NEWPORT, Maine — A broken dam gate has forced the town to move up the annual Sebasticook Lake drawdown and town officials are urging lake property owners to get their boats out of the water while they can.

“We’re requesting that they remove their docks and boats,” Town Manager Jim Ricker said Monday. “It’s crucial they get them out now while we have water at our boat launch.”

The chains that hold up the gate broke while town workers were preparing for Hurricane Irene.

Around 9:20 a.m. Sunday, one of the two chains holding up the gate broke, allowing water to flow over the gate. At 8:30 Monday morning, the second chain snapped.

“Because [the gate] is fully extended right now, depending on the amount of rain, the lake should be drawn down in three weeks,” Ricker said.

Ricker said the lake is drawn down about 8 to 9 feet each fall to flush out the algae buildup. The drawdown has been done for the past 30 years and was scheduled to start on Sept. 12.

People who have boats in the water are encouraged to get them out soon because the boat launch will be useful for only so long.

“A foot of difference on this lake makes a difference on this boat launch, safely, I should say,” said Ricker.

The broken chains came as a surprise as they were replaced last fall with stronger chains.

“We were all confident that it would be good for years and years to come. We really have no explanation as to why these chains keep breaking,” he said.

Ricker added that the town will hire an engineering firm to design a system that works with the present gate or replace it.