Third Herring Brook

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, and the Towns of Norwell and Hanover. With additional financial support from USDA, Massachusetts Environmental Trust, NOAA Fisheries, Trout Unlimited and the Conservation Law Foundation.

Third Herring Brook Restoration Map

Dam Removal

There are four dams on the Third Herring Brook that fragment the river, prevent fish migration, and degrade 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 is the first dam on the Third Herring Brook, one mile upstream from the North River, and is owned by Cardinal Cushing Centers. 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.


Tack Factory dam in 2013
Tack Factory dam in 2013

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 in 2015 will include continuation of vegetation monitoring in the former impoundment, including monitoring of invasive purple loosestrife (Lythrum salicaria). We will also be raising and releasing Galerucella sp. beetles, which feed specifically on purple loosestrife.

Petersons Pond Dam and Jacobs Pond Dam

Peterson’s Pond Dam, is 3.7 miles upstream of Tack Factory Dam and owned by the Hanover Mall, who have participated in initial discussions about restoration after the downstream dams have been removed. The fourth obstruction 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. This road is slated for future improvements by the Massachusetts Highway Department, and fish passage will be incorporated into that plan.

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 volunteer RIFLS program (you can volunteer too!). In 2015 the Town of Norwell (in partnership with the Town of Hanover, NSRWA, and MassBays) will receive 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.