES
Page 4
N90°00'00"E
-
1
,036
.83
'
N00°00'
0
0
"
E
-
9
4
4.
5
5'
TRACT 188
22.13 ACRES
963,970.29 SQ FT
S00°00'
0
0
"
E
-
3,
1
0
0.
7
6'N90°00'00"E
-
782
.64
'ΔΔ
35
0
355
360
365
37037538038539039540034
5
345
350350355355360360365365
370 370375
380
3853903954004054104154
2
0
425
370375380385390395ΔΔΔ
ΔΔΔ
Δ
ΔΔ
ΔΔ
ΔΔ
Δ
Δ
Δ Δ
Δ
Δ
Δ
Δ
Δ
ΔΔΔΔΔ
Δ Δ
Δ
Δ
Δ
Δ
Δ
Δ
Δ
340340345345350350355355360360365365370370375380385385
38539
0
390
390395395
395
400
405
410
415
420
425430 435
350355360365370375380385390395400405410415420425430
435
AREA 322.130 ACRESAREA 42.152 ACRESJESS GRIFFIN, PE
5 KINGSTON DRIVE
LITTLE ROCK, AR 72227
TEL (501) 690-3456
JGGRIFFINPE@GMAIL.COM
SIENNA LAKE SUBDIVIONPHASE ISIENNA LAKE PARTNERS, LLCCITY OF LITTLE ROCK, PULASKI COUNTY, ARKANSASiiffrGG.ESS
E No.17170J nivGRAPHIC SCALE 1"=80'
SIE
N
N
A
L
A
K
E
L
A
N
E
WINGFIELD COVE
S
I
ENNA
LA
K
E
D
R
IV
E
C2 SIENNA LAKE LANE DRAINAGE MAPDE
T
EN
T
ION
POND
SIENNA LAKE LANE
TIME OF CONCENTRATION - FAA EQUATION
Tc = ((0.03 * (1.1 - C)) * ((L^0.5) * (S^-0.333))) * 60
C25yr= 0.55
PERIOD 25 YR 100 YR
C100yr= 0.62
(min)I (in/hr) I (in/hr)
L = 1000 5 8.50 10.00
z =63 6 8.20 9.80
S = 6.300 7 7.90 9.50
16.961 8 7.70 9.10
14.802 9 7.40 8.80
10 7.10 8.50
STORM RUNOFF - RATIONAL METHOD 15 6.00 7.40
Q=CIA 20 5.40 6.60
C25d= 0.55 30 4.50 5.50
C100d= 0.62 40 3.80 4.70
A = 22.13 50 3.40 4.20
I25= 6.70 60 3.10 3.70
I100= 7.40
81.549
101.532
TIME OF CONCENTRATION - FAA EQUATION
Tc = ((0.03 * (1.1 - C)) * ((L^0.5) * (S^-0.333))) * 60
C25yr= 0.60
C100yr= 0.70
L = 1518
z =78
S = 5.138
20.332
16.265
STORM RUNOFF - RATIONAL METHOD
Q=CIA
C25d= 0.60
C100d= 0.70
A = 22.13
I25= 5.40
I100= 7.20
71.701
111.535
Residential - Single Family
area of the watershed (Acres)
assumed in inches per hour
assumed in inches per hour
Q=cfs 25yr
cfs 100yr
Residential - Single Family
maximum length of runoff for the area (ft)
change in elevation along L(ft)
% change in elevation along L divided by ∆z
Tc=min 25yr
min 100yr
assumed in inches per hour IDF VALUES FROM CITY OF LITTLE
ROCK DRAINAGE MANUALQ=cfs 25yr
cfs 100yr
BASIN: AREA 3 (PROPOSED)
Tc=min 25yr
min 100yr
Natural Vegetation - Clay Soil - Steep 7%
area of the watershed (Acres)
assumed in inches per hour
BASIN: AREA 3 (EXISTING)
Natural Vegetation - Clay Soil - Steep 7%
maximum length of runoff for the area (ft)
change in elevation along L(ft)
% change in elevation along L divided by ∆z
Page 1
SIENNA LAKE LANE
TIME OF CONCENTRATION - FAA EQUATION
Tc = ((0.03 * (1.1 - C)) * ((L^0.5) * (S^-0.333))) * 60
C25yr= 0.60
RETURN
PERIOD 25 YR 100 YR
C100yr= 0.70
Duration
(min)I (in/hr) I (in/hr)
L = 456 5 8.50 10.00
z =16 6 8.20 9.80
S = 3.509 7 7.90 9.50
12.653 8 7.70 9.10
10.122 9 7.40 8.80
10 7.10 8.50
STORM RUNOFF - RATIONAL METHOD 15 6.00 7.40
Q=CIA 20 5.40 6.60
C25d= 0.60 30 4.50 5.50
C100d= 0.70 40 3.80 4.70
A = 2.152 50 3.40 4.20
I25= 6.50 60 3.10 3.70
I100= 8.50
8.393
12.804
DETENTION NOT REQUIRED BUT AREA PROVIDED IF NEEDED
89.942 80.094 24.282
AREA 4 8.393 8.393 2.152
AREA 3 81.549 71.701 22.13
BASIN EXISTING PROPOSED AREA
CFS CFS ACRES
assumed in inches per hour IDF VALUES FROM CITY OF LITTLE
ROCK DRAINAGE MANUALQ=cfs 25yr
cfs 100yr
Tc=min 25yr
min 100yr
Residential - Single Family
area of the watershed (Acres)
assumed in inches per hour
BASIN: AREA 4 (EXISTING & PROPOSED)
Residential - Single Family
maximum length of runoff for the area (ft)
change in elevation along L(ft)
% change in elevation along L divided by ∆z
Page 2