SOUTHWICK — When the scheduled public meeting hosted by the National Resources Conservation Service about Congamond Lakes’ water quality, which are considered polluted by state and federal standards, was cancelled last week after Town Hall was closed because of a plumbing problem, there was a discussion about holding it remotely or postponing it.
“I wanted to postpone it and reschedule it,” said Richard Grannells, the chair of the Lake Management Committee, whose committee has been managing the lake for decades, working to improve its water quality.
His position prevailed, and for a specific reason.
“We need to show them how important the lake is, not only for Southwick, but for the state,” Grannells said about the public meeting now scheduled for 6 p.m., Thursday, Jan. 29, in the Land Use Room at Town Hall.
The “them” Grannells was talking about was a technical review team comprised of representatives from the NRCS and the Pare Corporation who are coordinating an effort to prepare a Watershed Plan and Environmental Assessment for Congamond Lakes in the Great Brook Watershed for flood protection of the ponds.
Chief Administrative Officer Nicole Parker also encouraged residents to attend the meeting.
“It’s one of our biggest assets, and keeping it clean and pristine is important to all of us,” Parker said.
The meeting is to “present the purpose and scope of the planning effort, [and] public input is encouraged to support evaluation of formulated alternatives,” according to the NRCS.
While significant progress has been made to increase and stabilize the ponds’ water quality, they are still considered polluted, according to federal and state standards, which is how a state Department of Environmental Protection analyst described it at a meeting held in November at Town Hall.
“The data management and water quality assessment section has analyzed the data and determined the Congamond Lakes are polluted,” said the Department of Environmental Protection Environmental Analyst Holly Brown.
In November, the DEP, NRCS and Pare Corporation representatives held a meeting in Town Hall to ask the town which of two options it might use to increase water quality; one was to create a “Total Maximum Daily Load” plan with a “pollution budget” that limits the total amount of a pollutant water can handle, limits the load from “point” sources like factories or sewage plants and limits “nonpoint” sources like fertilizer runoff.
The other is a nine-element watershed-based plan that would manage “nonpoint” sources through grants, partnerships and other voluntary programs, and is much less formal than a TMDL.
The Select Board, at the request of board member Diane Gale, will pursue the nine-element plan because it was less involved than a TMDL.
During the meeting next week, representatives from the LMC and NRCS, along with the technical consultant team, will provide information on the scope of the planning activities, various alternatives being considered for the assessment, answer questions and concerns about the planned activities, and seek public input, according to the NRCS announcement.
The announcement said that federal funding has been received to assist the town in developing the plan, but it has not yet been secured for the design or construction of these projects.
While the three great ponds are defined by the state as polluted, it’s not like there are industries or manufacturers using them to dump waste by-products; it is a product of 14,000 years of plants and trees decaying and falling to the bottom of the ponds, which Grannells calls “muck.”
That decaying material is loaded with phosphorus, which is a nutrient that drives the growth of “chlorophyll A” which creates the conditions in which algae grow.
Because of the high levels of phosphorus and chlorophyll in the ponds, the state classifies them as a Category 5 impaired water body and requires a mitigation plan.
Grannells said next week’s meeting will look at increasing water quality and preparing for a severe flood.
In the last eight months, technicians with Pare Corporation have done an on-the-ground survey of Great and Canal brooks to determine the potential cost of dredging each to minimize the amount of stormwater that gets into the ponds when it rains.
Dredging the brooks would be an enormous positive step to improve the ponds’ water quality, allowing them to naturally flush out the phosphorus-loaded sediment, Grannells said.
As for the possibility of the ponds’ flooding, in 2023, the LMC asked the NRCS to develop a plan to maintain the water levels of Congamond Lake in the event of a 100-year flood, an event that raises the level of a body of water between one and three feet, and has a 1% chance of occurring annually.
When the NRCS issued its preliminary report in June 2023, it offered four options to mitigate flooding in the ponds, including one of “take no action.”
Two options are characterized by the NRCS as “structural solutions.” One is to build an outlet pipe in North Pond, replace the culverts between the ponds, and install a larger weir at the entrance of Canal Brook. The other is to do all of those things, and also build a new weir on the Great Brook Canal.
The fourth option, called a “non-structural solution,” was to purchase and demolish 79 homes along the shore at risk for flooding in a 100-year storm.
The cost of the solutions in the NRCS report ranged from zero, for the “take no action” option, to $43 million for the “non-structural” option, to $54 million for the structural option that addresses Canal Brook only, and $72 million for the option that includes Great Brook.
The meeting will be a hybrid in-person and virtual meeting occurring at the Southwick Town Hall, 454 College Highway, Southwick, and https://parecorp.zoom.us/my/nrcs.ma at 6 p.m., Jan. 29. Assistance will be provided to anyone having difficulty in determining how to participate.
Comments or questions may be submitted until March 1 by mail to Congamond Lake — Great Brook Watershed Plan EA, c/o Pare Corporation, 10 Lincoln Road, Suite 210, Foxboro, MA 02035, or by email to Congamond@parecorp.com.
