The Third Herring Brook is a 5 miles tributary to the North River that forms the town border between Norwell and Hanover. Historically, like almost every coastal stream in our area, this brook supported a large population of river herring – hence the name!  The Third Herring Brook Restoration Project focuses on improving the continuity and streamflow of the Third Herring Brook. Our goal is to restore fish passage for river herring and Eastern brook trout by removing the 3 of the 4 dams on the stream and then putting a fish ladder under Rt 123 for fish to access Jacobs Pond.  Completing the Third Herring Brook restoration to its headwaters at Jacobs Pond would result in 5 miles of the mainstem opened (9.7 miles including tributaries) and access to 62 acres of spawning habitat at Jacobs Pond.

Map of Third Herring Brook Restoration Project

There were four dams on the Third Herring Brook that fragmented the river, prevented fish migration, and degraded river habitat.  Mill Pond Dam, owned by the South Shore YMCA was the first dam we removed on the Third Herring Brook in October of 2014. Downstream, the Tack Factory Dam, owned by the Cardinal Cushing Centers, was removed in late 2016/early 2017. In November of 2020, the Peterson Pond dam, owned by the Hanover Mall was removed. This was the last dam to be removed on this brook, resulting in the opening up 5 miles of mainstem and 9.7 miles with tributaries.  The removal of the 3 dams on this brook has led to the return of Eastern Native Brook Trout using the mainstem and the brook being classified as a Coldwater Fish Resource by the Commonwealth of Massachusetts providing additional protection. In addition, our river herring count volunteers have observed increasing numbers of river herring passing the former site of the Tack Factory dam, as they expand their range further upstream!

Further information regarding each dam that has been removed is described in these fact sheets about each dam removal.

Last Barriers on Third Herring Brook Removed
In 2022.  two concrete weirs were removed in the Third Herring Brook adjacent to the Hanover Crossing mall, the last barriers to fish passage in the brook downstream of Jacobs Pond. Boulders were also placed at the base of a bedrock outcropping in the stream to improve fish passage. The weirs and bedrock were not impediments as significant as the dams removed in the brook, but they still caused drops in the stream that would not be passable in lower flows. Now that this project is complete, the next and last phase of the Third Herring Brook Restoration will be the installation of a fish ladder at Jacobs Pond. We would like to thank our project partners at Hanover Crossing. This project was made possible with funding from the Massachusetts Department of Fish and Game and the Division of Ecological Restoration. Technical assistance was provided by the MassBays National Estuary Partnership and the NOAA Restoration Center. For more details on the history of these weirs, you can read an article from July, 2022.
Watch a video of the downstream weir being removed (1:01)
Watch a video of the upstream weir being removed (1:48) 3 Dams Removed, ~10 miles of Stream Habitat Reconnected

Tack Factory Dam before removal in 2017

Future Fish Passage Restoration to Jacobs Pond

The last impediment to fish passage on the brook is Jacob’s Pond Dam, 1.3 miles from Peterson’s Pond Dam, owned by the town of Norwell with a culvert under a state-maintained road – Route 123. We hope to start work at this site with Norwell and Mass Highway on fish passage in the near future!





Where’s the Water?

Third Herring Brook during the 2016 drought upstream of Hanover and Norwell wells

You can’t restore a river without water and in the Third Herring Brook human water demand is decreasing streamflows. Since 2008 streamflow has been monitored at three locations on the Third Herring Brook in partnership with MassDER through their volunteer RIFLS program (you can volunteer too!). The Third Herring Brook watershed supplies the drinking water wells in the towns of Hanover and Norwell.  These water supplies, particularly in the summertime, reduce streamflows in the Third Herring Brook, when water withdrawals in both towns increases substantially due to lawn irrigation. Both towns participate in our WaterSmart regional water conservation program and we continue to work with the communities to implement strategies that will reduce their summertime demand.

Partnering for Restoration – The restoration of Third Herring Brook is truly a group effort! Important partners include the MA Division of Ecological Restoration (MassDER), NOAA Fisheries Restoration Center,  Mass Bays South Shore Program, Cardinal Cushing Centers, South Shore YMCA, the Hanover Mall (PREP) and the Towns of Norwell and Hanover.

With additional financial support from USDA, USFWS, Massachusetts Environmental Trust, The Sheehan Family Foundation, Trout Unlimited, Sea Run Brook Trout Coalition, Sylvester Foundation, the Conservation Law Foundation and many private donors and members!

Read more about the power of partnerships here.