Paper: Characterizing #Drought Behavior in the #ColoradoRiver Basin Using Unsupervised Machine Learning — AGU

Map credit: AGU

Click the link to access the paper on the AGU website (Carl J. Talsma,Katrina E. Bennett,Velimir V. Vesselinov):


Drought is a pressing issue for the Colorado River Basin (CRB) due to the social and economic value of water resources in the region and the significant uncertainty of future drought under climate change. Here, we use climate simulations from various Earth System Models (ESMs) to force the Variable Infiltration Capacity hydrologic model and project multiple drought indicators for the sub-watersheds within the CRB. We apply an unsupervised machine learning (ML) based on Non-Negative Matrix Factorization using K-means clustering (NMFk) to synthesize the simulated historical, future, and change in drought indicators. The unsupervised ML approach can identify sub-watersheds where key changes to drought indicator behavior occur, including shifts in snowpack, snowmelt timing, precipitation, and evapotranspiration. While changes in future precipitation vary across ESMs, the results indicate that the Upper CRB will experience increasing evaporative demand and surface-water scarcity, with some locations experiencing a shift from a radiation-limited to a water-limited evaporation regime in the summer. Large shifts in peak runoff are observed in snowmelt-dominant sub-watersheds, with complete disappearance of the snowmelt signal for some sub-watersheds. The work demonstrates the utility of the NMFk algorithm to efficiently identify behavioral changes of drought indicators across space and time and to quickly analyze and interpret hydro climate model results.

Key Points

  • Unsupervised machine learning automatically identifies key sub-watersheds with significant changes in their future drought indicators
  • In the Colorado River Basin mountains, distinct differences in future runoff seasonality and intensity changes are established
  • Significant uncertainty in drought behavior is observed among the applied climate models
  • Plain Language Summary

    Our study applies a pattern recognition computer program to categorize regions with the Colorado River Basin (CRB), based on the modeled future behavior of several indicators important to drought. We use the results from models of climate and water to estimate how drought will change in the future. We then group the behavior of sub-watersheds based on identified similarities in their response to changes we observed. We show that areas of the Upper CRB could experience a large reduction in available water for evapotranspiration (for use by trees, e.g.,), and that future hydrologic conditions may more closely resemble those of the Southwest CRB regions today. We are also able to pinpoint which sub-watersheds should expect large losses in snowpack based on expected changes to spring runoff contribution to streamflow. The work is important in that it highlights a key tool that can be used for rapid assessment of vast amounts of climate and hydrology data in a region that may be critically impacted by future changes in extreme events, such as drought.

    Click the link to read “Colorado will lose half its snow by 2080 and look more like Arizona, federal scientists conclude” on The Denver Post website (Bruce Finley). Here’s an excerpt:

    “We see increased aridity moving forward”

    Parts of Colorado, Wyoming and Utah are drying out due to climate-driven changes in stream flows, and these states will shift to become more like the most arid states of the Southwest, federal researchers found in a scientific study published this week.

    The lead author of the study said Colorado will experience a 50% to 60% reduction in snow by 2080.

    “We’re not saying Colorado is going to become a desert. But we see increased aridity moving forward,” said hydrologist Katrina Bennett at the federal government’s Los Alamos National Laboratory in New Mexico.

    The researchers used an artificial intelligence “machine learning” system that allowed them to analyze massive amounts of data collected over 30 years including soil moisture, volumes of water in streams, evapotranspiration rates, temperature and precipitation across the varying landscapes within the Colorado River Basin. Tracking the West’s hydrology on such a scale previously would have taken years.

    Heading to the lake? #Colorado trying new tools, including Phosphorus-Free lawns, to combat toxic algae — @WaterEdCO

    Beach at Barr Lake, where agencies are working to remove toxic algae. May 31, 2022. Credit: Jerd Smith, Fresh Water News

    Click the link to read the article on the Fresh Water News website (Jerd Smith):

    Read the label on your lawn fertilizer bag and help save your favorite lake or reservoir from those smelly, pea-green algae blooms that shut down summer watering spots for weeks at a time.

