Lowering Laurel Lake to kill invasive species lauded, loathed
After six successful drawdowns to combat the two dominant invasive species in Laurel Lake, a citizens group is considering a deeper water-level reduction plan.
Citing the 2015 drawdown report, the Laurel Lake Preservation Association believes going from a 3 foot to a 5 foot drawdown each winter would kill off more of the Eurasian milfoil and zebra mussels that plague the lake. The LLPA says the previous four reports came to similar conclusions and the organization expects the same outcome for the yet-to-be generated winter of 2016 analysis.
"If we can't do something more effective, we would want to continue the drawdowns," said LLPA President Mark Aliminsky.
For the drawdowns to continue at any level requires additional permission from the Lee and Lenox conservation commissions, as the 170-acre body of water borders both towns, mostly located in Lee.
Since the winter of 2011, the two commissions and state Department of Conservation and Recreation have allowed drawdowns roughly from Nov. 1 to late February or well into March. The start date for refilling the lake to its normal depth depends on the amount of precipitation each winter. The order of conditions dictating how the drawdowns are conducted expired after this winter, according to LLPA officials.
Of the two commissions, Lenox has been reluctant to sign off on the drawdowns citing a more negative impact to northern end of the lake.
"When they draw down three feet, they dewater the wetlands on the Lenox side," said Chairman Neal Carpenter.
Carpenter added a deeper drawdown would be worse, noting an instance several years ago when the water was lowered for repairs to the Laurel Lake dam.
"When our end of the lake got drawn down five feet, there was no water left on our end," he said.
Formed in 1995, LLPA is comprised of lakefront homeowners and interested lake users working to improve the management of the lake, and more recently, the goal of eradicating Eurasian milfoil and zebra mussels.
Funded by a state grant, LLPA six years ago hired Water Resource Services to study the effects of the winter drawdowns. After the first five drawdowns, the Wilbraham firm concluded the milfoil is "rare in the drawdown zone but often abundant in deeper water."
As for the zebra mussels, the 2015 report states a five-foot drawdown would extend the kill zone for the mollusks to water depths up to eight feet.
Laurel Lake is ground zero for zebra mussels in Massachusetts, becoming the commonwealth's first documented case of infestation in the summer of 2008.
With help from the DCR, boat ramp monitors were hired and a boat wash station installed to ensure all watercraft were free of zebra mussels before and after entering the water off Route 20. The mollusks are spread from one waterway to another by hitchhiking onto boats that have been in infested lakes, ponds or rivers.
The Eurasian milfoil problem took root nearly 30 years ago, first discovered in Minnesota and has spread to nearly every state in the union. Making matters worse for Laurel Lake has been the runoff of plant growing nutrients from High Lawn Farm, a portion of which abuts the lake.
Another milfoil food source, sewage from inadequate septic systems on the Lenox side, may be a thing of the past, according to Carpenter.
He said nearly all the homes on Bramble Lane are hooking up to town sewer and five new septic systems have been installed at residences on Sargent Brook Road.
While Carpenter and his commission would like to see a more comprehensive watershed management plan for Laurel Lake, Water Resource Services found drawdowns are the best weapon to at least keeping Eurasian milfoil and zebra mussels in check.
"The result is the weeds are under control and we've reached equilibrium with the zebra mussels — for every 100 we kill only 100 grow back," said Harold Sherman a Lee member of LLPA.
Contact Dick Lindsay at 413 496-6233.
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