SW3230802_Supplement-EZ Form_20240530

SUPPLEMENT-EZ COVER PAGE
FORMS LOADED
PROJECT INFORMATION
1 Project Name Green Acres Subdivision
2 Project Area(ac) 14.71
3 Coastal Wetland Area(ac) 0
4 Surface Water Area(ac) 0.045
5 Is this project High or Low Density? Both High and Low Density
6 Does this project use an off-site SCM? No
COMPLIANCE WITH 02H.1003(4)
7 Width of vegetated setbacks provided(feet) 30
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)?
10 Is streambank stabilization proposed on this project? No
NUMBER AND TYPE OF SCMs:
11 Infiltration System
12 Bioretention Cell
13 Wet Pond 1
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
23 StormFilter
24 Silva Cell
25 Bayfilter
26 Filterra
FORMS LOADED
DESIGNER CERTIFICATION
27 Name and Title: Barry Fay,Project Engineer
28 ,Organization: American Engineering Associates
29 Street address: 8008 Corporate Center Dr.Suite 110
30 City,State,Zip: Charlotte,NC 28226
31 Phone number(s): 704-375-2438
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.
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Seal Date

DRAINAGE AREAS
1 Is this a high density project? Yes
2 If so,number of drainage areas/SCMs 1
3 Does this project have low density areas? Yes
4 If so,number of low density drainage areas 1
Is all/part of this project subject to previous rule
5 versions? No
FORMS LOADED
DRAINAGE AREA INFORMATION Entire Site 1 LD 1
4 Type of SCM Wet Pond Undetained
5 Total drainage area(sq ft) 640,859 531,938 108,921
6 Onsite drainage area(sq ft) 640,859 531,938 108,921
7 Offsite drainage area(sq ft) 0 0
8 Total BUA in project(sq ft) 248453 sf 226940 sf 21513 sf
New BUA on subdivided lots(subject to permitting)
9 (sq ft) 135420 sf 133370 sf 2050 sf
New BUA not on subdivided lots(subject to
10 permitting)(sf) 114041 sf 93132 sf 11755 sf
11 Offsite BUA(sq ft) n/a n/a n/a
12 Breakdown of new BUA not on subdivided lots:
-Parking(sq ft)
-Sidewalk(sq ft) 24494 sf 21505 sf 2989 sf
-Roof(sq ft)
-Roadway(sq ft) 80831 sf 72065 sf 8766 sf
-Future(sq ft)
-Other,please specify in the comment box
below(sq ft)
New infiltrating permeable pavement on
13 subdivided lots(sq ft)
New infiltrating permeable pavement not on
14 subdivided lots(sq ft)
Existing BUA that will remain(not subject to
15 permitting)(sq ft) 7708 sf
16 Existing BUA that is already permitted(sq ft)
17 Existing BUA that will be removed(sq ft)
18 Percent BUA 39% 43% 20%
19 Design storm(inches) 1.0 in
20 Design volume of SCM(cu ft) 19360 cf
21 Calculation method for design volume Simple Method
ADDITIONAL INFORMATION
Please use this space to provide any additional information about the
22 drainage area(s):

WET POND
1 Drainage area number 1 I
2 Minimum required treatment volume(cu ft) 19238 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?
Are the inlets,outlets,and receiving stream protected from erosion
7(10-year storm)? Yes
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)? Yes
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
WET POND MDC FROM 02H.1053
18 Sizing method used SA/DA
19 Has a stage/storage table been provided in the calculations? Yes
20 Elevation of the excavated main pool depth(bottom of sediment 646.00
removal)(fmsl)
21 Elevation of the main pool bottom(top of sediment removal)(fmsl) 647.00
22 Elevation of the bottom of the vegetated shelf(fmsl) 653.50
23 Elevation of the permanent pool(fmsl) 654.00
24 Elevation of the top of the vegetated shelf(fmsl) 654.50
25 Elevation of the temporary pool(fmsl) 655.80
26 Surface area of the main permanent pool(square feet) 7041
27 Volume of the main permanent pool(cubic feet) 27425 cf
28 Average depth of the main pool(feet) 3.90 ft
29 Average depth equation used Equation 2
30 If using equation 3,main pool perimeter(feet)
31 If using equation 3,width of submerged veg.shelf(feet)
32 Volume of the forebay(cubic feet) 4889 cf
33 Is this 15-20%of the volume in the main pool? Yes
34 Clean-out depth for forebay(inches) 48 in
35 Design volume of SCM(cu ft) 20665 cf
36 Is the outlet an orifice or a weir? Orifice
37 If orifice,orifice diameter(inches) 2.0 in
38 If weir,weir height(inches)
39 If weir,weir length(inches)
40 Drawdown time for the temporary pool(days) 2.7
41 Are the inlet(s)and outlet located in a manner that avoids short- yes
circuiting?
42 Are berms or baffles provided to improve the flow path? Yes
43 Depth of forebay at entrance(inches) 48 in
44 Depth of forebay at exit(inches) 36 in
45 Does water flow out of the forebay in a non-erosive manner? Yes
46 Width of the vegetated shelf(feet) 6 ft
47 Slope of vegetated shelf(H:V) 6:1
48 Does the orifice drawdown from below the top surface of the Yes
permanent pool?
Does the pond minimize impacts to the receiving channel from the 1-
49 Yes
yr,24-hr storm?
50 Are fountains proposed?(If Y,please provide documentation that No
MDC(9)is met.)
51 Is a trash rack or other device provided to protect the outlet system? Yes
52 Are the dam and embankment planted in non-clumping turf grass? Yes
53 Species of turf that will be used on the dam and embankment Bermuda
54 Has a planting plan been provided for the vegetated shelf? Yes
ADDITIONAL,;INFORMATION •
55 Please use this space to provide any additional information about the
wet pond(s):
2

WET POND
1 1
2

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 channelization 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) 3:1
5 Maximum velocity in the vegetated conveyances during the 10-year storm? 2.63
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? Yes
13 Have stormwater outlets been designed to prevent downslope erosion? Yes
14 Are variations to rule.1003 proposed? No
ADDITIONAL INFORMATION
15 Please use this space to provide any additional information about this low density project:
Ditch caluclations below are for the clear water ditch on the northern property boundary.The ditch will be lined with ECM.
Calculations for permissible shear stress have been included based on North American Green ECMDS v7.0.
Drainage Pervious
Swale Area BUA area C Q Slope V,,pw V,n,i Flow depth
(ac) (ac) lac) (cfs) (%) (fps) (fPs) (ft)
1 4.71 0.00 4.71 0.45 14.21 1.00 4.50 2.46 1.09
2 7.70 0.00 2.99 0.40 17.72 1.00 4.50 2.63 1.08
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