Hendrick Auto Mall Stormwater Management
Hendrick Automotive Group is one of the nation’s most successful automotive dealership groups, with dealerships located throughout the southeast and around the country. EMH&T has been partnering with Hendrick for more than a decade to develop new dealership sites and re-develop older sites; our history with this client is that we are capable of overcoming significant challenges related to zoning, building standards and regulatory compliance to deliver the site development results they are seeking. In particular, the stormwater management regulations in communities within North and South Carolina where Hendrick has developed numerous sites, are some of the more aggressive in the country, with strict requirements regarding the use of best management practices (BMP) to control both construction phase and post-construction water quality. An example of our ability to meet or exceed these standards is the dealer’s Automall project in Concord, North Carolina, where EMH&T designed a stormwater management facility to meet strict local and state-wide criteria which require 85% total suspended solids (TSS) reduction as well as nutrient load reduction associated with the target rainfall event. The site had several storm system outfalls that had to be accounted for in the hydrologic model which predicted flow rates under existing and proposed conditions, and was used to evaluate alternatives for stormwater detention. Considering the maintenance requirements of various stormwater best management practices (BMP) and the intended use of the site, the final site design included two dry detention basins, a wet detention basin, a surface sand filter, and an underground vault with an integrated water quality system. The project involved extensive coordination with the City’s engineering department throughout the design process to ensure our recommendations would be accepted as part of the final plan approval process.