Lake Mead Low Water Level

More from this show

There has never been less water in Lake Mead since it was filled then right now. The record low mark was hit Tuesday. Tom McCann, deputy general manager of the Central Arizona Project, will tell us how that impacts Arizona.

TED SIMONS: Water levels at Lake Mead sank to a record low earlier this week. The lake fell below a mark that will trigger a water supply shortage if recoveries aren't forecast before the end of the year. Tom McCann, deputy manager of the Central Arizona Project, good to see you again.

TOM MCCANN: Thank you.

TED SIMONS: What exactly are we talking about here?

TOM MCCANN: It's a couple of feet lower than it was a couple years ago. It's not really as big a deal as some people are trying to make it into. We've got rules that are in place that determine when we're going to have a reduction, a shortage. Your, we're getting closer to that point. You mentioned if the lake isn't projected to come back up, and in fact, it is. May was a pretty good month in terms of rainfall in the upper basin of Colorado and Lake Powell has come up. Right now we're anticipating the lake will be up several more feet before the end of the year.

TED SIMONS: I think the concern is this new level kind of hits that trigger mark. Talk to us about that.

TOM MCCANN: A lot of people kind of get mixed up. That trigger is not an instantaneous trigger. The decision is made once a year in August, based on the projection in August of what the level of the lake will be at the end of the calendar year. Really what we need to look at in August, coming up, what is the Bureau of Reclamation going to project as the elevation of Lake Mead by the end of this year. Right now they are actually predicting there is a negative legitimatable probability that it's going to be below 1075 by the end of the year.

TED SIMONS: And again, the 1075 was taken earlier this week. How many days ago was that, and could that level be different even now?

TOM MCCANN: It is. I looked at it earlier today, this morning, around midnight was 1074.9 something, and noontime it was 1075.0 something. It varies all the time.

TED SIMONS: In August now officially what happens? Would you look at the weather patterns, the water, the past and future?

TOM MCCANN: Bureau of Reclamation is the one that does the study, they do it every month. It's a 24-month study looking out years ahead. They take in the past record of what's happening in terms of precipitation, snowpacks, et cetera. They take in projected uses. They know what the states are going to be using out of Lake Mead. We have a pretty good idea because we have rules about how much water is released from Lake Powell every year. We know based on the elevation of Lake Powell how much water is going come down to Lake Mead. We can predict pretty closely based on that.

TED SIMONS: A lot of people never hear about Lake Powell, yes, Lake Powell feeds Lake Mead. If it hits the trigger marks what's going on at Lake Powell?

TOM MCCANN: That's a good question. It kind of depends ultimately on what the snowpack is like in the upper basin. Generally speaking, the guidelines put in place in 2007 have Lake Mead and Lake Powell operating in tandem. When Mead is down and Powell is up, we release more water from Powell to Mead F. Lake Mead is high and Powell is low, we wouldn't release as much. Lake Powell is sort of in the middle and Lake Mead is lower. We got a little extra water this year and we're projecting that next year we will get a little extra over the year.

TED SIMONS: So water management is a factor with Lake Mead.

TOM MCCANN: Oh, absolutely.

TED SIMONS: Let's say the forecast says this doesn't look good for January, it looks below 1075. What happened, what happens?

TOM MCCANN: Worst case, and right now there's still about a 50/50 chance of a shortage in 2017. The answer is the same then, too. In the first level of shortage below 1075, the Central Arizona Project will be about 20% offer supply. The people that are going to be impacted by that really are the farmers in Central Arizona. They are the lowest priority users within our system. The cities and the Indian tribes actually have a higher priority. Even if we have shortage it's not going affect the water that's available to the cities that comes out of people's taps. Not going to be any change there.

TED SIMONS: But up to 50% cut from CAP to agriculture, that is possible?

TOM MCCANN: About 50% of the water delivered to agriculture today, yeah. For those users, they would have choices to make. They could farm less, go back to groundwater pumping to make up the difference.

TED SIMONS: Are there incentives to leave some fields fallow and not use so much water?

TOM MCCANN: There are. We have put into place arrangements starting this year to leave additional water in Lake Mead for exactly the reason we're talking about. If we can find a mutually beneficial arrangement where they use less water this year, and leave that water behind, maybe that puts off that shortage for next year or the year after. Right now it looks like that's working.

TED SIMONS: But the bottom line, the Colorado River is overall indicating. Pretty much a general consensus here?

TOM MCCANN: I'd put it this way: The amount of water as a whole that's being used in the basin today is about the amount of water that we get on average. We haven't had average years lately so that's been a problem. Within the lower basin, the three states, Arizona, California, Nevada, and Mexico, we use more water every year than we get in. In the long term, in the next few years we need to address that problem so we don't have that bigger problem down the road.

TED SIMONS: All right, good to have you here, thanks for joining us, we appreciate it.

TOM MCCANN: Friday on "Arizona Horizon" it's the "Journalists' Roundtable." We will have more on how the U.S. Supreme Court's decision on the Affordable Care Act will impact Arizona. And we'll discuss how small charter schools were saved from massive spending cuts. Friday on the "Journalists' Roundtable." That is it for now. I'm Ted Simons, thank you so much for joining us. You have a great evening.

Tom McCann:Deputy General Manager of Central Arizona Project

Illustration of columns of a capitol building with text reading: Arizona PBS AZ Votes 2024

Arizona PBS presents candidate debates

An armed forces bugler playing the trumpet in front of the United States Capitol building.
airs May 26

National Memorial Day Concert 2024

Graphic for the AZPBS kids LEARN! Writing Contest with a child sitting in a chair writing on a table and text reading: The Ultimate Field Trip
May 26

Submit your entry for the 2024 Writing Contest

Rachel Khong
May 29

Join us for PBS Books Readers Club!

Subscribe to Arizona PBS Newsletters

STAY in touch

Subscribe to Arizona PBS Newsletters: