SW3240702_Supplement-EZ Form_20240801

SUPPLEMENT-EZ COVER PAGE
LOAD SUPPLEMENT FORMS
PROJECT INFORMATION � f
1 Project Name Performance Precast
2 Project Area(ac) 13.891 (Property Area 14.614 ac)
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) 30'wide buffers for Intermittent and Perennial Streams
8 Will the vegetated setback remain vegetated? Yes _
If BUA is proposed in the setback,does it meet
9 NCAC 02H.1003(4)(c-d)? N/A
Is streambank stabilization proposed on this
10 project? No
!NUMBER AND TYPE OF SCMs:
11 Infiltration System 0
12 Bioretention Cell 0
13 Wet Pond 1
14 Stormwater Wetland 0
15 Permeable Pavement 0
16 Sand Filter 0
17 Rainwater Harvesting(RWH) 0
18 Green Roof 0
19 Level Spreader-Filter Strip(LS-FS) 0
20 Disconnected Impervious Surface(DIS) 0
21 Treatment Swale 0
22 Dry Pond 0
23 StormFilter 0
24 Silva Cell 0
25 Bayfilter 0
26 Filterra 0
LOAD SUPPLEMENT FORMS
DESIGNER CERTIFICATION
27 Name and Title: Kate Underwood,PhD,PE
28 Organization: Daylight Engineering
29 Street address: PO Box 1804
30 City,State,Zip: Concord,NC 28026-1804
31 Phone number(s): 980-234-7500
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.
DI
` %%1 I 11 I I'
()
SEAL
Signature of Designer
n 7 033470 O7.
G0.1GINti-o?
;,
////ry£w. 4)
'//i111111111 ° Date

DRAINAGE AREAS
I 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 areas 0
Is all/part of this project subject to previous rule
5 versions? No
CLICK TO LOAD FORM
DRAINAGE AREA INFORMATION I Entire Site I (Wet Pond)
4 Type of SCM n/a Wet Pond
5 Total drainage area (sq ft) 508,040 418,496
6 Onsite drainage area (sq ft) 508,040 418,496
7 Offsite drainage area (sq ft) 0 0
8 Total BUA in project(sq ft) 317,324 317,324
New BUA on subdivided lots (subject to
9 permitting) (sq ft) 0 0
New BUA not on subdivided lots (subject to
_ 10 permitting) (sf) 317,324 317,324
11 Offsite BUA(sq ft) 0 0
12 Breakdown of new BUA not on subdivided lots: 317,324 317,324
- Parking (sq ft) 9,116 9,116
- Sidewalk(sq ft) 6,172 6,172
- Roof(sq ft) 39,770 39,770
- Roadway(sq ft) 0 0
- Future (sq ft) 0 0
- Other, please specify in the comment box
below (sq ft) 262,266 262,266
New infiltrating permeable pavement on
13 subdivided 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 permitting) (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 ft) n/a n/a
18 Percent BUA 62.46% 75.82%
19 Design storm (inches) 1 1
20 Design volume of SCM (cu ft) n/a 25,543
—Simple Method
21 1Calculation method for design volume n/a Runoff Volume
ADDITIONAL INFORMATION
22 Please use this space to provide any additional information about
The 262,266 sf of"Other" impervious area consists of the gravel lot, wash out
pit, batch plant, concrete driveway entrance, and concrete slab around the
building bay door entrances.

WET POND
1 Drainage area number 1
2 Minimum required treatment volume (cu ft) 25543 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? n/a
5 What are the side slopes of the SCM (H:V)? 3:1
Does the SCM have retaining walls, gabion walls or other
6 No
engineered side slopes?
7 Are the inlets, outlets, and receiving stream protected from Yes
erosion (10-year storm)? _
8 Is there an overflow or bypass for inflow volume in excess of the Yes
design volume?
Drawdown Orifice
9 What is the method for dewatering the SCM for maintenance? & Pumping out
bottom 2.5' of pond
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 N/A
with General MDC (10)?
14 Is there an O&M Agreement that complies with General MDC Yes
(11)?
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 desi ned b an NC licensed rofessional? Yes
WET POND MDC FROM 02H .1053
SA/DA and
18 Sizing method used Average Depth
Method
19 Has a stage/storage table been provided in the calculations? Yes
20 Elevation of the excavated main pool depth (bottom of sediment 641.00
removal) (fmsl) _
21 Elevation of the main pool bottom (top of sediment removal) 642.00
(fmsl)
_ 22 Elevation of the bottom of the vegetated shelf(fmsl) 648.00
23 Elevation of the permanent pool (fmsl) 648.00
_ 24 Elevation of the top of the vegetated shelf(fmsl) 649.00
25 Elevation of the temporary pool (fmsl) 649.50
26 Surface area of the main permanent pool (square feet) 11365
27 Volume of the main permanent pool (cubic feet) 44801 cf
28 Average depth of the main pool (feet) 3.94 ft
29 Average depth equation used Equation 2
30 If using equation 3, main pool perimeter (feet) n/a
31 If using equation 3, width of submerged veg. shelf(feet) n/a
32 Volume of the forebay (cubic feet) 7953 cf

33 Is this 15-20% of the volume in the main pool? Yes (15.1%)
_ 34 Clean-out depth for forebay (inches) 42
35 Design volume of SCM (cu ft) 26150 cf
_ 36 Is the outlet an orifice or a weir? _ Orifice
37 If orifice, orifice diameter(inches) 2 in
38 If weir, weir height (inches) 18 in
39 If weir, weir length (inches) 180 in
40 Drawdown time for the temporary pool (days) 4.08
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) 42 in
44 Depth of forebay at exit (inches) 48 in
45 Does water flow out of the forebay in a non-erosive manner? Yes
46 Width of the vegetated shelf(feet) 6
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
49 the 1-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 Yes
system?
52 Are the dam and embankment planted in non-clumping turf Yes
grass?
53 Species of turf that will be used on the dam and embankment n/a
54 Has a planting plan been provided for the vegetated shelf? Yes
ADDITIONAL INFORMATION No
Please use this space to provide any additional information about
55 the wet pond(s):