Lisa Rutherford: New method of calculating water use in Utah reveals desperation

Bill would use less accurate measure just to make Utah look better in water negotiations.

(Rick Egan | The Salt Lake Tribune) The Hite Marina and boat ramp are closed, as Lake Powell shrinks back to the Colorado River, on Wednesday, July 13, 2022.

During the 17 years I’ve followed water issues in Utah, gallons per capita per day use has been calculated by dividing the amount of delivered/diverted water by the population of the area using that water.

Bill SB119 (Per Capita Consumptive Use) intends to change water use calculation to a consumptive method.

The bill’s sponsor, Sen. Michael McKell, asserts that Utah’s the only state that doesn’t use the consumptive method, hence our high usage number.

But, consider New Mexico’s largest water provider. The Albuquerque Bernalillo County Water Utility Authority’s “WATER 2120: Securing Our Water Future” defines their gpcd as follows: Water usage rate is defined as the total water produced from all sources divided by the population (Water Usage Rate = Total water produced / Population) and is expressed in gallons per capita per day (gpcd).

That has resulted in usage of around 125 gpcd for their area of approximately 600,000 residents.

Thus, they are not reporting their water according to McKell’s consumptive method. They are reporting basically the same way that Utah’s been doing for years.

To learn more about consumptive measure, I contacted John Fleck, a water expert with the University of New Mexico. John serves on water panels, is often quoted regarding Colorado River issues, and has authored several books.

John confirmed that “Albuquerque’s water authority uses ‘delivery/diversion’.” John went on to say, “The problem is that pretty much everyone uses diversion because it’s a straightforward calculation, and consumptive use calculations are non-trivial. Las Vegas is a rare case where the calculation is easy. This is why the USGS abandoned consumption calculations 15 or 20 years ago and only does diversions.”

John also noted that if Albuquerque Bernalillo used the consumptive method their gpcd would be about 60 to 70 gpcd — half what they now report.

According to the state of Utah’s water data site, the state’s gpcd as of 2020 (latest official) was 256 gpcd. And Washington County’s, where I live, was 285 gpcd. I suppose if we use the consumptive method and our numbers are halved, as John Fleck suggested for the Albuquerque area, our state and Washington County figures might be 128 gpcd and 143 gpcd, respectively, still higher than Albuquerque’s.

A Utah Rivers Council website has a chart comparing average per capita municipal water use in various Southwest cities. The information may be a little dated, but Las Vegas’ gpcd is shown as 203 gpcd, Tucson’s 122 gpcd, and Phoenix’s 111 gpcd. So, even if Utah adopts this new calculation method, our numbers may still end up being higher than some who are competing for Colorado River water.

That’s what this is all about. Utah is trying to position itself better during these contentious Colorado River negotiations. That was made clear by SB119′s sponsor. He stated that he could not believe that Utahns who oppose this bill would want us to look bad during this difficult time. We don’t want Utah to look bad, but we don’t want gamesmanship either!

Even worse, unmetered secondary water is not measured under the new plan. That’s a large portion of our state’s water use. Those who use unmetered secondary water have until 2030 to have it metered. So, until then, under this new system, apparently that use will not be counted — at least, not in the new ‘official’ count, which I’m pretty sure will be the figure Utah uses in the Colorado River negotiations.

This bill looks like desperation to me. Do Sen. McKell and other proponents really think that the other six Colorado River Basin states and Department of Interior won’t know what’s going on with this finagling?

Lisa Rutherford

Lisa Rutherford, Ivins, is a 22-year resident of Southern Utah and a retired oil company employee. She is an advisor to Conserve Southwest Utah, but these opinions are her own.