SW3240804_Supplement-EZ Form_20240921

SUPPLEMENT-EZ COVER PAGE
FORMS LOADED
PROJECT INFORMATION
1 Project Name Beckingham Subdivision
2 Project Area(ac) 62.45
3 Coastal Wetland Area(ac) 0
4 Surface Water Area(ac) 2.08
5 Is this project High or Low Density? Low
6 Does this project use an off-site SCM? No
COMPLIANCE WITH 02H.1003(4)
7 Width of vegetated setbacks provided(feet) Yes
8 Will the vegetated setback remain vegetated? Yes
9 If BUA is proposed in the setback,does it meet NCAC 02H.1003(4)(c-d)? N/A
10 Is streambank stabilization proposed on this project? Yes
NUMBER AND TYPE OF SCMs:
11 Infiltration System
12 Bioretention Cell
13 Wet Pond
14 Stormwater Wetland
15 Permeable Pavement
16 Sand Filter
17 Rainwater Harvesting(RWH)
18 Green Roof
19 Level Spreader-Filter Strip(LS-FS)
20 Disconnected Impervious Surface(DIS)
21 Treatment Swale
22 Dry Pond 3
23 StormFilter
24 Silva Cell
25 Bayfilter
26 Filterra
FORMS LOADED
DESIGNER CERTIFICATION
27 Name and Title: Connor Horn,PE,Project Manager
28 Organization: WK Dickson&Co.,Inc.
29 Street address: 1213 W.Morehead Street;Suite 300
30 City,State,Zip: Charlotte,NC 28208
31 Phone number(s): 704.334.5348
32 Email: [e-mail]
Certification Statement:
I certify,under penalty of law that this Supplement-EZ form and all supporting information were prepared under my direction or supervision;that
the information provided in the form is,to the best of my knowledge and belief,true,accurate,and complete;and that the engineering plans,
specifications,operation and maintenance agreements and other supporting information are consistent with the information provided here.
Designer
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DRAINAGE AREAS
1 Is this a high density project? No
2 If so,number of drainage areas/SCMs 0
3 Does this project have low density areas? Yes
4 If so,number of low density drainage areas 3
Is all/part of this project subject to previous rule
5 versions? No
FORMS LOADED
DRAINAGE AREA INFORMATION Entire Site LD 1 LD 2 LD 3
4 Type of SCM Dry Pond Dry Pond Dry Pond
5 Total drainage area(sq ft) 2,629,717 254502 442026 342807
6 Onsite drainage area(sq ft) 2,629,717 254502 442026 342807
7 Offsite drainage area(sq ft) 0 0 0 0
8 Total BUA in project(sq ft) 459633 sf 85726 sf 159356 sf 110376 sf
New BUA on subdivided lots(subject to
9 permitting)(sq ft) 371800 sf 60500 sf 116500 sf 99125 sf
New BUA not on subdivided lots(subject to
10 permitting)(sf) 87833 sf 25226 sf 42856 sf 11251 sf
11 Offsite BUA(sq ft) sf sf sf sf
12 Breakdown of new BUA not on subdivided lots:
-Parking(sq ft) sf sf sf sf
-Sidewalk(sq ft) sf sf sf sf
-Roof(sq ft) sf sf sf sf
-Roadway(sq ft) 87833 sf 25226 sf 42856 sf 11251 sf
-Future(sq ft) sf sf sf sf
-Other,please specify in the comment box
below(sq ft) sf sf sf sf
New infiltrating permeable pavement on
13 subdivided lots(sq ft) sf sf sf sf
New infiltrating permeable pavement not on
14 subdivided lots(sq ft) sf sf sf sf
Existing BUA that will remain(not subject to
15 permitting)(sq ft) sf sf sf sf
16 Existing BUA that is already permitted(sq ft) sf sf sf sf
17 Existing BUA that will be removed(sq ft) sf sf sf sf
18 Percent BUA 17% 34% 36% 32%
19 Design storm(inches) 1.0 in 1.0 in 1.0 in
20 Design volume of SCM(cu ft) 7490 cf 13793 cf 9497 cf
21 Calculation method for design volume SCS-CN SCS-CN SCS-CN SCS-CN
ADDITIONAL INFORMATION
Please use this space to provide any additional information about the
22 drainage area(s):

LOW DENSITY
DESIGN REQUIREMENTS FOR LOW DENSITY PROJECTS FROM 02H.1003
1 Is project below density thresholds set forth in the applicable stormwater rule? Yes
2 Does project maximize dispersed flow and minimize channelizatlon of flow? Yes
3 Has the use of piping been minimized per.1003(2)(c)? Yes
4 Side slopes of the vegetated conveyances(H:V) 3 sf
5 Maximum velocity in the vegetated conveyances during the 10-year storm? 6.6
6 Are curb outlet swales proposed? No
7 Maximum longitudinal slope of curb outlet swale(s)(%)
8 Bottom width of curb outlet swale(s)(feet)
9 Maximum side slope of curb outlet swale(s)(H:V)
10 Minimum length of curb outlet swale(s)(feet)
11 Are treatment swales used instead of curb outlet swales?
12 Is stormwater released at the edge of the setback as dispersed flow? No
13 Have stormwater outlets been designed to prevent downslope erosion? Yes
14 Are variations to rule.1003 proposed? Yes
ADDITIONAL INFORMATION
15 'Please use this space to provide any additional information about this low density project:
All swales lead to pipe systems that either enter stormwater ponds or an outfall pipe sized/designed to outfall at a non-erosive
velocity.Vegetated strips/rip rap aprons are used on all outfalls and sent into a protected stream buffer before entering the
waterway.
