California rapidly depleting Central Valley groundwater
08 March 2011
Groundwater is being depleted in California’s Central Valley at a rapid rate, according to a team of researchers analyzing data from the Gravity Recovery and Climate Experiment (GRACE) satellite in a paper published in the journal Geophysical Research Letters. Famiglietti et al. warn that the current rate of groundwater depletion in the Central Valley may be unsustainable and could have “potentially dire consequences for the economic and food security of the United States.”
The authors used 78 months (October, 2003–March, 2010) of data from the Gravity Recovery and Climate Experiment satellite mission to estimate water storage changes in California’s Sacramento and San Joaquin River Basins. They found that the basins are losing water at a rate of 31.0 ± 2.7 mm yr-1 equivalent water height, equal to a volume of 30.9 km3 for the study period, or nearly the capacity of Lake Mead, the largest reservoir in the United States.
They used additional observations and hydrological model information to determine that the majority of these losses are due to groundwater depletion in the Central Valley. Their results show that the Central Valley lost 20.4 ± 3.9 mm yr-1 of groundwater during the 78-month period, or 20.3 km3 in volume.
Facing significant cuts in managed surface water allocations during periods of drought, farmers, in particular those in the drier San Joaquin Valley, are forced to tap heavily into groundwater reserves to attempt to meet their irrigation water demands – this in a region where groundwater dependence is already high. Under these conditions, groundwater use rates exceed replenishment rates, and groundwater storage and the water table drop. Given the naturally low rates of groundwater recharge in the San Joaquin Valley, combined with projections of decreasing snowpack [Cayan et al., 2006] and population growth, continued groundwater depletion at the rates estimated in this study may become the norm in the decades to come, and may well be unsustainable on those time scales.
—Famiglietti et al.
Resources
Famiglietti, J. S., M. Lo, S. L. Ho, J. Bethune, K. J. Anderson, T. H. Syed, S. C. Swenson, C. R. de Linage, and M. Rodell (2011), Satellites measure recent rates of groundwater depletion in California’s Central Valley, Geophys. Res. Lett., 38, L03403, doi: 10.1029/2010GL046442
California has a massive number of solar projects on the horizon, and the state has a massive amount of coastline on the Pacific. So, how about a solar powered aluminum smelting operation to produce bulk aluminum gallium alloy (95% aluminum, 5% gallium). Impure scrap aluminum could be used. Use the aluminum alloy & seawater to produce hydrogen (+ heat), then use the hydrogen + heat to produce baseload power for a desalination plant. The CO2 from the smelting operation could be captured & sequestered or sent to a nearby algae biofuel operation. Only question is what to do with the brine.
http://www.purdue.edu/newsroom/research/2010/101007WoodallBoats.html
Posted by: ejj | 08 March 2011 at 01:36 PM
It is insane to allow the population of the San Joaquin valley to increase when it's running out of water. Policy should be aimed at directing people elsewhere, especially by repatriation of immigrants.
Posted by: Engineer-Poet | 08 March 2011 at 04:50 PM
Engineer-Poet:
I find your post ironic, in that the San Joaquin valley is dry only because the copious water which used to flow there has been redistributed via dams, canals and pumping stations to corporate farms and urban users. Two hundred years ago the water-rich parts of the state included the central valley and the Owens Valley. LA now takes the Owens Valley water, of course. Perhaps those 'repatriated immigrants' should be sent there.
Posted by: Nick Lyons | 08 March 2011 at 05:41 PM
In principle, it is easier to move water than people. If USA is importing close to 15 million barrel of oil on a daily basis, it could import 15+ billion barrels of water per day. Of course there would be a price to pay but people would get use to pay more for fresh water as they are getting use to pay a lot more for fuel. Water may replace fossil fuels as an essential commodity.
Alternatively, at least for a few decades, USA could move its own water around the country. Water from some of large rivers could be captured before it flows into the ocean and piped to California and other States where it is in short supply. Unproductive dry lands could produce again.
Posted by: HarveyD | 08 March 2011 at 06:03 PM
Engineer-Poet: What do you think of my plan to hydrate the San Joaquin Valley via solar / hydrogen powered desalination with the Purdue hydrogen idea? It's clean and green, could provide a lot of secure high-paying long-term industrial jobs & secure a water source for the valley well into the future. They could recycle used aluminum & keep moving it around (from smelter to hydrogen production & back to smelter) almost in a closed loop to produce continuous baseload power. Use solar & processed aluminum during the day, and just processed aluminum at night. I just don't know what they would do with the brine...but there are many desal plants around the world so it shouldn't be that big of a deal.
