SW4220602_Stormwater Narrative_20220713

NORDFAB SYSTEMS,INC.
BUILDING EXPANSION PROJECT
150 TRANSIT AVENUE
THOMASVILLE, NC (DAVIDSON COUNTY)
STORMWATER NARRATIVE
May 2g 292
June 18, 2022
Nordfab, LLC currently owns & operates an existing manufacturing facility located at the end of Transit Avenue in
Thomasville, NC. The site is identified as PIN# 6789-04-90-0663, containing a total site area of 15.06 acres (1.15 acres of
which is a pond). Proposed improvements include construction of a new 54,000 SF pre-engineered building (adjacent to
the existing facility) and additional employee parking areas. Minimal grading will be required in the area of the proposed
building due to the already flat terrain in the area. Material excavated for the building slab and column foundation
construction will be utilized on the north end of the site for construction of a parking area.
The site lies within the Yadkin Pee -Dee River Basin and drains to Kennedy Mill Creek (Index # 12-119-7-2, Class C
waters). Generally speaking, the site drains from west to east, and runoff is conveyed through the site primarily by sheet
flow and existing swales/ditchlines — pre-existing piping systems are present to convey water under driveways and away
from the dock areas. The proposed improvements will provide for conveyance of stormwater via vegetated ditchlines,
though additional stormwater piping will be required to convey stormwater under new driveways for access to the
proposed gravel parking areas. Two (2) small area drains are proposed on the south end of the building and to move
water away from the new building footprint and existing parking area, due to the lack of existing topography in the area.
Stormwater runoff from the proposed project area will be treated by a temporary sediment skimmer basin during
construction. No major changes to existing drainage patterns are proposed as a result of the project. No new non-
structural or structural BMPs are currently proposed.
Calculations for the existing & proposed built -upon areas, supporting the Low -Density Development option is summarized
below:
Total Site Area:
15.06 acres
Existing Pond:
1.15 acres
Existing BUA:
4.87 acres
Total Project Area:
9.04 acres
Allowable BUA: 9.04 acres X 24% = 2.17 acres
Proposed BUA: 1.24 acres (new building
0.26 acres (new parking)
0.64 acres (future impervious allocation)
2.14 acres