SW1230501_Stormwater Narrative_20230612

NARRATIVE

STORM WATER/DETENTION
(STORMTECH CHAMBER SYSTEMS)

VERNER

550 North Louisiana Avenue
Asheville, NC 28806

This project is located at 550 North Louisiana Avenue in West Asheville on
the site of the Emma Elementary School. The parcel pin number is 9639-22-3201
and the total parcel area is approximately 13.71 total acres of which 6.12 acres are
the project area. The subject project generally consists of the construction of a new
childcare building and parking facilities. Total land disturbance for the project is
3.94 acres. The work includes clearing, grubbing, grading, and installation of
water, sewer, and storm drainage utilities.

Storm water facilities include curb inlets, drop inlets, junction boxes, and
connecting piping. These facilities have been designed for the 25-year storm event.
Storm water detention is provided utilizing two (2) StormTech below-ground
detention facilities with outlet structures with orifice and weirs capable of
controlling the post-construction runoff for the 10-year, and 25-year storm events
by reducing the rate of runoff to the pre-construction rates. Water quality is
provided utilizing the detention basins for storage to control the runoff from the 1-
inch rainfall event with a restricted orifice that will detain the runoff for an
extended period.

A summary of the pre-construction, post-construction, and detained flows
for the regulated design storms is attached.