Dam removal eyed to make way for herring in Neponset

Jeff Mucciarone

The state has been studying the feasibility of removing two dams and chemical contamination from the Neponset River in an effort to restore shad and herring runs, along with unimpeded boating and other recreational opportunities to a 17-mile section of the river from Walpole to the ocean.

The Massachusetts Riverways Program and Division of Marine Fisheries had initially planned to present findings last monthbut were forced to move their presentation back due to weather. The state will make its presentation Jan. 9 at 7 p.m. at St. Gregory School’s auditorium at 2214 Dorchester Avenue in Dorchester.

Two state-owned dams located on the border between Milton, Hyde Park and Dorchester have long blocked the river. Several sites along the river contain river-bottom sediments that are heavily contaminated with toxic polychlorinated biphenyls or PCBs, which were discovered during the course of the state’s study.

“Cleaning up the PCBs in the lower Neponset and removing the dams are critical next steps in a 40-year effort to make the Neponset and its tributaries the environmental and recreational jewels that our communities deserve,” stated Ian Cooke, Executive Director of the Neponset River Watershed Association, in December.

The Neponset River Watershed Association, a nonprofit organization dedicated to cleaning up the Neponset River, is encouraging members of all eight affected towns to attend the meeting to learn about the project and provide feedback. The meeting kicks off a public participation process the association hopes will lead to a decision by the state on how to proceed within the next three to six months. The affected towns include Canton, Walpole, Norwood, Westwood, Dedham, Milton, Quincy, Dorchester, Mattapan and Hyde Park.

United States Geological Survey (USGS) scientist Rob Breault will present his findings on PCB contamination in the Neponset River water and in river-bottom sediments. Jim MacBroom of Milone and MacBroom will also discuss findings on the various options for river restoration and PCB cleanup.

Both the Baker and the Tileston & Hollingsworth Dams are reaching the end of their design lives and thus must either be rebuilt or removed. Decommissioning the dams would restore a natural, free-flowing Neponset River, and herring, shad and other fish species would be able to return to sections of the river as far inland as Walpole, according to press materials provided by the watershed association.

Before the dams can be removed, river-bottom sediments must be cleaned up in Milton, Dorchester, Mattapan and Hyde Park, as they are heavily contaminated with PCBs, which is a toxic industrial chemical now banned in the United States. The cleanup is expected to cost $7 million to $9 million, according to the Milone & MacBroom reports.

Removing the two dams at the same time that sediment remediation occurs, would cost taxpayers an additional $500,000, while rebuilding, operating and maintaining the dams for the next 30 years could cost more than $7 million, according to press materials.

The benefits of the Neponset River restoration project would include restoring the ecology of the river, boosting sport and commercial fisheries, making it possible to canoe uninterruptedly from Walpole to the sea, protecting public health from toxic contaminants and reducing flooding in Lower Mills, according to the watershed association.

To RSVP for the event or to be notified about future public meetings, contact the watershed association at (781) 575-0354 or email Carly Rocklen at the watershed association at The tentative snow date for the event is Wednesday, Jan. 16, at the same time and place. For finalized information about the snow date, visit