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BYRON, CALIFORNIA—In a makeshift labora-tory that was once a refrigerated shippingcontainer, Joan Lindberg, a research biologistat the University of California (UC), Davis,shines a small flashlight into a 2-meter-diameter water tank. Two-centimeter pencil-thin f ish known as delta smelt dart awayfrom the light. These small fish, native to theSacramento–San Joaquin River Delta thatflows just beyond these tanks, are bred andfarmed out to fisheries biologists throughoutthe region who are racing to understand theirlife cycle, feeding habits, and vulnerabili-ties. It’s a race that’s now in full sprint, as thepopulation of delta smelt in their native habi-tat is in free fall.

Historically, millions of the fish swamthis delta, which sits just east of SanFrancisco Bay and is the largest estuary onthe West Coast of the United States. But a

survey of juvenile smelt conducted in Junefound only 37, down from 884 found a yearearlier. More than 700 smelt were killed thisspring by a series of massive pumps nearbythat suck a river’s worth of water out of thedelta and send it south to Los Angeles andSan Diego. But the water exports are onlyone of the smelts’ problems, with pollutionand invasive species also topping the list ofconcerns. Now, with the delta smelt teeteringon the edge of extinction, Lindberg and hercolleagues are looking into ramping up theirfish-breeding efforts to try to prevent thefish from going extinct. “We’re doing whatwe feel is prudent to save the wild f ish,”Lindberg says.

More than a kilometer up the road, a sec-ond set of massive pumps sucks out anotherriver’s worth of water and sends it primarilyto farmers in California’s Central Valley.

Here, as technicians survey fish caught in amesh bucket designed to pull fish from thewater before it’s sent to the pumps, they lookintently for smelt and other endangered fish.Today, no delta smelt are among the dozensof striped bass, catfish, and other fry caught.But one was snagged just days earlier, whichwas enough to send shudders through thisfarming community. “What comes out ofthat bucket can determine the economicfate of California’s cities and farms,” saysJeffrey McCracken, a spokesperson for theU.S. Bureau of Reclamation (BOR), thefederal organization that runs the CentralValley Project pumps.

The comment may sound hyperbolic, butit’s not. Twenty-five million Californians,nearly two out of every three, depend on thedelta for at least some portion of their drink-ing water. Central Valley farmers, the heartof America’s vegetable, fruit, and nut pro-duction, are even more dependent, as thedelta provides irrigation for about 1 millionhectares of farmland. And although waterfrom the delta has flowed to these users for

Delta Blues, California StyleThe hub of California’s freshwater system is plagued by crashing fisheries,high demand, invasive species, and pollution—and a major earthquakethere could devastate the state’s drinking water and agriculture

Sunken landscape. Drained fields have subsided well below

the waterways, requiring highlevees to keep the water at bay.

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decades, that might not always be the case. InMay, citing the U.S. Endangered Species Actand the hundreds of delta smelt killed at theState Water Project pumping facility nearby,a California Superior Court judge orderedthe pumps shut down for 10 days, a rare movethat fired a shot across the bow of water man-agers statewide. “This is a very importantwake-up call for California,” says LesterSnow, head of California’s Department ofWater Resources.

But the smelt is only the delta’s mostimmediate concern. Several other f ishspecies native to the delta are also in steepdecline, also battered by loss of habitat, pol-lution, and competition from hundreds ofinvasive species. Rising sea levels promptedby climate change threaten to push salt waterfrom San Francisco Bay much farther inland,possibly even overwhelming the southerndelta region where fresh water is drawn forpeople and irrigation. Finally, the delta ishome to a labyrinth of 1770 kilometers ofearthen levees designed to channel the delta’swater on its way to the bay. Those levees,some 130 years old, sit near six seismic faultsthat crisscross the region, and it’s widelyfeared that a major quake could produce cat-astrophic levee failures that would wipe outwater supplies for tens of millions of people(see sidebar, p. 444).