    That’s the message from water quality officials and city water utilities this year as the summer lawn and recreation season gears up.

    Algae blooms, long common in the Eastern United States, are becoming more frequent in Colorado lakes and reservoirs as a 20-year mega-drought reduces water levels, 90-plus degree days occur more often, raising water temperatures, and growing numbers of homeowners add phosphorous-laced lawn fertilizers to their grass.

    Blue-green algae produces toxins that can harm people and pets, and can also create odors and tastes that degrade water quality.

    The problem surfaced at Aurora’s Quincy Reservoir in 2020. Since then the city has taken the lead on trying new treatment methods, such as installing aeration devices that inject oxygen into the water. It has also spent millions on other treatments such as hydrogen peroxide and alum, which kill certain types of toxin-producing algae and, with alum, weigh the phosphorous down so that it falls to the bottom of the lake and becomes encased in silt and mud.

    But the biggest issue, by far, says Sherry Scaggiari, an environmental services manager at Aurora Water, is the increasing amount of phosphorous that finds its way from lawns into stormwater, and then into streams and lakes.

    “We are trying to get people to use less phosphorous on the grass. You need nitrates, but you don’t need phosphorous,” Scaggiari said.

    At Barr Lake State Park near Brighton the problem has triggered several efforts to clean up Barr and Milton Reservoir, which are owned by a private irrigation company. Steve Lundt, a scientist who sits on the board of the Barr-Milton Watershed Association, has been monitoring the watershed for some 20 years.

    Beach at Barr Lake, where agencies are working to remove toxic algae. May 31, 2022. Credit: Jerd Smith, Fresh Water News

    “People always ask, ‘Why is there so much phosphorous in these reservoirs?’ Well, there are 2.5 million people living in the watershed. That is half the population of the state.”

    Fixing Barr and Milton is a major undertaking. Treatments such as alum work best in water bodies, such as natural lakes, where water supplies aren’t released annually for irrigation. Much of the Barr-Milton system is used to irrigate farm lands on the Eastern Plains as well as to supply municipal drinking water. It drains and fills every eight months, roughly.

    “We would be adding alum almost continuously,” Lundt said, an expensive process that also expands the park’s carbon footprint because the alum has to be mined.

    Aurora, however, hopes it only needs to treat Quincy once every 10 years or so, according to Greg Baker, spokesperson for Aurora Water. But if phosphorous levels continue to rise, it may have to be done more frequently.

    Lundt is also using a method known as bio-remediation to remove some 8,700 carp, or roughly half of the local carp population, from Barr Lake since 2014. The invasive species is known for stirring up the sediment, releasing phosphorous into the water and creating a situation ripe for algae growth.

    This month the association plans to hold a fishing competition with a $2,000 prize for the angler who removes the most carp.

    And Aurora and Barr-Milton are looking at extensive planting programs along waterways leading to their reservoirs that will use plants, such as cattails, that are effective at removing phosphorous from water.

    Still, water officials say, the best tool, and perhaps most cost-effective, is to begin slashing the use of phosphorous-based lawn fertilizers.

    The Barr-Milton Watershed Association has been leading a campaign, called the P-Free Lawn Fertilizer campaign, to encourage consumers to omit phosphorous from lawn care for several years. And Water ’22, a year-long campaign to educate Coloradans on water issues, is also highlighting the issue. [Water ’22 is being led by Water Education Colorado, which sponsors Fresh Water News].

    Lundt said some 12 states have already outlawed phosphorous-enriched fertilizers’ use by homeowners unless they can prove their soils are short of phosphorous.

    Major fertilizer makers, such as Scott, have removed phosphorous altogether.

    “Fertilizer companies are on board, it’s a matter of just changing the culture of how we fertilize our lawns,” Lundt said.

    Jerd Smith is editor of Fresh Water News. She can be reached at 720-398-6474, via email at or @jerd_smith.

