Stonington – A portion of Route 27 was temporarily closed to all traffic Monday afternoon while crews worked to lower the level of a retention pond swollen by the rain, police said.

Stonington Police Capt. Jerry Desmond said Route 27 is closed just north of Jerry Brown Road where the pond started to spill over its banks. He said there was concern of a sudden flood of water and debris.

The Old Mystic fire department has joined town and state highway crews to pump water out of the pond. The road is expected to reopen later in the afternoon.