Arizona is one step closer to benefitting from desalinated ocean water as it looks for ways to adapt to dry conditions on the Colorado River.
Arizona water officials traveled to the site of the largest water desalination facility in the western hemisphere — in Carlsbad, California — to sign an agreement that could pave the way for transfers involving clean drinking water generated from the Pacific Ocean.
The San Diego County Water Authority currently operates the facility. That agency signed on to a Memorandum of Understanding with the Arizona Department of Water Resources, Central Arizona Project and Salt River Project. The Metropolitan Water District of Southern California, the Southern Nevada Water Authority and the federal Bureau of Reclamation were also part of the agreement.
By signing, the agencies committed to explore a way to exchange water from the desalination plant for water from the Colorado River.
While the agreement does not actually commit the states to start trading water, officials outlined the kind of deals that could materialize down the road.
Basically, instead of piping water from the coast to inland areas, agencies in both places would make a kind of trade. The San Diego County Water Authority would take more water from the desalination plant and leave some of its Colorado River supplies in the river itself, where a different agency — like the Central Arizona Project — could take it instead, for a price.
“This is an important step in addressing the goal of augmenting the water supplies of the Colorado River by creating a mechanism to deliver those supplies through an exchange using existing infrastructure,” Tom Buschatzke, Arizona’s top water official, wrote in a press release. “It represents the kind of innovation that Arizona and its Lower Basin partners believe is needed from all the Colorado River states to help stabilize the system in the long term.”
California-based officials also highlighted the benefits of using existing infrastructure to carry out exchanges. Such deals would be far cheaper and easier than building new desalination plants or long pipelines to physically move water to areas far from the coast.
The Carlsbad desalination plant cost $1 billion to build, and tens of millions to operate every year. However, it produces relatively little water — about 10% of the annual supply for the San Diego area.
The San Diego County Water Authority has not yet named a sale price for water that could be involved in the exchanges, but it would likely be expensive.
The water coming out of the Carlsbad facility today costs about $3,500 per acre-foot. A series of projections from 2023 show the cost of water climbing past $7,000 per acre-foot in the 2040s.
By comparison, the Central Arizona Project, which distributes Colorado River Water in the Phoenix and Tucson areas, currently sells its water for $365 per acre-foot.
In March, Sarah Porter, director of the Kyl Center for Water Policy at Arizona State University, told KJZZ that a transfer program for desalinated ocean water could be a “very tidy solution to a really big problem.”
“I think it's a win-win,” Porter said. “San Diego County Water Authority has an overbuilt desal plant, and they would like help paying for that most expensive water and there are water users in southern Nevada and central Arizona that are urgently looking for new water supplies because they're facing uncertainty, except for certainly very deep cuts.”
Read KJZZ’s earlier coverage of a potential desalinated water transfer program here.
New sources of water are an attractive proposition for Phoenix-area cities. Many of them could face steep cuts under soon-to-be-determined new rules for sharing the Colorado River, and desalinated water could help cover for the supplies they may lose under that new plan.
Full conversation from The Show
LAUREN GILGER: Well, Arizona may be a landlocked state, but in order to solve our water crisis, we might need to turn to the ocean. Desalination has long been a white whale in Arizona water, but now Arizona water leaders are taking a major step toward making it a reality. But it's more complicated than piping in desalinated ocean water to the desert, and it all says a lot about what the future of water in our region might look like. KJZZ's Alex Hager is covering it and joins us now to tell us more. Good morning.
ALEX HAGER: Good morning, Lauren.
LAUREN GILGER: OK. So, this involves a memorandum of understanding, got to love that phrase, with the San Diego County Water Authority, where there is a large desalination plant kind of in that region. I'm sure you've seen it if lots of folks have been to the ocean there. How would this work?
ALEX HAGER: So, the largest desalination plant in the Western Hemisphere is in Carlsbad, California, right across the street from the beach. You will see it if you know what you're looking for. And right now, it is producing about 10% of the water for the San Diego County area alone. But this deal would make it so San Diego County could lean harder on the water that it takes from that desal plant and take some of the water that it uses from the Colorado River, leave it in the river upstream. And then other users, like ones around Phoenix, could take that water instead, for a price.
LAUREN GILGER: OK, for a price. So, this would look at the Central Arizona Project, the CAP, right? These big canals that bring Colorado River water down to the Valley, to Tucson. They might be able to to get a little extra water out of this?
