The Town of Stettler is using its stored water supply after a semi rolled off a nearby highway and spilled fuel into a creek that flows into the Red Deer River.

The crash happened around 3:30 p.m. Thursday when the northbound semi, hauling two tanker trailers, lost control and rolled off Highway 21, about 1.6 kilometres south of Highway 11, near Content Bridge, according to police.

"One tanker unit tipped over; the other one remained upright," said Niki Thorsteinsson, a spokeswoman for the town.

An unknown amount of diesel fuel spilled into the creek. First responders tried to mitigate the spill by blocking off the creek with booms and a berm.

The semi crashed on Highway 21 approximately one mile south of Highway 11 near Content Bridge. (CBC/Google Maps)

In response, the town started drawing water to its treatment plant from a storage pond instead of the Red Deer River.

Thorsteinsson said the pond has enough water to supply the town for about 10 days.

Clean-up of the spill continued Friday and the river's water quality will be reassessed.

"It is not anticipated regular water treatment will be affected for any long term duration," the town said in a release.