‘Borrowing from the future’: What an Emerging Megadrought Means for the Southwest

PHOENIX – It’s the early 1990s, and Park Williams stands in the middle of Folsom Lake, at the base of the Sierra Nevada foothills in Northern California. He’s not walking on water; severe drought has exposed the lakebed.

“I remember being very impressed by the incredible variability of water in the West and how it’s very rare that we actually have just enough water,” said Williams, who went on to become a climate scientist at Columbia University. “It’s often the case there’s either too much or too little.”

Williams is the lead author on a report out this month in the journal Science detailing the extent of drought conditions in the American West.

The report found the period from 2000 through 2018 to be the driest 19-year span since the late 1500s, and the second driest since 800. In simpler terms, it’s an emerging megadrought, which is a drought that typically lasts decades.

“Drought conditions during the 2000s have actually been on average as severe as the driest on 20-year periods of the worst megadroughts of the last millennium,” Williams said in an interview with Cronkite News. “The cause is a combination of natural climate variability and human caused climate change.”

What sets this emerging megadrought apart from others, such as those recorded in the 1200s and 1500s, is that human activity is increasing the severity. Although past megadroughts had natural causes, the report found this natural phenomenon has been made worse by humans.

Nancy Selover, Arizona’s state climatologist since 2007, said there’s more to learn about the impact people have had on this recent drought, although she does classify Arizona as being in a megadrought now.

“I’m sure we’re contributing a little bit. I’m not sure how much we’re contributing,” Selover said. “It’s model output. And models are designed not to predict what’s going to happen, they’re designed for us to understand them and learn how the system works.”

It’s important to understand the difference between deserts and droughts, said Kathy Jacobs, the director of the Center for Climate Adaptation Science and Solutions at the University of Arizona.

“I think making a distinction between sort of living in a desert where it’s hot and dry, and understanding that we could be entering into decades long shortage situations that really throw all of our water supply projections for a loop is a really important distinction,” Jacobs said.

To make that distinction, Williams and his team employed methods first used in 1937 by researchers at the University of Arizona, who discovered the width of the annual growth rings in tree trunks corresponded to moisture availabilities, or soil moisture.

“Our measurement of drought is really a combination of tree ring records that come up to 1900,” Williams said. “And then that, stitched together with our climate derived estimates of soil moisture, brings us up to 2018.”

He said a megadrought isn’t a multidecade period in which every year is dry, but instead an extended period when the occasional wet years don’t come close to making up for the predominance of dry years.

If the concept of an emerging megadrought seems abstract, there’s a reason. Williams said people might not feel the immediate impact of water sources depleting due to groundwater pumping in California, Arizona and other states.

“We’ve been pulling out groundwater at a far faster rate than it actually gets replenished, and that has allowed us to get through this drought,” Williams said. “We’re basically borrowing from the future.”

Selover said it’s a future that’s likely to include more people in the Southwest.

“We now have more people here, so drought is a more significant issue than it ever was before,” she said. “We need to be very, very careful about how we deal with our water and how we deal with our temperature. Because those things going forward are going to be decreasing water and increasing temperature.”

The Colorado River is one example of decreasing water resources. Arizona, California, Colorado, Nevada, Utah, Wyoming and New Mexico depend on the river for water, but the amount of water each state is promised has been consistently overallocated.

“Each state is actually guaranteed more acre feet of water out of the Colorado River every year than actually flows in the Colorado River in an average year,” Williams said. “We’ve had an unsustainable relationship with the Colorado River for the last century, independent of climate change.”

Jacobs said it’s a relationship that hasn’t been properly addressed, especially considering the cultural significance the Colorado has to many people in the Southwest.

“It’s really important to recognize both, tribal, and environmental uses of water in both the main stem (of the river) and the tributaries,” Jacobs said. “Letting the river actually be a river and flow is something that’s valued by some people. Whereas now, we have essentially dried the entire river out so it does not reach the sea.”

Williams suggests that water in the 1,450-mile-long Colorado be reallocated as one way to improve the river’s condition. That’s difficult when the demands for water are so high.

Last year, after years of negotiations, President Donald Trump approved the Colorado River Drought Contingency Plan which outlines how much water the seven Colorado River Basin states can take from the river if reservoirs at Lake Powell and Lake Mead drop to critical levels. Despite the plan, Williams said the river still is in danger of drying up.

“The fact that the normal average year is actually getting drier and is projected to keep getting drier in the Colorado River means that we’re probably going to have to revise how much each state is allocated on the Colorado River substantially,” Williams said.

Beyond that, Jacobs stresses the need to elect representatives to the Arizona Legislature who care about the environment and to reach out to current legislators so they know how important tighter water regulations are to Arizonans and the state’s economy.