“The delta is a mess,” says Phillip Isenberg,who chairs the Delta Vision Blue RibbonTask Force appointed by California Gover-nor Arnold Schwarzenegger last year tocome up with potential solutions for thedelta. At a congressional field hearing onthe delta in Vallejo, California, earlier thismonth virtually all the participants agreedwith Isenberg that the Bay Delta is in crisisand the way it is currently managed isunsustainable. Now, Isenberg says, Califor-nians must make some hard choices con-cerning competing interests for the water,municipalities, farms, and the environmentbeing among them. “If we do not make thesedifficult choices, then extinction—whetherof a species or a way of life—may be thewater policy of California,” said Isenberg inwritten testimony.

Changing tides and riversIt’s a problem that’s been brewing for a longtime. The Sacramento–San Joaquin RiverDelta is the hub of California’s water sys-tem. It’s an expansive inland river delta com-prising 300,000 hectares of land interlacedwith hundreds of kilometers of waterways.Historically, those waterways shifted courseseasonally as water draining from the north-ern Sierra flowed down into neighboring

San Francisco Bay. That began to changeshortly after settlers flocked to the region inthe gold rush of the 1840s and 1850s. In1869, farmers began draining and dikingland within the delta, ultimately creating apatchwork of some 65 “islands.” However,unlike natural islands that rise above the sur-rounding water, the delta’s islands are actu-ally vast bowls ringed by levees to keep thewater at bay. Over time, this challenge ofholding back the tidal waters has steadilyincreased, as exposure of the former mudflats to the air has oxidized and compactedthe peat-rich soils, causing central farm-lands within the delta to subside a full 6 to8 meters below sea level. Delta farmers haveresponded by building their levees higher,fully engineering some of the breakwatersbut simply creating giant mounds of dirtwith most of the others.

The levees were only the first of majorchanges to the delta. With the levees in place,farmers within the delta itself began siphon-ing off roughly 1 million acre-feet (1.2 billioncubic meters) of water per year, enough toprovide the yearly water supply for roughly

2 millionCaliforniafamilies.As Cali-f o r n i a ’spopulationboomed in the early 20th century, other userseyed the delta’s abundant water. Beginning in1951, a series of five massive pumps at theC. W. Jones Pumping Plant began taking outwater for Central Valley farmers and nearbycommunities. Early on, the Central ValleyProject typically pulled out around 2 millionacre-feet of water per year. But over time, thatnumber has risen to around 3.3 million acre-feet (4 billion cubic meters) of water per year.Meanwhile, withdrawals by the State WaterProject, which sends water to southern Cali-fornia, have risen from about 1 million acre-feet (1.2 billion cubic meters) per year in 1968to 4.2 million acre-feet (5.2 billion cubicmeters) per year today. In a dry year, thosediversions can amount to about one-third ofall the water that would normally flowthrough the delta into San Francisco Bay. Thedraw from the pumps is often so great thatsome river channels through the delta actuallyflow backward, upstream toward the pumps ata pace too brisk for the smelt and other weakswimmers to escape.

Not everything in the delta is on its wayout. More than 200 invasive species nowmake the delta the most invaded estuary inthe world. The invaders, including every-thing from striped bass to a fast-growing

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Barely hanging on. The delta smelt, once prolific, isnow endangered.

Changed delta. Landsat image shows the delta’s patchwork ofsunken islands surrounded by hundreds of kilometers of waterways.

Sacramento andSan Joaquin Basins

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aquatic weed known as Egeria, havemarkedly changed the delta’s habitat. Urbandevelopment is also on the rise and isexpected to add another 130,000 homes in theregion over the next decade and more thandouble the region’s population to 7.7 millionby 2050. And pollution from urban runoff,sewage, and agricultural chemicals has alsobeen growing steadily.

