With reservoirs full and water rising, the rural municipality of Estevan has declared a new state of emergency.

Some 60 people are on voluntary evacuation notice in the RM in southeast Saskatchewan.

The Estevan area received 41 millimetres of rain on Tuesday, adding more water to the nearby Boundary and Rafferty reservoirs.

"[We] have advised everyone in the RM in the low-lying areas to evacuate or be ready to evacuate if the waters continue to rise," said Kelly Lafrentz, the reeve of the RM of Estevan. "We expect that's going to happen."

More water will have to be let out of the reservoirs because they're near capacity. The expected releases will cause the Souris River to rise 1.5 metres above where it was earlier this spring.

According to the Saskatchewan Watershed Authority the flood situation in the Estevan area is a once-in-100-year event.

It's hard to tell exactly what will flood next, said Lafrentz, who added that he's never seen anything like this in his life.

Many homes in the area were inundated with water two weeks ago when the first state of emergency was declared, but that water receded.

One community on flood alert is the village of Roche Percee where 30 homes may have to be evacuated. Provincial officials said the families were prepared to go at any time.

The town of Oxbow is also preparing sandbag dikes to guard against flood damage.

Saskatchewan has seen widespread flooding this year due to greater-than-usual amounts of snow last winter and the resulting heavy spring runoff.