Carmangay residents are being told their water is unsafe to drink or use, an Alberta Emergency Alert said Friday afternoon.

The village's chief administrative officer says the problem was identified Thursday.

"Yesterday we noticed that we had a leak on one of our water lines. It was quite a large job so we needed to bring in some external help to do that repair which was done earlier this afternoon," Heather O'Halloran said.

"Because of where the water line was situated, we weren't able to just isolate that one line, so we were required to turn the water off to the entire village."

A boil water order is in effect for at least three days. Residents are told to boil water for consumption for at least one minute or choose bottled water.

Carmangay has a population of about 260 and is roughly 160 kilometres southeast of Calgary.