While part of the research that needs to be done, the taboo on utilizing additional surface water storage for freshwater flows when needed by the Delta is maintained .
Delta study sees some hope
It won't be easy, experts say, but estuary, water supply can be protected.
By Matt Weiser - Bee Staff Writer
Published 12:00 am PST Thursday, February 8, 2007
A new study of the Sacramento-San Joaquin Delta concludes that restoring its natural saltwater ebb and flow could save dwindling fish species and ensure statewide water security.
These goals, long considered incompatible, have stymied water managers for decades. The study by the Public Policy Institute of California asserts both are achievable, but not without hard choices.
"It just takes some imagination and an ability to change the way we're doing things," said Ellen Hanak, an economist at the institute and co-author of the study with five UC Davis professors. "We need to recognize the Delta of the future cannot be all things to all people."
The Delta is the hub of California's plumbing, supplying water to 23 million people and 5 million acres of farmland. For 60 years, its artificial islands have served as a kind of switching yard, holding salty ocean water at bay so fresh water from Northern California rivers can be pumped swiftly southward.
The Delta is also the largest estuary on the West Coast, a habitat the size of Rhode Island that is home to many sensitive fish and bird species. Several native fish species are near extinction, partly because the powerful pumps have altered Delta water flows.
Scientists and policymakers fear that an earthquake or major flood could vaporize numerous Delta levees, drawing a pulse of seawater inland that would force the export pumps to stop for more than a year. This would cause devastating water shortages and billions of dollars in economic damage.
"The probability of having a catastrophic flood in the Delta is very, very high," said Jeffrey Mount, a another study coauthor and a geology professor at UC Davis.
The study recommends five approaches to avoid that disaster and produce a Delta that still benefits fish and people. All allow natural salinity changes in the western Delta, which would help native fish and drive out harmful invasive species that compete for food.
Two options revive the controversial peripheral canal that would divert water from the Sacramento River near the town of Hood and carry it south toward export pumps near Tracy. State voters rejected this idea in 1982 amid fears it would dry up the Sacramento River and cause the Delta to be abandoned.
But the new study suggests a smaller canal with regulated pumping could secure freshwater exports while allowing the Delta to be restored.
A third option would armor certain islands in the central Delta to create a secure channel to move fresh water through the estuary, while restoring surrounding areas.
The remaining two options rely instead on reduced water exports, possibly with additional water storage near the Delta, or allowing exports only when water is abundant, such as during floods.
The options range in cost from $1 billion to $4 billion, considered rough estimates. All are cheaper than the estimated $40 billion cost of a Delta disaster.