That combination has challenged fish pop-ulations for decades. Of the delta’s 29 nativefish species, 12 either have been eliminatedentirely or are currently threatened withextinction. Today, the delta smelt’s plight isforcing the issue, in part because it is seen asan indicator species for the health of the deltain general, much as the northern spotted owl’snumbers served as a proxy for the health ofold-growth forests in the 1980s and 1990s.

But an initial round of crises took shape inthe early 1990s, when Chinook salmon andother fish species were found to be in sharpdecline. Litigation by environmental groupsand requirements under the EndangeredSpecies Act triggered shutdowns of the waterproject pumps, water supply cutbacks, andwidespread complaints that the federal andstate agencies were often working at crosspurposes with one another.

In hopes of finding a way out, federal andstate leaders forged a collaborative researchand decision-making process known asCALFED to try to create a common visionfor improving the delta. The effort was widelyheralded for bringing more than 100 local,state, and federal government agencies thathave jurisdiction over some aspect of thedelta and its wildlife together with stake-

holder groups such as farmers, industry rep-resentatives, and environmentalists. Butbecause those stakeholders were unable toagree on major changes to the delta,CALFED leaders focused their efforts oncreating a robust science program for study-ing the delta, initiating numerous habitatrestoration projects, and developing a market-based system to pay farmers upstream fromthe delta to forgo water diversions in order tokeep the water in stream for fish.

Although CALFED’s science program inparticular has largely been viewed as suc-cessful in creating a vast knowledge base onwhich to base ecological decisions, recentlythe collaborative process has begun breakingdown. Ultimately, the delta’s problems stemfrom the fact that there isn’t enough water tosatisfy all the competing users, Isenberg

FROM CRISIS TO CATASTROPHE If and when the earth begins to shake along one of six major seismicfaults in and around the Sacramento–San Joaquin River Delta, the fate ofthe small, threatened delta smelt will no longer be the region’s biggestproblem. The delta is laced with more than 1700 kilometers of earthenlevees, many of which would likely breach in a major flood or quake. Theresults could make the devastation wreaked by Hurricane Katrina looktame by comparison. The system of delta levees, says Jeffrey Mount, ageologist at the University of California, Davis, “is in much worse shapethan anybody thought.”

In 2005, Mount and his Davis colleague Robert Twiss reported that overthe next 50 years there is roughly a two in three chance that a combinationof seismic activity and increasedflooding from climate change wouldproduce a catastrophic failure ofmultiple levees in the delta. Thoselevees surround farmland where theearth has subsided up to 8 meters inmany cases. If the levees collapseddue to a quake during a period oflow freshwater flows through thedelta, water to fill the 2.5 billioncubic meters of space in the island

basins would be pulled in fromSan Francisco Bay and SuisunMarsh at the mouth of the delta,drastically altering the fresh-water habitats and likely forcingthe shutdown of massive pumps that carry delta water to Central Valleyfarmers and millions of residents in southern California. According to a newanalysis by the California Department of Water Resources, repairs could top$30 billion and take from 1.4 to 6.4 years depending on the extent of thedamage. Indirect costs to communities that would lose access to water fromthe delta could exceed $50 billion.

Last year, California voters passed a bond measure making roughly$1 billion available for delta levee repairs and improvements. Mount calls

this “a nice start” that should helpbring some of the older levees up tothe most basic federal guidelinesbut adds, “they are sitting on poorfoundations and will be unstable inan earthquake.” The truth is, Mountsays, the economic fate of millionsof Californians currently dependson a maze of dirt piles that couldeasily give way with a little shovefrom nature. –R.F.S.

Shaky defenses. A break in a leveenear Holt in June 2004 sent waterpouring into fields and workersscrambling to shore up nearby levees.

Salty surge. Computer simulation shows salt waterpouring into the delta followinga levee-breaking earthquake.

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says. And CALFED lacked the political cloutto choose winners and losers. “I think it hasdone all it can do that isn’t controversial,”says Lois Wolk, a Democratic CaliforniaState Assembly member from the deltaregion west of Sacramento who has closelyfollowed delta issues.

