Indy Q&A: Southern #Nevada Water Authority General Manager on the #ColoradoRiver and preparing for a drier future — The Nevada Independent #COriver #aridification

Lake Mead low elevation. Photo credit: Department of Interior via ensia

From The Nevada Independent (Daniel Rothberg):

Colorado River officials face a math problem.

Already, there is not enough water flowing through the Colorado River to meet all of the demands on the watershed, which spans seven U.S. states and crosses into Mexico. And as the climate changes, scientists warn that those who depend on the watershed should plan to receive even less water each year…

Already, the Lower Colorado River Basin states that rely on Lake Mead — Arizona, California and Nevada — have been meeting to discuss and find funding for a program that would keep more water in the reservoir in an attempt to stave off further shortages and cuts. That plan would keep about 500,000 acre-feet in the reservoir next year and in 2023…

The states came together to develop the plan as part of a consultation clause in an existing 2019 agreement, known as the Drought Contingency Plan. That plan builds off of a set of operating guidelines for the river, approved in 2007 and set to expire in 2026. At the same time that water officials from the seven Colorado River states tackle near-term issues, they are all positioning to negotiate a new set of guidelines.

The Colorado River is governed by a series of overlapping laws, contracts, compacts and agreements, including the guidelines. Working within these structures, the states face a major challenge — to reduce use on the river and prepare for the worst-case scenario of a future with far less water to go around. Next month, water officials from across the basin are set to meet in Las Vegas to discuss that challenge and other issues facing the river.

John Entsminger, the general manager of the Southern Nevada Water Authority, said he is “cautiously optimistic” that the states will be able to find a way to lower use “because of the structures we’ve already put in place.” He noted that if Lake Mead were to hit 1025 feet above sea level, current agreements would already trigger cuts of about 1.3 million acre-feet of water.

The Nevada Independent spoke to Entsminger about the negotiations and how dry of a future Colorado River water officials should plan for. Our conversation has been edited for clarity and length.

What do you see as the greatest challenge facing the Colorado River moving forward?

I hate to be obvious, but the biggest challenge for the river is we have a lot less water than people have legal entitlements.

How does that play into discussions around management as they’re evolving right now?

It makes the interstate and international discussions much more difficult, because really what you’re ultimately doing is negotiating to divide up a far smaller pie than what was believed to be the case in the 20th century.

Brad Udall: Here’s the latest version of my 4-Panel plot thru Water Year (Oct-Sep) of 2021 of the Colorado River big reservoirs, natural flows, precipitation, and temperature. Data (PRISM) goes back or 1906 (or 1935 for reservoirs.) This updates previous work with
@GreatLakesPeck.

You mentioned not that long ago, testifying in Congress, that “the river community is far from a consensus about how dry of a future to plan for.” What are some of the differing opinions right now? And where are people on establishing that baseline of what the future looks like for the river?

I was on a panel at the University of Colorado Law School within the last six weeks or so. And a couple people on the panel were asked that question of how dry a future should we be planning for, and I said I thought an 11 million acre-feet annual flow of the river is probably a good place to start based upon what I’ve heard from folks like Jonathan Overpeck and Brad Udall and other smart climate scientists.

But there were some folks on that panel that threw out a number of 13 to 14 million acre-feet, which, frankly, is quite a bit more water than the average of the last 20 years. So I think just from that exchange, you can see that there isn’t currently a consensus on what sort of worst-case scenario should we be planning for, as we negotiate operating guidelines for post-2026.

Let’s take that number, 11 million acre-feet. What would it mean in terms of water use to get to that number?

As a basin (seven states plus the country of Mexico), we’re currently using about 14 [million acre-feet]. So it would mean finding a way to cut current uses by three million acre-feet and not add any new uses, at least without retiring a commensurate amount of existing uses.

Knowing how hard it is to reduce use, that sounds like a very big challenge. Do you think that’s an achievable goal?

That’s the amount of water that Mother Nature gives us. We don’t really have a choice whether or not to achieve it. You have to find a way to live within the amount of water that nature actually gives you.

Signing ceremony for the Colorado River upper and lower basin Drought Contingency Plans. Back Row Left to Right: James Eklund (CO), John D’Antonio (NM), Pat Tyrell (WY), Eric Melis (UT), Tom Buschatzke (AZ), Peter Nelson (CA), John Entsminger (NV), Front Row: Brenda Burman (US), and from DOI – Assistant Secretary of Water and Science Tim Petty. Photo credit: Colorado River Water Users Association

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