How I Spent My 16 June: Day 2 - Toward Sustainable Groundwater in Agriculture Conference

Day 2 was about as good as Day 1. Last day today, and I have to figure out what the take-aways are since Iam on the final panel this afternoon.

Note that most of the Power Points will be posted on the conference site.  

Here goes.

Morning Plenary Session
Another trio of excellent speakers enlightended us: Dr. Bill Alley, Groundwater Chief of the USGS; Dr. Stephen Foster, former head of hydrogeology at the British Geological Survey and now at the World Bank; and Dr. Bridget Scanlon of the Bureau of Economic Geology at the University of Texas.  

Alley spoke on Challenges in Groundwater Supply and Quality on the US. It was a very food overview, looking at pumpgae, storage, recharge, and discharge. He spoke of the need for monitoring, something O.E. Meinzer, often called the father of modern hydrogeology, noted in 1935. Yes, the more things change, the more they remain the same.

He showed an interesting graph demonstrating that groundwater used for irrigation has leveled off in the 17 Western states but is rising in the 31 Eastern states. The Western states are still far ahead, though.

Alley made the importnat point that even small storage depletions in storrage can produce large c effects on surface water bodies. He cited the San Pedro River basin of southern Arizona, where a dstorage ecrerease of 1% has caused streamflow depletion problems.    

Foster spoke of the boom in groundwater for irrigation in DCs and drew upon his extensive experience while with the BGS and the World Bank, where he now heads GW MATe, the Groundwater Management Team.

He made the interesting observation that hydrogeology and socioeconomics not only define the problem but also constrain the solutions. He spoke of some failures and successes with groundwater management for irrigation, starting with  Mexico. There, groundwater management failed because no investment was simultaneously made in agrarian reform and too many consultants told too many different stories. But in worked in the Deccan Traps region of India, where a charismatic leader convinced locals not to use drilled wells for irrigation supply but only for drinking water. Dug wells were to used for irrigation. Local management also succeeded in Mendoza, Argentina, for the wine grape growers.

Several other points he made:

1) discourage irrigation of alfalfa for arid zone livestock operations (Duhhhh....);

2) irrigation efficiency will not save water unless non-recoverable groundwater is targeted; and

3) piecemeal approaches to regulation, economic intervention, or technical innovation are likely to be unsuccessful.

The final keynote was Scanlon, aleay a delight to hear. She was speaking on GRACE - no, not the religious type, but the satellite sensing GRACE that has been used to measure changes in total water storage and groundwater storage over very large regions (c. 400,000 square kilometers).  She gave a brief, lucid explanantion of what  GRACE can and cannot do (prayer might help). She spoke of applications to India's Ganges region and the USA's High Plains aquifer (HPA) and Central Valley. She noted that the depletion in the HPA is only about 8% of total storage (recall Alley's earlier comments).

Summary:

1) useful tool for large spatial scales and c. 7-day temporal resolution;

2) error is on the order of + or - 10 mm (equivalent depth of water);

3) disaggregation into change in groundwater storage depends upon GLDAS models (need to improve moedling to include surface water and groundwater, irrigation); and

4) calculation of trends depends upon time period and interannual variability.

Odd 'n Ends
Keith Knapp, UC-Riverside: when it comes to existing definitions of sustainability, wee need to get beyond platitudes and focus on more quantitative definitions.

Howard Passell, Sandia National Laboratories, spoke about SNL's efforts to teach stakeholders  to devlop their own water resource-ecosystem-economic  models. He described work done in Iraq. This is the so-called' mediated modeling' approach using system dynamics models.

 Elena López-Gunn of the Water Observatory of Spain's Marcelino Botín Foundation, addressed groundwater governance in Spain and the alignment of science and policy. She identified four policy issues: diffuse pollution; overabstraction; economic water productivity; and illegal water use. She also identified important tools: water footprint analyses, co-management by groundwater users' associations, and transparency indicators. Upshot: sustainable agriculture and sustainable groundwater management are linked.

Reed Maxwell of the Colorado School of Mines focused on groundwater and climate change. He demonstrated the use of the fully-integrated watershed model ParFlow. He applied the model to the Little Washita River watershed in central Oklahoma. He concluded that climate change impacts on groundwater depend upon feedback mechanisms between groundwater processes and the land surface water-energy balance.

Sargent Green,California Water Institute: in the San Joaquin Valley, "water districts have done a good job of managing groundwater." That's a bit misleading, because water (irrigation) districts have access to surface water during parts of the year, so whwhen a farmer has surface water she doesn't need to pump as much (or any) groundwater. That's good groundwater management by the districts? Not all areas in the SJV have water districts and surface water for irrigation, so I guess we can assume they practice bad groundwater management.

Tom Glover,Westlands Water District, discussed the groundwater-agriculture nexus in the USA's largest irrigation district. Westlands used to pump 800,000- 1,000,000 acre-feet each year during the 1950s and 1960s. Once its framers gained access to surface water, that figure dropped to 100,000 - 200,000 acre-feet per year. So I guess that's another example of "good groundwater management.

Important Thing I Learned
Good groundwater management does exist in California. Uh-huh...

"Your golden retriever may drink out of the toilet with no ill effects. But that doesn't mean that humans should do the same." -- San Diego Tribune, quoted by Robert Glennon

Comments

[installing irrigation systems]

Hey, love the quote at the end. Though it's actually pretty sad. We have to consider where does most of the pollution come from, especially the pollution contaminating our waters. Not only sewer water, but the industrialized farming etc. Anyway, it's good reading your posts and getting twitter updates. :)

[Michael]

Hi, Chris.

Thanks for commenting.

I agree with you, and asked Green about that.

I updated the post and included some more information. But it doesn't negate your comment at all. Essentially, the water districts do a 'good job' because when they have SW to distribute, they get the irrigators to quit pumping and use the SW. I'm sure that's a tough sell - quit spending your money to pump GW and use this cheap SW. Duhh....

[Chris Brooks]

'Sargent Green,California Water Institute: in the San Joaquin Valley, "water districts have done a good job of managing groundwater."'

I find that statement utterly astonishing. If they're doing a good job in the SJV I wonder what he would regard as doing a bad job? It boggles the mind.