The Washington County sheriff's office said a large water main break in Oakdale caused a giant sink hole under Interstate 694 on Sunday.

The interstate remains closed in both directions between 10th Street and 34th Street, just north of Interstate 94.

About 9 a.m. Sunday an Oakdale resident noticed water pouring out from beneath I-694 and into a nearby marshy area.

Minnesota Department of Transportation spokesperson Kevin Gutknecht said a 12-inch water main pipe near the interstate sprang a leak.

"It has caused water to seep up onto the roadway," said Gutknecht. "It's created a sinkhole underneath part of the roadway, consequently we've shut the roadway down."

The view from the 15th Street bridge on southbound I-694 in Oakdale. Tim Nelson | MPR News

The running water appears to have flowed under the northbound lanes of the interstate, then washed out a section of median and completely washed away the road bed under the south bound side of the freeway.

By the time crews shut off the water, a 5-foot deep hole had opened under the pavement, although the roadway itself remained intact.

The State Patrol rerouted traffic off I-694.

On Sunday night, MnDOT had crews working at the scene.

Gutknecht said MnDOT will likely close four miles of the interstate between I-94 and Highway 36 for several days. The agency says to use Interstate 35E as a detour.

The roadway carries tens of thousands of cars a day, and MnDOT said drivers should start planning now for traffic impacts.

Oakdale police spokesperson Michelle Stark said they're asking Oakdale residents to conserve water. They expect the entire city's water supply to be affected.

Traffic backs up along Interstate 694 near Oakdale after a water main break caused a sinkhole on Sunday. Tim Nelson | MPR News

"Those individuals who will see a duration with larger impacts will be notified door to door, home to home," said Stark.

Stark added it was lucky someone noticed the water flow and called the city before the interstate pavement failed.

She said the city got an alarm that its water tower was draining early Sunday, but crews couldn't find the leak until it surfaced on the interstate.