Around 50 people showed up Saturday morning to hear about a proposal to remove the Watertown Dam, and restore the area to how it was before the first dam was put there in the 1600s.
The Charles River Watershed Association organized the tour, and the group is advocating for the dam to be removed to allow more fish and wildlife to travel up and down the Charles River, and also because it poses a risk of failure in a major storm, said CRWA Executive Director Emily Norton.
The first dam in the area of the current Watertown Dam was a grist mill built in 1634 by early colonists. A dam replacing the original one was built in 1814, which included a fishway to allow fish to migrate upstream to spawn. The current dam was built in 1955 after the older one was damaged by Hurricane Diane, and the current fish ladder was built in 1972, according to the Historical Society of Watertown. There were natural falls in the area prior to the first dam.
While the fish ladder, which is inside a concrete box on the south side of the dam, allows for some species to get upstream, other species of fish and other animals struggle or cannot get up the ladder, said Ben Gahagan, a diadromous fish biologist with the Massachusetts Division of Marine Fisheries.
Gahagan studied the types of fish going up the ladder using a camera put inside the fish ladder, and by tagging fish and seeing if they make it up stream.
“We observed 100s of herring (going up the fish ladder) and only 30 to 40 shad, and not the fat females,” Gahagan said.
He was asked whether putting in a better fish ladder would take care of the problem of fish spawning, but Gahagan said that with the best ones, “high 80s percent is the best case,” for species that can traverse the ladder. Some fish will try to come up the other side of the river, and do not make it. Other species of fish, such as smelt, cannot go up the fish ladder, nor can turtles and salamanders, Gahagan said.
Some on the tour said the pool of water behind the dam provides an area for birds and animals to live all year, because it rarely freezes over. They worried this would be lost.
The Watertown Dam has been classified as a Significant Hazard for failure, according to the Town of Watertown’s draft Hazard Mitigation Plan. This means a failure “may cause loss of life and damage to home(s), industrial or commercial facilities, secondary highway(s) or railroad(s), or cause the interruption of the use or service of relatively important facilities.”
While the main part of the dam is made of concrete, a portion along the south shore of the river near the fish ladder is made of earth. That area could be vulnerable during a major storm, with water washing over it, and potentially causing a failure, Norton said.
If the dam breached, the mitigation plan said, water could impact the Galen Street Bridge, and shut down roads along the river, such as the main Watertown Square intersection, Charles River Road and Nonantum Road. Facilities parks would have to be evacuated, including the Charles River Greenway with the Braille Trail, the Watertown and Newton yacht clubs, Daly Rink and Daly Field, and the Community Rowing boat house.
According to a CWRA feasibility study, “Watertown Dam has no functional purpose at this time. Although it could theoretically be used to supplement flood control measures downstream, the relatively small storage volume and lack of historical need make this use unnecessary.”
Many on the tour said they like the falls created by the Watertown Dam, and enjoy seeing the wildlife, including the large herons and other birds that gather to eat the fish.
Others were concerned about the sediment that has settled behind the dam because some of it is from the days when the Charles River was heavily industrialized by mills along the shore. If the dam is removed, the sediment would be tested, and pollutants would be dug out and trucked out to a disposal facility, a representative from the CWRA said.
If the dam is removed, the river would return to free flowing stream, said Robert Kearns, Climate Resilience Specialist with the CWRA.
“There is a natural change of elevation,” Kearns said. “You will still have water gurgling over rocks. It will not be the same but it will still be pretty.”
People on the tour requested that a graphic representation be made to show what the river would look like if the dam was removed.
Norton pointed to an example of a similar project in Exeter, N.H., where the Great Dam was removed.
While the CWRA has been calling for the removal of the dam, they do not have control of the property. The Watertown Dam is owned by the Massachusetts Department of Conservation and Recreation (DCR).
Residents on the tour asked why the project should be done now. Norton said that she is hopeful the project could get some of the money earmarked for water infrastructure and climate resiliency from the federal ARPA (American Rescue Plan Act). She said the last time there were recovery funds after the economic downturn of the late 2000s, the projects that got approval were the ones that had solid plans in place.
The tour was just the start of the process, Norton said. More community meetings will be held, and opportunities to give feedback.