United Water says their crews arrived to several inches of water on the roads just after 5:30 this morning. They say it took them until about 6:30 a.m. to get the water line shut off.
Nearby streets were shut down for several hours, and Boise Police recommends drivers avoid the area and take alternate routes when possible.
"We noticed there was significant flooding so we had to shut down the roadway," officer Dave Saindon said.
As of 11 a.m. Friday, traffic was still reduced down to one lane. Only southbound traffic can access the bridge, while northbound traffic still was restricted.
Murky standing water was soon replaced by thick mud and spots of sand.
Water was also shut off to nearby Clearwater apartments and a local business on Park Blvd.
"Woke up and there was a knock on the door and little pink note on the door that said our water will be off from 8:00 a.m. until 2:00 p.m.," apartment resident Dustin Heeney said.
Heeney said he was frustrated he didn't have water in his apartment.
"It's a big hassle," he said."You always need water! Fresh water for showers. We're not going to be able to take a shower before work and that's a big hit right there."
United Water tells KBOI they expect to spend the afternoon working on the street where the pavement caved. First they'll dig up the ground and repair the broken line, then they'll work with ACHD to assess the damage and figure out a permanent solution.
Spokesman Dennis Fickes said they haven't pinpointed a cause, but do not believe the incident was weather related.
"Typically if we have a real deep frost in the ground can actually move and right now that's not the situation," Fickes said. "It warmed back up a few weeks ago and the frost came out of the ground. There isn't that much frost on the ground right now."