“Most of the people who come here for tourism are coming because they want to see the beautiful parts of the state,” Jacobs said. “Many of those beautiful parts are connected to rivers and water supplies. There are billions of dollars generated by the state’s economy by people who are here for ecotourism, and we could easily build that into a much more profitable path.”

At the end of the day, the spirit of continued water conservation efforts can be traced back to that image of a young Park Williams on Folsom Lake. The lesson learned, he said, is how precious water is.

“The stakes for humans are higher than they’ve ever been before,” Williams said. “And as we change the climate, one of the things that is most predictable is that the distribution of water is going to change. Trying to figure that out before it really becomes a crisis, I think, is one of the most valuable things we can do.”

This story is part of Elemental: Covering Sustainability, a multimedia collaboration between Cronkite News, Arizona PBS, KJZZ, KPCC, Rocky Mountain PBS and PBS SoCal.

City Uses Reclaimed Water to Bring ‘Dead’ Arizona River Back to Life

TUCSON – Along a parched riverbed where only dust and wild grasses have held sway for the past 70 years, the Santa Cruz now flows.

As of June 24, under the watch of Tucson Water Department officials, a section of the river just west of downtown will receive a maximum of 2.8 million gallons a day of treated effluent to restore the riparian area and help replenish aquifers as part of the Santa Cruz River Heritage Project.

Last weekend, the water flow stretched almost 2.5 miles, far surpassing the city’s expectations. To reduce this excess, Fernando Molina, a spokesman with Tucson Water, said the city lowered the flow Monday, and the water has since receded to about 1 mile in length.

The goal is to keep the river flowing north just past Congress Street, about a half mile south of its current stopping point near Speedway Boulevard, he said.

Tucson officials say the water stretched almost to Speedway Boulevard before the city slowed the flow. (Photo by Dylan Simard/Cronkite News)

Tucson Water director Tim Thomure said the water was available because the city has over-prepared for expected growth and advances have been made in conservation technology and awareness.

“As of 2016, and it’s still true today, we were using the same amount of potable water in Tucson as we were in the mid-1980s, with 200,000 more people and a much more robust economy,” he said. “Because water conservation and efficiency was actually moving faster than new-growth demand for water.”

Most effluent enters Arizona rivers as a means of disposal, Thomure said, but the Heritage Project’s approach of using reclaimed water to restore an ecosystem is the first of its kind in the state.

He called the river the “birthplace of Tucson,” saying the project will honor the river’s rich history and connected culture.

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Humans have used the Santa Cruz since about 1,200 B.C., according to the city’s Heritage Project history page. First used by the Hohokam for drinking water, irrigation and fishing, the river was quickly depleted in the late 1800s when settlers began pumping groundwater.

Dan Stormont, with Sustainable Tucson, a volunteer group, called the project an exciting effort by the city but said it’s not a solution on its own.

“It’s just a Band-Aid, honestly,” he said. “It’s a way to restore the natural flow to a small section of the river and make it look the way it used to look – and that’s going to be a challenge, too, because of course it’s not just a river anymore, it’s also a flood control channel.”

Some concerns have been raised about the project, including an increased threat of floods during monsoon season, the potential toxicity of effluent and doubts over whether some of the predicted positive effects – such as increased tourism – will actually materialize.

Thomure acknowledged the decision to restore a section of the Santa Cruz was made quickly, and that only time will reveal whether these concerns are valid.

The city was required to study the reclaimed water’s quality and quantity, as well as how it would interact with existing groundwater stores, before the project was allowed to move forward, he said. The new water, Thomure said, is just as safe as – if not safer than – the natural river water.

Stormont noted concerns about the water’s safety but said it’s likely safer than some water that already enters the river.

“When you consider anytime it rains, we get a large rain, it’s washing all the hydrocarbons off the street, the heavy metals for brake pads, all of that stuff is running into the rivers and being infiltrated as well,” he said. “The effluent that’s being discharged is much cleaner than most of the runoff from the street.”

However, the effluent being pumped into the Santa Cruz River isn’t 100% purified, Thomure said, because city officials feared that “over-engineered” water would not promote the most natural ecological growth possible. He advised visitors to avoid swimming or drinking the river water.

Tucson resident Deandra Binder’s dog Rat (front) and Whitney Noel’s dog Zinnia (back) enjoy their new, cool place to play at the mouth of a recently awakened section of the Santa Cruz River. (Photo by Deandra Binder)

Whitney Noel and Deandra Binder of Tucson, who took their dogs for a walk along the riverbed at the mouth of the revived portion, said they’d like the city to make the waterfront more accessible to visitors.

“I think it’s going to bring tons of people out,” Noel said. “There’s no water down here. Even the spots out at Tanque Verde Falls, different areas that we go to … , just to get to water in the summertime.”

Thomure said if the project receives continued public support and proves to be sustainable, the city would be open to enacting similar projects farther down the river. This section, at least, is here to stay.

