HomeMy WebLinkAboutCity Hall Parking Lot Seepage BedCity of Meridian
City Hall Parking Lot West Side
Seepage Betl R1 Sizing
100 -Year Re ... rare. Interval
Using ITB Zone A Chart Interpolated F.rA 100 Year Storm
Drainage Area
13463
Sq. Ft.
Ron Off Coeffcient
0.95
Addi0o..115°%
Volume
do ft
Bed Length "'
68
FI.
Bed Width
11
FL.
Bed Depth
3
FL
Percolation Rate
8
In.Mr.
Predevelopment Discharge Rale
0
cfs max.
Drain Bed Volga 40
12"Pipe Volume 0.79 Cu- FU Fl.
Bed Slomge Volume 13.28 Cu. FL/FL
Storage Volume Avail 903 Cu. Ft.
Rational Formula Q=CiA
" Percolation Area = Bottom Area Over Sand Filler Bed
Check velocity through sediment box
Q = CIA, where C=0.95. k-1 1.736.f. and i=1.21 for 2 -year design stone at time concentration = 10 minutes
2 -year Q=0.31 cfs
Areabehveen battles .1`1000 -gallon sediment box=6.67sk Therefore. velocity= 0.05glass
�c d
FYJ.
North Basin Seepage Bed Design Calcs.xls 412712015
Storm
Duration
Storm
Intensity
fruhr
Ron Off
Rale
cfs
Run Off
Volume
cuff
Addi0o..115°%
Volume
do ft
Percolation
Volume
cult
Pre -(level.
Rale
cfs
Pre-Devel.
Volume
cu ft
Total
Discharge
cuff
Betl
Storage
tug
Adfieri Slomge
Required
on
10
Min.
3.11
0.91450
549
631
4.987
0.00
0.00
4,987
903(3,259)
30
Min.
1.82.
0.53517
963
1,108
14,960
0.00
0.00
14,960
903
1
H[
7.75
0.338161.217
1,400
499
0.00
0.00
499
903
'(2)
2
Hr.
0.66
0.19407
1,397
1,607
097
0.00
0.00
997
903
__J20)
6
Hr.
0.30
0.08822
1,905
2,191
21992
0.00
0.00
2,992
903
(1,704)
12
Hr.
0.190
0.0556]
2,414
2,7]6
5,984
0.00
0.00
5,984
903
(4,111)
24
Hr.
0.12
0.03529
3049
3,506
11.968
OLD
0.00
11,968
1 903
(9505)
Drain Bed Volga 40
12"Pipe Volume 0.79 Cu- FU Fl.
Bed Slomge Volume 13.28 Cu. FL/FL
Storage Volume Avail 903 Cu. Ft.
Rational Formula Q=CiA
" Percolation Area = Bottom Area Over Sand Filler Bed
Check velocity through sediment box
Q = CIA, where C=0.95. k-1 1.736.f. and i=1.21 for 2 -year design stone at time concentration = 10 minutes
2 -year Q=0.31 cfs
Areabehveen battles .1`1000 -gallon sediment box=6.67sk Therefore. velocity= 0.05glass
�c d
FYJ.
North Basin Seepage Bed Design Calcs.xls 412712015
Drainage Area
Run Off Coefficient
Bed Length
Bed Width
Betl Depth
Percolation Rate
Predevelopment Discharge Rate
City of Meridian
City Hall Parking Lot West Side
Seepage Betl e2 Sizing
100 -Year Recurrence Interval
Using ITD Zone A Chart Interpolated For A 100 Year Storm
10999
Sq.FL
0.95
Run Off
Rale
is
56
Ft.
11
Ft.
3
Ft.
B
InlHr.
0
cfs max.
Drain Betl Voids 40 %
12" Pipe Volume 0.79 Cu. FI./Ft.
Bed Storage Volume 13.28 Cu. FtAFL
Storage Volume Avail. 744 Cu. Ft.
Rational Formula Q=CiA
" Percolation Area= Bottom Area Over Sand Filter Bed
Check velocity through sediment box
Q = CIA, where C=0.95. A=9,999 sf, and 1=1.21 for 2 -year design storm at time concentration =10 minutes
2 -year Q= 0.26 cfs
Area between baf9es of 1000 -gallon sediment box= 6.67af, Therefore, velocity = 0.04 f lsec
South Basin Seepage Bed Design Calcsoda 4127/2015
Storm
Duration
Storm
Intensity
inthr
Run Off
Rale
is
Run OR
Volume
ca ft
Addllional 15%
Volume
so it
Percolation
Volume
cuff
Pre-Devel.
Rate
cis
Pre -Dever.
Volume
Gulf
Total
Discharge
Cu it
Bed
Storage
cult
Additional Storage
Required
calf
_10
Mia
3.11
0.746 2
446
515
4,107
0.00
0.00
4107
744
(4,335)
Min. n.
1.62
0.43858
786
904
72,320
0.00
0.00
12,320
744_
(12,160)
1
Hr.
T.15
0.27586
993
1,142
411
OAO
0.00
417
744
(92)
2
Hr.
0.66
015832
1,140
_ 1311
821
_---- D.00
0:00-.....g21
744
(254)
6
Hr:
0.30
0.07196
1,554
1.788
2,4640.00
0.00
2,469
744
11;42(
12
Hr.
0.190
0.04556
1,969
2,264
4,928
0.00
0.00
4;920
744
(3,407)
_._
_
24
He
O.12
0.02679
2,487
2860
9,656
0.00
'0.00
9,856
744
'77,739)
Drain Betl Voids 40 %
12" Pipe Volume 0.79 Cu. FI./Ft.
Bed Storage Volume 13.28 Cu. FtAFL
Storage Volume Avail. 744 Cu. Ft.
Rational Formula Q=CiA
" Percolation Area= Bottom Area Over Sand Filter Bed
Check velocity through sediment box
Q = CIA, where C=0.95. A=9,999 sf, and 1=1.21 for 2 -year design storm at time concentration =10 minutes
2 -year Q= 0.26 cfs
Area between baf9es of 1000 -gallon sediment box= 6.67af, Therefore, velocity = 0.04 f lsec
South Basin Seepage Bed Design Calcsoda 4127/2015