by Colton Lochhead, Las Vegas Review-Journal, April 27, 2022
As Lake Mead’s water level continues to fall amid the worsening drought, Southern Nevada water managers are revving up their newest pumping station to make sure water keeps flowing to Las Vegas even in the worst of scenarios.
Workers with the Southern Nevada Water Authority on Wednesday removed an energy dissipator from the first of 34 valves at the authority’s low-lake-level pumping station, making the pump fully operational. The move to convert the station to full operations comes after the nation’s largest man-made reservoir dropped far enough to expose the top of its highest-level intake straw for the first time in its history.
“It’s the worst it’s ever been,” said Colby Pellegrino, deputy general manager of resources at the water authority, of the current state of water resources in the western U.S.
“We’re experiencing hydrologic conditions and reservoir storage levels that are lower than they’ve ever been except for when these facilities were initially being filled,” she added.
Completed in April of 2020 at a cost of $522 million, the pumping station was built to ensure that water flows to the Las Vegas Valley even if the reservoir shrinks another 160 feet to its “dead pool,” the point at which Hoover Dam would be unable to release water downstream.
John Fleck, a water expert at the Utton Center at University of New Mexico School of Law, said he never expected that the low-level pumping station would need to be turned on this early.
Fleck said that over the last two years the “bottom has dropped out” of the flows of the Colorado River that at one time would have been difficult to anticipate.
“If you had asked me to sit down and do the math two years ago, I would have told you there was a remote possibility, but not likely. And the remote possibility is what happened,” Fleck said.
Future-proofing
The water authority turned on 22 of the 34 pumps fitted with dissipators on April 1 to start feeding water to the Alfred Merritt Smith Water Treatment Facility, water authority Deputy General Manager of Engineering Doa Ross said. The remaining 12 pumps will be turned on if the lake falls to an elevation of 1,010 feet.
The lake dropped below 1,060 earlier this month, a point in which the pressure on the system is low enough for the authority to remove the 1,100 pound dissipators and fully open the valves, Ross said. The water authority expects that the remaining dissipators will be swapped out by June.
When it comes to major infrastructure projects, the two-year buffer the authority had between completion of the project and hitting the point of needing to turn it on “is almost too close for comfort,” Ross said.
“The fact that we’re here with this facility completed almost two years to the day before needing it is a testament to the forethought of this organization in this valley,” Ross said.
As of this week, the top of the reservoir’s first intake straw now sits above the water line. That means that water is only coming through a second older straw and a newer third straw that draws water from one of the deepest spots in the reservoir. That bottom-of-the-lake straw, along with the low-level pumping station, has the ability to fully supply the valley’s water needs and more should the reservoir’s levels drop far enough to expose the second intake straw, Ross said.
Fleck credited the authority for investing in the project to protect from what many viewed previously as a remote risk, one that he referred to as a low-probability, high-consequence event that has now come to pass.
“Las Vegas looks really smart,” Fleck said. “If Las Vegas hadn’t done that, the rest of us in the Colorado River basin would be in this terrible problem.”
Recent cutbacks
While Southern Nevada has positioned itself to be able to deliver water even as the drought worsens, the rapid changes are leaving other jurisdictions scrambling to adjust.
Lake Powell fell below 3,525 feet for the first time ever last month, sparking concern among Western water managers. Federal data shows it will likely drop even further before rebounding above the level next spring.
Earlier this month, the Department of Interior proposed taking an unprecedented step of holding back 480,000 acre feet of water — roughly the amount of water to serve about 1 million households — in Lake Powell that would normally flow downstream to Lake Mead.
Last week, the seven Colorado River basin states — Nevada, Arizona, California, Colorado, New Mexico, Wyoming and Utah — all agreed with the request.
“We recognize the urgency created by current conditions in the Basin; in fact, hydrologic conditions in the Basin have continued to decline since your April 8, 2022, letter to the Governors’ representatives,” the states wrote in response.
The proposal from the federal officials looks to reduce the risk of Lake Powell from dropping below 3,490 feet, a level at which Glen Canyon Dam could no longer produce power.
The agreement from the basin states shows that they are “still willing to roll up their sleeves and do the hard things together, instead of turning to the courts or litigation,” Pellegrino said Wednesday.
In Southern California, water managers took the drastic step this week in declaring a water shortage emergency and mandating that outdoor water usage be limited to just one day per week for parts Los Angeles, Ventura and San Bernardino counties, affecting roughly 6 million people, the Los Angeles Times reported.
The Metropolitan Water District plans to monitor water use and, if the outlook does not improve, could order an all-out ban on outdoor watering as early as September.
Looking forward
Pellegrino said that the Colorado River has been over-allocated by about 3 million acre-feet per year over the last half-decade, with demand far outstripping the river’s current supply.
“We have to make some course corrections in the way that we use water,” she said.
The latest Bureau of Reclamation projections for Lake Mead, released in February, point to about a one-in-three chance that by 2026 the reservoir will drop below 1,020 feet, a number that Fleck said “we’ve all watched for years as a bottom we just don’t want to go past.”
Those kinds of dire projections, Fleck said, used to be discussed in idle chats and long-term planning documents as far-off possibilities. But not anymore.
“These things that we used to talk about in hypotheticals are now happening in real time and it’s just a little striking and unnerving to live through,” Fleck said.
Contact Colton Lochhead at [email protected] Follow @ColtonLochhead on Twitter.