    A ‘Perfect Recipe for Extreme #Wildfire’: #NewMexico’s Record-Breaking, Early Fire Season — The New York Times

    Map credit: National Interagency Fire Center

    Click the link to read the article on The New York Times website (Tim Wallace and Nadja Popovich). Here’s an excerpt:

    The explosive, early start to this year’s Southwestern fire season reflects the convergence of long-term trends — a forest landscape overgrown after decades of aggressive fire suppression and parched by drought; springtime temperatures warmed by human-caused climate change — and more immediate dangers, like the relentless winds that have fanned the flames. It’s an ominous sign for the rest of the American West, where the fire season tends to start later, but where conditions are similarly primed to burn…

    Propelled by strong winds, warm temperatures and low humidity, the combined fire moved quickly through dry, overgrown forests and grasslands. Fire crews fought to slow its advance, but the inferno’s fast pace and extreme behavior often hampered their containment efforts. On the gustiest days, which saw winds reach up to 80 miles per hour, firefighting planes and helicopters had to be grounded and crews were prevented from reaching the front lines.

    Similar conditions have fueled wildfires across New Mexico. The Black fire in Gila National Forest exploded in mid-May to become the second largest blaze burning in the state. It has continued to grow, forcing nearby evacuations as recently as this weekend. Another large springtime wildfire near the village of Ruidoso in the south of the state, which has since been contained, destroyed or damaged more than 200 structures and left two people dead…

    This spring, the risk factors aligned for an extreme fire season in New Mexico, said Park Williams, an associate professor at the University of California, Los Angeles, who studies long-term drought trends and the effects of climate change. Much of the state saw its driest or near-driest April on record. Springtime temperatures were above average, too. Those conditions, typical for the Southwest during a La Niña climate pattern, added to longer-term risks: forests left overcrowded and unhealthy by decades of aggressive fire suppression; a mega-drought that created a tinder-dry landscape; and the background warming caused by the burning of fossil fuels and other human activity. Add high winds to the mix and you have “the perfect recipe for extreme wildfire,” Dr. Williams said.

    Watering restrictions hit the West in worst #drought in 12 centuries Southern #California, #Utah, #Arizona and others impacted — The Deseret News

    West Drought Monitor map May 31, 2022.

    Click the link to read the article on the Deseret News website (Amy Joi O’Donoghue). Here’s an excerpt:

    This is how bad it is getting: The Metropolitan Water District in California is a wholesale supplier of water with 26 member agencies representing 80 cities and communities. CBS News reported that the district’s water delivery network supplied just 5% of the water local areas had requested. It is also prepared to levy a fine of $2,000 per acre-foot of water to those areas that fail to meet the state’s water savings goal. An acre-foot is enough water to cover a piece of land roughly the size of a football field water one foot deep.

    In May, the city of Mesa, Arizona, declared a water shortage, and officials there are instituting severe water restrictions at their own facilities. Salt Lake County is in a similar mode, shooting for water savings by asking parks and recreation leaders to cut back on water use as much as possible while still keeping ballfields and golf courses functional.

    #Water Cuts Are Coming for the West — Stateline

    Lake Powell, just upstream from Glen Canyon Dam. At the time of this photo, in May 2021, Lake Powell was 34% full. (Ted Wood/The Water Desk)

    Click the link to read the article on the Stateline website (Matt Vasilogambros):

    Conservation should not feel like belt-tightening but like an opportunity, said Heather Cooley, director of research at the Pacific Institute, an Oakland-based think tank. She and her colleagues found in a recent study that California could reduce urban water use by more than 30% by making sustainability investments, tripling water reuse and recycling and recapturing rainwater.

    The American West’s culture around water must become more realistic, she said. Climate change is making the region—already two decades into the worst megadrought in 1,200 years—hotter and drier. Adopting sustainable practices and investing in new infrastructure not only will save water, but also cut greenhouse gas emissions that worsen climate change, Cooley said.

    “We can still wash our clothes. We can still have beautiful landscapes. We can still shower and flush the toilet,” she said. “We just need to do it efficiently.”

    Throughout the West, grassy outdoor landscapes don’t match the native arid ecosystems, said Amanda Begley, associate project manager for the Water Equity Program at TreePeople, an environmental education program serving Southern California. Native plants and trees such as sage brush and oak use less water, cool neighborhoods and attract biodiversity, butterflies, birds and bees.

