This post is authored by the Charles River Watershed Association (CRWA). The analysis and opinions in the post are those of the CRWA. Senator Brownsberger shares it for discussion without endorsing the analysis and opinions.
Along the Charles River Greenway, near the bustling Watertown Square and Galen Street Bridge, you will find a site of rushing water over a concrete structure. Many know this site to be the spillway of the Department of Conservation and Recreation (DCR)’s Watertown Dam. Watertown Dam is an aging, 180-ft long, 8-ft high concrete weir structure located in the Charles River in Watertown, MA. Previous dam structures at the site were originally built to power industry of the 1800s and the current dam now serves no purpose, whether it be for power, water supply or flood control. Instead, it is a barrier to a free-flowing Charles River, impeding migratory fish passage, destroying the river ecosystem, and harming climate resilience.
The current dam is a “significant hazard potential” structure in fair condition. If it were to fail during a severe storm, flooding may put downstream areas in Brighton, Newton and Watertown “at risk of loss of life, damage to property and critical infrastructure, and large-scale economic disruption,” according to the Watertown Dam Removal Feasibility Study . Removing the spillway will eliminate any chance of catastrophic dam failure.
This is becoming more significant with stronger storms and increased rainfall occurring more frequently as a result of a changing climate.
The feasibility study also found that if the dam were to be removed, there would be no changes in flooding downstream. Additionally, flood elevations would be reduced by six feet as far as half a mile upstream of the dam.
On the ecological and ethical side, dam removal has the potential to welcome migratory fish populations back to an additional forty miles of the Charles River ecosystem, restoring life to our river and healing historic wrongs. Kristen Wyman from the Natick Nipmuc Indian Council spoke about the significance of the potentially removing the Charles River Dam in Natick as a member of the Town of Natick Charles River Dam Advisory Committee:
“Who would have ever thought, my ancestors, that I’d be speaking here a couple of hundred years later about the potential removal of one of those dams. I am encouraging us to think long-term about the possibility of that fish being revived because we do not give up that hope as Indigenous people, we will never give up that hope. We know that all things are possible.”
– Kristen Wyman, Nipmuc leader and member of Natick Nipmuc Tribal Council, Charles River Dam Advisory Committee Meeting on November 9, 2021.
Every spring, migrating alewife, American eel, American shad, blueback herring and rainbow smelt migrate through the Charles River into Watertown. While some Alewife and blueback herring can pass the fish ladder on the Watertown Dam, many fish cannot pass through. The fish ladder is on the shallower side of the river and very few fish stray from the deep water, where the water is colder. Thus, many fish never even find the ladder and cannot proceed past Watertown.
A study by the Massachusetts Division of Marine Fisheries and the U.S. Fish and Wildlife Service has found that the female American shad are unable to climb the ladder at Watertown Dam. Removing the dam would allow free passage for the fish unable to climb ladders.
Removal would also eliminate the congregation of fish trying to get up the ladder and decrease the subsequent instances of predation and poaching.
Not only is the dam bad for fish passage, it degrades the quality of the water in the Charles River in the impoundment, or ponded, section of the river upstream of the dam.
Because the water is slowed down, water temperatures increase and dissolved oxygen levels decrease – bad for fish and other aquatic wildlife. These conditions can also lead to increases in potentially harmful algae or cyanobacteria outbreaks in the river, which can be a danger to folks on the water and dogs who may go into the water.
Additionally, the benthic, or bottom, habitat in the impoundment stretch of river would improve after dam removal, making it better suited for macroinvertebrate bugs that fish feed on and a better habitat for the fish species to move and thrive.
In June 2021, the Massachusetts Division of Ecological Restoration (DER) released the final draft of the Watertown Dam Removal Feasibility Study. The report confirms removing Watertown Dam is indeed feasible.
With the bipartisan infrastructure law in place, federal funding from agencies such as the National Oceanic and Atmospheric Administration (NOAA), U.S. Fish and Wildlife Service, Army Corps of Engineers, US Department of Transportation, and more, are being made available for dam removal and restoration projects like the Watertown Dam. The migratory fish make this project competitive for funding, especially from NOAA.
Speaking of costs, because this dam is owned by DCR, taxpayers are on the hook for ongoing inspection and maintenance of the dam structure. Removal would be a one time cost with all of the environmental benefits and eliminate any ongoing maintenance for a structure which is not currently serving a purpose.
In conclusion, removal of the Watertown Dam offers the opportunity to improve habitat, transform water quality, restore native plants, improve recreational paddling passage, and remediate contaminated sediment, increase climate resilience for future extreme weather events, and protect downstream areas from future flooding.