An uncontained oil spill has forced Prince Albert, Sask., to stop drawing water from the North Saskatchewan River and warn residents that its reservoir could run out by mid-week.

A Husky Energy pipeline leaked an estimated 200,000 to 250,000 litres of oil and oil-thinning chemicals into the river near Maidstone, Sask., before it was shut off on Thursday. The amount that leaked was approximately what would fit inside two rail tanker cars.

On Friday, the community of North Battleford stopped drawing water from the river and turned to well water instead.

Booms were put in place, but they failed to stop the slick from travelling hundreds of kilometres to Prince Albert.

The city of 35,000 people closed pools, laundromats and carwashes Monday. It warned residents that they will face $1,000 fines if they water their lawns during the state of emergency.

City workers are attempting to build a temporary pipeline to draw water from the South Saskatchewan River.

In the meantime, Prince Albert is considering tapping into a storm retention pond that could provide up to five more days of water.

So far, less than half of the oil has been cleaned up, according to Environment and Climate Change Canada’s Lo Cheng. The oil no longer just on the surface of the water, complicating efforts.

Sam Ferris, from Saskatchewan's Water Security Agency, said that close to 70,000 people have been affected by the spill and that it could take weeks -- even months -- to rectify.

Wes Kotyk, from Saskatchewan's Environment Ministry, said that four birds including a blue heron, a frog and a fish have been found dead as a result of the spill.

Husky Energy vice-president Al Pate apologized Monday and said the company accepts “full responsibility for the event and the cleanup.” He promised to “make things right.”

Pate added that the pipeline was built in 1997 and has been subject to a rigorous corrosion monitoring program.

With a report from CTV’s Manitoba Bureau Chief Jill Macyshon and files from The Canadian Press