The number of flooded communities under states of emergency in southeastern Saskatchewan has climbed to 36 as water levels continue to rise in some areas.

Floodwaters triggered by torrential rains have forced nearly all of the roughly 250 residents of Gainsborough, Sask. from their homes, provincial officials said Monday.

Displaced residents were staying with family or friends in the nearby community of Carnduff, while others were in RVs or camper trailers.

In Yorkton, 66 residents were forced from their homes on the lower levels of four apartment buildings in the city.

More than 240 millimetres of rain has been reported in some areas of the province, and another 15 millimetres was expected Monday.

“Our staff were working as late as approximately 2:30 a.m. this morning, moving sandbags and pumps into municipalities where they are having difficulties with sewer issues or pumping out basements,” said Duane McKay, the province’s commissioner of emergency management.

“In addition to that, because of the size of this, we’ve activated wildfire management crews from the Ministry of Environment to support our operation and to assist us in responding to municipalities.”

Moosomin Mayor Larry Tomlinson said after a weekend of storms, many of the boats and docks on the town's lake have been washed away. Trees have come down in the high winds and roads have become impassable.

"We haven't had this scale (of flooding) in years and years. This is probably the worst one I've seen," he told CTV News Channel.

Tomlinson estimates that close to half of the homes in his town of 2,500 have been flooded.

"Some of them have as high as three or four feet of water in their basements, and it's going to be a long clean-up," he said.

Saskatchewan’s Water Security Agency said levels continue to rise rapidly on Round and Crooked lakes east of Fort Qu’Appelle.

Creeks also continued to swell around several other communities, washing out local roads, bridges and culverts. It wasn’t known when water levels could peak.

“There’s a lot of localized (flooding) issues out there right now,” said the agency’s Patrick Boyle.

“The land was already very wet and saturated, so this (rain) is adding on top of it.”

As of Monday, 15 sections of highway were under water, including on the Trans-Canada Highway, which was closed between Balgonie and Whitewood. Highway 16 was also closed from Elfros to Dafoe due to washouts and high water.

SaskPower said about 200 customers were without electricity across southeastern Saskatchewan on Monday.

With files from CTVNews.ca's Angela Mulholland