Vallejo city officials are telling some residents to only use water "if absolutely necessary" because sediment has gotten into water from the Swanzy Reservoir, affecting about 1,000 households.
The affected households are along Lemon Street to Interstate 780 to Laurel Street and south to Pueblo Way, west to Porter Street and north back to Lemon Street, city officials said.
While city officials said the water is safe to drink, despite debris and discoloration, residents should limit usage. Residents may experience no or low water pressure and may see discolored water and sediment coming from their faucets, city officials said.
City officials said the problem arose when the sensor in the Swanzy Reservoir's closed system gave a false reading, causing sediment to be sucked from the bottom into the system.
City crews are working to remove the dirt from the lines.
Swanzy Reservoir is located in south Vallejo, in the hills of the Glen Cove neighborhood near the Interstate 80 Al Zampa Memorial Bridge, which connects Vallejo and Crockett on westbound 80.
The reservoir is one of the oldest reservoirs in the city, dating back to the early 1900s, city officials said.
Vallejo has an estimated population of 121,299, according to the 2016 U.S. Census.