2012-2014 BDCP Blog


Click here to contact us with your questions or comments about the BDCP Blog.

Go Back

Part I: The Delta - Origins of Controversy

By Jerry Meral, Deputy Secretary, California Natural Resources Agency

Californians have been debating the role of the Delta and the best way to move water to where it's needed for nearly 70 years. The recently released draft Bay Delta Conservation Plan and accompanying draft Environmental Impact Report/Environmental Impact Statement (EIR/EIS) reflect the ongoing evolution of Delta water policy in the critical areas of supply, water quality, environmental impacts, species preservation and the interests of the Delta communities. This is the first of a three-part blog that summarizes how our understanding of these issues has changed in relation to the dynamic growth of California and our constantly expanding appreciation of the needs of its environment.

Part I: The Delta - Origins of Controversy

The State Water Project was developed to bring water from Northern California to support the growing needs of the Bay Area, Southern California and the Central Valley after World War II. As it was being designed in the 1950s, the Department of Fish and Game (DFG) was concerned that increasing the draw of water across the Delta -- on top of existing diversions by the U.S. Bureau of Reclamation through the Delta Cross Channel -- would draw millions of young fish (especially salmon, striped bass, and other sports fish) into dead-end channels in the south Delta. Although state and federal screens would capture many of them, some would still be lost in the process of trucking and relocation mortality. Other fish would inevitably be destroyed by predators and the operation of water export pumps.

DFG was supported in this view by commercial and sport fishing interests, and by powerful recreational boating advocates. The boaters wanted to isolate the water project's operations from the Delta channels for fear that some of those channels might otherwise be closed to boating in order to facilitate the export of water.

The combination of these forces helped convince the Department of Water Resources to advocate for a Peripheral Canal to divert water from the Sacramento River and convey it around the eastern periphery of the Delta to the state and federal pumps near Tracy.

Delta residents then as now strongly opposed any proposal to bypass the Delta or reduce the flow of water through it. Further consideration of the proposed bypass facility was set aside during the construction of the first stages of the State Water Project. The election of Governor Reagan in 1966 led to reduced support for public works. Although planning on the Peripheral Canal slowed during his tenure, Governor Reagan at the end of his second term, in 1974, did allow the Department of Water Resources to prepare an Environmental Impact Report on the Canal.

With the arrival of the first gubernatorial administration of Jerry Brown, concerns about fish and recreational boating continued, but new concerns were added. Saltwater from San Francisco Bay is repelled from the Delta during low-flow periods by releasing water from upstream state and federal dams. Hydrologists at that time believed that when water was being exported from the Delta, it was necessary to release enough water from upstream dams to allow some fresh water to pass around the west end of Sherman Island on its way to the South Delta pumps. There were concerns that some of this water was lost to San Francisco Bay. Hydrologists thought that by building the Peripheral Canal, the export water could be isolated from the water released to repel salt, and saved in reservoirs for eventual export.

Today hydrologists believe that these losses are not substantial enough to measure accurately. More important, increased water quality requirements in the Delta largely rendered the concern moot. This is an example of how improved knowledge and increased regulation have eliminated old concerns but created new ones.

Another increasing concern in the 1970s focused on the reduction of water quality as water passed from the Sacramento River to the Delta pumps. Natural chemicals in organic Delta soils add trihalomethane precursors (THM precursors) to the water. These chemicals come from water pumped from the farmed islands and discharged into Delta channels to keep the soil dry enough for agriculture. Carcinogenic THMs form from THM precursors when the precursors go through the water treatment processes that were standard during that era.  

Modern treatment processes remove these chemicals, but concerns about contaminants in the Delta have certainly not diminished.  The costs that California consumers pay for treatment to restore water quality after its passage through the Delta would be significantly reduced with an isolated facility. In addition, the dissolved salts in the water exported from the south Delta are 100 percent greater than the fresher water from the Sacramento River. This makes Sacramento River water more attractive for those who wish to encourage the recycling of municipal wastewater.

Coming next: The Delta in Our Time

Facebook Twitter DZone It! Digg It! StumbleUpon Del.icio.us NewsVine Reddit Blinklist Add diigo bookmark