Lots going on with respect to California water in the past 10 days or so. I will focus on California groundwater because it often gets short shrift from people who should know better. What else is new?
So let's see what's going on with California groundwater (not that I haven't done this before - see an earlier post). "Oh, no!" you say, "Here he goes again!" Got that right!
Cadiz
Last night the Santa Margarita Water District voted to advance the Cadiz water project (see news release). If you want to see what I think, you can read Emily Green's excellent coverage of this issue (her two most recent posts are 14 July 2012 and 30 July 2012) and the Pacific Institute's comment.
Groundwater in the California Water Discourse
The McClatchy newspapers in Sacramento, Fresno, and Modesto recently published an editorial on the need to consider and protect California's groundwater in the current water debate. The editorial addressed both quality and quantity problems. Amen!
Here is what the California Farm Water Coalition said in response to the editorial:
For years farmers have been concerned with the overdraft situation of their water supplies from the aquifers. This concern was one reason why Californians supported the construction of the State Water Project and the federal Central Valley Project that delivered surface water to farms, homes and businesses. Dependable surface water supplies enabled farmers to turn off their irrigation pumps that lifted water from the aquifer to their fields. The water from the aquifer remained as an insurance policy when years of drought diminished the supply of surface water. However, environmental regulations that restrict water flowing through the Delta to Central Valley farms have caused farmers to increase groundwater use to keep their farms productive. The solution to much of California's groundwater problem is to fix the surface water problem. Governor Brown's recent announcement to move forward with water supply reliability and ecosystem restoration projects will go a long way to improve the situation for California's groundwater.
Concerned? Have they done anything about it on a regional basis, like lobbying for statewide oversight? But I like the attitude - give us surface water so we won't pump groundwater unsustainably. Makes sense to me!
But the CFWC is correct - it was the unsustainable pumping of groundwater that provided some of the impetus for the massive surface water projects to bring water from the north to south.
That leads me to the penultimate topic...
Groundwater Overdrafting
The aforementioned editorial also cited the excellent studies by Jay Famiglietti and Bridget Scanlon on the overdrafting of Califonia's groundwater. But this overdrafting is nothing new; I noted several years ago that this problem has been known for scores of years:
But this realization is nothing new, although the amount of pumpage may be. Groundwater has been pumped unsustainably (mined or overdrafted) in the Central Valley for decades. When I took Aquifer Mechanics from the late Dr. Gene Simpson in 1971, the Central Valley was already one of the 'poster children' for groundwater mining (we didn't refer to it as 'unsustainable pumping') and land subsidence. Pumpage had long since
exceeded recharge, and when coupled with the necessary geologic conditions, land subsidence resulted.
Here is a classic photo of USGS hydrologist Dr. Joe Poland standing by a
utility pole near Mendota, CA, that graphically illustrates over 50 years of subsidence, 1925-1977. At this location the subsidence was about 29 feet, at the time the maximum amount of subsidence in the San Joaquin Valley.Subsidence in the Valley had been noted as early as 1935, as mentioned in this 1970 paper by USGS hydrologist Ben Lofgren that we used in Gene's class:
I know some people extol the virtues of local groundwater management in California and I am certainly not opposed to such approaches. But there needs to be some state oversight, because pumping or polluting groundwater in one groundwater district/basin can have effects outside the boundaries of that district/basin. And you also have the likelihood of multiple aquifers in the vertical dimension, which means that water pumped in a given district can come from different source areas. Groundwater reservoirs don't necessarily follow political or watershed boundaries. Groundwater management is less straightforward than surface water management, but many people don't understand that fact.
California water people must realize that in terms of water availability, the future will likely be different from the past (less of it) and that groundwater must be dealt with in a better manner than it has in the past. Irrigators and other pumpers can not simply pump groundwater to make up for reduced surface water whenever they want to. Groundwater and surface water need to be managed conjunctively.
C'mon folks - you've known about this dismal state of groundwater management for many years. Time to bite the bullet and fix it, even if it means saying 'No!" to some folks.
"The definition of insanity is 'Doing what you have always done and expecting a different result.'" - Albert Einstein
Michael, thanks for reminding us of this critical, and usually ignored, issue and resource.
Here are two 2009 blog posts I wrote on California's looming groundwater crisis. Maybe I should just repost it... too little has changed.
http://blog.sfgate.com/gleick/2009/07/14/californias-looming-groundwater-catastrophe/
http://blog.sfgate.com/gleick/2009/12/15/stealing-water-from-the-future-californias-massive-groundwater-overdraft-newly-revealed/
Posted by: PeterGleick | Wednesday, 01 August 2012 at 01:12 PM
For what it's worth, the new California climate change assessment has a report on using groundwater to mitigate drought: http://www.energy.ca.gov/2012publications/CEC-500-2012-017/CEC-500-2012-017.pdf The water districts studied were all on the coast, where they get more rainfall.
Many more reports here: http://www.climatechange.ca.gov/adaptation/third_assessment/
Posted by: BT | Wednesday, 01 August 2012 at 12:44 PM