Environment and Climate Change Canada (ECCC) has issued rainfall warnings for dozens of Saskatchewan communities near the Alberta border, with 40 to 80 millimetres expected over the weekend.

The rainfall warnings extend eastward, covering Kenaston, Davidson and surrounding areas along Highway 11 between Saskatoon and Regina.  

ECCC says heavy rain could fall in a short amount of time on Saturday before tapering off in the evening.

"Where that heavy rainfall warning is in the Kindersley-Leader area," Rose Carlsen, an ECCC meteorologist, said. "We're thinking that by Sunday morning they could see up to 80 millimetres in some areas. There might be some embedded thunderstorms within that larger area of rain."

ECCC warns heavy downpours can cause flash floods and water pooling on roads, as well as localized flooding in low-lying areas is possible. People can check the latest alerts here.

Saskatchewan's Water Security Agency (WSA) sent out a public advisory on Friday afternoon that the South Saskatchewan River between Lake Diefenbaker and the Alberta border is at risk of flooding due to high rainfall.

Sean Osmar, a spokesperson for the WSA, said Lake Diefenbaker has sufficient capacity to take on this water, but the level of the lake is expected to increase one metre in the next 10 days. 

The WSA says it expects the increased runoff into the South Saskatchewan River will make the river flow about 15 per cent faster between Lake Diefenbaker and Saskatoon.

"Take sensible precautions," Osmar said. "Be aware that the flows and the levels can change rapidly, especially with this rain storm coming. Always check local conditions before you go out. And if you have a dock on the lake, you might want to consider pulling it out until those levels cut in and adjust."

In preparation for increased flows along the river, officials in Alberta began increasing reservoir releases.