Lake Onota Drawdown Discussion Continued by Conservation Commission
PITTSFIELD, Mass. — The Lake Onota Preservation Association voiced concerns last week over a 2-foot drawdown rate that is less than the Generic Environmental Impact Report approved 3- to 6-foot drawdown.
Project scientist of ESS Group Alex Patterson introduced this proposal to the Conservation Commission accompanied by the city's Park, Open Space and Natural Resource Program Manager James McGrath.
ESS Group provides power and renewable energy, coastal engineering, and water resource management consulting services.
The city has been conducting an annual drawdown at the lake for more than 20 years. In the past, the Conservation Commission has approved an orders of conditions that included options for both a 3-foot and 5.5- to 6-foot drawdown of the lake during the winter.
In 2004, a Generic Economic Impact Report was created to lay out the parameters of the drawdown.
The goal of drawdown is to manage growth of aquatic species along the shoreline of the lake and to protect the shoreline and the structures along it from ice damage during the winter.
The city has been working closely with the state Department of Environmental Protection to determine the best course of action and the parameters that would be acceptable moving forward for drawdown.
The city has the option to conduct up to a 6-foot drawdown, but right now proposes to conduct up to a 2-foot draw. This is less than that recommended in the impact report for lake management and is based on the consultation with DEP on what the best path forward will be.
A 2-foot drawdown would expose about 48 acres of the lake bottom, which is about 7.5 percent of that surface area. It would also reduce the volume of the lake by up to 1,200 acre-feet, which is about 9 percent of the lake's volume.
Drawdown would begin on or after Oct. 15 of any given year and would be completed by Dec. 1. The lake would be refilled by April 1 if there is no ice. If there is, refill would be completed by April 15.
In addition, Onota Lake has priority habitats, which are based on the known geographical extent of habitat for all state-listed rare species, both plants and animals, and is codified under the state's Endangered Species Act, and estimated habitats that are a subset of priority habitats.
The city requested and received a preliminary termination from Natural Heritage Program. This is a pre-filing requirement for ecological restoration limited projects that are located in estimated habitats.
Natural Heritage has determined that the work would not adversely affect the estimated habitat associated with the lake but must approve the project in general as it relates to the priority habitat.
President of Lake Onota Preservation Association Michael Reardon called in to speak on behalf of LOPA in saying members do not support the 2-foot drawdown. He said they would like to see the drawdown be consistent with recommendations because they believe that long experience, science, and current knowledge supports those recommendations.
Reardon asked that principal scientist for Water Resource Services LLC Ken Wagner call in to comment on this drawdown. Wagner asked that certain aspects of drawdown science be on record.
"Lake management is a three-legged stool," he said. "I am really just here to discuss the science."
Wagner stated that for drawdown to be done properly it requires careful consideration to science, which he believes has not been considered in the 2-foot drawdown proposal.
He said scientists have learned a lot in the16 years since the Generic Environmental Impact Report was created.
"GEIR guidance of 3 feet has been upheld as a depth below that no agency should have a problem," he said. "There's nothing that I know about Lake Onota that suggests any need to change from 3 feet to 2 feet."
Wagner also said the start date of drawdown and refill are less important than the temperature of the water. Start and end dates are irrelevant to ecology, as fish cannot read a calendar, he said.
He believes that these dates have been picked for regulatory reasons and abused ever since. If drawdown and refill are done on a schedule that doesn't rely on the lake's natural season changing, a lot of damage can be done, Wagner said.
Both he and LOPA would like better explanations for drawdown numbers and dates provided by the city, he said, adding "transparency would be nice."
The Conservation Commission unanimously agreed on a continuance of this until the next meeting on Oct. 29.
Tags: conservation commission, lakes, ponds,
