SW6220704_Stormwater Narrative_20220804

FLEET TEM PLE
ENGINEERING
PLLC
5245 Red Hill Church Rd
Coats, NC 27521
910.658.2446
[e-mail]
Firm License P-2357
Edison Acres
Upper Little River Township, Harnett County
07.14.2022
PROJECT NARRATIVE
Project & Site Description
The purpose of this project is to develop a 55.3 acre residential subdivision. The
property is existing farmland and woodland. Existing topography drains to the east
and west at slopes of approximately 1% - 25% to Walkers Creek (east) and to an un-
named tributary Bear Branch (west). Wetlands have been delineated on site. No
wetlands will be disturbed during construction of the property The Site is limited to
maximum 24% impervious area upon build -out (Low Density Development).
Adjacent Property
The land uses in the surrounding areas are residential and agricultural.
Soils
The soils in this project consist of Bb (Bibb loam, frequently flooded), BnB (Blaney
loamy sand, 2 to 8% slopes), CeD (Cecil fine sandy loam, 8 to 15% slopes), DoA (Dothan
loamy sand, 0 to 2% slopes), GaD (Gilead loamy sand, 8 to 15% slopes), NoB (Norfolk
loamy sand, 2 to 6% slopes), and PaE (Pacolet fine sandy loam,15 to 25% slopes)
Bb is categorized as poorly drained, moderately permeable, and is poorly suited to
most urban and recreational uses. BnB is categorized as well drained, moderately
slowly permeable, and is moderately suited to most urban and recreational uses. CeD
is categorized as well drained, moderately permeable, and is moderately suited to
most urban and recreational uses. DoA is categorized as well drained, moderately to
moderately slowly permeable, and is moderately suited to most urban and
recreational uses. GaD is categorized as moderately well drained, moderately slowly
permeable, and is moderately suited to most urban and recreational uses. NoB is
categorized as well drained, moderately permeable, and is well suited to most urban
and recreational uses. PaE is categorized as well drained, moderately permeable, and
is poorly suited to most urban and recreational uses.
Planned Stormwater Management, Erosion and Sediment Control
As shown on the Erosion Control Plan the project will be controlled and stabilized with
diversion berms, silt fence, rock check dams, and temporary skimmer basins with
baffles. Diversion berms will be constructed from topsoil graded from the site and will
be backed with silt fence where needed. All measures will be constructed and
maintained to NCDEQ & Harnett Countystandards and requirements.

After erosion control measures are removed. Surface waters from the roadway areas
will drain via grassed roadside ditches to owner maintained grassy swales which will
convey the runoff from the property. 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% (Low Density Development).
Proposed impervious limits as follows:
IMPERVIOUS AREA CALCULATIONS:
TRACT AREA: 2,407,038 SF (SS.26 ac.)
SURFACE WATER AREA: 32,390 SF
TRACT AREA - SURFACE WATER AREA: 2,374,648 SF
IMPERVIOUS AREA ALLOWED: 24% MAX (LOW DENSITY)
2,374,648 SF X 0.24=569,915 SF MAXIMUM ALLOWABLE IMPERVIOUS
IMPERVIOUS AREA BY DESIGN
65,203 SF ASPHALT
495,000 SF(11,000SF/LOT X 4S LOTS)
560,203 SF TOTAL IMPERVIOUS BY DESIGN
560,203sf/2,374,648= 23.6%