California’s water wars appear to be entering a new chapter as the U.S. Department of Justice and Department of the Interior announced a lawsuit on Thursday against the State Water Resources Control Board over a controversial plan that would divert more water from New Melones Reservoir to the Sacramento-San Joaquin Delta.

A joint press release stated that civil actions were filed in both state and federal court alleging that the board failed to comply with the California Environmental Quality Act by approving amendments on Dec. 12 to the Water Quality Control Plan for the San Francisco Bay/Sacramento-San Joaquin Delta Estuary.

“The environmental analysis by the (board) hid the true impacts of their plan and could put substantial operational constraints on the Department of the Interior’s ability to effectively operate the New Melones Dam, which plays a critical role in flood control, irrigation, and power generation in the Sacramento region,” said Assistant Attorney General Jeffrey Bossert Clark, of the DOJ’s Environmental and Natural Resources Division.

Part of the plan would require an average of 40 percent unimpaired flows in the three tributaries of the San Joaquin River, which are the Stanislaus, Tuolumne and Merced rivers. That would reduce the amount of water for humans by 14 percent, according to the State Water Resources Control Board.

The Department of the Interior wrote a letter to the board last year opposing the plan that stated the increased flows would also reduce the average amount of water stored in New Melones Reservoir by 315,000 acre feet per year.

The board argued the increased flows are needed to prevent an ecological crisis in the Delta, the primary source of drinking water for more than half of all residents in California and irrigation for a third of its farmland.

According to the press release, the board didn’t comply with the law that requires state and local government agencies to identify significant environmental impacts of their actions and avoid or mitigate those impacts if possible by allegedly:

• failing to provide an “accurate, stable and finite project description,” because the project description and the one analyzed by the board were materially different;

• masking potential environmental impacts by including carryover targets and other reservoir controls in its analysis of impacts, and;

• inadequately analyzing certain potential impacts of the plan, specifically regarding water temperature, related water quality conditions, and supply.

The increased flows would put operational constraints on the Bureau of Reclamation, which is under the Department of the Interior and operates New Melones Dam, according to the press release.

The release further stated the plan would make it more difficult for the bureau to meet the congressionally authorized purposes of the reservoir, which include flood control, irrigation, municipal and industrial uses, power generation, and recreational opportunities.

“The plan poses an unacceptable risk to Reclamation’s water storage and power generation capabilities at the New Melones Project in California and to local recreational opportunities,” said Bureau of Reclamation Commissioner Brenda Burman in the press release.

While Tuolumne County doesn’t have any water rights in New Melones Reservoir, which straddles Tuolumne and Calaveras counties, local officials have said it’s a boon to the local economy as a draw for recreation and provides local public agencies with low-cost power.

A letter sent by the Department of the Interior to the board last year warning of potential lawsuit stated that the reservoir attracted roughly 450,000 visitors in the 2016-17 fiscal year, up from 286,842 visitors in the 2014-15 fiscal year when the water level was at a near-historic low in the midst of a five-year drought.

The state is also being sued over the plan by a number of other entities, including the Oakdale and South San Joaquin irrigation districts, who each have historic water rights that make them first in line for a portion of the water that flows into the reservoir each year.

Contact Alex MacLean at or (209) 588-4530.