Southern Californians have been drinking from the Feather River — and washing in it, flushing with it and sprinkling it over their lawns — for nearly a half century without giving it much thought, so the emergency at distant Oroville Dam provides a jolting reminder of our dependence on the wetter, northern part of the state. A disaster there could easily become a crisis here.
Oroville is the linchpin of the State Water Project, the massive engineering feat that brings Northern Sierra water from the Feather River to the Sacramento, through the Sacramento-San Joaquin River Delta, into the California Aqueduct, over the Tehachapis and to our faucets. This season’s storms have filled the dam to capacity, so managers diverted water onto a concrete spillway to keep it from topping the earthen dam itself. When damage to the spillway was spotted, water managers switched to an unpaved, and previously unused, emergency spillway — but the water releases carved up the hillside, sending debris down the Feather River, threatening further erosion and prompting the evacuation of more than 100,000 residents downstream, including in Yuba City, Marysville and once-remote towns and cities that are increasingly becoming commuting suburbs for greater Sacramento.
California is an extremely engineered environment. Decades ago, the natural state of affairs in years like this one had previously been flooding in the Sacramento and San Joaquin valleys. Since 1960, the State Water Project has helped to protect Northern California cities, towns and farms from floodwaters while providing usable water to Central Valley farms and Southern California homes. Ratepayers here, as elsewhere, help keep the system in repair. The project binds Californians to each other, despite the difference in precipitation between the wet north and the dry south. A catastrophe at Oroville Dam — for example, spillway-loosened detritus blocking flow to the delta — could cause a water-supply emergency here, despite all the rain.
Engineers (and taxpayers and ratepayers) have provided Southern California useful redundancy in water delivery systems. Los Angeles gets water via William Mulholland’s Owens Aqueduct and later extensions, and the region relies heavily on Colorado River and Lake Mead. But import of Owens water has been limited to mitigate environmental damage east of the Sierras, and the water level at Lake Mead remains so low that delivery cutbacks may be on the horizon.
There will likely be lessons learned about how the state should manage water from the emergency at Lake Oroville, but it is too early at this point be certain what they are. Meanwhile, Californians will have to keep the names and distant places — the Feather River, the Oroville Dam, the Owens, the Colorado, Lake Mead — in the forefront of their minds as we make decisions to sustain, supplement or abandon the water projects that have made the state what it is today.