Central California Levees Have State Flirting with Disaster
Built to channel the Sacramento, Cosumnes, Mokelumne and San Joaquin rivers and the lacy Delta region where they converge en route to San Francisco Bay, the levees bring flood protection to a vast swath of fertile farmland and urban areas, including Sacramento. They also funnel 7.5 million-acre-feet of water to drinking water transmission pumps in Tracy. click here to view map
But the aging earthen levee system offers marginal protection at best. Construction began in the mid-1800s and much of it rests on organic loam or a deep layer of sand. The dikes are susceptible to seepage that can lead to blowouts in extreme flooding events.