SW6221007_Stormwater Narrative_20221102

Spout Springs Self Storage
And
Miracle Movers Warehouse
Storm Water Management Statement
Harnett County, NC
Owner/Developer: Miracle Movers,
1471 NC 24, Cameron, NC 28326
Consultant:
HILLIARD ENGINEERING
Contact: Jarrod E. Hilliard, PE, CFM
PO Box 249 Sanford, NC 27331
[phone]
NC License No. P-0836 Date: 10/13/22

A. Spout Springs Self Storage and Miracle Movers Warehouse, Mayer Road and NC 24,
Johnsonville, NC, Harnett County
B. Developer/Owner: Miracle Movers; Consultant: Hilliard Engineering, PLLC (contact
information on cover)
C. The existing project site is a mix of residential and commercial use
1. A vicinity map is included with this Statement
2. A USGS map is included with this Statement along with a Harnett County Soil Survey for
the project area
3. This project area does not contain any water impoundments or wetlands. Water from this
project flows into Barbeque Creek. The stream classification is as follows:
Stream Index: 18-20-13
Stream Name: Barbeque Creek
Description: From source to Upper Little River
Classification: C
Date of Class.: June 30, 1973
River Basin: Cape Fear
D. The site is not located within a conservation zoning nor a watershed district
E. Impervious Area Calculations:
Buildings: 192,485 sf
Asphalt Paving: 135,679 sf
Gravel Paving: 83,224 sf
Concrete Pad: 799 sf
Concrete Sidewalk: 2,702 sf
TOTAL IMPERVIOUS AREA: 414,889 sf
PROJECT AREA: 791,207 sf
IMPERVIOUS PERCENTAGE: 52.44 %
F. The project site is subject to Phase II Post Construction Storm Water regulations.
1. The project is subject to a high -density threshold of 24% impervious area.
2. A very small amount of off -site storm water affects this project and will be conveyed via
storm water piping to the storm water control measure to be treated.

3. Wet Pond:
Q10 pre: 15.90 cfs
Q10 post: 55.66 cfs
Q10 wet pond outflow: 10.98 cfs
Q25 pre: 17.58 cfs
Q25 post: 61.55 cfs
Q25 wet pond outflow: 12.04 cfs
G. Downstream Analysis, if required:
1. See drainage map within the storm water calculations for drainage areas
2. Significant increases in velocity and flooding are not anticipated from this project based
upon the use of the wet pond for mitigation; which is designed to contain the 100-year
storm and larger.
3. A driveway culvert extension is proposed for this project as show on the site plans.
4. The total drainage area in which proposed impervious area exists for this project is 12.93
acres. The point where the development becomes less than 10% of the total watershed is
at a point approximately 1,450 If downstream from the discharge point of the proposed
wet pond for this project
5. As long as erosion control measures are maintained prior to permanent stabilization, and
the wet pond is properly constructed and maintained, no adverse impacts are anticipated
from this project.
6. Detention is proposed for this project in the form of a wet pond.