Tracy-area water managers are watching closely as a major source of local water supplies has become the center of lawsuits challenging the state’s proposed redistribution of Sierra runoff water in this region.
Among the water agencies that filed suits last week against the State Water Resources Control Board is the Manteca-based South San Joaquin Irrigation District, which provides as much as 70 percent of the city of Tracy’s potable water.
Tracy-area irrigation districts, including Banta-Carbona, West Side and Byron Bethany, also depend on water flowing in the lower reaches of the San Joaquin River and southern Delta.
Joining SSJID in the suit filed in Tuolumne County Superior Court were the Turlock and Oakdale irrigation districts and the City and County of San Francisco. The Modesto Irrigation District has filed a separate legal challenge.
Rick Gilmore, general manager of the Byron Bethany and West Side districts, reported that those districts have no plans at this time to file any kind of legal challenge, “but we are monitoring the situation closely.”
He said there was still a possibility that the state water board and water agencies could reach agreements on how water is allocated, obviating the need for further legal action.
The suits, filed Jan. 10, challenge a Dec. 12 decision by the state water board to approve a Bay-Delta water quality control plan that would limit the proportion of natural flows — without dams and diversions — in the river system that are available for agriculture and municipal uses. The shift would provide more water for wildlife, mostly salmon.
The irrigation districts rely on flows from the San Joaquin River’s tributaries and the Tuolumne and Stanislaus rivers to provide quantity and quality of water.
The city of Tracy has an annual contract with Manteca’s SSJID for 10,000 acre-feet of high-quality Sierra runoff water pumped through a pipeline from Lathrop to Tracy’s water tank near Linne Road. That water is mixed with water of lesser quality from the Delta-Mendota Canal that is processed at the city’s water treatment plant at Tracy Municipal Airport.