A half-dozen water agencies have cast their lot with environmental groups in calling on California to study a scaled-down alternative to the $14 billion Sacramento-San Joaquin River Delta tunnels endorsed by Gov. Jerry Brown to bring water from north to south.
Proponents say a single, smaller tunnel coupled with investments such as water recycling and desalination would result in more water for cities and farms. They say it also would be better for the environment and cost less - with construction estimated at $5 billion to $7 billion.
Agricultural groups say a scaled-down water conveyance would be devastating to farmers in the Central Valley, who rely on the delta to irrigate thousands of acres of crops.
The proposal is a sign of how California's water wars have evolved.
"The big fight over the delta used to be between environmentalists and thirsty cities who wanted more water," said Barry Nelson, senior policy analyst at Natural Resources Defense Council, which supports the alternative. "But now, there's a growing list of cities whose plan it is to become less reliant on the delta and to invest in local solutions. There's common ground there."
The health of the delta, the hub of California's water delivery system, has long been deteriorating. Massive pumps which draw drinking water for more than 25 million Californians and irrigate vast expanses of crops are blamed for declines in once-abundant fish populations.
Declines in tiny delta smelt, salmon and other species have spurred regulations that curtail delta pumping. In dry years, limited water deliveries have led some farmers to let fields lie fallow and communities to impose water-use restrictions.
In July, Brown and Interior Secretary Ken Salazar announced support for massive 35-mile twin tunnels to carry water south. The proposal also includes plans for more than 100,000 acres of floodplain and tidal marsh habitat restoration.
The project, called the Bay Delta Conservation Plan, must satisfy two goals: restore the estuary's fragile ecosystem and provide a more stable water supply to residents and farmers.
Officials say the tunnels would divert water beneath the delta, lessening the impact of pumps on fish. The amount of water to be diverted would be determined once the project is built, based on the health of the species.
The entire project would cost $23 billion. Water agencies would pay $14 billion for construction and $5.8 billion for operations. Some $3.2 billion for habitat restoration would come from a voter-approved bond on the November 2014 ballot.
During his State of the State address Thursday, Brown said construction costs would be similar to the London Olympics. "But this project will serve California for hundreds of years."
Environmental groups and seven water agencies want the state to examine their newest proposal as a stand-alone alternative during the environmental review process, which is be completed by the end of the year. State officials will decide whether to include the new alternative for consideration.
In addition to a smaller conveyance and investment into local projects, the new proposal includes strengthening delta levees to protect the water supply from earthquakes, investing in more south-of-delta storage, and 40,000 acres of habitat restoration. Total cost is estimated at $14 billion to $16 billion.