The Third Herring Brook Restoration Project focuses on improving the continuity of the Third Herring Brook, which flows into the North River and forms the border between Norwell and Hanover.  The NSRWA has been working for over a decade to restore the Third Herring Brook to a natural, free-flowing state, which will provide proven, scientifically-based benefits to the riverine ecology. It will also reduce liability and ongoing costs to dam owners on the Third Herring Brook. Our approach primarily focuses on dam removal, with a secondary focus on flow and water quantity. Our goal is to restore fish passage for river herring and eastern brook trout as well as improve the habitat in the system.

Partnering for Restoration – The restoration of Third Herring Brook was awarded Priority Project status by the MA Division of Ecological Restoration (MassDER) in 2012. Other important partners to restoring Third Herring Brook include the Mass Bays South Shore Program, Cardinal Cushing Centers, South Shore YMCA, Prep/Hanover Mall and the Towns of Norwell and Hanover, With additional financial support from USDA, Massachusetts Environmental Trust, NOAA Fisheries, US Fish and Wildlife Service, Trout Unlimited, Sea Run Brook Trout Coalition and the Conservation Law Foundation.


Dam Removal

There were originally four dams on the Third Herring Brook that fragmented the river, prevented fish migration, and degraded river habitat. Completing the Third Herring Brook restoration to its headwaters at Jacobs Pond would result in 4 miles of stream opened (9.7 miles including tributaries) and access to 59 acres of spawning habitat. Read more about why we should consider dam removal for restoring our rivers.

Tack Factory Dam

Tack Factory Dam was the first dam on the Third Herring Brook, one m

Tack Factory dam in 2013
Tack Factory dam in 2013

ile upstream from the North River, and was owned by Cardinal Cushing Centers. It was removed in 2017. There are 5.7 miles of tributary that enter the Third Herring Brook upstream of Tack Factory Dam, some of which are cold enough to support documented populations of wild brook trout. Read more.


Mill Pond Dam

Mill Pond Dam was the second obstruction on the Third Herring Brook, 2.4 miles from Tack Factory Dam and owned by the South Shore YMCA. It was removed in October of 2014, becoming the first dam removal in the North and South Rivers watershed.

Post-restoration work at Mill Pond Dam included continuation of vegetation monitoring in the former impoundment and monitoring of invasive purple loosestrife (Lythrum salicaria). We raised and released Galerucella sp. beetles, which feed specifically on purple loosestrife, as a management technique.

Petersons Pond Dam 

Peterson’s Pond Dam was 3.7 miles upstream of Tack Factory Dam and owned by the Hanover Mall. It was removed in Fall 2020, opening 1.3 miles of stream and completing the dam removals on the Third Herring Brook.

Peterson Pond Dam
Peterson Pond Dam prior to removal, 2020

Jacobs Pond Dam

The fourth obstruction on the brook is Jacob’s Pond Dam, owned by the town of Norwell with a culvert under a state-maintained road. We are working with the Town of Norwell on plans to provide fish passage into the 59-acre Jacob’s Pond.

Flow and Water Quantity

Since 2008 we have been monitoring flow at three locations in the Third Herring Brook in partnership with MassDER through their RIFLS program. In 2015 the Town of Norwell (in partnership with the Town of Hanover, NSRWA, and MassBays) received funding from the state Sustainable Water Management Initiative grant program  to model instream flows and municipal demand in the Third Herring Brook watershed, similar to what was done in our First Herring Brook Restoration Project.