weather icon Partly Cloudy

Lake Mead may face deeper pumping to protect water quality

The Southern Nevada Water Authority already pumps water to the Las Vegas Valley from near the bottom of Lake Mead. But it may need to pump from even deeper in the shrinking reservoir to protect the quality of that water.

The water authority’s board of directors on Thursday approved spending $1.4 million to evaluate if changes need to be made to the straw that brings water from near the bottom of Lake Mead and determine if the intake should be even lower to ensure that water quality isn’t jeopardized if the nation’s largest reservoir continues its precipitous drop.

The need to evaluate comes less than a year after plunging levels at Lake Mead led the water authority to turn on its low-lake-level pumping station to draw water from the third intake straw and less than three years after the $1.5 billion project was completed.

The third straw was designed to ensure that the authority could continue to deliver water to Las Vegas even if the reservoir fell to dead pool, or where water could no longer pass through Hoover Dam downstream to Arizona, California and Mexico. That intake now sits at 875 feet in elevation, which is 20 feet below Lake Mead’s dead pool.

Southern Nevada Water Authority General Manager John Entsminger told the board that authority officials feel confident in their ability to pump water to the valley from the straw’s current depth. But there are concerns about what happens if the surface of the lake gets closer to that intake.

“As the lake continues to go down, we are concerned that we could see some increased water quality issues, including warmer water and more turbid water, so we want to evaluate what we would need to do to lower the intake riser,” Entsminger said.

Lake Mead is slightly more than one-quarter full, with the top of the lake sitting about 150 feet above the reservoir’s dead pool mark. The latest projections from the Bureau of Reclamation released this week forecast the lake to drop another 30 feet in elevation over the next two years in the most probable scenario.

The top of the third intake straw sits about 80 feet above the bottom of Lake Mead. But the base of that straw is in the channel of what was once the Colorado River before Hoover Dam was built nearly a century ago.

The authority expects to evaluate several options, from shortening that straw and lowering where the top of the intake sits to constructing settling basins such as those used along the Mississippi River to remove sediment and turbidity from water, Entsminger said after the meeting. Decisions about how and when to move forward with any kind of alterations will be driven by the analysis of water quality expected at various lake elevations in the coming years.

“In our DNA, we’re planners. So now we’re seeing where lake elevations have gotten to since we brought these facilities online,” he said. “We just want to optimize our operations because it may be far cheaper to take 10, 20, 30 feet off of that intake riser than installing new treatment facilities.”

The evaluation will be done by Jacobs Engineering Group Inc. On top of analyzing different options and water quality scenarios, the evaluation will include potential costs for modifying the intake and pumping station, according to planning documents for the project.

The proposed schedule to complete the evaluation is eight months.

Contact Colton Lochhead at clochhead@reviewjournal.com. Follow @ColtonLochhead on Twitter.

Don't miss the big stories. Like us on Facebook.
BCHS: 2023 and beyond

Boulder City High School saw 125 students graduate Tuesday night at Bruce Eaton Field. Dozens of students have received college scholarships totaling just under $7.5 million. It was the school’s 82nd graduating class.

Council votes to adopt $47M budget

As much as it is attractive for many people to compare a city budget to their own household budget, there is one fundamental difference that was noted multiple times when the City Council met to adopt the budget for fiscal year 2024.

Power rates, sources explained

The rate paid by Boulder City for power purchased on the open market rose from 3.945 cents per kWh in 2018 to 23.859 cents per kWh in 2023, an eye-popping increase of 500% or six times the 2018 cost. But what exactly does “open market” mean?

Grad Walk: Emotional tradition marches on

Garrett Junior High Principal Melanie Teemant may have summed it up best when she asked, “Where else do you see this?”

Southern Nevada Veterans Healthcare System holds town hall

The VA Southern Nevada Healthcare System held a veterans’ town hall at its medical center last month. The 60-minute moderated meeting featured representatives from the local health care system, the veteran benefits administration and others. The participants discussed the recent PACT Act, and additional national and local activities. Although the meeting was sparsely populated, much information was nevertheless presented to those in attendance.

City Council agrees to raise utility rates

Power costs on the open market have gone from about 25 cents per kilowatt hour in 2018 to $1.56 per kilowatt hour today, a more than six-fold increase.

BCHS Grad Night: A tradition for 33 years

It’s one of the most memorable nights in a young adult’s life. But it can also be one of the most tragic.