    “Now that we’re up against a wall, we can’t really ignore the climate we’re in anymore,” she said. “Are lawns the best use of our drinking water? I think no.”

    But replacing lawns costs money. Communities throughout California provide rebates to incentivize new native landscape investments, but many people can’t afford the upfront price tag, said Bruce Reznik, executive director of Los Angeles Waterkeeper, an environmental advocacy group. Direct-install programs can lift the financial burden for low-income households, he said.

    “It’s doable,” he said. “It’s not going to be easy. It’s not going to be cheap. But it’s going to be doable.”

    ‘We Should All Do Our Part’

    States and cities across the West have taken steps in recent years to account for drought, which has devastated the Colorado River and drastically lowered water levels at Lake Mead and Lake Powell.

    Water regulators in southern Nevada are increasing rebates for homeowners and business owners to remove their grass, adding to a successful lawn-removal program in the region. Turf already is banned for new developments. Nevada lawmakers last year passed legislation that prohibits Colorado River water to be used on “non-functional” grass at commercial properties, apartment complexes and street medians. The law goes into effect by 2026.

    Some cities in Colorado, Montana, New Mexico and Utah also have lawn watering restrictions in place. Colorado lawmakers this year passed a bill that pays residents to remove their ornamental lawns.

    Cities generally are using less water than ever before, even with booming population growth, said Mark Squillace, a professor of natural resources law at the University of Colorado Law School. Tackling water shortages means changing the way states manage water, he said, especially for infrastructure projects that divert limited Colorado River water and for agriculture, which accounts for around 80% of water use in the West.

    Drinking water sometimes is used to grow water-intensive crops such as alfalfa, he pointed out, most of which are exported to other countries. He finds this “insane.”

    “We should all do our part, but we should recognize that we’re not going to solve our problems on the backs of our cities,” he said. “We should be more conscious about using water in our lives and in our homes. But at the end of the day, it’s not going to be enough.”

    While statewide water restrictions may be inevitable, Squillace is hesitant to say they’ll solve water shortages. Solutions should be tailored for their communities, he said.

    Licensed under a Creative Commons Attribution-Noncommercial-NoDerivatives 4.0 International License (CC-BY-NC-ND 4.0).
    Story by: Stateline, an initiative of The Pew Charitable Trusts.

    #EastTroublesomeFire caused by humans, officials say; #CameronPeakFire cause remains unsolved — The #FortCollins Coloradoan

    East Troublesome Fire. Photo credit: Northern Water

    Click the link to read the article on the Fort Collins Coloradoan website (Miles Blumhardt). Here’s an excerpt:

    The East Troublesome Fire, the second-largest in state history, was human-caused, the U.S. Forest Service announced Friday. Investigators came to that conclusion based on evidence gathered from where the fire started. Considering the area and time of year the East Troublesome Fire began, the agency’s news release stated, a hunter or a backcountry camper may have caused it, potentially by accident.

    The fire started about 15 miles northeast of Kremmling in the Arapaho National Forest on Oct. 14, 2020. It was fully contained Nov. 30, 2020, but not before it burned 193,812 acres and destroyed more than 360 homes as well as more than 200 other buildings. The Rocky Mountain Insurance Information Association estimated losses from the fire at about $543 million. The cost to fight the fire was $15.7 million, according to the National Interagency Coordination Center…

    A burnt sign on Larimer County Road 103 near Chambers Lake. The fire started in the area near Cameron Peak, which it is named after. The fire burned over 200,000 acres during its three-month run. Photo courtesy of Kate Stahla via the University of Northern Colorado

    The cause of the Cameron Peak Fire, the largest wildfire in state history, is believed to be human-caused but is still under investigation.

    The Cameron Peak Fire burned 208,913 acres during a 112-day run that started Aug. 13, 2020, in the Roosevelt National Forest about a 65-mile drive northwest of Fort Collins. It destroyed 461 buildings, including 224 homes, and 17 business structures, and was the most expensive fire to fight in state history with a suppression cost of $133.3 million, according to the National Interagency Coordination Center.