A return to the courts

About the only thing that isn’t controversialthese days is the fact that delta smelt’s num-bers have plummeted, along with those of thearea’s other pelagic fish, which spend at leastpart of their life cycle in the ocean or inbrackish estuaries. But just what is causingthe crash isn’t as obvious. According to thereport released in March by a collection ofstate and federal water agencies known as theInteragency Ecological Program (IEP), theculprits likely include impacts from pollu-tion, invasive species, and water exports.Among the specif ic concerns, the IEPreported that agricultural pesticides knownas pyrethroids have been shown to be acutelytoxic to aquatic life, and their use has morethan doubled to over 115,000 kilograms peryear in the delta, in part to combat noxiousaquatic weeds. Of the exotics, one of themost worrisome has been the Asian clam, afilter feeder that consumes phytoplankton.Those phytoplankton are the primary foodsource for zooplankton, which in turn are aprimary food source for the delta smelt.

With the delta smelt’s numbers in steepdecline, and CALFED’s inability to forcemajor changes, environmental groups havereturned to the courts. “Litigation has oustedcollaboration as the dominant means ofsolving water issues,” says David Nawi, anattorney with Environmental Mediation inSacramento, California. Last year, a trio ofenvironmental groups challenged theU.S. Fish and Wildlife Service’s (USFWS’s)2004 biological opinion, which outlines theagency’s strategy for protecting the species.Among other things, they argued that theagency failed to cite the best available sci-ence by not using the latest surveys of smeltabundance and not taking climate changeinto account. On 25 May, a federal judgeagreed, tossing out the old biological opinionand forcing a rewrite, which is expected nextyear. Just what remedies the judge will orderin the meantime is scheduled to be decidednext month, and court cases on other threat-ened species and challenges to delta-areadevelopment also remain in the works.

According to attorney William Stelle, a vet-eran of several endangered species battles whois now working on Bay Delta conservation, therecent court decisions are likely to be the begin-

ning of a very eventful year thatcould decide the fate of the deltafor decades to come. In November,Isenberg’s Delta Vision task forceis scheduled to deliver its recom-mendations for the region. Anotherset of stakeholders, meanwhile, isworking to create the Bay DeltaConservation Plan to address water-quality and habitat-restorationneeds for the ecosystem. Yetanother group of academic andnonprof it policy researcherschimed in earlier this year with a report thatoutlined five viable ways forward for the delta,including managing the estuary for environ-mental rehabilitation and “armoring” the lev-ees around selected islands to ensure that thefresh water continues to flow through the deltain the event other levees give way.

The list of recommendations will con-tinue next year, when USFWS and BOR areexpected to release their revised manage-ment plans for the delta smelt, which are likelyto govern operations for the next 5 years.And finally, state officials announced thismonth that they intend to ask voters for a new$5.9 billion bond measure to build two newdams and begin detailed studies of a canalthat would remove irrigation and municipalwater from higher up the delta and channel itdirectly to the south delta pumps to avoid

sucking fish. California voters overwhelm-ingly rejected a similar proposal in 1982.But Schwarzenegger recently voiced hissupport for the plan.

What’s not clear yet is how these courtdecisions, ballot measures, and regional plansare likely to mesh, and whether they’ll come intime to save the delta smelt. “The delta smeltwill be very lucky if it makes it,” says PeterMoyle, a fisheries biologist at UC Davis.

Perhaps, then, it’s little surprise that inter-est in UC Davis’s smelt-breeding program istaking off. “It’s not something any fish biolo-gist wants to do,” Lindberg says. “It would bepreferable to restore the natural healthy deltaecosystem. But if the population is nearingextinction, then people are willing to considerthe possibility of going down that road.”

–ROBERT F. SERVICE

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Increased demands. Exports ofwater outside the delta from twopumping stations (yellow and purple) have soared. Low flows into the delta in August 1992 led tosaltwater encroachment (right).

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