The Bay Delta Water Plan and the Threatened Water Supply to Sacramento

Now that effects of climate change are visible in the landscapes and ecosystems across the world, it is about time that policy is responding to changes predicted by computer models. According to these predictions, in California, a dramatically shrunken Sierra Nevada snowpack will produce less runoff, with changes to seasonal timings that will mean more rain and less snow in the winter leading to decreased snowmelt in spring and summer, resulting in drastic depletion of the Sacramento water supply.

By the year 2060 – maybe even earlier – water levels in the Folsom Reservoir could be so low for one year in ten that it will cease to be a reliable water source for the city. It will likely become what is known as a ‘dead pool,’ meaning that although there may still be some water behind the dam, it will no longer flow from the outlets. Similar predictions have been made for the Shasta and Oroville reservoirs, and access to water from the American River is also predicted to be under threat.

Water wars

Discussions about improving the water supply to the area by creating new diversions from the Sacramento-San Joaquin Delta have continued for decades. In the 1982 referendum on the issue, a proposal to move the main diversion point from its current position near Tracy in the south Delta was rejected, resulting in further decades of argument between the vested interests of the cities, farmers and conservationists – the so called ‘water wars,’ which can also be characterized as an argument between the dry south and the wetter north.

The importance of the Delta to California’s economy cannot be overstated. A large proportion of the nation’s supply of fresh vegetables, fruit and nuts are produced in the San Joaquin and Santa Clara valleys, which rely on Delta water, and the many river channels that crisscross the hundreds of square miles of the Delta’s islands are important migratory routes for Chinook salmon, on which an important sector of the West Coast fishing industry is dependent. The delicate and complex balance of fresh and salt water in the estuary supports several other native fish species, but recent years have seen severely reduced populations. Measures introduced to protect the Delta smelt and salmon have reduced water supplies to cities and farms, and the current infrastructure for water delivery has been recognized as vulnerable to disruption.


Change was inevitable. After seven years of studies, federal, state and local leaders, together with some of the major Southern California and San Joaquin Delta water suppliers, introduced the Bay Delta Conservation Plan (BDCP), whose aim was to address all these issues and to balance the needs of fish, farms and cities (this is available for public review until April 14, 2014). The plan is commonly known as ‘the tunnel project’ because of its proposed diversion of a portion of the water flow in the Sacramento River to pass underneath the Sacramento-San Joaquin Delta in two 35-mile tunnels.

This has caused concern amongst conservationists and politicians alike, notably by Friends of the River and the Sacramento City Council. Preliminary analysis on the plan’s environmental impact has shown that the likelihood of the dead pool effect occurring would not be reduced by the building of the tunnels, and that in some months and in certain conditions it may even worsen the effect. The Council also criticized the plan for its short term view, that it would do nothing for the predicted long term problems of the region’s water supply, and that it concentrated on stabilizing water flow to southern areas of the state while giving no assurances about solving the threat of water shortages in Sacramento.

Arguments over the plan highlight the difficulties in deciding California’s future water supply based on reasonable assumptions today. Even the most rigorously designed computer models show varied water supplies.  Slight changes in the assumptions can result in significantly varied scenarios and diametrically opposed positions being defended by politicians and vested interests. For example, the Department of Water Resources (DWR) deputy director for water management, Paul Helliker, has shed doubt on the dead pool problem, stating: ‘The driver of these future conditions is the climate change assumptions. What we’re showing is that there is no impact from BDCP operations on either Folsom or Shasta.’

Action and criticism

In October 2013 a proposed Final Draft Delta Science Plan was published, which outlined the stages for future development of the Sacramento-San Joaquin Delta water supply system. Its aim is to protect declining native species while maintaining the water supply and building up the economy of California, and to act as a catalyst to promote the sharing of scientific knowledge and expertise that will lead to workable solutions. It acknowledges that conflicting ideas hinder the decision-making process and slows the development of important infrastructure projects. The risks of damage to the fragile Delta water system by droughts, floods, earthquakes or climate change is severe, and there is a pressing need for decisive action to be taken. To this end, the 2009 Delta Reform Act created the Delta Stewardship Council, which now has the task of implementing the BDCP.

However, in June 2013, Friends of the River and a coalition of environmental groups from Southern and Northern California with Delta farming and fishing communities filed a lawsuit in the San Francisco Superior Court asserting that BDCP violates the California Environmental Act, the 2009 Delta Reform Act and the California Administrative Procedure Act. The coalition claims that BDCP and its environmental impact report have failed to disclose or analyze the potential damage to the Delta, the rivers of Northern California and the endangered native fish species by the diversion of huge quantities of fresh water from the Sacramento River, and has requested that the court suspend implementation of the plan, including construction of the tunnels, until all legal requirements have been met. Senior counsel for the coalition, Bob Wright, has described the plan as the worst threat to these rivers in their history, and that the state authorities have embarked on this plan to move large volumes of water with no regard for the consequences. He said: ‘Seeking relief from the courts is now necessary to protect our rivers and fish from this arbitrary, destructive action.’

Plowing Ahead

With season of drought well underway, following a record breaking dry year, pinned against a thirst for California’s economy to grow, the BDCP must leverage its scientific expertise and broad coalition to determine how to take the long-view to benefit the most stakeholders, while doing the least harm. Given the wide-ranging interests of municipalities, industry, infrastructure development, agriculture, and winter recreation, steering consensus will take strong  and sustained leadership. Can underground transport and storage be implemented legally and managed responsibly? If so, these infrastructure investments would positively impact economic growth and long-term water security. Regardless, while the future of Sacramento’s water is reconfigured in the courts, the root causes of climate change and water scarcity plow ahead.

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