The Bay Delta Conservation Plan, known as the BDCP, is a federal and state initiative financed by California's water contractors, which includes recommendations for a twin tunnel project in the delta to carry water to vast farmlands and thirsty cities.
The plan's first four chapters, released by the California Resources Agency, spell out the dismal state of the delta and detail conservation strategies to restore its dwindling fish species.
The chapters include a description of the proposal unveiled by Gov. Jerry Brown in July: the 35-mile twin underground tunnel project that would replace the delta's current pumping system. It would cost $14 billion to construct. The costs would be covered by water contractors.
The chapters also describe more than 200 biological goals and objectives for 57 fish and other species - such as the growth rates of individual fish and overall increases in a species' population - which will guide implementation of the plan over coming decades. That means if species don't recover or don't recover quickly enough, less water would be pumped, water officials said.
The delta pumps water to 25 million people and to 3 million acres of farmland. But in recent years, as fish populations continued to plummet, federal management plans have limited the amount of water that can be pumped from the delta in order to protect fish species.
In addition to the twin tunnels, the plan also calls for creation of more than 100,000 acres of new habitat - floodplains, tidal marshes and grasslands - at a cost of $3.2 billion; 30,000 acres of that habitat would be created in the next 15 years.
Water contractors and federal and state officials said the twin tunnels, coupled with new habitat, would improve the delta ecosystem, protect the delta from levee failures and earthquakes, and strengthen the state's water supply.
That's because the twin tunnels would take water in the north of the delta, preventing threatened fish such as salmon and delta smelt from traveling toward and getting caught up in the deadly pumps in the south, as they do today, proponents said. The project would also come with state-of-the-art fish screens.
Critics, including environmentalists and delta activists, said the project would harm delta species and destroy the delta's agriculture because it proposes to take more water out of the delta and it's not known how the plan will actually affect the delta ecosystem.
Officials said they plan to release other chapters of the BDCP in April. They hope to release a full final draft of the plan by the summer, when it will be open to public comments. The plan still needs state and local approval before construction and habitat preservation work can begin.
If the plan is approved, it would take at least 10 years to build the twin tunnels.