MASHPAUG POND WATER QUALITY MONITORING

Much of the stormwater management work led by the Stormwater Innovation Center and the Providence Parks Department is focused right in Roger Williams Park. The park receives runoff from the surrounding neighborhoods and nearby streets during rain events.

​

Another major source of water entering the park’s pond system is Mashapaug Pond, located upstream. Water from Mashapaug flows into Roosevelt Lake.  Like Roger Williams Park, Mashapaug Pond struggles with water quality issues including excess nutrients, bacteria, high temperatures, low oxygen levels, and recurring cyanobacteria (blue-green algae) blooms.   The Treatment Train at the inflow to Roosevelt lake is designed to filter and treat some of this incoming polluted water, but ideally, the source water quality from Mashapaug Pond, also needs to be improved.

​

To address these challenges, the Rhode Island Department of Environmental Management (RIDEM) is introducing a new stormwater permit under its Residual Designation Authority. This Mashapaug General Permit will apply to properties in the watershed—including Mashapaug, Spectacle, and Tongue Ponds in Cranston and Providence, that aren’t currently regulated under existing permits. It will require properties with one acre or more of impervious surface (like rooftops and parking lots) to implement practices that reduce pollution and manage stormwater more effectively. The new permit will also require the most heavily paved properties to develop a Stormwater Management Plan (SWMP) to prevent runoff pollution from reaching local waterways.

​

To support this effort, the Stormwater Innovation Center, Providence Parks, and the EPA Narragansett Lab have deployed a real-time water quality monitoring buoy in Mashapaug Pond. This data will help track improvements over time as new stormwater projects are implemented through the City of Providence’s TMDL Implementation Plan and pollution from nearby commercial properties is reduced with the new RDA permit requirements.