Nearly 150 people have been evacuated from a Saskatchewan First Nation because of rising water levels and the threat of more flooding.

An emergency Social Services official says several homes have already flooded on the Cowessess First Nation, about 150 kilometres east of Regina.

The First Nation evacuated a low-lying subdivision because there is concern water could breach access roads.

The Saskatchewan Watershed Authority says water levels are still rising in the Qu'Appelle River, which runs from Lake Diefenbaker, northwest of Regina, across Saskatchewan to the Manitoba boundary.

The watershed authority expects the river to overflow along the entire Qu'Appelle valley in the next week to 10 days.

It warns that some areas could see near-record flooding.