The Conservation Commission at a brief meeting Tuesday night returned to the issue of invasive weed management at Lake Maspenock, agreeing to a winter drawdown of the lake as a “toolbox item” previously proposed by the Department of Public Works.

DPW Director John Westerling explained that the Lake Maspenock Weed Management and Control Advisory Group recently completed a survey of the lake.

“They found that the condition of the lake and the weeds in the lake were very, very bad,” he said.

While the water quality remained good, “the amount of weeds was extreme,” according to Westerling.

To combat this problem, the committee proposed a drawdown of the lake, which he said had been an effective strategy used five years ago at a minimal cost. Westerling requested an 8-foot drawdown after receiving this request.

He added that this also was performed two years ago, but that it was not as effective then because of the mild winter.

Previously, the DPW would draw down the lake every three years as part of the operational maintenance plan for the dam to either 5 or 8 feet. Because of the situation, Westerling provided information to the Conservation Commission on the day of the meeting that included feedback from town consultant and certified limnologist David Mitchell.

Commission member Ted Barker-Hook asked Westerling if he is “under a time crunch” to perform the drawdown, as commission members have not had a chance to review the report. Westerling replied that the opening of the dam typically is performed “in late September or early October.”

The water flow, if too heavy, would impact the wildlife living in and around the lake, Westerling explained. Draining the lake too quickly would “exceed that recommended flow rate.”

Chair Jeff Barnes recommended a standard annual drawdown as the best course of action at this time. This would give commission members time to review the information as well as the drawdown results before the next meeting.

Said Barnes: “If everything looks good, we can give the thumbs-up for the extended drawdown, and you can open the gate even further.”

Westerling called the strategy “a sensational plan,” and no vote was required, as it is a standard procedure. He also urged lake abutters and possibly the Lake Maspenock Preservation Association (LMPA) to pull the weeds near home property lines by hand while the water is at a lower level as another toolbox strategy.

Later in the meeting, committee members described a recent tour they took of the north basin of Lake Maspenock to personally observe the weed growth.

Committee member Ed Harrow noted that he saw some properties didn’t have a planting filtration system.

“I sympathize with the people on the lake dealing with this,” he said. “The fact that the plan came in for a drawdown pleased me greatly.”

Previously there had been a passionate debate in town about the potential use of herbicides to control the invasive weeds. While some claimed the weeds were a nuisance mostly experienced at the end of the summer, others claimed they could be a potential hazard if swimmers unfamiliar with them were to panic and ingest water.

Barker-Hook added that he observed more weeds during the lake tour than in past visits.

“It was not a scientific trip, nor am I a scientist,” he added. “But it sure seemed to me that the closer we were to those yards that aren’t doing what we have asked people to do, the more weeds there were. To me, it was a noticeable part of our spin around the lake.”

Bridge approved across stream in Hopkinton Town Forest

In other Conservation Commission news, the commission approved an exemption request for the construction of a foot bridge across a stream at the “blue trail” in Hopkinton Town Forest by the Open Space Preservation Committee (OSPC). OSPC member Steve Levandosky explained that it would be about 30 feet in length and 2 ½ feet wide. It would be similar to another bridge at Hopkinton Town Forest that the commission approved earlier this year and built in sections.

“There are steppingstones that people currently use to get across,” he explained as he showed a picture of the location. These can become slippery and are not conducive to bike riding or running, he added.

A vote was not required because it was an exemption request.

Hearings continued until Oct. 18 meeting

The meeting had no new hearings. Previously continued hearings on The Trails development’s drainage improvement plan and 103 Wood Street resource area delineation were continued until the next meeting on Oct. 18.