Congress and the Yuma Desalting Plant

It’s hard to know whether Arizona Republican Sen. Martha McSally’s “Water-Energy Technology Demonstration and Deployment Act” is a serious bill. Congress doesn’t do much of anything these days, so probably not. But, serious or not, it is a very bad idea masquerading as a good-sounding one.

The good-sounding idea is the creation of a partnership between the U.S. Bureau of Reclamation and the Department of Energy to do neat stuff involving water and technology and energy demonstration etc. The bad part is a congressional intervention to goose the restart of the Bureau of Reclamation’s Yuma Desalting Plant.

I’m all for having a conversation about restarting YDP. But Congress is a lousy place to do it.

The Yuma plant has a long and checkered history. Completed in 1992 to desalinate agricultural drain water on its way to Mexico, the YDP has essentially never been used. This has always pained Arizona, which suffers under Law of the River math that leaves it increasingly vulnerable to Colorado River shortages. The details are crazy complicated, but essentially every acre foot of water cleaned up at the YDP and put to some human use is an acre feet less risk to Arizona.

So from Arizona’s perspective, what McSally is trying to do makes sense. Not “Water-Energy Technology Demonstration and Deployment” sense, but Colorado River water shortage sense. But there are important environmental tradeoffs, which is why the YDP has always been part of the broader discussions among states, national governments on both sides of the U.S.-Mexico border, and environmental groups.

The problem is that every acre foot of water cleaned up at the YDP and put to some human use is lost to one of the last fragments of habitat in the Colorado River Delta.

The tradeoff is the Ciénega de Santa Clara, an environmental haven that is currently the beneficiary of the water that would otherwise go to the YDP. Here’s Audubon’s Jennifer Pitt explaining its significance:

Mexico manages the Ciénega de Santa Clara as a federal natural area with the highest protections of its Biosphere Reserve program, and it is listed in the International Ramsar Convention on Wetlands. Notably, the Ciénega is home to 70 percent of the world’s remaining population of the Yuma Ridgway’s Rail, listed as an endangered species in the United States. Indeed these birds travel back and forth between the two countries.

The Colorado River is so completely developed that it no longer flows down its final 100 miles. The water supply for the Ciénega de Santa Clara originates as Colorado River water that, after irrigating farms in Southern Arizona, flows as brackish water too salty for farming and then drains into a canal that has fed the Ciénega for nearly 50 years. Senator McSally’s legislation would eliminate this water supply, and destroy the Ciénega.

I happen to agree with Jennifer on this, but it’s a reasonable thing to debate. Is it better to continue to send this water to the Ciénega, or to clean it up and put it to human use?

In my 2016 book Water is For Fighting Over, I drilled down into the history of YDP as an example of the benefits of considering tradeoffs like this in the context of the broad collaborative framework of Colorado River problem-solving. This is the part where all the interested parties get together to work through the tradeoffs. An important part of this collaborative tradition in the Colorado River Basin is the norm that members of Congress don’t try run bills that do an end run around the process, trying to advantage their state at the expense of others.

As one of my friends complained in the face of a similar example some years back when a member of Congress (yeah, from Arizona) tried a similar move, it’s just not the way we do things on the Colorado River.


  1. where would the salt and other pollutants go?

    at least along the sea you know where the waste ends up, back in the sea. inland would they pump it underground and hope it doesn’t destroy someone’s acquifer?

  2. During the Yuma Desalting Plant year-long Pilot Run in 2010, makeup water was provided to the Cienega by the US, Mexico and NGOs.

    Why couldn’t this be done again? There is lots of brackish groundwater available in the Colorado River delta.

  3. Charles – Yes, that was one of the benefits of the process that led to the pilot run – it arose out of the basin-scale collaborative process in a way that considered the tradeoffs and mitigated the harms. A process that considered the benefits and mitigated the costs seems likely to generate such a similar solution if it does lead to a YDP restart.

    That’s the problem with McSally’s approach – it seems to be an end run around such a process.

    Songbird – The brine would likely be returned to the concrete drain that currently carries ag waste water down to the Gulf of California.

  4. The water users of the United States and Mexico collectively turned the Delta, which was once almost two million acres of biologically rich wetland, into a desolate stretch of parched sand. I don’t think ~120kaf/y of saline water to the Cienega is too much penance for that sin (and I say that as one of those water users). There are plenty of ways to make up for the volume sent to the Cienega, rather than eliminating it. And all of them would require consultation and agreement among water manages, instead of Congressional fiat.

  5. so is that ag waste in the drain the same water that is currently going to the wetland or is that yet a different drain/canal?

    Sue, you got it, that the river no longer gets any water each year is a tragedy. humans need to learn to live within the carrying capacity of the environment and not rely upon things which cause further damage. giving back something to help heal something we’ve destroyed should not be a minor aside at the tail end of an agreement but a first priority.

    the more we destroy the less capacity there is in the end for everything including us…

  6. McSally’s bill is nothing more than a PR stunt–a way to appear to be doing something on the Colorado River without any risk of it actually happening. If she had talked to anyone knowledgeable about the Yuma Desalting Plant (doubtful), she would know that the plant cannot be operated without extensive repairs and capital improvements, which Reclamation estimated nearly a decade ago would cost anywhere from $160-450 million, plus another $25-40 million in annual operating costs. That’s never going to happen. The YDP, as originally designed and intended, is dead.

    But there are other, far less expensive ways to satisfy the US obligations under the 1974 Salinity Control Act and Minute 242, conserve water in Lake Mead AND preserve the environmental values of the Cienega. In 2013 we described one such alternative: construct a pipeline to transport the 100KAF Wellton-Mohawk drain water to Imperial Dam where it would be mixed with roughly 6MAF of Colorado River water that passes that point every year, eliminating the need to release an additional 100KAF from Mead every year. At the same time, the US could increase pumping from the 242 well field and dedicate 50 KAF/yr of that water to the Cienega. The total cost of that alternative was estimated at around $100 million, which would be funded by non-federal parties in return for ICS credit, with an annual operating cost of about $4 million–less than Reclamation spends today to NOT operate the YDP.

    Unfortunately the proposal never got any traction because entities that take their Colorado River water from Imperial Dam objected to the 20-30 ppm expected increase in salinity there, despite the fact that (1) 20-30 ppm is within the normal variation of salinity at Imperial and (2) the salinity at Imperial today is far less than it was in the past (less than 700 ppm in recent years), largely through the work of the Title 2 Salinity Control Program to which those water users do not contribute.

  7. Pingback: McCann: McSally’s bill to restart the Yuma Desalting Plant “nothing more than a PR stunt” – jfleck at inkstain

  8. The mandate to operate the long-defunct Yuma Desalting Plant is a mistake. It is bad for the birds and for our existing agreements with Mexico.

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