The 20-inch main was reported broken sometime Friday night underneath the railroad tracks between Sereno Drive and Tuolomne Street, parallel to Broadway Street. Repair crews were deployed immediately and have been on the scene ever since.
More than 30,000 people, about half the city, have reduced water pressure. "We really don't have enough water to fight fires or deal with anything on pretty much the west side of town," Vallejo Battalion Chief Cliff Campbell said.
The fire department called in water tender trucks from neighboring agencies to help. "At this time we're trying to prepare for the worst case scenario from the fire standpoint," Campbell said.
City leaders could not say how old the pipe is or how much water is being lost. "At this point we're trying to pump the water out of the cavern so we can get in there and turn the water off," Vallejo Acting Information Officer Joanna Altmon said.
The water in the city is safe to drink, but officials are asking residents to avoid using water in the affected area until the break is repaired in order to help keep positive water pressure on the line.
Officials isolated the area impacted by the water main break to an approximate four to six block area east of Broadway Street between Tuolumne Street and Sereno Drive, and east to Peach Street.
Crews are at the scene working on repairing the water main break. Officials say water will be turned off within the affected area by 5 p.m. in order to conduct repairs and water service is expected to be completely restored by 4 a.m. on Sunday.
Drinking water is available at fire station 23 at 900 Redwood Street and at fire station 28 at 970 Nimitz Avenue on Mare Island, EOC spokeswoman Elicia Ricciardi said.
Residents who cannot leave home can have water delivered to them by calling the EOC at (707) 648-5526. Officials say water will be available until 8 p.m. on Saturday.
The City of Vallejo has activated the Emergency Operation Center at 1220 Marin St.
Broadway Street is closed between Sereno Drive and Garibaldi Drive and the railroad has been shut down to rail traffic.
Vallejo Sanitation and Flood Control District is working with the city to clear storm drains and direct water flowing from the main break down the drains. Water is being pumped from a mobile home park that is being affected.
Some living living in the mobile home park that flooded said the response by emergency officials was slow. "The city didn't have anything ready or aware of what to do and how to handle it and so we lost like I said thousands and thousands of gallons of water," Mahlon Hopkins said.
Mutual aid is being provided by the cities of Benicia, American Canyon, Fairfield and Dixon, and the Vacaville and Suisun Fire Protection Districts in the form of 2,000 to 3,000 gallon water tendres tha twill support fire suppression efforts as needed.
Salvation Army is prepared to assist as needed.
Bay City News contributed to this report.