SW1230801_Supplement-EZ Form_20230922

SUPPLEMENT-EZ COVER PAGE
FORMS LOADED
1PROJECT INFORMATION
1 Project Name Ferncliff Ret-New Substation
2 Project Area(ac) 9.94
3 Coastal Wetland Area(ac) 0
4 Surface Water Area(ac) 0
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) 128
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
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: Joshua A.Peeler
28 Organization: Duke Energy Carolinas,LLC
29 Street address: 526 S.Church St.
30 City,State,Zip: Charlotte,NC 28202
31 Phone number(s): 704-530-7772
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 REC ' 11 ;. 3
1 ! Is this a high density project? No
2 If so, number of drainage areas/SCMs 0 DENR-L AND QUALITY
3 Does this project have low density areas? Yes VORMWATER PFRMITTNl , y
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
4 Tvna of .q('M W/ nofafnH C ,wnlo \lon.+of—1 Q—'Io
5
Total drainage area (sq ft) _ 432891
Onsite drainage area (sq ft) 432891
336676 96215
336676 9d215 -
9045 sf 13939 sf
6
7
Offsite drainage area (sq ft)
8
Total BUA in project (sq ft)
22984 sf
9
New BUA on subdivided lots (subject to
permitting) (sq ft)
10
New BUA not on subdivided lots (subject to
permitting) (sf)
11
Offsite BUA (sq ft)
12
Breakdown of new BUA not on subdivided lots:
- Parking (sq ft)
- Sidewalk (sq ft)
- Roof (sq ft)
- Roadway (sq ft)
- Future (sq ft)
- Other, please specify in the comment box
below (sq ft)
5%
6.6 in 6.6 in
13
New infiltrating permeable pavement on
subdivided lots (sq ft)
14
New infiltrating permeable pavement not on
subdivided lots (sq ft)
15
Existing BUA that will remain (not subject to
permitting) (sq ft)
16
Existing BUA that is already permitted (sq ft)
17
Existing BUA that will be removed (sq ft)
18
Percent BUA
19
Design storm (inches)
20 IDesign
91
volume of SCM (cu ft)
Calculation methnd fnr riasinn vnh ImR
ADDITIONAL INFORMATION _
Please use this space to provide any additional information about the
22 idrainaae area(s):
values provide are for 25-yearl24-hour storm based on industry
ird swale design storm event.

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) 4:1
5 Maximum velocity in the vegetated conveyances during the 10-year storm? 4.44
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:
Due to the low density,vegetated swales were implemented onsite to mitigate the runoff as an LID practice.There is a low point
on site which acts as a dry detention pond with a 15-inch culvert outlet pipe.This feature was not implemented as a requirement
but constructed for access and future maintenance to transmission line towers onsite.The detention area has been shown in the
routing calculations and does provide some detention qualities to reduce the post-cionstruction runoff.
Drainage Pervious
Swale BUA Q Slope V,ii%„ V,„,,,1 Flow depth
# Area area
(ac) (cfs) (%) (fps) (fps) (ft)
(ac) (ac)
1 2.04 0.15 1.89 0.35 14.54 1.10 5.40 3.11 0.80
2 1.04 0.06 0.98 0.34 6.16 1.40 5.91 3.71 0.58
3 1.67 0.32 1.35 0.42 10.21 2.60 7.94 4.44 0.70
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