ALEX HAGER: That's right. I mean, they are potentially facing big cuts. There is less water in the Colorado River than there used to be. The people who are in charge of water agencies around here generally acknowledge that we are not going to see, you know, the nation's largest reservoirs fill back up with water. So, they're looking where else can we go to get water? And this kind of exchange is one of the ways that you can get more water in the systems that bring the Colorado River to Arizona without actually having to build new pipes or pumps.
LAUREN GILGER: And this is interesting, too, Alex, because desalination is like notoriously expensive, right? And that desal plant that you're talking about there, the biggest in the Western Hemisphere in Carlsbad ... it costs a lot of money to to make that water, to make that water clean enough to drink, right?
ALEX HAGER: That's right. This plant cost $1 billion to build. It costs tens of millions to operate every year. And like I said earlier, for all that money, it produces relatively little water. So, that high cost means that the water that comes out of that plant is pretty expensive. So, you know, today the water costs about $3,500 per acre-foot. For comparison, the CAP currently sells water from its canal for about $365 per acre-foot. So, it is not going to be cheap. But in a world where there is just realistically not going to be more water coming into the Colorado River, the amount that we pay for the water we can get from that system might be going up in the future.
LAUREN GILGER: Right. So, that's the inevitable question. This is expensive, desalinated water is expensive. What would a deal like this mean potentially for, you know, how much we all pay for water? Are we looking at inevitably higher prices going forward?
ALEX HAGER: It stands to reason that down the road, we will probably be paying for more water as there is less of it to go around. However, I think on balance, when you look at how much water costs now, you know — if you look at the amount that it costs to run this desalination plant, well, I'll put it this way, the amount that we pay for water now has been relatively immune to changes in how much is actually available because of the way that our system works. ... It is only in the future that we are going to start to see the drought and the lack of availability of water start to catch up.
LAUREN GILGER: So, we haven't paid more yet, but it's coming. ... OK. So, Alex, what strikes me here is that this kind of exchange is like a jigsaw puzzle, right? Like, it's like moving around water and who pays for what and where the water goes. Is this kind of what the future of water might look like here, because we're not going to have more in the river and, you know, we're looking at a drier future in general?
ALEX HAGER: Yeah. Nature is making less available to us, so it's forced the people in charge to get creative, and this is what getting creative looks like. It means that, you know, because it's so expensive to build a new desal plant, it means going to the one that we already have and, you know, creating a a legal mechanism to get that water here instead of creating a big pipe. It means investing in other technologies that can sort of create more water with, you know, with an acknowledgment that we are not going to get more naturally.
LAUREN GILGER: Yeah. OK. Let's talk about some of those other technologies before I let you go. Right. Like, we hear a lot about advanced water purification, what has sometimes been called toilet to tap. Will the future of water in the Southwest also look like things like that — other ways of purifying water so that we can drink it?
ALEX HAGER: It will, and in the relatively near future as well. The city of Phoenix itself is is working and is physically building a new facility that can take sewage, can take wastewater, treat it to drinkable standards, and put it right back into the system. I have visited this facility in Phoenix. I have visited similar ones in California, and the science checks out. There are a lot of very smart people who know that this is safe and have and say that it is a useful way to stretch out the water that we already have.
Like I said, you know, scientists say it would take three, four, five epic snowy years in a row to refill these reservoirs, and based on the way that things have been looking, that is not likely to happen. And the people in charge recognize that they are going to have to kind of do it themselves. And doing it yourself, if you're a city or a water agency in the arid Southwest, looks like creating a sort of complicated legal deal that might be expensive to get water from a place that has a desalination facility or building an advanced water purification facility to stretch out the water you already have and get more use out of it.
LAUREN GILGER: Are there other technologies, other things that you're looking at, Alex, as we look at kind of that jigsaw puzzle and the way that this all might piece together in the future?
ALEX HAGER: I think advanced water water purification is going to be the big one. When we look at where the money is being spent right now, it's that treating wastewater and making it drinkable again that I think is going to be the first big thing that we see helping cities in the arid Southwest weather the drought crisis.
LAUREN GILGER: OK. We'll leave it there. KJZZ's Alex Hager covers water for us and is here to tell us more about all of this now. Desalination, all of these technologies all on the horizon. Alex, thank you very much for coming on. Appreciate it, as always.
ALEX HAGER: Always good to be here.
