Schools and businesses were closed for a second day and thousands of residents still couldn't go home Wednesday as a weakened timber dam threatened to give way and spill a 6-foot surge of water into downtown Taunton (search).

The danger may not end even if crews safely drain excess water behind Whittenton Pond Dam (search). Forecasters said a weather system now in the Midwest could hit the already waterlogged region this weekend and Hurricane Wilma also affect New England after speeding across Florida.

"The good news: dry weather until Saturday," Mayor Robert G. Nunes (search) said at a midday news conference. "The bad news: significant rain on Sunday."

The wooden dam buckled earlier in the week under the pressure of the heavy rain that flooded parts of the Northeast, prompting the evacuation of thousands of residents. The threat worsened after some of the dam's timbers broke and washed away.

Nunes said crews were easing pressure on the dam by allowing water through it and another dam farther upstream. The water in Lake Sabbatia (search), the reservoir above Whittenton Pond Dam, had dropped by more than 6 inches since Tuesday but remained several feet above normal.

"Both dams are performing as they should," said Fire Chief Joseph Rose. "But there is still a substantial amount of pressure on them."

Taunton, a working-class city of 50,000 about 40 miles south of Boston, will remain under a state of emergency until early next week, Nunes said, but he could not say when residents and business owners would be allowed back.

"This is a minute-by-minute situation," Nunes said. "Until we can really get some assurances that things will be OK, it's really a wait-and-see situation."

Officials fear a dam break could send 6 feet of water surging through downtown Taunton, about a half-mile downstream.

Sens. Edward Kennedy and John Kerry, who toured the dam site with Gov. Mitt Romney and other lawmakers early Wednesday, said they'll push for quick federal assistance for residents and business owners displaced by the threat.

Since the beginning of the month, Taunton has received 111/2 inches of rain, with more than 7 inches of that from Friday through Sunday.

Whittenton Pond Dam, one of about 3,000 private dams in the state, was inspected two years ago and was considered in fair condition at that time, Romney said.

One of the owners, Steve Poelaert, said work to restore the dam was to have begun last Friday, but was delayed by the heavy rain.

The 12-foot-high Whittenton Pond Dam dates to 1832, and is near homes and businesses. It was built to power a textile mill but no longer has any industrial purpose. The city last flooded in 1968, when the same dam broke.

Forecasters said Hurricane Wilma could cross Florida before heading north through the Atlantic toward New England. A separate system now in the Midwest also could bring rain by the weekend, National Weather Service meteorologist Matthew Belk said.

"The flooding danger this weekend is starting to shape up to be fairly significant," Belk said. "Our ground is pretty saturated now."