Advertisement
YOU ARE HERE: LAT HomeCollectionsNews

Sacramento-San Joaquin Delta's ecological decline is breathing new life into bypass proposals

A plan for a huge tunnel is the leading contender as the state looks for a way to save the delta at the same time it slakes thirsts in Southern California.

November 24, 2010|By Bettina Boxall, Los Angeles Times

Reporting from the Sacramento-San Joaquin Delta — A drilling rig bit into the bed of California's biggest river, hauling up sage-green tubes of clay and sand the consistency of uncooked fudge.

The rig workers rolled the muck into strips, dried it in sugar-sized cubes and crushed them under their palms. They packed slices into carefully labeled canning jars for testing at an engineering lab.

They were taking the river bottom samples for a $13-billion project that would shunt water around — or under — the Sacramento-San Joaquin Delta to the big aqueducts that ferry supplies south.

Nearly three decades after a proposed delta bypass was killed by voters in a divisive initiative battle, the idea is back in vogue.

Pumping water from the delta's southern edge has helped shove the West Coast's largest estuary into ecological free fall, devastating its native fish populations and triggering endangered species protections that have tightened the spigot to San Joaquin Valley farms and Southern California cities.

The mounting delta problems, along with the potential threats of a rise in sea level and a major earthquake, have turned the attention of state and federal agencies to an "alternative conveyance": either a canal or, more likely, a 40-mile water tunnel system that would be the nation's longest, some 150 feet beneath the delta.

But the plans, still in draft stage, follow years of failed attempts to stem the delta's collapse while quenching California's thirst —- leaving open the question of whether it is possible to do both.

The urban and agricultural water districts that would pick up the tab for the bypass hope to restore or increase their water deliveries. But already, the giant Westlands Water District, a volatile player in California water politics, has lost confidence that will happen. It angrily announced this week that it was pulling out of the planning process.

Environmentalists and delta advocates warn that if the new project ramps up water exports, it will accelerate the delta's decline, further imperiling the delta smelt, hurting water quality and threatening migrating salmon.

"I am uncertain about how this will work out," said UC Davis geology professor Jeffrey Mount, who has repeatedly warned of the delta's vulnerability to a destructive earthquake. "The only certainty I have is that if it doesn't work out, we will all get worse together."

*

Matt Nobriga, a U.S. Fish & Wildlife biologist, peers over the edge of a boat in the central delta. The water is clear. A bright green forest of aquatic plants waves slowly in the current. "If you want to go bass fishing," he said, "this is the spot."

It is a scene befitting a fresh-water lake. And it is all wrong for the tidal estuary, a snapshot of how profoundly 150 years of human intervention has upended nearly everything about the place. The delta's look, seasonal rhythms, fish and wildlife all bear little resemblance to the "swampland" roamed by elk and grizzlies that Gold Rush settlers were eager to drain and turn into farms to feed booming San Francisco.

A tranquil maze of farm islands, duck hunting clubs and winding channels, the delta retains a seductive 19th century pastoralism. Narrow levee roads connect 100-year-old towns with a few hundred residents. Great blue herons flap in slow motion toward the horizon. Orchestras of blackbirds play in the breeze-rustled reeds. Fishermen drift down sloughs, oblivious to all but a tug on their lines.

The idyllic image is deceiving. From an ecological standpoint, the delta is more artificial than natural. Armies of invasive plants and aquatic life, such as largemouth bass and the Brazilian waterweed that Nobriga pointed out, have taken over. Natives like the once-abundant Chinook salmon and delta smelt are on the endangered species list or headed there.

The delta's fragile peat soils have vanished in the wind during more than a century of farming, leaving behind a network of sunken islands that have turned much of the delta into California's Holland. More than 1,000 miles of weak earthen levees, some built in the mid-1800s by laborers with wheelbarrows, imprison the web of water channels that used to wander and flood freely, providing a rich fish nursery and pantry.

The list of players in the delta's ecological slide is long and varied. But the two giant pumping plants northwest of Tracy, one operated by the U.S. Bureau of Reclamation, the other by the state Department of Water Resources, are the most conspicuous villains.

Their combined energy of 468,000 horsepower surpasses that of 100 diesel locomotives — enough to reverse the flow of southern delta channels, pull fish to their deaths and sabotage the natural ebb and flow of brackish and fresh water that shaped the delta's tidal ecology.

Advertisement
Los Angeles Times Articles
|
|
|