Interns discover 32 unmapped stormwater outfalls in Seekonk

Interns discover 32 unmapped stormwater outfalls in Seekonk

By Kate McPherson, Riverkeeper

Hundred Acre Cove is a small embayment in northern Narragansett Bay that has been closed to shellfishing for several decades due to high bacteria. In 2018, Save The Bay received grant funding through the Southeast New England Program to look at sources of pollution in the watershed in an effort to restore water quality in the Cove. While working with the town of Seekonk, one of the towns in Hundred Acre Cove’s watershed, the Department of Public Works revealed to me that their stormwater system, although well known to their own staff, was not mapped electronically.  As our Riverkeeper, I saw an opportunity for Save The Bay to gather needed data for not only the SNEP project, but also to assist the DPW in more effectively maintaining and testing water quality.

A catch basin in Seekonk, which catches flowing rain water.

This past July, Save The Bay brought together a team of intrepid interns to help create a complete map of the stormwater system. Interns Jacob Cytrynbaum and Shannon West worked to develop custom forms for a mobile app called ArcGIS Collector, a program that would allow us to take new data, including the size, material, condition, and location of an outfall pipe. The program also allows users to take photographs and add them to an existing GIS map. Two new interns, Kevin Bell from West Hartford and Kyle Gray of Warwick, were assigned to the task of driving every road in Seekonk to check for stormwater catch basins, and sleuth to find outfalls, only some of which were mapped. In early July, I trained the intern team to use the app to navigate, with one intern using the iPad and the other driving, and also to read the landscape and surface topography.  

Stormwater systems generally consist of a catch basin, or a grate in the pavement, where water from rain storms flows into. Typically, sand and debris will fall to the bottom of the basin, and pipes connect water from multiple basins in a network that runs under roadways. The network ultimately converges into an outfall: the last pipe where water flows into the watershed. The whole system is a gravity fed maze, sometimes with unexpected twists, turns, and inputs. Our intern team shined a flashlight inside the catch basins throughout Seekonk to see how many pipes were in there, and to “follow the flow” down stream to the outfall. 

‘Following the flow’ led interns to this stormwater outflow.

As part of the project Kevin and Kyle were asked to work independently as a pair, communicating with me as the project lead and with Dave Cabral, the DPW director in Seekonk who provided support. From July 23 to August 27, Kevin and Kyle visited 138 stormwater outfalls. The Town of Seekonk was previously aware of 135 outfalls in town, and knew that some of these were not on an electronic map. Overall, they found 32 previously unmapped outfalls in town, 20 of which were within the Hundred Acre Cove watershed.  In addition to finding unmapped outfalls, Kevin and Kyle took data indicating the condition of the outfall, whether the Department of Public Works needed to trim vegetation for access, and if immediate repairs or cleaning were needed. This information was very valuable to the town of Seekonk!

Kevin and Kyle not only took valuable data for our project and the Town, but represented Save The Bay in the community.  They had many opportunities to speak with folks about stormwater issues, including flooding and how stormwater impacts water quality in the river and wetlands in the watershed. The data our interns collected has already been used by the DPW to prioritize trimming overgrown easements, cleaning and repairing pipes within the system. I can only be so many places as our sole Riverkeeper, and I’m grateful for the interns and volunteers who help Save The Bay do meaningful work.  The Town of Seekonk was thrilled that this project allowed them to update information for all of their outfalls, and the DPW plans to begin testing priority outfalls for contaminants in the coming months.