“We expect the water to be discharged to the river indefinitely,” Thomure said. “There will be times where we turn off the flow to maintain the system. There’ll also be times when we turn off the flow when monsoon rains are actually happening and we have natural flows, but this will be a flowing stream from here on out.”

Noel said she hopes the increased river flow instills a sense of pride in Tucson residents and visitors.

“I think a lot of people are going to take pride in it and hopefully keep it really clean,” Noel said. “I would totally volunteer to come down here and clean it up.”

Stormont said this project may be a stepping stone toward further habitat restoration efforts in Tucson.

“It’s not the answer to all our problems, but it is an exciting project that I think does give people some motivation to see what our rivers could look like if we are more careful in how we manage our water,” he said. “Hopefully it’s the first step towards restoring the flow of our rivers in Tucson.”

This story is part of Elemental: Covering Sustainability, a multimedia collaboration between Cronkite News, Arizona PBS, KJZZ, KPCC, Rocky Mountain PBS and PBS SoCal.

Beavers: An unlikely ally in the battle against drought in the West

LANDERS, Wyo. – It’s no secret that water is a problem in the West. But what isn’t as well-known is the role the humble beaver has played in helping to maintain wetlands and ponds across the arid landscape. Their populations were decimated during the fur trade in the 20th century and their numbers dropped dramatically from 400 million to just 100,000 by the end of the twentieth century.

Now the beaver is making a comeback, scientists think they have an important role to play in fighting drought.

To many ranchers and landowners out here, the beaver is a destructive little beast. Not only can it wreak havoc on irrigation systems, it can take down trees, nibble through fiber-optic internet cables and cause the occasional flood. But wildlife biologist Jeremy Maestas says there’s much more to the animal.

“Just through their diligence and 24-hour work ethic, they’re making amazing things happen in the streams,” Maestas said. “And because they’ve been here for millennia, the plants that live here have evolved with their browsing and beavery.”

The beaver is essentially a walking, talking ecosystem, Maestas said. Instead of just using dams to control water, we could also follow the beavers lead, which he called a “sticks and stones” approach.

“Rather than diesel fuel and Tonka toys, we just direct the water to move sediment and grow vegetation, and do all the good things we want the ecosystem to do,” Maestas said.

One of those good things includes storing more water in the ground. Across the West, most precipitation comes in the wintertime. But when snow melts quickly, it rushes down a stream and into a river, far away from where it’s needed.

But if snowmelt encounters something like a beaver dam, Maestas said, the water gets delayed.

“The longer that we can keep that on the landscape, we increase the productivity of those plants,” he said. “And ultimately leads to more drought resilience, right? These sponges fill up with water. It’s like putting money in the piggy bank for those lean times.”

Lean times, like when you don’t get a lot of snow. Or when rising temperatures mean snowmelt happens early and the rush of water comes too soon for peak water demand in the growing season.

“But it really isn’t until you get down in the mud and you start building these that you understand the process that you’re trying to fix,” Maestas added.

So one afternoon in early August, about 40 people got their feet wet — and muddy — building a few of these beaver-esque dams on a Nature Conservancy testing ground in Wyoming. The group mostly included people from agencies like the Bureau of Land Management and Wyoming Game and Fish.

“I feel like this is the perfect day to try something new,” said Corissa Busse, who works for the Nature Conservancy in South Dakota.

She and the others spent about a day and a half in the classroom, learning what makes a beaver tick. They won’t have the power of chisel-like teeth, so workshop instructor Joe Wheaton told them to be creative.

“You’ll have shovels — very useful,” Wheaton said. “You’ll have buckets. Please don’t put the buckets back together without cleaning them first. You’ll have loppers. You’ll have hands. Make sure everybody’s got gloves, everybody’s got eye protection.”

They brought some untreated fence posts to build the dams, but otherwise, they had to use supplies from the area just like a beaver would. That meant willow branches, sticks, stones and mud. The materials allow the structure to be porous. Water can trickle through, but flows will slow enough to soak deep into the ground.

Maestas said there’s another big difference between this and a regular dam.

“We don’t want to be constantly coming back in here with human labor and effort trying to keep it alive,” he said. “So the sooner we can turn it over to Mother Nature, to do her job, the better off we’re all going to be.”

By Mother Nature, Maestas means beavers. Once these human-made dams are established, they will re-introduce the animal into the area.

Maestas said this won’t work everywhere, especially in more populated areas, or places where the animal could interfere with infrastructure. But in the right setting, Maestas said, “We’re bringing nuisance animals into areas where they’re wanted.”

That way, he said, maybe beavers can begin to solve the problem of water in the West.

This story was produced by the Mountain West News Bureau, a collaboration between Wyoming Public Media, Boise State Public Radio in Idaho, Yellowstone Public Radio in Montana, KUER in Salt Lake City and KRCC and KUNC in Colorado.