Mar. 8—HAVERHILL — You may have driven past it many times without ever noticing. It's easy to miss.
But if you pause and look as you enter Lafayette Square from Winter Street, you'll see a small dam controlling the flow of Little River. The dam, which looks like a small waterfall, is just north of where Winter Street crosses over the river, and well below the sight line of drivers.
The dam has been there since the early 1800s when it powered the Stevens Mill at Winter and Stevens streets, but now the city is considering demolishing the dam for several reasons. They include preventing future flooding upriver along Apple Street and Little River Street, both of which are in the Acre neighborhood, and creating the possibility of the vacant Stevens Mill building being redeveloped into housing.
In recent years, developers have converted many former factories to apartments and condos in the downtown. Redeveloping the Stevens Mill building would extend that trend outside the downtown.
City officials say the sale of the Stevens Mill property to a developer has been hindered in part by liability associated with dam ownership.
Little River originates in Kingston, New Hampshire, and flows over the dam, through a tunnel that passes under the downtown, emptying into the Merrimack River.
The dam slows the flow of water in the area, creating an upstream pond-like backup. That backup ensures there is typically enough water approaching the dam to allow for a steady flow past it and into the tunnel under downtown.
City officials said they are eyeing removal of the dam as a way to prevent future flooding from heavier rainfall and rising temperatures expected to result from climate change. The increased rainfall and higher temperatures are predicted to melt snow and ice upriver at a faster pace, maintaining a steady flow of water toward the downtown tunnel and eliminating the need for the dam.
Any aesthetic value provided by the brown water currently cascading over the dam would be replaced by a more pleasant, greenish, smooth flow resulting from removal of the dam, officials said.
Haverhill has received two grants — one for $70,000 and the other for $130,000 — to assess the potential impact of climate change and what the city can do to prepare for it. The city partnered with Fuss and O'Neill, a state-certified firm, to do a climate change assessment and develop a list of things that can improve the situation. A study will examine the potential impacts of removing the dam and the uninterrupted flow of water that would result.
City officials said benefits of removing the dam include better public access to the river, fish more easily passing through the area, the addition of green spaces and recreational areas for the public, reduced risks of flooding in the Acre neighborhood, and possible redevelopment of the Stevens Mill property.
Officials said the dam is in poor condition and hurtful to the environment, and that its removal would improve water quality by eliminating stagnant water, thereby helping wildlife.
Removal of the dam would also eliminate potential flooding, which could damage the Winter Street bridge, the nearby railroad bridge, the river tunnel running under downtown, and a wall at the neighboring Haffner's gas station site, officials said. A study shows the gas station and three other chemically hazardous sites near the dam could be impacted in the event of major flooding, officials said. They said removing the dam and allowing an uninterrupted flow of water would reduce the chance that flooding will impact those sites.
The public is invited to comment on the future of the dam during an online forum to be held in English and Spanish on March 24 at 6 p.m.
Visit https://cms3.revize.com/revize/haverhillma to find a registration link that will be posted several days before the forum.