The California Bay-Delta Imbroglio: Hell AND High Water

If you've been a semi-faithful reader of this pages, you've noted that I have posted very little on the California water situation, in particular, the Bay-Delta issue. The latter is an extremely complicated issue, one on which I have not really spent much time. I found far more important items to discuss, like whether groundwater is one word or two, or writing puerile April Fools' Day posts.

But two days ago we had Dr. Jeffrey Mount of the UC-Davis Department of Geology and Co-Director of UCD's Center for Watershed Science (CWS) speak on the past, present, and future of the Bay-Delta system, with an emphasis on the Sacramento-San Joaquin Delta. The prognosis is not good, which is no surprise.

This post is based upon Jeff's excellent presentation:  Hell AND High Water in the Sacramento-San Joaquin Delta: Implications for California's Water Supply.

Some background is in order. Jeff and his CWS-UCD colleagues, notably engineers Jay Lund and William Fleenor, ecologist Peter B. Moyle, and economists Richard Howitt and Ellen Hanak (of the PPIC), have published two studies on the Sacramento-San Joaquin Delta, Envisioning Futures for the Sacramento-San Joaquin Delta (download free) and a more recent one, Comparing Futures for the Sacramento-San Joaquin Delta (also a free download). These formed the basis for Jeff's talk. He spent much of his time summarizing these two publications, concluding with the futures comparison.

I was quite surprised at what we had done to the Delta. We have 'reclaimed' 700,000 acres. I knew 'some' land had been lost since we began farming the Delta but I had no idea it was something like 2.6B cubic meters. That has caused many of the islands in the Delta to be below sea level (in some cases tens of feet), and is the reason why levee protection is such a critical issue (1100 miles of levees).

Jeff noted the drivers of change in the system: 1) sea level rise; 2) seismicity; 3) changing inflows; 4) land subsidence; and 5) economics (competing public interests and limited public funds).

This map shows the huge Bay-Delta watershed and the various water projects; 26M people rely on the Delta for their fresh water - 7.5 MAF is exported annually. Yet with sea level rise a threat, the Delta will became more saline as sea level rises and salt water migrates farther upstream. A one-foot (0.30 m)  rise in sea level would essentially mean that the Delta, as currently engineered, could not supply any fresh water for export. A one-meter (3.3 feet) rise would inundate all the islands in the Delta.

Not good, folks.

Cutting to the chase, here are some key conclusions from the "Envisioning" study:

• Sea level rise will increase salinity, no matter what
• Island flooding will increase in frequency and consequence with time
• Low resiliency (willingness to pay) means permanently flooded islands
• Large impacts on water supply
• Delta of the past is gone; Delta of the present is unstable and at a tipping point; Delta of the future is going to be very different and irreversible
• "Restored" aquatic habitat in abundance, but unseen historically

One key element: the current water supply strategy must change.

So what's next? Jeff then described the futures comparison, in which they assumed that water supply and ecosystem sustainability were of equal value. They evaluated four water supply strategies:

• No export of freshwater
• Current strategy - through the Delta
• Dual strategy - through and around the Delta
• Peripheral Canal - completely bypassing the Delta - taking freshwater out above the Delta, and then going east of the Delta to the pumping stations south of the Delta. 

Obviously, the "no export" strategy is best for the ecosystem, but politically unacceptable.

So what was the best alternative? The Peripheral Canal (light green N-S line on the right side of the map).

Jeff was surprised by that result, and said it didn't make many people happy. He is personally not a strong supporter of the PC, already defeated once during the 1980s - I think I even recall voting for it - but he supports their study's results.

It'll be interestering to see if California can muster the political will to do whatever needs to be done 

In any case, we got an excellent 45-minute tour of the Bay-Delta issue from one of the experts.

Want more information? Check out Aquafornia and Aguanomics.

I don't think I'll be revisiting this issue any time soon.

And I thought the Colorado River basin was a mess.

"When it comes to the future, there are three kinds of people: those who let it happen, those who make it happen, and those who wonder what happened." -- John M. Richardson, Jr.

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Comments

[PAUL F . MILLER]

Thank you for posting of my blog ... Authentically Wired ... I am honored and grateful. I trust my effort continue to prove worthy of further notice.

Respectfully,

Paul F. Miller

[David Zetland]

Michael -- thanks for the plug. I invite interested readers to read my opinion in favor (http://aguanomics.com/2008/08/yes-on-peripheral-canal.html) and then against the PC (http://aguanomics.com/2008/12/reconsidering-peripheral-canal.html).

As Howitt's former student, I appreciate the work in the report, but it's also important to note a FLAW in their simulation calibrations (overestimating the cost of desal and CA's 2050 population) that makes the PC *less* desirable (vs. cutting off exports).

I gave a one-hr talk on the PC yesterday to a class, and I'll be posting the audio in the next few days....