Dam removal on Third Herring Brook

What is it going to take to restore our watersheds and their fisheries? We can get a sense of what will be needed when we view the effort put into removing just two relic dams on Third Herring Brook, a tributary of the North River, a tidal river that flows thirteen miles inland from its mouth at the town of Scituate on the South Shore of Massachusetts.

Beginning during the colonial era, more than 300 years of dam building placed about 65 dams into the North and South River watershed. Actually, there were more, but some, over decades, have been taken down by floods. Often these dams were only partially removed by nature, and even though they are no longer counted as dams, they still impound water and block fish passage. Of the remaining dams in the North South Rivers system, only one to date has been removed through human effort – the Mill Pond Dam on Third Herring Brook. And despite the fact that this ancient rock walled dam was classified, over10 years ago, as a “high hazard dam” by the Mass. Office of Dam Safety, and that its owners, the Hanover YMCA, wanted it removed, people successfully argued to keep the dam and its “pond” in place.

That was 10 years ago, when the Massachusetts Riverways Program (now the Department of Ecological Restoration), the YMCA, and the North and South Rivers Watershed Association, received funding from American Rivers to remove the dam, and actually had permits from the Hanover Conservation Commission for the removal. Because Third Herring Brook forms the boundary between the towns of Hanover and Norwell, permits had to come from both towns before work could begin. And Norwell, apparently succumbing to public pressure, denied the permit request to remove a high hazard dam that was a huge liability to its owner – a dam that for hundreds of years had blocked fish passage, disrupted sediment transport and heated the water in summer – because a few people in Norwell wanted “their pond”.

It was only after a flood managed to partially breach the Mill Pond Dam, resulting in a significant reduction in the size of the impoundment, that the dam removal process was renewed. Now the choices were clear: to restore the “pond” and the dam would cost well over a million dollars. The less expensive, and more ecologically sound action, was to restore a more natural channel for Third Herring Brook. This time permits came from both towns, and with $160,000 in grants acquired by NSRWA staff, and YMCA funds, the Hanover YMCA was able to remove a section of the Mill Pond Dam and restore a channel for Third Herring Brook.


Third Herring Brook at Mill Pond Dam

Not far down stream of Mill Pond Dam is the Tack Factory Dam. Tack Factory is the first dam of the Third Herring Brook system, and it blocks fish passage – now that Mill Pond Dam has been addressed – to about 10 miles of Third Herring and its coldwater tributaries. Smelt, native brook trout, herring eels and sea lamprey have all been denied passage up or down Third Herring Brook for over a hundred years by this relic dam that spans the brook just above head of tide.

Tack Factory Dam in late summer

Spillway at Tack Factory Dam in summer

The owners of Tack Factory Dam, The Cardinal Cushing Center, want to remove the dam and return natural stream function and fish passage to Third Herring Brook. To do this, they have partnered with the NSRWA, Trout Unlimited, NOAA, the Division of Ecological Restoration, Mass. Environmental Trust, and the Sea-Run Brook Trout Coalition. They have now arrived at the point where engineering plans are near completion and permitting can begin. But once more, a few pond abutters living on the Norwell side of Third Herring Brook want to maintain “their pond”, and some have publicly stated that they do not care about the ecological damage that the dam has been doing to the stream for the past 100 plus years. A couple of the “pond” advocates have declared that they expect Cardinal Cushing Center, a non profit charity serving children with disabilities, to pay for the repair of the dam and placement of a fish ladder at an estimated cost of $1 million dollars. And none of the abutters, who want the “pond” to remain in place, are willing to assume the costs and liabilities associated with repairing and maintaining the Tack Factory Dam. One even threatened to sue.

If removing the remaining dysfunctional dams that choke our watersheds is going to take as much time and effort as these two small dams are taking, we have a serious problem. Climate change, collapsing marine fisheries and diminishing water quality will not wait for a prolonged and needlessly expensive process that is stalled further by petulant self interest at each crumbling dam. What is needed is a watershed approach to dam removal and the restoration of our rivers and their fisheries. To do this legislation needs to be passed and public policy needs to be developed that focuses on restoring the function and connectivity of our rivers. If the climate change predictions are true (the outlook appears more grim with each passing day), the coming generations – our grandchildren – will be facing enough problems over the course of this century, much of it unfortunately, a direct result of our excessive reliance on fossil fuels.

Unlike the amount of carbon that has already built up in the atmosphere, dams are a problem that we can begin to successfully address now. With the removal of Mill Pond Dam there are 64 dams remaining in the North and South River watershed. Most of them have no purpose. They long ago killed off the salmon, along with much of the brook trout, smelt, herring, striped bass and eels that the watershed once supported, with the result that the marine food base has been compromised. The problem of our disconnected, dysfunctional river systems is one that we can fix, and need to fix if our society is to survive the changes to our planet that now appear to be underway. For the North and South Rivers, we hope that Mill Pond Dam is just one dam down with many more to come.

Brook Trout from Third Herring Tributary

       A native brook trout from a Third Herring Brook tributary

Warren Winders 10/31/14