SW3220301_Design Calculations_20220519

UPDATED
APRON AND SAND FILTER SIZING
CALCULATIONS
For
MINI STORAGE USA, INC
MINI WAREHOUSE PROJECT
Union County
l``` t�5t•,;;;: � �!m a u:: r:gr9r
SEAL =
20165
ppppp,
Kevin E. Herring
ENGINEERING
16101 SAw Rod
Oadm, NC28129
51w-cf-m

Job: Mini Storage USA
Job No. Date
5/11/2022
Sheet
Subject: Apron Cales Al
By
KEH
Chk By
APRON: Al (15" HDPE)
Pipe Diameter, Do 15 Inches or 1.25 Feet
RECEIVING OUTLET (CHANNEL / SHEET FLOW): SHEET
Apron Length, L= 11 Feet (from Fig 8.06a) pipe
Channel Width, b= 0.5 Feet 1 Tw H
Side Slope, MA = 3 :1
H (2/3 Pipe Dia): = 0.8 Feet
Apron Width, W1 = 3.75 Feet (3 Pipe Dia.) b
Apron Width, W2 = 12,3 Feet
d6o Stone Size = 0.5 Feet (from Fig 8.06a) = 6 inches
Apron Thickness, t= 13.5 inches
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Job: Mini Storage USA, Inc Job No.
Date
5/11/2022
Sheet
Subject: Sediment Chamber Sizing - Updated
By
KEH
Chk By
Design Storm Depth(in)
1
DA(sf)
66130 = 1.519 Ac
IMP(sf)
56830 = 1.305 Ac
IMP(%)
85.89%
Rv
0.8230
'Rag-411 SxirPreAreai;
1-he minimum surface area for the sedimentation basin is deternnined by the Cannp
Hazen Equation,
A, { ft 1 = [240 * R, ( iuirlfess) * A,, (acres)] * Rr, � jt
Ro Design storm depth (in)
• Aw Drainage area to the rind filter (acres)
• 12,.- Volumetric iuinolf coefficient (unitless)w0.05+0,0M(%Imp)
c• Imp. Percent of impervious of land draining to the sand filter
Minimum Sediment Area, As = 300.03 sf Total SA at Outlet Orifice Elev =
Area of Sand Chamber =
Where: Rv = 0.8230 Area for Sedment Chamber
Ad = 1.52 Ac
Rd = 1.0 inch As=
3430 sf
1715 sf

Job: Mini Storage USA, Inc Job No. Date 5/11/2022 Sheet
Subject: Sand Filter Sizing - Updated By KEH Chk By
Design Storm Depth(in)
1
DA(sf)
66130 = 1.519 Ac
IMP(sf)
56830 = 1.305 Ac
IMP(%)
85.89%
Rv
0.8230
WQV= 4537.9 cf
WQV(Adj)= 0.75xWQV= 3403 cf
tiefird Filter fish! Swfi ce• Area:
The minimum surface area for the sand filter bed i..r determined by [)arcy's Law:
A fft-(wQti'Xd, )
(R Xt k 1t, + d, )
• di: flepth of the sand filter bed, (fty 'Ibis should be a nunimum of 1.5 ft.
• k: Coefficient of permeability for the sand filter lx-d=3 5 (ft/day).
+ t: time required to wain the WQV through the sand fitter t+e d (day). This
time should be 40 hours (1.(>6 daYs). Wentcr fur Watershed Protection. 1996.)
• hA: Average head (ft)
o Determine the average head of water above the sand filter. The
average head above the sand filter is half (if the maximum head on
the filter (Center for Watershed Protection. 1996.
Minimum Sand Filter Area, Af = 501.75 sf
Where: WQV =
4537.9 cf
df =
1.5 ft
k =
3.5 ft/day
t =
1.66 days
hA =
0.83 ft
4538cf
Use Area = 520 sf (Sand Bed)
Sand Chamber Area = 1725 sf
Outlet Orifice Elev.
559.30
Sand Surface at Elev.
557.63
Max head (hmax)
1.67 ft
Avg head (hA)
0.835 ft

