SW6220905_Stormwater Narrative_20220929

Hayes Pointe
Harnett County, NC
Storm Water Narrative
7/13/22
The objective of this project is to construct the infrastructure for a single-family
residential development and utilize a proposed wet detention pond, and moderately high to
high infiltration rates of the existing soil, to treat the storm water runoff from the project.
Although the overall project's impervious area does not exceed the 24% threshold for high
density projects, it is our understanding that the general statues require the project to be
defined as high density anytime a significant amount of storm water piping conveys storm
water along the roadway of the project; as opposed to conveying the runoff from one side of
the road to the other. As such, this project is being submitted as a high -density project and is
being treated as such.
Storm water runoff from the site will be conveyed to the wet detention pond. The
outlet of the wet pond will have a min. 50' vegetated filter beyond the rip rap outlet apron and
could be increased as necessary. The outlet Swale is designed with near 0% grade in order to
slow the release of the storm water runoff and allow it to infiltrate as much as possible into the
existing soils prior to discharge for an added level of treatment.
The wet pond has been designed in accordance with NCDEQ DEMLR BMP manual
requirements for the 1 year 24 hour storm and up to the 100 year storm. Based upon the size
of the wet pond, it is unlikely that any storm will overtop the pond dam.
• K' I
HILLIARD
v
ENGINEERING
3417 Winterwind Circle 7/13/22
Sanford, NC 27330
NC License No. P-0836
[phone]