SW3100301 - Hopewell Baptist Church - Worship Addition (2)

Permit No
(to be provided by DWQ)
OF W A TF9
®�A
�? OG
.M
NCDENR
STORMWATER MANAGEMENT PERMIT APPLICATION FORM
401 CERTIFICATION APPLICATION FORM
WET DETENTION BASIN SUPPLEMENT
This form must be filled out, printed and submitted.
The Required Items Checklist (Part 111) must be printed, filled out and submitted along with all of the required information
I. PROJECT INFORMATION
Project name Hopewell Baptist Worship Addition
Contact person Kevin Westra
Phone number '704-496-6297
Date 1115!_2018
Drainage area number 1 _ _ 1
II. DESIGN INFORMATION
Site Characteristics
Drainage area
_
1,308,044iffz
Impervious area, post -development
443,531;fe
% impervious
33.91 %
Design rainfall depth
2 9 (post-pre)E in
Storage Volume: Non -SA Waters
Minimum volume required
Volume provided
Storage Volume: SA Waters
15" runoff volume
Pre -development 1 -yr, 24 -hr runoff
Post -development 1 -yr, 24 -hr runoff
Minimum volume required
Volume provided
Peak Flow Calculations
Is the pre/post control of the lyr 24hr storm peak flow required?
1 -yr, 24 -hr rainfall depth
Rational C, pre -development
Rational C, post -development
Rainfall intensity 1 -yr, 24 -hr storm
Pre -development 1 -yr, 24 -hr peak flow
Post -development 1 -yr, 24 -hr peak flow
Pre/Post 1 -yr, 24 -hr peak flow control
Elevations
Temporary pool elevation
Permanent pool elevation
SHWT elevation (approx at the perm pool elevation)
Top of 1 Oft vegetated shelf elevation
Bottom of 1 Oft vegetated shelf elevation
Sediment cleanout, top elevation (bottom of pond)
Sediment cleanout, bottom elevation
Sediment storage provided
Is there additional volume stored above the state -required temp pool9
Elevation of the top of the additional volume
72,135.ft3
100,284! ff3
OK, volume provided is equal to or in excess of volume required
;ft3
y �? (Y or N)
291 in
0 301(unitless)
0 651 (unitless)
3 301 in/hr OK
16.96 fC1sec
0 70 0sec
-16 26 0sec
518 001 fmsl
514.001 fmsl
505 OOi fmsl
514 501 fmsl
513 500sl
509 OOlfmsl
508.00, fmsl
100 ft
y (Y or N)
" 518 Olfmsl OK
Form SW401-Wet Detention Basin -Rev 9-4/18/12 Parts I & If Design Summary, Page 1 of 2

JK
II. DESIGN INFORMATION
Surface Areas
Permit No
Area, temporary pool
______197,920
19,920, ftz
10i 1
Area REQUIRED, permanent pool
12,557 tY
OK
SAIDA ratio
0 961(unitless)
301.1
Area PROVIDED, permanent pool, A,._pd
19,9201ft'
OK
Area, bottom of 10ft vegetated shelf, Amt_"neir
16,2731 fe
y ; (Y or N)
Area, sediment cleanout, top elevation (bottom of pond), A�,yo d
8,027: ff
OK
Volumes
OK
—------- - -- - -- - -- — -- — -- — - ----- -
pump pond down
Volume, temporary pool
_
1 200 84 ft3
OK
Volume, permanent pool, Vp._pw
69,069!fe
Volume, forebay (sum of forebays if more than one forebay)
10,193! ft3
Forebay % of permanent pool volume
148%%
Insufficient forebay volume
SAIDA Table Data
Design TSS removal
_
851%
Coastal SAIDA Table Used?
n _ _ _ I (Y or N)
Mountain/Piedmont SAIDA Table Used?
y J (Y or N)
SAIDA ratio
0 96 (unitless)
Average depth (used in SAIDA table)
Calculation option 1 used? (See Figure 10-2b)
_ n (Y or N)
Volume, permanent pool, Vp__pod
69,069 ft3
Area provided, permanent pool, A�„2Pw
19,920 ff
Average depth calculated
4 20'ft
OK
Average depth used in SAIDA, d.„ (Round to nearest 0 5ft)
4 2;ft
OK
Calculation option 2 used? (See Figure 10-2b)
y ; (Y or N)
Area provided, permanent pool, Ap„_,Oi
19,920 ff2
Area, bottom of 1Oft vegetated shelf, Abo, �hejr
16,273 ff
Area, sediment cleanout, top elevation (bottom of pond), Abp d
8,027 fe
"Depth" (distance b/w bottom of 10ftshelf and top of sediment)
4 50 ft
Average depth calculated
4 201ft
OK
Average depth used in SAIDA, d., (Round to down to nearest 0 5ft)
4 21 ft
OK
Drawdown Calculations
Drawdown through orifice?
Diameter of onfice (if circular)
Area of orfice (if -non -circular)
Coefficient of discharge (Co)
Driving head (Ha)
Drawdown through weir?
Weir type
Coefficient of discharge (CW)
Length of weir (L)
Driving head (H)
Pre -development 1 -yr, 24 -hr peak flow
Post -development 1 -yr, 24 -hr peak flow
Storage volume discharge rate (through discharge orifice or weir)
Storage volume drawdown time
Additional Information
Vegetated side slopes
Vegetated shelf slope
Vegetated shelf width
Length of flowpath to width ratio
Length to width ratio
Trash rack for overflow & orifice?
Freeboard provided
Vegetated filter provided?
Recorded drainage easement provided?
Capures all runoff at ultimate build -out?
Drain mechanism for maintenance or emergencies is
Forth SW401-Wet Detenbon Basin -Rev 94/18/12
r—y (Y or N)
4 00, in
hn2
0 621(unitless)
1 281ft
n (Y or N)
j (umtless)
(unifless)
Eft
- Ift
16.961 f3/sec
0 70! ft3/sec
0 491 f3/sec
2 361 days OK, draws down in 2-5 days
(to be provided by DWQ)
1
OK
10i 1
OK
100ift
OK
31 1
Insufficient flow path to width ratio Must not short-circuit pond
301.1
OK
y I (Y or N)
OK
1 01ft
OK
y ; (Y or N)
OK
y "I (Y or N)
OK
y I (Y 0r N)
- - --
OK
—------- - -- - -- - -- — -- — -- — - ----- -
pump pond down
Parts I & II Design Summary, Page 2 of 2