SW3230802_Stormwater Narrative_20230810

American Engineering Associates-Southeast,PA.
A AM E RICAN 8008 Corporate Center Drive,Suite 110
Charlotte,NC 28226
Engineering OFFICE: 704.375.2438
www.American-EA.com
Green Acres Subdivision
Stormwater Calculations
Site Narrative
The proposed project, Green Acres Subdivision, is a 37-lot single-family development located in Cabarrus County,
North Carolina, in the Town of Mt. Pleasant.The proposed project is a 14.027-acre development, with
approximately 14 acres of denuded area.The proposed development is located on Green Acres Circle which
connects to NC-73 south of the property.The western and northern boundaries of the site are undeveloped
existing parcels consisting of trees and open fields.
This construction site includes the clearing and grubbing of existing brush and wooded land, grading of the
existing site, and the construction of 37 single-family homes, roads, sidewalks, and associated infrastructure.
Site development and grading will occur in one stage. That stage will have three phases of erosion control. The
on-site temporary sediment basin has been appropriately designed for phases 1 and 2 of construction, while
phase 3 will use inlet protection, perimeter silt fence and silt fence outlet,the final proposed BMP, and any other
necessary erosion control measure as noted on the plans. Erosion and sediment control measures were sized
using North Carolina Department of Environmental Quality(NCDEQ) requirements.
Pre-Development Conditions
The project site is located within an area having a zone designation X by the Federal Emergency Management
Agency (FEMA) on Flood Insurance Rate Map (FIRM) Number 3710565100K and 3710565100K, both with a date of
identification of November 16, 2018. The existing property consists of woods, open space, and two mobile homes
that will be removed for construction.
Existing stormwater runoff primarily drains towards the southern boundary of the site and then discharges off-site
through an existing 60" culvert. Pre-developed drainage conditions can be reviewed on the drainage area maps
located in the Appendix.
The soil types identified within the project area are ChA(Chewacla sandy loam), CuB2 (Cullen clay loam), EnB
(Enon sandy loam), MeB (Mecklenburg loam), and SfB (Sedgefield sandy loam). The soil types identified were
used in determining the Curve Numbers (CN's)for the onsite and offsite runoff.
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