Drainage Pervious
Swale Area EWA area C Q Slope V,„ow V.„,„, Flow depth
(ac) (ac) (ac) (cfs) (%) IfPs) (fps) (ft)
1 0.78 0.00 0.60 3.53 6.90 4.01 0.30
2 0.44 0.00 0.60 1.99 0.90 1.66 0.38
3 1.20 0.00 0.60 5.44 4.90 4.03 0.42
4
5 3.00 0.00 0.60 13.59 2.70 5.44 0.64
6 3.00 0.00 0.60 13.59 7.40 6.61 0.30
7
8 1.00 0.00 0.60 4.53 8.80 8.04 0.32
9 1.00 0.00 0.60 4.53 3.10 4.71 0.43
10
11 1.81 0.00 0.60 8.20 4.80 4.80 0.37
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DRY POND
1 Drainage area number 1 2i1 3
2 Minimum required treatment volume(Cu ft) 7490 cf 13793 cf ll 9497 cf
GENERAL MDC FROM 02H.1050
3 Is the SCM sized to treat the SW from all surfaces at build-out? Yes R Y-es Yoc
4 Is the SCM located away from contaminated soils? Yes Yes Yes
5 What are the side slopes of the SCM(H:V)? 3:1 3:1 3:1 ____
Does the SCM have retaining walls,gabion walls or other No Yes Yes
6 engineered side slopes?
Are the inlets,outlets,and receiving stream protected from erosion Yes Yes Yes
7 (10-year storm)?
Is there an overflow or bypass for inflow volume in excess of the Yes Yes Yes
8 design volume?
9 What is the method for dewatering the SCM for maintenance? Drawdown Orifice Drawdown Orifice Drawdown Orifice
10 If applicable,will the SCM be cleaned out after construction? Yes Yes Yes
11 Does the maintenance access comply with General MDC(8)? Yes Yes Yes
12 Does the drainage easement comply with General MDC(9)? Yes Yes Yes
13 If the SCM is on a single family lot,does(will?)the plat comply with N/A N/A N/A
General MDC(10)?
14 Is there an O&M Agreement that complies with General MDC(11)? Yes Yes Yes
15 Is there an O&M Plan that complies with General MDC(12)? Yes Yes Yes
16 Does the SCM follow the device specific MDC?
17 Was the SCM designed by an NC licensed professional? Yes Yes Yes
DRY POND MDC FROM 02H.1062
18 SHWT elevation(fmsl)
19 Elevation of the bottom of the dry pond(fmsl) 612.00 604 582
20 Distance from bottom to SHWT(feet)
21 Elevation of the temporary pool during the design storm(feet) 614.22 ft 606.42 ft 584.45 ft
22 Ponding depth of the design storm(feet) 2.22 ft 2.42 ft 2.45 ft
23 Will the dry pond be uniformly graded to flow toward the outlet? Yes Yes Yes
24 Is a low flow channel being provided? No No No
25 Are the inlet(s)and outlet located in a manner that avoids short- Yes Yes Yes
circuiting?
26 Will berms or baffles be provided to increase the flow path? No No No
27 What method of pretreatment will be provided? N/A N/A N/A
28 Design volume of SCM(cu ft) 13197 19494 16166
29 Diameter of drawdown orifice(in) 1.5 in 3.0 in 2.0 in
30 Drawdown time for the temporary pool(hours) 80 Hours 76 Hours 120 Hours
Does the pond minimize impacts to the receiving channel from the Yes Yes Yes
31 1-yr,24-hr storm?
32 Is there a small permanent pool near the orifice to prevent No No No
clogging?
33 Will the outlet be designed to prevent clogging? Yes Yes Yes
34 Are the dam and embankment planted in non-clumping turf grass? Yes Yes Yes
35 Species of turf that will be used on the dam and embankment Bermuda/Fescue Bermuda/Fescue Bermuda/Fescue 1`
36 Will trees and shrubs be prevented from growing on the dam and Yes Yes Yes embankment?
ADDITIONAL INFORMATION_ _
Please use this space to provide any additional information about
37 the dry pond(s):
No Bores for Seasonal High Water Table based on current pond locations
have been taken.
I
Dry Pond 4 4:26 PM 8/21/2024