SW5240201_Supplement-EZ Form_20240219

SUPPLEMENT-EZ COVER PAGE
FORMS LOADED
PROJECT INFORMATION
1 Project Name WRENN FARMS
2 Project Area(ac) 30
3 Coastal Wetland Area(ac) 0
4 Surface Water Area(ac) 0
5 Is this project High or Low Density? High
6 Does this project use an off-site SCM? No
COMPLIANCE WITH 02H.1003(4)
7 Width of vegetated setbacks provided(feet) 6
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? 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: Michael V.Zaccardo,PE-Sr.Project Manager
28 !Organization: Timmons Group
29 !Street address: 5410 Trinity Road,Suite 102
30 !City.State,Zip: _ Raleigh.NC 27607
31 !Phone number(s): _ 919.532.3281
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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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% No
4 If so,number of low density drainage area; 0
Is all/part of this project subject to previous rule
5 versions? No
FORMS LOADED
DRAINAGE AREA INFORMATION Entire Site
4 Type of SCM Wet Pond
5 Total drainage area(sq ft) 1,306,800 1.097,712
6 Onsite drainage area(sq ft) 1097712
7 Offsite drainage area(sq ft) _ 0 _
8 Total BUA in project(sq ft) 482811 sf 464812 sf
New BUA on subdivided lots(subject to permitting)
9 (sq ft) 201300 sf 201300 sf
New BUA not on subdivided lots(subject to
10 •ermitting)(sf) 281511 sf 263512 sf
11 Offsite BUA(sq ft) N/A N/A
12 Breakdown of new BUA not on subdivided lots
-Parking(sq ft) 5698 sf 5698 sf
-Sidewalk(sq ft) 37020 sf 37020 sf
-Roof(sq ft) 115870 sf 115870 sf
-Roadway(sq ft) 99954 sf 99954 sf
-Future(sq ft) N/A N/A
-Other,please specify in the comment box below
(sq ft) 22970 sf 3010 sf
New infiltrating permeable pavement on subdivided
13 lots(sq ft) N/A N/A
New infiltrating permeable pavement not on
14 subdivided lots(sq ft) N/A N/A
Existing BUA that will remain(not subject to
15 •ermittinq)(sq ft) N/A N/A
16 Existing BUA that is already permitted(sq ft; N/A N/A
17 Existing BUA that will be removed(sq ftj, N/A N/A
18 Percent BUA 37% 42%
19 Design storm(inches) 1.0 in
20 Design volume of SCM(cu ft) 18533 cf
21 Calculation method for design volume SA/DA Ratio
ADDITIONAL INFORMATION
Please use this space to provide any additional information about the
22 drainage area(s):
10'Multi Use Path,Mail Kiosk

WET POND
1 iDrainage area number 1
21Mlnimum required treatment volume(cu ft) I 13612 cf
GENERAL MDC FROM 02H.1050
3 is the SCM sized to heat 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
ski,.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)? Yes
If the SCM is on a single family lot,does(will?)the plat comply with
13 General MDC(10)? Yes
14 Is there an O&M Agreement that complies with General MDC(11)? Yes
15 Ns 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.11M
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 401.00
removal)(fmsl)
21 Elevation of the main pool bottom(top of sediment removal)(fmsl) 402.00
22 Elevation of the bottom of the vegetated shelf(fmsl) 407.00
23 Elevation of the permanent pool(fmsl) 407.00
24 Elevation of the top of the vegetated shelf(fmsl) 408.00
25 Elevation of the temporary pool(fmsl) 408.56
26 Surface area of the main permanent pool(square feet) 18533
27 Volume of the main permanent pool(cubic feet) 79581 cf
28 Average depth of the main pool(feet) 4.00 ft
29 Average depth equation used Equation 3
30 If using equation 3.main pool perimeter(feet) 468.0 ft
31 If using equation 3,width of submerged veg.shelf(feet) 6.0 ft
32 Volume of the forebay(cubic feet) 13988 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) 13612 cf
36 Is the outlet an orifice or a weir? Orifice
37 If orifice,orifice diameter(inches) 3 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 berrns or baffles provided to improve the flow path? Yes
43 Depth of forebay at entrance(inches) 72 in
44 Depth of forebay at exit(inches) 72 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 No
permanent pool?
Does the pond minimize impacts to the receiving channel from the 1-
49 yr,24-hr storm? Yes
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
Please use this space to provide any additional Information about the
55 wet pond(sp
2