Friday, January 29, 2010

The Drought & Dams

One of the reasons that isn’t mentioned in this story from the Sacramento Bee, is the lack of water storage to capture whatever additional rainfall occurs in this—at least so far—very nice water season; and until we solve that issue, the rainfall, copious or not, won’t make a lot of difference.

Our population has grown substantially since the last major dams were built decades ago, and without new ones—or raising existing ones—like this previous post noting how Shasta could be raised quite a bit based on its original engineering, tripling its storage, and the construction of the Auburn Dam, would go a long way towards solving our water and flood protection needs for a long time.

An excerpt.

“The question now gurgles up from every storm drain and creek in California: Is the drought over?

“The simple answer is no. The reasons why are not so simple.

“Two weeks of heavy rain and snow – nice as it is – cannot entirely erase three years of drought statewide.

“For starters, California's largest reservoirs are far from full. This includes Shasta, Oroville and Folsom, all vital storage points for state and federal water supply canals.

“These reservoirs likely won't fill completely with the snowpack on the ground now, especially if there is no more of it by April Fools' Day.

"Until we get the reservoirs back to normal and see a normal to slightly above normal spring snowmelt coming, it would be perilous to suggest the drought is over," said Rob Hartman, hydrologist in charge at the California Nevada River Forecast Center, an arm of the National Weather Service in Sacramento. "There's a lot of winter yet to go and anything could happen."

“Beyond that, and despite the state's economic woes, California keeps growing. That means ever-greater water demand, which each year pushes total salvation from drought further away.

“Nature gives California a finite water supply, whether it's snow in the mountains or groundwater deep beneath our feet. It is now widely recognized that all of our water supplies are overtapped.

“The governor's Delta Blue Ribbon Task Force, for instance, revealed in 2008 that state officials have granted water rights equal to eight times the average annual flow in the Sacramento-San Joaquin Delta watershed, which catches half of California's precipitation. Even more water-rights applications are pending.

“Climate change throws another wrench in the works. Global warming is expected to bring more rain and less snow. This will mean less water melting from the mountains to slake California's thirst through summer and fall.

“Environmental protections are another limitation. To save salmon and protect water quality in the Delta, federal officials have ruled that we must divert less water.”