The Blackstone Town Hall site is located adjacent to Blackstone River, which flows through the Southwest portion of the town. Originally the south parish of Mendon, MA, Blackstone was incorporated as a town in 1845. Historically, several manufacturing establishments were situated on the Mill and Blackstone rivers. Today, however, the Town Hall site is mostly surrounded by residential neighborhoods with single family homes.
The majority of stormwater runoff from the Town Hall parking lot and adjoining streets was discharged untreated, to either a wetland stream adjacent to the property, or directly into the Blackstone River. As a result, the Blackstone River is currently classified as a Category 5 impaired water body on the Massachusetts 303(d) List of Impaired Waterways.
The Town Hall site is located on St. Paul Street, where it bridges over the Blackstone River and provides access to Roosevelt Park. Given the configuration of the site, the parking lot and adjacent areas experience frequent flooding and contribute polluted stormwater runoff to the wetland stream adjacent to the park. In addition to addressing flooding and stormwater management issues, the Town selected the site for the project to serve as a model for neighboring municipalities and to help educate the public on the practice of stormwater retrofits.
The design team proposed several Low Impact Development (LID) strategies for retrofitting the Town Hall site in an effort to resolve flooding issues, treat stormwater runoff and recharge groundwater. The design also included an underground rain water harvesting system that could provide irrigation to the recreational fields, in order to minimize the use of potable water.
Strategies presented to the Town included porous pavement, bioretention areas and a rainwater harvesting tank. Of these, the Town implemented bioretention areas to treat the parking lot runoff.