SW5240602_Design Calculations_20240704

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neiengineering.com 303-431-7895
12600 W Colfax Avenue,Suite C500,Lakewood,CO 80215
NCDEQ Post-Construction Stormwater Permitting Group
512 N. Salisbury Street, Office 640E
Raleigh, NC 27604
June 25, 2024
RE: Red Bud Solar Stormwater Management Administrative Review
Kaitlin Peck,
In response to your email on 6/25/24 this letter is being provided as part of the Red Bud Solar
Post-Construction Stormwater Permit Application. Included with this letter is the Low Density
calculation table from the NCDEQ Supplemental EZ form and a summary table of all temporary
diversion swales proposed as part of this project. Please note that these swales are intended only
to divert runoff to temporary sediment basins during construction and will not be retained at the
end of the project when the basins are decommissioned.
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06/25/2024
Thank you for your attention in regard to this submission.
Best Regards,
Digitally signed by
Ryan D Brick pate 202406.25
12:47:27-06'00'
Ryan Brick
[e-mail]
12600 W Colfax Ave, Suite C500, Lakewood CO 80215
303-431-7895
Red Bud Solar

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 to 1
5 Maximum velocity in the vegetated conveyances during the 10-year storm?
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 - L
15 Please use this space to provide any additional information about this low density project:
All ditches on site that drain to High Quality Waters are temporary and will not be retained after construction.

Red Bud Temporary Diversion Ditch Summary Table
Velocity Channel Shear Dimensions
Diversion Flow Q V Capacity Stress Bottom Side Max Liner Material
Ditch ID (cfs) Width Slope Depth
(fps) (cfs) (lb/ft-) (ft) (ft/ft) (ft)
_ V1, V2 1.1 2.65 2.78 0.69 ! 0.10 4.00 0.50 Straw with Net
_ 1.A 1.8 4.26 18.39 1.02 3.00 3.00 0.80 Straw with Net _
3.A 4.9 4.49 7.95 1.14 5.00 3.00 0.30 Straw with Net
5.A 6.1 4.06 6.82 0.99 3.00 3.00 0.40 Straw with Net
_ 7A.A 2.9 3.85 16.62 0.83 3.00 3.00 0.80 Straw with Net
_ 8.A 2.6 3.85 6.46 0.89 3.00 3.00 0.40 Straw with Net
13.A 0.4 4.94 21.33 1.37 3.00 3.00 0.80 Straw with Net
13.6 1.3 4.35 7.31 1.13 3.00 3.00 0.40 Straw with Net
19.A 1.7 4.56 7.67 1.25 3.00 3.00 0.40 Straw with Net
_ 23B.A 8.7 3.82 22.60 0.72 5.00 3.00 _ 0.80 Straw with Net
26.A 2.3 3.78 6.36 0.86 3.00 3.00 0.40 Straw with Net
26.B 10.6 3.80 19.45 0.76 4.00 3.00 0.80 Straw with Net
_ 27.A 9.7 4.27 11.73 1.00 4.00 3.00 0.50 Straw with Net
28.A.1 16.5 5.33 31.56 1.41 5.00 3.00 0.80 Straw with Net
28.A.2 16.5 3.00 17.76 2.50 5.00 3.00 0.80 Rock Riprap D50=9
_ 28.A.3 16.5 4.01 23.73 0.80 5.00 3.00 0.80 Straw with Net
28.B 34.5 5.27 43.85 1.24 8.00 3.00 0.80 Straw with Net
28.0 1.6 4.04 10.66 1.38 0.10 4.00 0.80 Straw with Net
_ 28.D 17.2 2.55 20.36 2.58 0.10 4.00 1.40 Rock Riprap D50=9
28.E.1 7.4 3.54 18.13 0.66 4.00 3.00 0.80 Straw with Net
_ 28.E.2 7.4 2.85 14.58 2.37 4.00 3.00 0.80 Rock Riprap D50=9
_ 28.E.3 7.4 2.78 _ 14.24 2.26 4.00 3.00 _ 0.80 Rock Riprap D50=9
_ 29.A 16.5 5.04 _ 25.82 1.33 4.00 3.00 _ 0.80 Straw with Net
29.B 3.7 3.77 16.28 0.80 3.00 3.00 0.80 Straw with Net
29.0 4.9 4.60 5.38 1.31 3.00 3.00 0.30 Straw with Net
30.A 2.2 3.77 16.28 0.80 3.00 3.00 0.80 Straw with Net
_ 33.A 5.6 3.87 16.73 0.84 3.00 3.00 0.80 Straw with Net _
34.A 2.4 4.83 20.88 1.31 3.00 3.00 0.80 Straw with Net
35.A 1.5 4.13 17.85 0.96 3.00 3.00 0.80 Straw with Net
_ 38.A 12.1 3.66 21.67 0.67 5.00 3.00 0.80 Straw with Net
39.A 15.9 4.47 16.76 1.01 6.00 3.00 0.50 Straw with Net
40.A 3.1 4.60 7.73 1.27 3.00 3.00 0.40 Straw with Net
41.A 4.1 4.36 7.33 1.14 3.00 3.00 0.40 Straw with Net
_ 43.A 3.9 3.64 6.11 0.79 3.00 3.00 0.40 Straw with Net
_ 44.A 12.5 4.42 26.17 0.97 5.00 3.00 0.80 Straw with Net
48.A - BYP 4.6 4.43 10.98 1.05 5.00 3.00 0.40 Straw with Net
49.A 4.1 3.34 5.61 0.67 3.00 3.00 0.40 Straw with Net
_ 52B.A 7.4 3.90 8.77 0.89 3.00 3.00 0.50 Straw with Net
_ 52A.A 1.1 4.36 18.84 1.07 3.00 3.00 0.80 Straw with Net _
56.A 0.7 4.45 3.20 1.30 3.00 3.00 0.20 Straw with Net
60.A 3.4 3.51 5.90 0.74 3.00 3.00 0.40 Straw with Net