As of October 4, the State of California had entered its 4th year of a raging drought that shows no sign of abating. A drought that a growing number of studies are linking to human-caused climate change. A drought that appears to be readying to level a terrible blow at residents, communities and farmers living in the increasingly dessicated Central Valley region.
State reservoirs, despite ever-heightening restrictions on water use, were 43 percent lower than is typical for this time of year. And the state’s largest reservoir — Lake Oroville — had declined to 30% of capacity by early October (record lowest level is 27 percent capacity set in 1977).
All the while, NASA’s GRACE gravity sensor is providing a record of a historic drying that has been ongoing since at least 2002.
(NASA/UC Urvine graphic showing California water loss through June of 2014.)
The above image is a visual representation of NASA gravity sensor measurements of California ground water losses over the past 12 years. What the sensors — a pair of minivan sized satellites that use microwave altimetry to measure changes in the planet’s gravity — have found is that California’s Central Valley has been losing 4 trillion gallons of water each year for the past three years running.
It is a massive loss of water with far-reaching impacts including greatly reducing the flows of the San Joaquin and Sacramento Rivers.
The loss of ground water is primarily due to increasing rates at which both communities and farmers are tapping well water supplies to make up for the massive deficits of the ongoing drought. Overall, more than 600,000 wells feed individual homes, small communities and farms throughout the Central Valley. As wells dried up, residents and growers in the region turned to deeper and deeper drilling — tapping water further and further underground.
The result is a very rapid depletion of the aquifer water store. A depletion starkly visible to NASA satellite sensors. A race for the last remaining drops of an ever-shrinking pool of water.
(Lake Oroville at full in 2011 [top frame] and nearing bone dry during August of 2014 [bottom frame]. Image source: Paul Hames, California Department of Water Resources and Justin Sullican, Getty Images.)
100,000 Wells about To Go Dry
Such a massive and rapid depletion of the ground water supply can’t go on without having a severe impact. And it appears now that some communities, residents and growers with more tenuous links to California’s rapidly dwindling water are already starting to feel the effects. As of October, fruit and nut exports from California were down by 8% on the back of merciless drought conditions and dwindling ground water supplies.
More ominously, however, is the fact that many Central Valley residents are already at the point where wells won’t produce at all. By mid-September, towns like Porterville and Seville saw hundreds of residents without running water. In hardest hit Tulare County, 1,000 of the region’s 7,300 residents had lost access to running water due to well failure. In this most extreme of cases, victims of water shortage were forced to haul bottled water to homes from local stores or relief centers set up by firefighters and state emergency personnel.
Tulware may well be California’s canary in the drought coal mine as recent reports find that as many as 100,000 wells — about 1/6th of all the wells in the Central Valley — could go dry by mid October without a bout of well-replenishing rains. And with heatwaves rising under a powerful blocking high pressure system that has dominated the California climate for nearly two years now, the likelihood of such rains appears to be starkly low.
(Blocking high keeping California dry is plainly visible in the October 12 European Model weather forecast. Image source: ECMWF.)
Weather forecasts continue to show the emergence of ridiculously resilient high pressure systems over California and the near shore Pacific. Rain-bearing low pressure systems continue to be deflected northward into Alaska and British Columbia. Such forecasts indicate that October may well be a very difficult month for the water-strapped State. And with ridging continuing to be the dominant influence, it appears California may be facing another water-poor late fall and early winter going forward.