SW6210701_Stormwater Narrative_20210721

Hoch
ngch P.A.
Joe E. Godwin Sr., P.E., P.L.S.
Consulting Engineers & Surveyors
1403 NC Hwy 50 South
Benson, NC 27504
Brothers Steel Erectors and Welding, LLC
Grove Township, Harnett County
STORMWATER NARRATIVE
Phone: [phone]
[phone]
Fax: [phone]
Email: [e-mail]
Project Description
The purpose of this project is to develop a 2 lot residential subdivision. The subdivision site is 26.62
acres and is located along Carson -Gregory Road (SR 1547) approximately 5,100 feet north of its
intersection with NC Highway 55 in Grove Township, Harnett County, NC. Construction of Streets and
utilities as well as temporary skimmer basin area and permanent detention pond has been considered in
this land disturbance activity for a total disturbance of 11.5 acres.
Site Description
The site is existing woods and open farmland. Existing topography drains to the north with slopes
ranging from approximately 2% - 15%. The site is designed for under 24% impervious area upon build -
out (Low Density Development).
Adjacent Property
The land uses in the surrounding areas are residential and undeveloped.
Soils
The soils in the project area consist primarily of DoA (Dothan loamy sand, 0 to 2% slopes), DoB
(Dothan loamy sand, 2 to 6% slopes), DtB (Dothan gravelly loamy sand, 0 to 6% slopes), and NoC
(Norfolk loamy sand, 6 to 10% slopes). DoA is categorized as well drained, moderately permeable, and
is moderately suited to most urban and recreational uses. DoB is categorized as well drained, moderately
permeable, and is moderately suited to most urban and recreational uses. DtB is categorized as well
drained, moderately permeable, and is moderately suited to most urban and recreational uses. NoC is
categorized as well drained, moderately permeable, and is well suited to urban and recreational uses.
Planned Erosion and Sediment Control
As shown on the Erosion Control Plan the project will be controlled and stabilized with diversion berms,
silt fence, straw w/net matting, rock check dams, and temporary skimmer basins w/baffles. Topsoil will
be wasted on -site as non-structural fill material and berms will be constructed from topsoil graded from
the site. Skimmer basins will be constructed with baffles and outlet protection. All measures will be
constructed and maintained to NCDEQ standards and requirements.
After erosion control measures are removed. Surface waters from the roadway areas will drain via
grassed roadside ditches to grassy swales which will convey the runoff to an owner maintained &
constructed wet pond. Impervious areas on some portions of the lots will surface drain through the
grassed yard areas over the natural contours of the Site. Project impervious percentage is limited to 24%.
Proposed impervious limits as follows:
1,159,567SF*0.24=278,296SF MAX IMPERVIOUS AREA
ROADWAY AREA: 13,165SF
2 LOTS @ MAXIMUM 80,000SF/LOT: 160,000SF
TOTAL IMPERVIOUS BY DESIGN: 173,165SF (14.9%)