The release of rising waters from reservoirs along the Souris River is threatening to flood homes near Estevan, Sask., residents say.

The danger comes on the heels of a torrential downpour in southern Saskatchewan on Friday that led to a state of emergency in Weyburn and flooded streets in Regina and Saskatoon.

The storm raised levels on reservoirs along the Souris, forcing provincial officials to release water from the Rafferty dam to ease the pressure, and that could mean trouble for people living downstream.

Guy Mehler, who feared the outflow would consume his house near the Souris River not far from Estevan, made one desperate telephone call for help and was grateful when more than a dozen neighbours and friends showed up with enough equipment to build an earthen wall nearly two metres tall around his home.

Water erupts from a sewer cover in Weyburn, Sask., on Saturday. (Kent Morris/CBC)

"I was feeling real low, but when these guys show up, your attitude and feeling changes real quick," he told CBC News. "We've got the men and the equipment and we're not going to stop until we feel we're safe."

Mehler said he and his son can only wait and hope for the best.

"My son and I are going to hang around and keep watch on it," he said. "If there are any weak spots when the water does come up, we have the equipment to patch it up. If it gets too high, we'll just evacuate."

The village of Roche Percee, southeast of Estevan, could be flooded within two days, Mayor Reg Jahn said, affecting up to 30 homes.

"There's gonna be one house that's totally destroyed," he told CBC News. "I don't know what that lady's gonna do. She lives off two minimum-wage jobs and, you know, she'll lose everything. But she's still got her life. You know, it's hard."

The river can't be diked to save those homes because it will destroy a bridge and flood the entire town of about 160 people, the mayor said.

State of emergency

Earlier in the day, Weyburn declared a state of emergency after receiving more than 60 millimetres of rain, leading to an electrical failure and effluent overflow at the city's sewage lift station. Municipal officials are advising residents to boil their water just to be safe.

"We haven't seen an emergency like this in our community for many years, and this is a strain on our systems, obviously, it's a strain on the people," Weyburn Mayor Deb Button said.

Engineers have been called in to assess the sewer station.

'I was feeling real low, but when these guys show up, your attitude and feeling changes real quick.'— Guy Mehler, a homeowner grateful for good friends

Elsewhere in the city, firefighters needed a boat to rescue dozens of people from a mobile home park on the outskirts early Saturday.

The Souris River has reached the highest level he has ever seen, city manager Bob Smith said Saturday. The city is beginning to return to normal, Smith said, though the town's infrastructure has reached its saturation point. Water in flooded basements is beginning to recede. Homeowners also got a bit of help from the City of Regina, which sent 35 pumps to help drain flooded basements.

The flash flooding caused when nearly 80 millimetres of rain fell in Yellow Grass and Radville added to Weyburn's woes, which is downriver from the two communities. Highway 39, which runs through Weyburn, has been shut down.

Those displaced by flooding are staying at the local hockey rink until they can get back in their homes.

Streets in both Saskatoon, which saw a power failure in the downtown core, and Regina had to be closed overnight due to flooding.

In Regina, wind gusts hit 70 km/h overnight, ripping branches from trees and downing others. "We heard a big crash and looked out and there was one of the city trees had fallen over and all across Victoria Avenue," Regina resident Murray Loose said.

Several other trees around the city were torn from the roots because of the strong wind. City workers have already cleaned up most of the debris.

The towns of Assiniboia and Mortlach also saw major downpour, each receiving about 65 mm overnight.

With files from the CBC's Kent Morrison and Sheryl Rennie, and The Canadian Press