SW4210704_Supplement-EZ Form_20210803

Permit No.
(to be provided by DWQ-
��an�tiVN
Nr v
STORMWATER MANAGEMENT PERMIT APPLICATION FORM o
NCDENR
401 CERTIFICATION APPLICATION FORM
DRY EXTENDED DETENTION BASIN SUPPLEMENT
This form must be filled out, printed and submitted.
The Required Items Checklist (Fart 111) must be printed, filled out and submitted along with all the required information.
1. PROJECT INFORMATION,' .
Project name
Dolcetlo
Contact person
Rich Glover
Phone number
336-886.5523
Date
7/7/2021
Drainage area number
1
11, DE$IGN INFORMATION
Site Characteristics
Drainage area
566,393.00 ft2
Impervious area
185,566.00 ft2
% Impervious
0.33
Design rainfall depth
1.00 in
Peak Flow Calculations
1-yr, 24-hr rainfall depth
2.84
in
Rational C, pre -development
0.40
(unitless)
Rational C, post -development
0.50
(unitless)
Rainfall intensity: l-yr, 24-hr storm
0.12
in/hr
Pre -development 1-yr, 24-hr peak flow
0.62
ft3/sec
Post -development 1-yr, 24-hr peak flow
0.78
ft'/sec
Pre/Post 1-yr, 24-hr peak control
0,16
ft'/sec
Storage Volume: Non -SA Waters
Minimum required volume
16,264.00
ff3
Provided volume
28,381.00
ft3
OK
Sediment storage volume provided
7,096.00
ft3
OK
Storage Volume: SA Waters
1.5" runoff volume
ft3
Pre -development 1-yr, 24-hr runoff volume
ft3
Post -development 1-yr, 24-hr runoff volume
ft'
Minimum required volume
ft3
Provided volume
ft3
Sediment storage volume provided
ft3
Basin Design Parameters
Drawdown time
3.80
days
OK
SHWT elevation
718.00
fmsl
Basin bottom elevation
720.00
fmsl
OK
Storage elevation
724.00
fmsl
Basin side slopes
3.0
:1
OK
Top elevation
729.00
fmsl
OK
Freeboard provided
1.60
ft
OK
Basin Bottom Dimensions
Basin length
118.00
it
Basin width
7200
—it
Length to width ratio
1.60
:1
OK
Form SW401-Dry Extended Detention Basin-Rov.3 Parts I. & II. Design Summary, Page 1 of 2

Permit No.
Additional information
(to be provided by DWQ)
Total runoff volume captured by basin
7.81
ac-in
Forebay is not required
Forebay provided
N
(Y or N)
Is basin in a recorded drainage easement?
Y
(Y or N)
OK
Does basin capture all runoff at ultimate build -out?
Y
(Y or N)
OK
Is a sediment depth indicator included?
Y
(Y or N)
OK
Does the basin include a drain?
Y
(Y or N)
OK
Form SMal-Dry Extended Detention Basin-Rev.3 Parts I. & 11. Resign Summary, Page 2 of 2

A%
Permit No.
(to be provided by DWQ)
III. REQUIREDITEMS CHECKLIST
Please indicate the page or plan sheet numbers where the supporting documentation can be found. An incomplete submittal package will
result in a request for additional information, This will delay final review and approval of the project. Initial in the space provided to
indicate the following design requirements have been met. If the applicant has designated an agent, the agent may initial below. If a
requirement has not been met, attach justification.
Pagel Plan
Initials Sheet No.
1. Plans (1" - 50' or larger) of the entire site showing:
Design at ultimate build -out,
- Off -site drainage (if applicable),
- Delineated drainage basins (include Rational C coefficient per basin),
- Basin dimensions,
- Pretreatment system,
- Maintenance access,
- Proposed drainage easement and public right of way (ROW),
- Overflow device, and
- Boundaries of drainage easement.
-10 ) A 2. Plan details (1" = 30' or larger) for the bioretention cell showing:
- Basin dimensions
- Pretreatment system,
- Maintenance access,
- Outlet structure,
- Overflow device,
- Flow distribution detail for basin inflow, and
- Vegetation specifications.
1 3. Section view of the basin 0" = 20' or larger) showing:
- Side slopes, 3:1 or lower,
- Pretreatment and treatment areas, and
- Inlet and outlet structures.
6. A construction sequence that shows how the dry detention basin will be protected from sediment until the
entire drainage area is stabilized.
_M W0,W 7. The supporting calculations.
-I 1k) S8. A copy of the signed and notarized operation and maintenance (0&M) agreement.
_t L" 5 07 9. A copy of the deed restrictions (if required).
Sd�c)ft,�lf- 10. A soils report that is based upon an actual field investigation, soil borings, and infiltration tests. County
soil maps are not an acceptable source of soils information.
Form SW401-Dry Extended Detention Basin-Rev.3 Part Ill. Required Items Checklist, Page 1 of 1