Posted by: ejj | 08 March 2011 at 06:12 PM
Why import freshwater when California is on the Pacific Ocean...desalinate saltwater with renewable energy (solar) and baseload hydrogen power from aluminum / gallium alloy. There's probably some old industrial facilities along the coast of California that could be retrofitted / reutilized.
Posted by: ejj | 08 March 2011 at 06:41 PM
@ejj: I like desalination for California (lots of sunshine, lots of coastline, lots of people living near the coast). Brine disposal is an issue, however--starting to become a problem in the Persian Gulf. California coastal waters may not be as problematical, I should think, considering the strong currents offshore, such that with properly designed outfalls deadly concentrations would be avoided.
Posted by: Nick Lyons | 08 March 2011 at 09:09 PM
The Central Valley lost 20.3 km3 over almost 7 years, equivalent to 5,362,692,662,900 gallons for 7 years, 766,098,951,843 gallons per year. The world's largest desalination plant is the Jebel Ali Desalination Plant (Phase 2) in the United Arab Emirates capable of producing 300 million cubic metres of water per year, or 79,251,615,707 gallons per year. So you'd still need 10 of the largest desal plants in the world to make up for the groundwater withdrawals.
Posted by: ejj | 09 March 2011 at 05:21 AM
Do ejj's http://www.purdue.edu/newsroom/research/2010/101007WoodallBoats.html pilot plant for a few $million and evaluate - the sooner, the better.
Posted by: kelly | 09 March 2011 at 08:11 AM
Population california 37M, polulation UAE 5M.
Small interventions could easily reduce consumption.
At this moment, not a single insect suffers from the water depletion.
At 20mm/year, there is still for at least 100 years to consume befere it's depleted. By then we need new technology developed. At this moment there are more imprtant priotities.
Posted by: Alain | 09 March 2011 at 08:44 AM
Ditto to Alain: "Small interventions could easily reduce consumption."
Also: California spends a huge portion of its water budget growing water-intensive crops (rice/cotton). If we weren't practically giving the water from federal water projects away to agribusiness, the stress on CA water supplies would be much less. California is naturally rich in water, but there are limits. Being more intelligent about allocation of the resource is the way to go, IMHO.
Posted by: Nick Lyons | 09 March 2011 at 11:50 AM
There are ways to reduce water consumption for agriculture. Israel has met this challenge years ago. However, since we eat more and more and California is one of the most productive place for many crops, more and more water will be required.
Why not pipe it in from Louisiana where it is often flooding due to too much of it?
Posted by: HarveyD | 09 March 2011 at 12:39 PM
I think there should be an Abengoa - Alcoa - Siemens joint venture in California for this...get Vinod Khosla involved too...
Posted by: ejj | 09 March 2011 at 02:17 PM
Posted by: Engineer-Poet | 09 March 2011 at 09:40 PM
@E-P:
If we weren't giving water away to agribusiness, the argument for employing illegal immigrants in California would vanish overnight (along with the crops). Democrats can't allow that, they depend on them to swell their voter base.
Interesting viewpoint. If you examine the history of the federal water projects in CA, I think you will find that all parties end up bending over for agribusiness--and the small farmers for whom the projects were originally built got the shaft.
Posted by: Nick Lyons | 09 March 2011 at 10:18 PM
There are more than one solution.
As California's population grows towards 100 M and USA's towards 600+ M, more and more water will be required in every State. California will require proportionally more because people will continue to move West for many reasons.
Reducing body weight by up to 50% AND EATING LESS WOULD HELP.
Getting rid of the 400+ M pets or keeping smaller one may help.
Conservation may also help. Israel has learnt how to do it.
Ocean water desalination may also help but is expensive.
Pumping in fresh surplus water from other States may be part of the solution.
Importing fresh water from Canada is another solution.
A mix of 4 or 5 solutions may eventually be required.
Posted by: HarveyD | 10 March 2011 at 12:46 PM
Build 20 nuclear plants in southern California to desalinate all the seawater we need, and for good measure tear down the Hetch Hetchy dam. We could start on Monday.
Posted by: richard schumacher | 12 March 2011 at 10:35 AM