How Much Water Does the Colorado Really Have, Part II

Colorado River Basin

Colorado River Basin

Some of my favorite water people like to point out that we don’t have a problem of water shortage here in the arid West, but rather a problem of water allocation. In the comments, the mysterious DG seems to be in that camp, offering this on what will happen when the Colorado comes up short:

At our present consumption rate, the river will come up short. I guess that some farmer in the Imperial Valley will have to limit his seven yearly cuts of Alfalfa down to five. I’ll throw another brick into the toilet tank and a water park in Phoenix will be shutdown.

The question is what societal mechanisms we have to allocate shortage. That’s the real point of the exercise for me, and suggests I spend entirely too much time on the science and engineering and not enough on the messy legal-political-social science side of this discussion. The science is relatively easy in comparison.

(map courtesy University of California)


  1. This has been a very visible part of the discussion over the last few years around water usage in the Murray-Darling area in Australia, too: given that there’s less water, how to sustainably utilise it along a few thousand miles of river frontage?

  2. I think it’s important that people understand what the social and political systems have to work with, though. The societal mechanisms are tough, but if people don’t accept the science, social and political systems won’t do anything. (See global warming.)

    It’s probably my scientist bias, but I think the journalism you do about the natural (and engineered) system is really important, even if the unresolved questions are social/political/economic in nature.

  3. John,

    The point I was making is that we all make some adjustments to a reduced water supply. No more, no less.

    Your question about societal mechanisms to cause people to think about shortage is exactly what Barnett’s report was about. Make people aware of the worst that could happen. However, the worst will not happen if some accommodations are made… I guess that journalism takes a hand here.

    Kim brings the political aspect into the thread. Most Bloggers are aware of the political differences between upper basin and lower basin states (right Kim?) Politics happens at several levels. Think basin level.Think environmental level. Think stake holder level.

    BTW, Mrs. G says that I’m a mystery to her too.


  4. John — Stick with what you’re good at (comparative advantage!) and then work with economists like me. As you may suspect, I spend a LOT of time on the socio-political-economic allocation of water.

    WRT the Colorado, the first thing to do is give every state (within upper and lower) the same % haircut when the river goes below Compact figures. THEN allow for water trades so that the water ends up with highest and best use.

    Read more on markets, etc. at my blog (

  5. David –

    The problem with leaving the socio-political-economic stuff to you is that you might be wrong! Plus, that wouldn’t leave me with anything for the next book.

    Re the haircut: Flying cars also would be nice. In other words, sounds cool, but I have yet to see anyone within the system who thinks there is a snowball’s chance in hell of renegotiation of the Compact along those lines, however great in principle it might be.

  6. We in Arizona would love to see equal apportionment of any shortages on the River. California, OTOH, which has rights on the river senior to AZ, would expect compensation if that were to occur. But would just as soon keep their water, thank you very much. As John notes, there are technical solutions (I would include economic solutions in this category) and there are social-political/legal solutions. And there is a wide gap between the two. As I see it, only extreme crisis can bridge the gap.

  7. I don’t agree that Arizona would favor equal apportionment of shortages if that includes the upper basin. As it stands now, the upper basin must deliver 8.34 maf per year (on a rolling 10 year average) to the lower basin (7.5 maf for the lower states and the rest for Mexico, but the Mexican water is subject to dispute). I think it is unlikely that the lower states (and California in particular) would agree to change that.

    For what its worth: Arizona is still banking River water (i.e., putting it into underground storage).

Comments are closed.