A transformer failure at a TransAlta power station near Banff has cut power to the surrounding area and stopped traffic between the mountain town and Canmore.

People reported hearing a loud noise that sounded like an explosion Saturday night at the substation.

However, TransAlta spokesperson Stacey Hatcher says there was no explosion — instead, the transformer was flooded when the plant tried to release excess water into an emergency spillway.

Instead of following the spillway, Hatcher said the water backed up into the facility and flooded the transformer.

No one was injured in the incident, but the flooding has knocked out power to Banff and Lake Louise. It also forced officials to shut down roads in the area.

Backup generators are functioning at the local hospital and police station, but as of Saturday night emergency vehicles are no longer able to get through on the highway.

Hatcher says they are unsure when the power will be restored.

She says the transformer room has to be drained before crews will be able to work on repairing the equipment.