LONDON (AP) — Emergency workers are racing to lower water levels behind a damaged dam in northwest England as forecasters warn more bad weather is on the way.

Pumps have reduced the water level in Toddbrook Reservoir by half a meter (20 inches) since Thursday, but authorities warn that pressure on the 180-year-old dam remains severe.

More than 1,000 people were evacuated from the town of Whaley Bridge, about 175 miles (280 kilometers) north of London. The government says it may be several days before residents can return to their homes and is urging people to be patient.

The dam was damaged last week after heavy rains sent torrents of water rushing over its spillway. Britain's meteorological office is warning of further rain on Sunday, with the risk of floods and lightning strikes.