SW6231201_Supplement-EZ Form_20240305

SUPPLEMENT-EZ COVER PAGE
.DADED
PROJECT INFORMATION
— 1 Project Name Duke Energy Old Bluff Church Road Laydown Yard
_ 2 Project Area(ac) 29.91
_ 3 Coastal Wetland Area(ac) p
_ 4 Surface Water Area(ac) 1.01
_ 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) _ 50
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 0
12 Bioretention Cell 0
_13 Wet Pond 0
14 Stormwater Wetland 0
15 Permeable Pavement 0
16 Sand Fitter 0
17 Rainwater Harvesting(RWH) 0
18 Green Roof 1 0
19 Level Spreader-Filter Strip(LS-FS) 0
20 Disconnected Impervious Surface(DIS) 0
0
21 Treatment Swale 0
22 Dry Pond 0
23 StorrnFilter 0
24 Silva Cell 0
25 Bayfilter 0
26 Filters
IFORMS LOADED I
DESIGNER CERTIFICATION Parrks
27 Name and Title: Nick ick aMcA s
29 Organization: 621 Hillsborough Street,Suite 500
29 Street address: Raleigh,NC 27603
)-- City,State,Zip 919-413-8322
31 Phone number(s): ----— [e-mail]
32 Email:
Certification Statement: ortin information were prepared under my direction or supervision;that the
I certify,under penalty of law that this Supplement-EZ form and all supp 9
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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SEAL • = Signature of 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 _ 1
Is all/part of this project subject to previous rule
5 versions? No
FORMS LOADED
DRAINAGE AREA INFORMATION Entire Site LD 1
4 Type of SCM _
5 Total drainage area(sq ft) 1302789 _ 1302789
6 Onsite drainage area(sq ft) 1,302,789.00 _ 1302789
7 Offsite drainage area(sq ft)
8 Total BUA in project(sq ft) 245682 sf 245682 sf
New BUA on subdivided lots(subject to
9 permitting)(sq ft) N/A N/A
New BUA not on subdivided lots(subject to
10 permitting)(sf) N/A N/A
11 Offsite BUA(sq ft) N/A N/A
12 Breakdown of new BUA not on subdivided lots:
-Parking(sq ft) 245682 sf 245682 sf
-Sidewalk(sq ft) N/A N/A
-Roof(sq ft) N/A N/A
-Roadway(sq ft) N/A N/A
-Future(sq ft) N/A N/A
-Other,please specify in the comment box
below(sq ft)
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 19% 19%
19 Design storm(inches) N/A N/A
20 Design volume of SCM(cu ft) N/A N/A
21 Calculation method for design volume
ADDITIONAL INFORMATION
Please use this space to provide any additional information about the
22 drainage area(s):
Clean Water Bypass was sized using the 10-year storm intensity of 7.93
inches per hour.

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
5 Maximum velocity in the vegetated conveyances during the 10-year storm? 4.12
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:
The proposed laydown yard consists of a clean water diversion ditch to redirect run-on to the laydown area. The laydown area
will consist of a geotextile fabric overlain with stone on top of the existing ground to minimize disturbance. Silt fence with J-
hooks and silt fence outlets are proposed at the downstream portion of the stone laydown yard,before the vegetated buffer
begins. The laydown yard will be removed after overhead transmission line project is complete. The site will be restored to the
pre-project conditions which is agricultural use.
Drainage Pervious
Swale BUA Q Slope Vanow Vanoai Flow depth
# Area area
(ac) (cfs) (%) (fps) (fps) (ft)
(ac) (ac)
1 8.71 0.00 8.71 0.40 27.63 1.00 4.50 4.12 1.08
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