Editor’s note: Allie Mazurek, engagement climatologist and researcher at the Colorado Climate Center, wrote this piece following a July 31 symposium in Estes Park convened by the Colorado Climate Center to commemorate the 50th anniversary of the Big Thompson Flood. The event brought together experts, including several from CSU, to share flood-related research and practices with water managers, government officials, academics, flood survivors and others. Participants reflected on the progress made since the Big Thompson Flood while emphasizing the work that remains to strengthen preparedness and resilience for future flooding.
Flash floods are one of several extreme weather-related phenomena that Colorado faces. And at the end of July, we reflected on the 50th anniversary of one of the deadliest, most devastating floods in our state’s history: the Big Thompson Flood of July 31, 1976.
Damage to Highway 34 from the Big Thompson Flood.
July 31, 1976: It was a Saturday, the eve of Colorado’s 100th anniversary of statehood. Hundreds of people, including many from out of state, were spending the holiday weekend recreating in the Big Thompson Canyon: a winding topographic feature that provides a scenic thoroughfare between Loveland and Estes Park.
The weather was reported to have been partly cloudy that afternoon, but conditions began to shift in the early evening. