The Sacramento-San Joaquin River Delta near Stockton is shown. Pumping… ( Los Angeles Times )
Southern California's most important lake is located in a distant part of the state and has a name most of us wouldn't recognize. Clifton Court Forebay, between Oakland and Stockton, forms the manufactured headwaters of the manufactured river known as the California Aqueduct, which over four decades has supplied millions of residents from the Bay Area to the Mexican border with drinking water and thousands of growers from Santa Clara to Santa Maria to San Diego with irrigation. Engineers warn that in the event of a major earthquake, Clifton Court could fail and the aqueduct could run dry, leaving much of the state without that water for three years or more.
Even without a big quake, though, the forebay, the aqueduct and the water they bring are under threat.
Clifton Court is at the southern end of the remarkable region known as the Sacramento-San Joaquin River Delta, where the snowmelt from the western Sierra drains into the San Pablo and San Francisco bays and forms the briny heart and lungs of the state. For thousands of years the delta was intermittently marsh and dry land, shallow sea and freshwater wetland, changing with the daily rise and fall of the tides, the annual patterns of mountain precipitation and the more mysterious rhythms of drought, flooding and seismic upheaval. The delta we know today was created in the 19th and early 20th centuries when Chinese laborers began building levees of dirt and tule, letting dry land appear and allowing farmers to grow asparagus, grain and fruit trees.
The manufactured delta is intrinsically linked to Clifton Court and the California Aqueduct, because its levees divide the Sacramento and San Joaquin river snowmelt from the brackish water that would naturally make its way inland from the Pacific. Without the levees, and without the constant watch and repair efforts of the growers who live in and farm the century-old, sunken islands, the seawater would resume its primordial possession of the region. The aqueduct would bring to Central Valley irrigation ditches and Southern California faucets nothing but useless saltwater from the San Francisco Bay. That could happen even without earthquakes or rising oceans caused by climate change, if the levees aren't constantly patrolled and patched.
Over the last few decades Californians have learned that what has provided millions of them their lifeblood and their living has brought destruction to an environment that is as essential to human life here as the water wrung from it. Our efforts to hold back the seawater have upset the natural balance in the delta. Much of the dry land that emerged from the marsh turns out to be composed of eons' worth of reeds and grass; when the nearly pure carbon dries out in the sun, it simply burns up and blows away. A change in the chemistry of the water and soil upsets the life cycle of microscopic organisms, and that in turns affects the migrating fish — the salmon and steelhead — that were once part of vast Pacific fisheries that in turn supported a fishing industry, not to mention an ocean ecosystem.
Pumping has put the much of the delta well below sea level, just as it has dried out the sponge that was once the San Joaquin Valley and left residents and farmers more dependent than ever on transported water. Non-native plants and fish have undermined the natural system that was once California from the Cascades to the Tehachapis.
If we just dismantled the California Water Project, the earlier federal Central Valley Project and the dozens of interconnected canals and pumping systems that built and sustain the state's cities and agriculture, many scientists say, California could still not repair itself. Get rid of the delta farmers, and there is no one to safeguard the levees, the region is inundated with seawater, Central Valley farms go dry and Southern California goes thirsty. In the Bay Area some once said — some still say — let L.A. go thirsty, forgetting that the same aqueduct that brings us water brings it as well to the East Bay and the Silicon Valley. Some in Southern California argue that the farms in the west San Joaquin should go dry, because they never should have been there in the first place — but such an assertion being made in such a naturally dry part of the state is sufficiently ironic to answer itself.
For decades California has fought over its water, and argued which faction has a moral and legal right to how much of it. There have been decades now of deadlock and delay. But court rulings protecting the environment have taught growers, city dwellers and others about the state's natural limits — and those interests have, for three years now, engaged in a remarkable conversation about how to proceed together.