SW3221005_Supplement-EZ Form_20240717

SUPPLEMENT-EZ COVER PAGE
LOAD SUPPLEMENT FORMS
PROJECT INFORMATION
1 Project Name Boulder Run
2 Project Area(ac) 128.169
3 Coastal Wetland Area(ac) 0
4 Surface Water Area(ac) 2.496
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) 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)? Yes
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 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: Brian LaFranchi
28 Organization: Dewberry Engineers Inc.
29 Street address: 9300 Harris Corners Parkway
30 City,State,Zip: Charlotte,NC,28269
31 Phone number(s): 704-631-5206
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
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) 5,583,042 _ 5,583,042
6 Onsite drainage area(sq ft) 5,583,042 _ 5,583,042
7 Offsite drainage area(sq ft) 0 0
8 Total BUA in project(sq ft) 701630 sf 701630 sf
New BUA on subdivided lots(subject to
9 permitting)(sq ft) 496650 sf 496650 sf
New BUA not on subdivided lots(subject to
10 permitting)(sf) 204980 sf 204980 sf
11 Offsite BUA(sq ft) N/A N/A
12 Breakdown of new BUA not on subdivided lots:
-Parking(sq ft)
-Sidewalk(sq ft)
-Roof(sq ft)
-Roadway(sq ft) 202895 sf 202895 sf
-Future(sq ft)
-Other,please specify in the comment box
below(sq ft) 2085 sf 2085 sf
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 13% 13%
19 Design storm(inches)
20 Design volume of SCM(cu ft)
21 Calculation method for design volume
ADDITIONAL INFORMATION
Please use this space to provide any additional information about the
22 drainage area(s):
Other category is the asphalt trail along King James Blvd.

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) 2:1,3:1,4:1
5 Maximum velocity in the vegetated conveyances during the 10-year storm? 7.07
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:
Vegetated Conveyances#1,3,4,6A,6B,12,14,15,16,17,18,19,22,23,26,and 27 have higher slopes and velocities,
therefore,SC250 matting has been proposed for these conveyances and the allowable velocities have been updated below to
reflect this matting.
Drainage Pervious
Swale BUA Q Slope V,,,,,, V,.,,, Flow depth
Area (ac) area C# (cfs) (%) (fps) (fps) (ft)
(ac) (ac)
1 7.39 Ditch 1 -- 0.60 31.57 4.20 9.50 6.58 0.86
2 0.48 Ditch 2 -- 0.60 2.05 4.20 5.50 3.55 0.44
3 3.65 Ditch 3 -- 0.60 15.59 3.90 9.50 5.49 0.59
4 1.96 Ditch 4 -- 0.60 8.37 4.50 9.50 5.19 0.73
5 0.19 Ditch 5 -- 0.60 0.81 2.50 5.50 2.32 0.34
6 0.73 Ditch 6A -- 0.60 3.12 8.00 9.50 5.04 0.45
7 1.30 Ditch 6B -- 0.60 5.57 10.20 9.50 5.99 0.32
8 0.66 Ditch 7A -- 0.60 2.82 6.10 5.50 4.44 0.46
9 0.26 Ditch 7B -- 0.60 1.11 4.80 5.50 3.21 0.34
10 0.31 Ditch 8A -- 0.60 1.32 4.00 5.50 3.13 0.38
11 0.41 Ditch 8B -- 0.60 1.75 2.80 5.50 2.94 0.44
-
12 0.30 Ditch 9 -- 0.60 1.28 5.30 5.50 3.46 0.35
13 0.38 Ditch 10 -- 0.60 1.62 5.50 5.50 3.72 0.38
14 0.99 Ditch 11 -- 0.60 4.23 4.10 5.50 4.23 0.58
15 2.19 Ditch 12 -- 0.60 9.36 5.00 9.50 5.56 0.75
16 0.30 Ditch 13 -- 0.60 1.28 1.70 5.50 2.26 0.43
17 4.38 Ditch 14 -- 0.60 18.71 6.00 9.50 6.76 0.68
18 3.20 Ditch 15 -- 0.60 13.67 8.00 9.50 7.07 0.54
19 1.86 Ditch 16 -- 0.60 7.95 7.10 9.50 5.79 0.68
-
20 3.73 Ditch 17 -- 0.60 15.93 3.00 9.50 4.54 0.80
21 0.58 Ditch 18 -- 0.60 2.48 7.00 9.50 4.52 0.43
22 0.97 Ditch 19 -- 0.60 4.15 7.00 9.50 4.76 0.54
23 0.69 Ditch 20 -- 0.60 2.95 5.70 5.50 4.37 0.48
24 0.72 Ditch 21 -- 0.60 3.08 7.10 5.50 4.42 0.25
25 0.88 Ditch 22 -- 0.60 3.76 11.50 9.50 5.70 0.33
26 1.62 Ditch 23 -- 0.60 6.92 7.00 9.50 5.55 0.64
27 0.49 Ditch 25 -- 0.60 2.09 5.00 5.50 4.13 0.48
-
28 1.18 Ditch 26 -- 0.60 5.04 9.50 9.50 5.71 0.40
29 0.59 Ditch 27 -- 0.60 2.52 8.00 9.50 4.29 0.44
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