NEW MILFORD — FirstLight Power Resources has finally begun drawing down Candlewood Lake, later than originally planned due to an abundance of rain and warmer winter temperatures.

The lake is expected to reach its drawdown level of 420 feet by the end of the month.

FirstLight, which owns and operates the Housatonic hydropower system, lowers the lakes each winter, though the level differs on the year and whether it is a deep or shallow drawdown. This year is a deep drawdown, which is about 10 feet below recreational level.

Drawdowns are one of the tools used to control the invasive Eurasian watermilfoil, which has plagued lake users for years. The plant presents recreational challenges because it can tangle with boat propellers and presents safety risks to swimmers who might get caught in the weeds.

The drawdown works best when the roots of the plant are exposed to the freezing temperatures, essentially killing it.

Candlewood’s drawdown was expected to start in December but the weather kept delaying it.

“This winter has been highly unusual to this point, particularly given the amount of rainfall we’ve had,” said FirstLight spokesman Len Greene. “We’ve had historical amounts of rainfall and river flows on the Housatonic, which has been at or near flood conditions throughout the fall. In order to avoid making these conditions worse downstream of the Rocky River station, we had to delay the start of the drawdown.”

Candlewood is lowered at the Rocky River station in New Milford where the water enters the Housatonic River and then flows downstream.

The warmer weather also affected the audit, which is done in the winter and summer to show the amount of power the station can generate and is used to determine the rates with ISO New England.

“In a typical year, we would perform the audit when temperatures remain below freezing for several consecutive days while the lake is at its maximum elevation,” Greene said. “Unfortunately we weren’t able to do that this year, which also contributed to the delay.”

The conditions have now pushed the company outside of the window to do the audit and the drawdown.

“In order to ensure that we are able to conduct the deep drawdown, we decided to forego the audit entirely and absorb the commercial impact to the company,” Greene said.

The lake will return to recreational levels by the start of fishing season in early April.; 203-731-3345