SW5211202_BUA Allocations_20220203

CA 6
Project: Nash 97 Solar, LLC
Nash County, NC
Date: 12/13/2021
By: I Graham, PE
Checked: M. Carreon, PE
1. SSW-SWU-101 BUA Calculations Backup
045182 —
It3
Total Property Area (ac)
23.3
ac
From E&SC Permit Approval Letter (9/28/2015)
Total Coastal Wetlands Area (ac)
0
ac
Surface Waters (ac)
0
ac
Total Project Area (ac)
23.3
ac
Basi In Drainage Area i
Receiving Stream Name
Turkey Creek
New River Basin
Stream Class
C; NSW
Stream Index Number
27-86-3-(1)
Total Drainage Area (sf)
1,014,948
On -site Drainage Area (sf)
1,014,948
Off -site Drainage Area (sf)
0
Proposed Impervious Area (sf)
47514
1.1
ac
% Impervious Area (total)
4.68%
22.2
oc (Grassed Areas
(See BUA max.
below)
Impervious Surface Area Drainage Area 1
On -site Buildings/Lots (sf)
0
On -site Streets (sfJ
44297
DWG
On -site Parking (sf)
0
On -site Sidewalks (sf)
0
Other on -site (sf)
3217
3008
Equipment Pods (DWG)
209
Foundation Posts (Piles); assume 4-inch diameter
(Total No, of Posts =2,396 )
Future (sf)
0
Off -site (sf)
0
Existing BUA (sf)
0
Total (sf)
47514
2. NOTES
a. Nash County Is a Phase 2 Tipped County
b. Subject to Urbanizing requirements per 15A NCAC 02H.1017
c. BUA is 24% max.

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Project: Nash 97 Solar, LLC
Nash County, NC
Date: 12/13/2021
By: 1. Graham, PE
Checked: M. Carreon, PE
3. NCDEQ Stormwater Design Manual (Rev. 12-13-2018) E-6 Solar farms
Regulatory Requirements:
DEMLR allows solar panels associated with ground -mounted solar farms to considered pervious
Other structuures associated with the solar farm - buildings, entrance roads, transformers (concrete pads) and
footings are still considered impervious.
Recommendation 2: Disconnect runoff from solar panel arrays
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i TMW��.
3
The project has been installed to allow for vegetation under and in between the solar arrays; and the terrain slopes
are less than 8% along the disconnection flow path (see dimensions below); however, it does not meet the 80%
minimum threshold.
Recommendation 6: Limit vertical clearance to less than or equal to 10 feet
The project solar panel maximum heights are less than 10 feet, which helps prevent erosion and scourig
along the dripline (see Solar Panel and Racking System Details provided).
Solar Panel Width M
13.10
per As -Built ALTA
Row Spacing (ft)
9.21
per As -Built ALTA
Average Slope (%}
5.70%
per Civil Plans
< 8%
Yes
DL Ratio
70.3%
Reference Plans for overall vegetated open space areas.
>80%
No
Figure 9. Disconnection of flow path between solar panels when average slope is
less than 8%.
Solar Panel Width o X F<
Disconnection Length t X it I Solar Panel Width m X it
Avg Slope 5 8%
In general, the minimum disconnection length between two rows of solar panels is equal to the
width of each row, as shown in Figure 1. However, some panel layouts include horizontal gaps
between individual modules that allow stormwater to drip off the panels at intervals much
smaller than the width of each row. In these instances, the solar farm can be designed with a
smaller disconnection length, provided that they will not cause concentration of stormwater
runoff. The disconnection length should not be less than 80% of the total solar panel width.