SW3231101_Stormwater Narrative_20231102

PROJECT NARATIVE
The proposed project, "Aurora at Price Mill Creek" is a residential subdivision that is located in Wesley
Chapel, Union County, North Carolina. The site is located on the east and west side of Weddington Road
(NC Hwy. 84). The proposed main entrance will be located approximately 1,600 feet East from the
intersection of Underwood Road and Weddington Road. There will be one stream crossing to access the
rear of the property.
The project site is located in Zone X and Zone AE per FIRM Map for Union County, North Carolina— Map
Number 3710449600J, Effective Date: October 16, 2008. The existing site consists of woods and open
fields. Price Mill Creek bisects the property from north to south and runs along the western boundary.
The existing storm water runoff flows towards Price Mill Creek and has a 100-year floodplain associated
with it. There are no known flooding problems located either downstream or immediately adjacent to the
site.
The proposed site will be a single family residential subdivision consisting of 35 lots. There will be four(4)
paved streets and four (4) cul-de-sacs, valley curb, and concrete sidewalks. There will be a total of two
(2) Stormwater Control Measures; (1) dry detention with sand filter and (1)wet detention basin installed to
detain and treat storm water runoff from the proposed development as necessary. All runoff from every
house will be detained and treated within the SCM. The project will disturb approximately 40 acres.
On site erosion control measures will be provided throughout the construction phases. The erosion
control plan will have two (2) phases and two (2) stages. These erosion control measures include five (5)
skimmer type sediment basins that have been designed to meet the North Carolina Erosion and
Sediment Control Planning and Design Manual.
Conclusion
The proposed SCM's and associated control structures (risers) and outfall pipes have been designed to
meet the water quality requirements for:
• Treat the first 1 inch of rainfall to remove 85% TSS removal.
• Detention requirements for the 1-year, 24-hour storm event.
• Detention requirements for the 2-year, 24-hour storm event.
• Detention requirements for the 10-year, 24-hour storm event.
• Detention requirement for the 25-year, 24 hour storm event.
In conclusion, due to existing site conditions and proposed runoff control measures, the proposed project
is not anticipated to have negative impacts on downstream or adjacent properties.