Report finds Sacramento-San Joaquin delta among most vulnerable rivers

Kelly Zito in the San Francisco Chronicle: The river system that makes up the backbone of the state's economy ranks as one of the most imperiled watersheds in the nation, putting at risk drinking water for millions of Californians as well as billions of dollars worth of crops and urban infrastructure, according to an annual report on the country's most important waterways.

The Sacramento-San Joaquin River Delta, whose fingers extend from the slopes of Mount Shasta in the north to vast farm fields near Fresno in the south, is "extremely vulnerable to catastrophic failure" from over-pumping and declining ecosystems, according to American Rivers, a Washington, D.C., conservation group.

And increasingly, surging storm waters and rising sea levels induced by global climate change threaten to ravage the delicate network of levees and channels that route water through the confluence of the two rivers and protect low-lying cities such as Sacramento, Lathrop and Stockton.

"The (levee) system is fragile, old and degraded ... and the delta is the most important estuary in North America," said Jeffrey Mount, a prominent UC Davis watershed scientist and American Rivers board member. "And there's no money to fix it. That's why there are hard choices to come."

Water supplies from the delta slake the thirst of some 23 million Californians and hundreds of thousands of acres of the nation's richest agricultural land. In recent years, however, cracks in the system have turned into yawning gaps in the face of drought, rising oceans, pollution, invasive species, and aging pipes and canals…..

The San Francisco Bay area from space