Rev1_Sand Filter Post 011022 Type it 24-hr 100yr Rainfall=8.09"
Prepared by HydroCAD SAMPLER 1-800-927-7246 www.hydrocad.net Printed 2/11/2022
H droCADO 10.10-7a Sampler s/n S17943 © 2021 H droCAD Software Solutions LLC
This report was prepared with the free HydroCAD SAMPLER, which is licensed for evaluation and
educational use ONLY. For actual design or modeling applications you MUST use a full version of
HydroCAD which may be purchased at www_hydrocad.net. Full programs also include complete technical
support,training materials, and additional features which are essential for actual design work.
Stage -Area -Storage for Pond 3P: SCM (continued)
Elevation
Surface
Storage
(feet)
(sq.ft�
(cubic-feet)
558.72
2,986
2,258
558.73
2,993
2,288
558.74
3,000
2,318
558.75
3,008
2,348
558.76
3,015
2,378
558.77
3,022
2,409
558.78
3,029
2,439
558.79
3,037
2,469
558.80
3,044
2,500
558.81
3,051
2,530
558.82
3,059
2,561
558.83
3,066
2,591
558.84
3,073
2,622
558.85
3,080
2,653
558.86
3,088
2,684
558.87
3,095
2,714
558,88
3,102
2,745
558.89
3,110
2,777
558.90
3,117
2,808
558.91
3,124
2,839
558.92
3,132
2,870
558.93
3,139
2,901
558,94
3,146
2,933
558.95
3,153
2,964
558.96
3,161
2,996
558,97
3,168
3,028
558.98
3,175
3,059
558.99
3,183
3,091
559.00
3,190
3,123
559.01
3,198
3,155
559.02
3,206
3,187
559.03
3,214
3,219
559.04
3,222
3,251
559.05
3,230
3,283
559.06
3,238
3,316
559.07
3,246
3,348
*Qadl El 559.08
3,254
3,381
559.09
3,262
3,413
559.10
3,270
3,446
559.11
3,278
3,479
559.12
3,286
3,512
559.13
3,294
3,544
559.14
3,302
3,577
559.15
3,310
3,610
559.16
3,318
3,644
559.17
3,326
3,677
Elevation
Surface
Storage
(feet)
(sq-ft)
(cubic -feet)
559.18
3,334
3,710
559.19
3,342
3,744
559.20
3,350
3,777
559.21
3,358
3,811
559.22
3,366
3,844
559.23
3,374
3,878
559.24
3,382
3,912
559.25
3,390
3,946
55926
3,398
3,979
559.27
3,406
4,013
559.28
3,414
4,048
559.29
3,422
4,082
559.30 _
_ 3,430
4,116 pp ap Berm I Oudel Weir
559.31
3,438
4,150
559.32
3,446
4,185
559.33
3,454
4,219
559.34
3,462
4,254
559.35
3,470
4,288
559.36
3,478
4,323
559.37
3,486
4,358
559.38
3,494
4,393
559.39
3,502
4,428
559.40
3,510
4,463
559.41
3,518
4,498
559.42
3.526
wQv Et
559.43
3,534
4,569
559,44
3,542
4,604
559.45
3,550
4,639
559.46
3,558
4,675
559.47
3,566
4,711
559.48
3,574
4,746
559.49
3,582
4,782
559.50
3,590
4,818
559.51
3,598
4,854
559.52
3,606
4,890
559.53
3,614
4,926
559.54
3,622
4,962
559.55
3,630
4,998
559.56
3,638
5,035
559.57
3,646
5,071
559.58
3,654
5,108
559.59
3,662
5,144
559.60
3,670
5,181
559.61
3,678
5,218
559.62
3,686
5,255
559.63
3,694
5,291