Van Nuys, Calif. — If you live in the U.S. Southwest, the meager snowpack in the Rockies is hard to ignore. For good reason, it's the source of drinking water for millions and vital for agriculture. The question weighing on many people’s minds is whether the current “snow drought” could be our new normal.
According to Peter Goble, assistant state climatologist with the Colorado Climate Center at Colorado State University, climate models do suggest that snow droughts are likely to become more common in the future.
In large part, he says, that’s because as we heat up the atmosphere with greenhouse gases, precipitation will more likely fall as rain rather than snow, which will either evaporate or be taken up by plants before it can flow into waterways, like the Colorado River. Even though we’re not done having cold, snowy winters just yet, he says, “Based on what we're seeing, both in our climate observations and some of our climate models, it makes sense to really prepare to do more with less.”
But less could be more. At least, that’s the plan in Los Angeles. If less water is going to fall from the sky or come through aqueducts, the city will just “make” their own. “When we're done in the next two years,” says Jesus Gonzalez, with the Los Angeles Department of Water and Power (LADWP), we will “have a new water supply for the city of L.A., producing enough water for almost half a million people.”
A Glass Half Full
I met with Gonzalez, the manager of recycled water and groundwater at LADWP along with Ryan Thiha with LA Sanitation & Environment (LASAN), who is the project director for the L.A. Groundwater Replenishment Program at the Donald C. Tillman Advanced Water Purification Facility in the San Fernando Valley northwest of downtown L.A. The facility treats wastewater from homes and businesses. Some of that clean water is used by industrial users and to irrigate parks and the rest flows via the Los Angeles River (LA River) to the ocean. But now, the plan is to store it underground.
That’s because the facility sits above a massive groundwater basin—some 226 square miles in size. Currently, this aquifer is at about half of its capacity, but it’s a glass half full.
“The city of L.A. has this tremendous resource, the San Fernando Groundwater Basin aquifer. It can hold almost two years of water supply for the entire city of L.A.” A new Advanced Water Purification Facility (AWPF) at Tillman plans to fill that basin. Gonzalez, Thiha, and I are standing at the future plant's construction site, which is crawling with heavy equipment as cranes lift beams and concrete into place. Gonzalez says the new water recycling facility will be the size of three Costco buildings stacked one on top of the other. When it comes online at the end of 2027, most of the purified water it creates from homes and businesses will be stored in the aquifer for a not rainy day.
That will give L.A. a source of locally controlled, drought-proof water supply that could be pumped during dry years, says Gonzalez. It will be a reservoir that he says would be less vulnerable to earthquakes and less dependent on imported supplies from the Colorado River and Northern California. (About 90 percent of the city’s water supply is imported. The other ten percent is groundwater.)
Ultimately, the facility will purify up to 45 million gallons per day, using three processes—ultrafiltration, reverse osmosis, and ultraviolet advanced oxidation—all without increasing water rates for customers thanks to state and federal grants helping to offset the nearly $1 billion price tag. Had L.A. gone with a desalination plant, Gonzalez says, it would have been five to ten times more expensive—and used way more energy.
The water purification plant will require energy too, but LADWP is also a power company, and part of its long-term strategy is to develop more renewable energy sources. As it stands today, they are getting nearly 60 percent of their energy from renewable sources. “So,” Gonzalez says, “DWP has strategically been developing water supplies for water security, while also on the power side, investing in the development of renewable supplies.”
The LA River, Reborn
Since 1984, the Tillman plant has cleaned wastewater—to strict federal standards—from households and businesses in the San Fernando Valley and discharged most of it into the adjacent LA River.
Historically, the river was ephemeral, able to change from a small creek in the dry season to a ferocious torrent in the winter, where it would capriciously change course to find a new route to the Pacific Ocean. It was the lifeblood for Indigenous Tongva and Chumash people who lived along its banks. The Tongva tribe created a movable village, known as Yangna, in what today is downtown Los Angeles.
The 52-mile LA River is now channelized and tamed in a “concrete coffin,” following years of floods in the 1930s. It's mostly fed by discharges from the Tillman plant as well as the Glendale Water Reclamation Plant to the east. The Groundwater Replenishment Project, of which the new Tillman Advanced Water Purification Facility will play a key role, also recognizes the importance of sustaining the environment, namely the LA River.
The LA River Ecosystem Revitalization project will be the largest ecosystem restoration project in the entire country—a $4 billion investment in improving the health of the LA River and providing community and ecological benefits. As it’s done in the past, the Tillman facility will continue to send water to the river and currently studies are being conducted about the needed flows to maintain habitats and recreation.
“Forever Water”
After Tillman is complete and the next drought strikes, the city will retrieve groundwater from the aquifer, clean it again, and distribute it to taps of L.A. customers, who eventually will send it down their drains.
In the past, that wastewater would have been treated at the Hyperion Water Reclamation Plant near the Los Angeles International Airport (LAX) before being discharged to the ocean. Within the next two decades, as a part of the Pure Water Los Angeles initiative, Hyperion will also become a major recycling facility and send its purified water back to the San Fernando Valley to begin the loop again.
Gonzalez says there is a significant amount of infrastructure that will be needed to close that loop, and that the program will be implemented in phases, but by 2052, the recycled water from Hyperion should begin to replenish the San Fernando Valley. That water will then be spread across their entire system. So, Gonzalez says, “In other words, the cycle and that closed system will continue.”
In a funny sidenote, I tell them that I tried to explain the city’s recycling plans to my mother, (who lives in the San Fernando Valley), and she said, “You mean they’re making forever water?” Gonzalez and Thiha both laugh. “That's a great way of describing it.” Gonzalez smiles and adds. “Yes, it’s a cycle that almost can never end.”
By 2040, Los Angeles plans to have 70 percent of its water supply coming from local sources, with most of that being recycled. So, as the expression goes, what happens in L.A., stays in L.A. 💧