Nation & World

Lessons emerge as 7 thirsty states war over Colorado River water

U.S. to decide on apportionment as demand grows with populations in West, supply shrinks due to drought

9 min read
Scott Horsley.

“Slow things are not as dramatic, don’t catch attention. They go unnoticed, all as we get deeper and deeper involved in the problem,” said Scott Horsley, water resources expert, about the Colorado River crisis.

Stephanie Mitchell/Harvard Staff Photographer

Seven Western states, which include some of the fastest-growing in the nation, get some of their water from the Colorado River. How it is distributed is guided by the 100-year-old Colorado River Compact, which has come under intense scrutiny in recent years as a two-decade-long drought has shrunk supply even as demand has risen. Late last month, the states belonging to the compact missed a federal deadline to come up with an agreement to make water use meet the river’s declining capacity, leaving the decision in the hands of the federal Bureau of Reclamation. The Gazette discussed what it all means with Scott Horsley, an instructor in water resources policy and watershed management in the Sustainability Graduate Program at the Harvard Extension School.


Scott Horsley

GAZETTE: There was a recent article on the crisis over Colorado River water that called it a “slow-motion disaster.” How would you characterize it?

HORSLEY: That is a good way to put it. Slow things are not as dramatic, don’t catch attention. They go unnoticed, all as we get deeper and deeper involved in the problem. The stressors are slow-moving too: climate change, development in the watersheds, and changes in the water demand. This agreement has been in effect a little over 100 years, and we’ve known for quite a while that it’s not working that well.

GAZETTE: What would you say are the big factors at play? Everybody knows there’s been a drought for over two decades, but is it more complicated than that?

HORSLEY: Another big factor is over-allocation of the resource. A hundred years ago, they didn’t know as much as we know now, but they made estimates of flow in the river. And as time went on, it should have been fairly clear that they were getting close to over-allocating the water in the river. Another thing with the allocation is they are missing some important stakeholders. One is the fish, the ecosystem that depends on the river. Another is Native Americans, who were there before we were. It’s common in these types of agreements that the original stakeholders aren’t really listed, though Native Americans are part of the Arizona allocation. There’s a lot of discussion about older rights versus newer rights in deciding who gets water, but I would argue that there were at least a couple of parties before the Californians.

GAZETTE: And what we’re talking about is the Colorado River Compact’s method of allocating rights. Certain places come first, and others come second?

HORSLEY: The way that water has been divided in the Western U.S. is by “rights of prior appropriation,” either from court decisions or permit decisions. It’s essentially who came first, who made the claims first in a legal way. The rights are divided into senior and junior rights. The best example of the senior right is Imperial Valley, California. They came in early on and put a huge demand on the river. The more recent one is Arizona, which is considered a junior right. And when there’s not enough water, the junior rights holders are the first to get cut.

GAZETTE: So that gives the junior rights people incentive to come to the negotiating table and perhaps gives the senior rights people a little incentive to sit back and wait?

HORSLEY: Exactly, and that’s what’s happening.

“Pricing is one tool that can be used to conserve water — but we need to be sensitive to lower-income populations and affordability.”

GAZETTE: If this was followed to the letter, could California and other states with senior rights get what they can out of the Colorado and leave Phoenix dry?

HORSLEY: I don’t know that Phoenix would go to zero, but I would imagine they would go to some low level that might be considered a base level of survival, getting drinking water to people but limiting all other uses. But essentially, yes, if you were to follow the compact, that’s what would happen. The people more recently in, the junior rights, would get severely limited.

GAZETTE: And we’re not talking here just about lawns and swimming pools in the desert, right?

