With California enduring the driest year on record, water is now more precious than ever before. There is an ongoing battle for control of one of California’s most vital water resources: the Sacramento-San Joaquin Delta. The Sacramento and San Joaquin Rivers converge in the Central Valley before heading out to sea, forming an intricate network of streams, canals, marshes, and sloughs that comprise the delta. As home to the largest wetlands in the state, the delta hosts a plethora of ecosystems and millions of acres of agricultural fields, as well as drinking water for two-thirds of the state. This expanse of waterways is smack dab in the middle of a battle between farmers, fishermen, conservationists and the government- all stakeholders vying for control.
Water exports are pushing the Delta to the verge of an ecological collapse that could have a devastating impact on the fishing and agriculture industries and the supply of drinking water. The current system has been compared to a “broken pipe” that does not provide a dependable water supply for farmers and California residents and damages the already frail ecology of the Delta. The outcome of this will impact the water you drink, the crops you consume, and the fish you eat- not just in California, but around the world.
Ecological impacts of the current system
At the present, powerful intake pumps draw water from the southern end of the delta. They are capable of pumping out tens of thousands of gallons of water per second. This process has already impacted the natural environment. The export of freshwater has allowed saltwater from San Francisco Bay to penetrate deeper inland, exposing a number of animals and plants to high salinity levels. Higher salinity also provides a more favorable environment for invasive species that can outcompete natives for habitat and food.
One little fish in particular has drawn a lot of attention – the endangered Delta smelt. This finger-size fish can only tolerate a narrow range of salinity, and its habitat in the Delta has shrunk considerably over the last decade. The siphons of the Delta pumps can suck in and grind up small fish like the Delta smelt. To diminish the threat to fish, the water flows through special screening facilities on its way out of the delta. The fish are captured or “salvaged” at these screens, then loaded into trucks and released in another location of the Delta.
There are many problems with this capture and release process. Around 15 million fish per year are captured at the screens, but only a small percentage actually survive the rough screening process. The dump sites for live salvaged fish are often the same spots over and over, unintentionally creating a feeding ground for predators that now know where to pick off the confused little fish.
It’s not just the Delta smelt that is being threatened; many fishermen and conservationists fear that Chinook salmon runs will not endure a drying river in the coming years.
Twenty years ago, the Central Valley Project Improvement Act (CVPIA) was passed with the intention of doubling the wild salmon runs in the Bay-Delta. The goal was to have a population of 990,000 naturally spawning adult salmon by 2002. The index above shows that we were well on our way to succeeding, reaching 63% of the goal just five years after the passage of the CVPIA. This was a huge success – it proved that with the right initiative California could absolutely recover salmon populations. If things had continued as planned, we would have met and possibly even surpassed the salmon doubling goal.
But after another 5 years, everything changed. The export pumping from the Delta was increased by 20% in 2000-2006 to meet the demands of Central Valley agriculture, essentially turning the delta into a death trap for juvenile fish. This very likely was responsible for, or at least contributed significantly to, plummeting numbers of salmon and the consequential collapse of the salmon fishery in 2008 and 2009. There are of course many other factors to consider as well, such as ocean conditions, predators, and overfishing. But we have powerful evidence of our impact on the basic life cycle of the salmon. Adults return to their home stream to spawn three years after hatching. Each year has its own cohort – a group of salmon that hatched at the same time. The first drop in population occurred with the 2003 run, which would have been the juvenile cohort in 2000 – the first year that pumping was increased. Each year thereafter, the number of adult spawning salmon steadily declined. In 2009 pumping levels were brought down to a more sustainable level. We can see the run in 2011 increased in number when the adults from the 2009 juvenile cohort returned to spawn. This provides important evidence that proper water management in the Delta is essential for depleted fish populations to rebound.
The Delta tunnel controversy
The Delta provides critical habitat for numerous fish, birds and other wildlife. It also supplies 25 million Californians with drinking water and its flows sustain a $30 billion agricultural industry. With impending threats such as urban growth, pollution, aging levees, the possibility of earthquakes, and climate change, everyone agrees that the water infrastructure for the Delta must be improved. However, not everyone agrees on the proposed solutions. Decades of conflict and disagreement have resulted in gridlock. The ultimate goal is to protect the delicate ecosystems of the Delta that provide habitat for animals and plants while improving the reliability of the water supply for California’s farmers and residents.
The California Department of Water Resources (DWR) is working in partnership with federal agencies and local water districts to change the way that California diverts the flow of the delta to farms and Southern California Cities. The newest proposal surrounds the construction of two massive tunnels that would draw water further upstream on the Sacramento River. The proposed tunnels would each be 40 feet wide and run 35 miles long from Freeport to Tracey and would be able to carry almost the entire flow of the Sacramento River during the dry season. These tunnels would whisk the valuable water away to farms and cities in the south before it ever reaches the Delta. The cost of building the tunnels runs in the tens of billions of dollars.
Earlier this month, the Bay Delta Conservation Plan (BDCP) released an environmental impact assessment for the tunnels and opened it for public comment – all 34,000 pages of it. By diverting the water upstream on the Sacramento River, the installation of these tunnels could have, and will have, a substantial effect on how water flows through the wetlands. Proponents of the plan say that the tunnels will return the water flow to historic levels and work towards restoring the ecosystems of the Delta while providing a reliable water supply for farmers and California residents. Opponents say the diverted flow could be destructive for the sensitive plants and animals that are already suffering from a lack of adequate water and habitat.
Resolutions for the Delta
With so much at stake, it is hard to imagine that any resolution will be agreed upon anytime soon. It is likely that this debate will continue for years. Unfortunately, the water situation in California is desperately in need of economic and ecological repair. Communication and compromise between the numerous stakeholders is key to unraveling California’s water woes and insuring a sustainable future for residents, farmers and fishermen.