Seeking Cures for an Ailing Ecosystem

As the threat of global warming looms on the horizon, Californians are confronting a rash of problems in one of their most important natural treasures, the Sacramento-San Joaquin Delta

  • Hannah Schardt
  • Aug 01, 2007
IN THE CENTURY and a half since gold was first spotted in California's foothills, a more precious Golden State treasure--the vast delta that lies where the Sacramento and San Joaquin Rivers meet and flow into San Francisco Bay--has been dramatically reshaped by humans. The 1,500-square-mile Sacramento-San Joaquin Delta was once a biologically rich, wild tangle of streams and marshes. But these days, the region is drained by pumps and divided by 1,100 miles of levees in order to provide drinking water for 22 million Californians and irrigation for the most productive agricultural system in the country. And though the delta still provides habitat for more than 500 species of wildlife--including 20 endangered species--Californians are now confronting the reality that this most valuable of resources is not inexhaustible.

"Since 2000, water exports have risen to their highest levels on record and the health of the delta ecosystem has plummeted," says Mindy McIntyre, water program manager at the Planning and Conservation League, NWF's California affiliate.

The list of what ails the delta is long and growing. Runoff from farms, factories and cities pollutes the water. Invasive species push native plants and animals out of their habitat. Flood-control levees, strained by the increased demands of rapid residential development, are at risk of crumbling--disastrously so, if a major earthquake should occur. Giant pumps move much of the rivers' water downstate to Southern California's thirsty farms and cities. And scientists fear that rising sea levels--caused by global warming--could turn the vast estuary into an inland salty sea.

In recent years, populations of several of the region's aquatic species have dropped to their lowest numbers ever recorded. The threatened delta smelt, for example--a small, nearly translucent fish that is considered a canary in the coal mine of the region's hydrologic health--has lost as much as 95 percent of its population in the last 25 years and now hovers close to extinction.

Earlier this year, conservation groups filed an emergency petition to include the fish, which lives nowhere else, on the federal Endangered Species List. Meanwhile, chinook and other salmon runs in the San Joaquin River have declined by 90 percent from their historic highs. And while millions of waterfowl and shorebirds--including the northern pintail duck, green-winged teal and sandhill crane--either breed in or migrate through the delta, their populations are increasingly suffering from habitat loss in the region. One thing is clear: The precarious state of this national treasure can no longer be ignored.

"All the stars have aligned" to make people finally recognize the seriousness of the situation, says John Cain, the director of restoration programs for the Natural Heritage Institute, a San Francisco-based nonprofit group. First, the 2004 levee failure of one delta island flooded 12,000 acres of farmland and cost the state $90 million to repair. Then, in 2005, Hurricane Katrina devastated the city of New Orleans, in part because of the catastrophic failure of Louisiana's levees. And a number of recent studies have highlighted the increasing fragility of the delta ecosystem, particularly at a time when rapid residential and commercial development is squeezing the system to what many scientists fear is the breaking point.

"It's not hard to imagine that by 2030, there will be a completely urbanized ring around the delta," says Cain, leaving water managers with less flexibility to flood uninhabited land in order to relieve pressure on the levees. Compounding the problem, many of the delta's levee-protected tracts are actually depressions that lie as far as 20 feet below sea level. That's because the region's peat soil is highly unstable, the product of eons of native tule grass sprouting, growing, dying and being reincorporated. When exposed to the air, the soil decomposes, emitting carbon dioxide and causing the islands to subside even further. According to Huey Johnson, the former head of the state's Resources Agency and the founder of the nonprofit Trust for Public Land, "you can sow a lot of carrots in that fertile delta soil and act like you've got paradise, but what you've really got is a ticking time bomb." And global warming, he says, could be just the thing to ignite that bomb.

If the rise in global temperatures follows the predictions of most climate scientists, "we could have a sea level rise of a foot, or even higher," says Lester Snow, director of the state's Department of Water Resources. Studies also indicate that by 2050, with warming temperatures causing more precipitation to fall as rain and less as snow, California will have lost a quarter of the snowpack in the Sierra Nevada mountain range. The snowpack now acts as a giant reservoir, releasing water slowly in the summer. Such a change could lead to increased flooding, particularly since so much of the land lies below sea level.

"We're starting to factor global warming into our planning for different projects," says Snow. Still, many conservation groups believe that state agencies, including Snow's, are harming the delta by exporting more water than the ecosystem can tolerate. The state, adds McIntyre, is also "failing to inform the public of potential impacts of climate change on delta-dependent wildlife and water deliveries."

Johnson, who has hunted and fished the delta for decades, believes that global warming could be the impetus for its salvation. An increasingly toxic delta, guarded by crumbling levees and at constant risk of catastrohic flooding, is the kind of public health risk that grabs the public's attention. "It's the unifying theme we've been waiting for a long time," he says. "If you can get the public stirred, get people to understand that the health of their children and grandchildren depends upon it, well, maybe that's what it's going to take."

From conservationists to farmers to Governor Arnold Schwarzenegger, everyone with a stake in the delta's future seems to agree that a solution to the region's problems must be large-scale and comprehensive, not merely a collection of short-term fixes. Earlier this year, Schwarzenegger named a blue-ribbon task force to draft a comprehensive plan for a healthy, sustainable delta.

Cain says such a plan must include a sharp curb on further urbanization; a flood control bond measure approved in last November's election could provide funds for the state to buy up and protect key delta lands. "We have the opportunity right now to create a buffer around the delta, to give us flexibility to manage climate change," he says. But before the new task force can come up with a real solution, it must answer what McIntyre calls a fundamental question: How much fresh water does the delta need to sustain its ecosystem?

In the meantime, those who live on and love the delta are watching it continue to degrade. Bill Jennings, the executive director of the California Sportfishing Protection Alliance, lives a stone's throw from the San Joaquin River and has spent thousands of hours boating in the region's waterways. "There's no way to convey the many faces of the delta in words," he says. "When you're out there on your boat at sunset, and there's this purple sky, and the birds come out and you're inching down the canal with ethereal bird sounds all around--I can't convey what a marvelous tapestry it is. It would be a tragedy to lose this."

Senior Associate Editor Hannah Schardt visited the delta while reporting this article.

NWF Priority

Protecting the Great Waters

Many of the nation's large-scale water ecosystems face potentially catastrophic declines in their natural functions due to a number of problems, including global warming. NWF currently is involved in efforts to protect several of them, including the Great Lakes and Everglades, through federal legislation, grassroots organizing and education. To learn more, visit In California, the Planning and Conservation League (PCL), an NWF affiliate, is working with other groups to secure and maintain sufficient water supplies in the Sacramento-San Joaquin Delta to sustain wildlife. Together with NWF, the PCL also has launched the California Climate Outreach Campaign, a statewide effort to advance state, regional and national initiatives to combat global warming.

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