SW5200201_SW Narrative_20200213

Shipman Engineering, PLLC
Town of Benson Lee Street Athletic Complex
Stormwater Design Narrative
Project Overview
The Lee Street Athletic Complex Improvements Project is a Town of Benson funded development project
to expand and improve the existing Dr. PK Vyas Park located at near the intersections of Lee Street, Elm
Street, and Mann Street in the downtown area of the Town of Benson.
Currently, the park features two baseball fields, as well as an existing parking lot, play equipment, and
miscellaneous recreation league athletic equipment and facilities. Our proposal is to expand the park to
convert some existing green space into two additional baseball fields, as well as the addition of a new
field house, additional on -street parking, and conversion of existing green space into a multi -use field as
shown on the drawings. Associated infrastructure such as sidewalks, dugouts, and other features will be
constructed as well.
Stormwater Management Strategy
The existing site is currently extremely low density, with an existing impervious percentage of 6.27%
within the project limits. With the addition of proposed impervious areas associated with the site
improvements, and additional 15,360 square feet of impervious will be added, bringing the overall total
to 8.77% impervious.
From a Nitrogen Export perspective, calculations yield a new export of 2.95 Ibs/ac/year, which is below
the 3.6 Ibs/ac/yr threshold required for treatment/buydown.
The impervious calculations, nitrogen calculations, and project area/drainage basin breakdowns can be
found on sheet C-15 of the construction drawings. Based on the calculation results, we conclude that no
active stormwater management for peak flow attenuation, water quality volume, or nitrogen removal is
required for the project.
Shipman Engineering, PLLC 919.900.0006
137 Middlegreen Place [e-mail]
Holly Springs, NC 27540 NCBELS License P-1963