It happened around 5 a.m. Thursday and flooded Alhambra Avenue, Berrellessa Street and Jones Street. The water main break is having an impact on traffic, with drivers unable to get through Berrellessa or Jones streets.
It was a rude awakening for residents after the water main broke. The break created a large sinkhole in the middle of the street along with a sea of water and large amounts of mud.
"And there was a river running down the street; it was kind of scary because it looked like the street was buckling up," said neighbor Jim Williams.
It took crews two hours to shut off the water. They said it's tough to find the valves when they're buried under several inches of water. They were also dealing with traffic on busy Berrellessa Street.
"It was certainly gushing pretty good. Raised the street up here. And so I'm sure it's tens of the thousands of gallons, at a minimum," said city engineer Tim Tucker.
By mid-afternoon, city crews moved in to repair the underground pipe and the large hole in the street. At one point, they inserted a tiny camera to make sure the sewer lines were okay.
Michael Briant lives just up the hill from the rupture. He decided to pull up a chair and watch the repair effort.
"I was working on the house, so instead of working on the house, I'm watching them work. It's always nicer to watch somebody else work than do it yourself," he said.
Martinez is served by two reservoirs and today's water main break drained about one-sixth of the city's water supply.