Some Decembers, serious mud flats rim the border of Candlewood Lake's 60 miles of shoreline.

Those are the years of deep drawdowns, when the lake's level drops by nearly 10 feet.

This winter, there is a narrower ribbon of lake bottom. FirstLight Power Resources, the lake's owner, is dropping down the lake by only four feet.

"It's our understanding they'll complete the drawdown by the end of the month,'' Larry Marsicano, executive director of the Candlewood Lake Authority, said last week.

Timing is critical. The trick is to expose the shallows to harsh weather for at least a month.

"We'd really like it to stay down 30 to 60 days,'' Mr. Marsicano said.

Charles Burnham, spokesman for FirstLight, said the utility began the drawdown this month but stopped it because of a maintenance issue at the power substation near the Rocky River hydroelectric plant in New Milford.

The lowering allows lake residents to repair their docks and lake walls. It's also the major management tool that lake officials use to control Eurasian watermilfoil.

This non-native, invasive water plant is the bane of the lake. It grows in extensive, thick mats that can cover acres and clog boat propellers and swimmers' limbs alike.