SW1221002_Supplement-EZ Form_20231208 (2)

DRY POND
1 Drainage area number 1-3& 1-4
2 Minimum required treatment volume(cu ft) 17597 cf
GENERAL MDC FROM 02H.1050
3 Is the SCM sized to treat the SW from all surfaces at build-out? Yes
4 Is the SCM located away from contaminated soils? Yes
5 What are the side slopes of the SCM (H:V)? 3:1
6 Does the SCM have retaining walls, gabion walls or other engineered No
side slopes?
7 Are the inlets, outlets,and receiving stream protected from erosion Yes
(10-year storm)?
8 Is there an overflow or bypass for inflow volume in excess of the Yes
design volume?
9 What is the method for dewatering the SCM for maintenance? Drawdown Orifice
10 If applicable,will the SCM be cleaned out after construction? Yes
11 Does the maintenance access comply with General MDC(8)? Yes
12 Does the drainage easement comply with General MDC(9)? N/A
13 If the SCM is on a single family lot, does (will?)the plat comply with N/A
_General MDC(10)? _
14 Is there an O&M Agreement that complies with General MDC(11)? Yes
15 Is there an O&M Plan that complies with General MDC(12)? Yes
16 Does the SCM follow the device specific MDC? Yes
_ 17 Was the SCM designed by an NC licensed professional? Yes
DRY POND MDC FROM 02H.1062
18 SHWT elevation (fmsl) 2112.61
19 Elevation of the bottom of the dry pond (fmsl) 2114.1
20 Distance from bottom to SHWT(feet) 13 ft
21 Elevation of the temporary pool during the design storm (feet) 2120 ft
22 Ponding depth of the design storm (feet) 6 ft
23 Will the dry pond be uniformly graded to flow toward the outlet? Yes
24 Is a low flow channel being provided? No
25 Are the inlet(s)and outlet located in a manner that avoids short- Yes
circuiting?
26 Will berms or baffles be provided to increase the flow path? No
27 What method of pretreatment will be provided? Forebay
28 Design volume of SCM (cu ft) 19394
29 Diameter of drawdown orifice(in) 1.9 in
30 Drawdown time for the temporary pool (hours) 40
31 Does the pond minimize impacts to the receiving channel from the 1- Yes
yr, 24-hr storm?
32 Is there a small permanent pool near the orifice to prevent clogging? No
33 Will the outlet be designed to prevent clogging? Yes
34 Are the dam and embankment planted in non-clumping turf grass? Yes
35 Species of turf that will be used on the dam and embankment KY Fescue at 5
Ibs/1,000sf
36 Will trees and shrubs be prevented from growing on the dam and Yes
embankment?
ADDITIONAL INFORMATION
37 Please use this space to provide any additional information about the
dry pond(s):
The July 2022 geotechnical report gives a minimum SHWT depth of greater
than 34" below existing elevation for Ksat-2.The existing surface elevation at
the time of the boring was 2119.38, and the existing surface elevation prior to
the construction of the previously approved project SW1190702, dated May
2020, was 2112.61.
Dry Pond 1 2:26 PM 12/4/2023