HORSLEY: Actually, I think those are major drivers. Some of these places are using about three times as much water per capita than we are in the Northeast, and I would argue that a lot of that is for nonessential uses. The biggest culprit, in my opinion, is lawn irrigation, turf irrigation. Lawn irrigation is a large water demand in climates with year-round growing seasons. It’s obviously not essential, especially in a critical situation like this. The state of Massachusetts uses 65 gallons per capita as a goal, and that assumes about a 10 percent outdoor water usage number. Metro Boston has done a lot of good conserving work — we’re down around 45 — but these guys are at about three times that. It’s admittedly warmer there, so you might drink a little more water when you’re traveling in California. And I don’t think they use much more for cooking there, and I don’t think showers are much longer. So what this boils down to is a lot of outdoor water usage, and specifically lawns.

GAZETTE: Is a solution simply raising the price of water? Keep going up until you see the lawns going away?

HORSLEY: I think pricing is one tool that can be used to conserve water — but we need to be sensitive to lower-income populations and affordability. A progressive water-rate structure can provide low rates for a base level of essential water usage with significantly higher unit rates for nonessential usage, such as lawn irrigation.

I’m working for the town of Manchester by the Sea on the North Shore here in Massachusetts, assisting them with water-management issues. They too are having a very difficult time getting enough water, especially during periods of drought. They’re at 78 gallons per person per day, which is above the 65-gallon goal for the state, and nearly double metro Boston’s 45. They have some large estate properties that use a huge amount of water on their lawns, so they are looking at increasing rates in the upper pricing tiers. The problem with that is even if you brought the water bill up to $1,000 a year — or $2,000 — for some of these landowners, they will simply continue to pay it. The elasticity of the price is a really tricky thing. I think a water rate structure is part of it, but you may not get all of the response you want if you simply rely on that.

GAZETTE: Is regulation the only other way to go? Public education I imagine will get some people.

HORSLEY: Education, peer pressure, prices, and regulation are the drivers. It will work differently in different places with different people. Smart growth and sustainable development practices can significantly lower the water footprint. Stormwater management is another tool that can offset water uses. As an example, infiltrating rainwater runoff from rooftops to replenish groundwater systems that provide baseflow to the river can help.

GAZETTE: Any chance that the “atmospheric rivers” that pounded California with weeks of rain helped the situation?

HORSLEY: The climate change stuff is tricky. For the most part, there’s less snowpack in the mountains that provide snowmelt to the Colorado River. So in that sense, climate change has been a negative and hurting the situation. Rising temperatures also increase evaporation and transpiration by plants, reducing the available amount of water. Whether or not these extra rainfall events might mitigate that, I don’t know. Either way, it’s hard to depend on that going forward.

GAZETTE: So this is not a “wait for the drought to break” kind of problem. It’s looked at as a shift in the climate regime that will require deeply rethinking this whole thing?

HORSLEY: That’s true. And again, during the last 20 years when they’ve been having drought conditions and climate change is becoming more evident, they’re still building new subdivisions, developing more properties, creating more demand. And while demand has been going up, supply has been going down. It doesn’t take a genius to figure out that you’re going to run into a problem at some point.

GAZETTE: Is it likely that the Colorado River Compact will have to be thrown out and redone or is there a way forward under this current agreement?

HORSLEY: Frankly, this has been something we’ve been talking about for a very long time, and the fact that it’s coming to a head is a great thing. Where it will end up, I don’t know. It’s unlikely that the states are going to come to a mutual agreement here, and California looks like it’s going to be the most unlikely to agree. I suspect that there will be much more stringent controls on nonessential water uses and a greater focus on sustainable development practices. How that actually happens will ultimately have to come through state law, an amended agreement, or a court decision. The court is where a lot of the Western water law has been settled. It’s highly likely to go there, and that’s not necessarily a bad thing.

GAZETTE: Are there higher stakes here? This seems to be a clash between the right to live wherever you want and the fact that California grows an awful lot of food we eat.

HORSLEY: My view is that we like to grow food in areas where there isn’t necessarily a lot of rainfall, but there is a lot of sun. We also like to live in beautiful, sunny climates, where there may not be a lot of water. Those aren’t bad ideas if you have extra water that you can bring there without impacting others. But are these sustainable things? We’re finding out that the answer is “not as much as we had hoped.” We’re going to have to make some adjustments.