The intersection of East Walnut and North Plum streets in Lancaster, Pa., was prone to traffic accidents because of a dangerous merge lane where drivers had decreased visibility. The intersection also was prone to flooding during rainstorms, which flowed into the combined sewer system and then into waterways during high-volume periods.
The city of Lancaster was under increasing pressure from the U.S. Environmental Protection Agency to reduce raw sewage overflow, and needed to find a way to reduce runoff and pollution that led into the Chesapeake Bay. The original solution of building and installing larger tanks to store and release storm water at much lower volumes was the first proposed solution, but proved to be cost-prohibitive.
Designers needed to juggle a number of project challenges simultaneously, traffic safety and storm water treatment being the top priorities. The eventual solution combined green infrastructure and road realignment to improve storm water runoff and roadway conditions.
A rain garden was installed to capture and absorb rainwater that would have gone into the city’s overburdened sewer system. The rainwater is directed into a large cistern and is used to irrigate a nearby vegetable garden. A large outdoor patio near the intersection made of permeable material captures storm water from the roof of Lancaster Brewing Co.
The entire project manages and redirects 1.7 million gal of storm water annually, keeping it out of the city’s sewer system. Since its completion in March 2013, the project has won a “BUBBA” (Best Urban BMP in the Bay Award), which recognizes the best urban BMPs installed in the Chesapeake Bay watershed.