SW3240703_Stormwater Narrative_20240801

165 Brumley Ave NE
DAYL I G H T � �, Conc 980.234 7500
ENGINEhFfING
daylighteng.com
PPI Office and Welding
Stormwater Narrative
Existing Conditions:
The project site is located at 70 Zane Road in Midland, NC in Cabarrus County. The site is located on one of the lots
of the recently constructed Smith Industrial Subdivision. A web soil survey found soils on the to be made up of Tarrus
silt loam — Hydrologic Soil Group B, Herndon silt loam — Hydrologic Soil Group B, and Kirksey silt loam — Hydrologic
Soil group C. There is no existing on-site impervious area.
Proposed Improvements:
The proposed project consists of the construction of a 12,414 sf building with a parking lot and large gravel lot. The
lot will be curbed and the gravel lot will be enclosed with fencing. A sidewalk is proposed along the driveway and
building frontage. Handicap parking, bicycle parking, and a dumpster enclosure is located on site. The building will
be served by an off-site septic system.
Stormwater Treatment:
To provide treatment and attenuation for the site, a sand filter stormwater control measure (SCM) is proposed.
Stormwater will be collected by storm drainage systems that will convey drainage into the sand filter to be treated.
For this project, we are treating the first inch of rainfall and attenuating the 1-year and the 10-year storm for post
construction runoff per Phase II State Stormwater Permitting.
The required treatment volume was calculated using the discrete NRCS Curve Number Method for Runoff Depth.
We are treating and attenuating almost all onsite impervious area. The area that is not being treated is the front of
the driveway, as it slopes back towards Zane Road and cannot be caught and routed into the pond.