4 September 2006ContraCostaTimesMatt Weiser
On New Year's weekend, Barbara Flores went three days without sleep, and not because she was partying.
Flores and other anxious residents of Sherman Island, on the western edge of the Delta, spent the opening days of 2006 battling one of the biggest floods they'd ever seen.
Waters rose to the crest of the island's levees. Wind-whipped spray from crashing waves blew over the levee in a stinging fusillade, threatening to flood the island.
"We came close. Real close," said Flores, manager of Sherman Lake Resort on the island's western tip. "The only reason it didn't flood is because the wind stopped."
The Sacramento and San Joaquin rivers converge at Sherman Island, putting Flores in the cross hairs of the Delta's biggest wind and waves. This makes Sherman Lake Resort, humble and weather-worn though it is, one of the world's top windsurfing destinations.
But the resort has another distinction: It is highly vulnerable to sea level rise from impending global warming.
The resort sits at one of the lowest levee points in a flood-control system that protects the Delta as a fresh-water supply for 23 million Californians -- from computer wizards in Silicon Valley to financial gurus of Los Angeles.
If these critical levees on the Delta's front line failed, seawater would rush into the Delta, poisoning the estuary with ocean salts and forcing water export pumps and canals to be shut down.
This is a big enough threat in the conventional 100-year storm that flood managers plan against.
But new research suggests climate change makes this troubling scenario even more likely.
Warmer temperatures could cause a 1-foot sea level rise in the Delta by 2050, according to a new report by the state Department of Water Resources. Added to severe winter storm conditions, the report finds, this would likely overtop not just Sherman Island, but also Webb Tract and Jersey Island, nearby islands also considered vital to Delta water quality.
Global warming is also expected to reduce the Sierra snowpack. This means less water stored for summer runoff but boosts winter river flows, putting additional strain on levees across the Central Valley, including Sacramento's.
And that's not all. Climate scientists estimate sea levels could go up an additional foot by 2100.
"We are not, at this point, doing anything about it -- at our peril," said Jeffrey Mount, a geology professor at UC Davis who has documented additional threats to the Delta from earthquakes and weak levees. "There is little doubt the situation is changing, and changing very rapidly, and we have got to come up with a strategy to adapt."
There is broad agreement among scientists that these effects will come to pass. Sea levels are already trending upward, rising 8 inches in the past century. But uncertainty lingers about how fast change will come, and how big it will be.
At first, swollen rivers will pose a bigger threat than sea level rise, said Dan Cayan, a climate scientist at the Scripps Institution of Oceanography in San Diego.
"Later on, what happens is that sea level rises so much that you hardly even need a storm to create an event that is kind of exceptional," said Cayan, who studied the issue for the California Climate Change Center. "They're potentially bad events and they could overtop structures."
The vast majority of scientists agree that human activities contribute to climate change. Burning fossil fuels to make electricity and move vehicles releases carbon dioxide, which traps more of the sun's heat in the atmosphere.
Temperatures will climb in western North America between 3.6 and 9 degrees Fahrenheit by 2069, according to the Intergovernmental Panel on Climate Change, the leading scientific authority on global warming.
The heat is melting glaciers, adding water to the oceans, which also expand thermally as water temperatures increase. Low-lying lands all over the planet are likely to be swallowed by the sea as a result.
Weather patterns are changing, too. Global warming is blamed for more and stronger hurricanes worldwide, such as Hurricane Katrina that devastated the Gulf Coast one year ago.
Californians are starting to understand how global warming could damage the Delta. Failure of the Sherman Island levees, for instance, could cause salt intrusion, widespread water scarcity, crop failures and job losses.
Peter Gleick, president of the Pacific Institute, an Oakland-based think tank, fears the state isn't moving fast enough to protect the Delta.
"The truth is, we knew a lot 20 years ago (about climate change) and nobody was listening," he said. "We know a lot more now and people are beginning to listen. But 20 years has gone by, and we don't have another 20 years to do nothing."
State officials say they are moving quickly to understand the risks.
By 2008, DWR will complete a comprehensive study of the risks to the Delta environment, its infrastructure and water supplies. This will guide a follow-up plan to make the region sustainable in the face of climate change and earthquakes.
Billions may have to be spent armoring some islands. Others might have to be abandoned. Major new plumbing may be needed to carry fresh water from the Sacramento River to pumps in the south, bypassing the fragile Delta completely.
"We can either sit here and let the Delta change around us, as it will, or we can help guide this," said Jerry Johns, DWR deputy director. "There's a sense of urgency that now's the time to make it happen. As far as I'm concerned, everything is on the table."
But others say the state is neglecting important actions, such as water conservation and controls on development in flood plains.
These are needed now to accommodate growth and public safety, argues Jonas Minton, a senior project manager at the Planning and Conservation League.
Minton, a former DWR deputy director, said the state has not imposed water conservation mandates in years, despite Gov. Arnold Schwarzenegger's support of strategies to combat global warming.
"I haven't seen any new initiatives from this administration on conservation," Minton said. "There's a notion that climate change is somebody else's problem to solve."
He pointed to the California Water Plan Update, a state forecast released every five years. Its purpose is to help local governments plan growth. But Minton said the 2005 plan did not signal any loss of water due to global warming, though the state's own computer models show a smaller snowpack could mean 10 percent less water statewide.
The state has identified water conservation as a vital strategy to accommodate urban growth, and DWR has urged local agencies to adopt voluntary measures, Johns said. But he acknowledged more needs to be done.
Another major hurdle: Some Delta stakeholders still question global warming. There is more agreement about the threat than ever, but lingering doubts could hinder action. Once the state's research is done, it will ask local people to help decide how to avoid future threats.
"On a personal level, I'm not so sure that global warming is a happening thing," said Tim Neuharth, a pear grower on Sutter Island in the Delta. "Should we do something about it now? Well, maybe."
Some water agencies, however, are preparing for a time when the Delta won't be available as a fresh water source.
The Inland Empire Utility Agency serves 800,000 customers in San Bernardino County. It gets 30 percent of its water from the Delta.
The agency has launched massive water conservation efforts and provides treated wastewater for landscaping through a new system of pipes. It is recharging groundwater to avoid relying on Delta imports.
It is also working directly to combat global warming by operating two power plants that make electricity from dairy waste, and its headquarters is powered by solar panels.
General Manager Richard Atwater said all these efforts fit together. If we get control of climate change, maybe sea levels won't rise enough to threaten the Delta. But he said we must be ready just in case.
"We've looked at lots of studies that say the probability of the Delta islands failing are significant," he said. "There's a lot of discussion and debate about it. But I think action is something that we need to see."
