Grange Insurance Headquarters Expansion
The incorporation of Green Infrastructure into urban sites has gained broader acceptance as a way to reduce stormwater runoff into nearby rivers and waterways. The Grange Insurance Headquarters expansion in urban Columbus, Ohio, is an excellent example of the connection between Green Infrastructure and an urban site. EMH&T provided civil/site engineering for this 10-story office expansion in the Brewery District of Columbus. To meet Ohio EPA and City water quality regulations, numerous atypical sustainable stormwater techniques were initiated, including: a complex hydraulically designed raised runnel system that channels roof rainwater into a rain garden, water storage for irrigation, three buried detention systems, and a planter/buried tank combination releasing captured stormwater into a public combined sewer system. With these systems in place, the development site is equipped to optimize post-construction water quality treatment for frequent rainfall events and also manage larger, infrequent storm events. The green infrastructure features designed for this development site reduced construction costs by 25% compared to a more traditional buried pipe system.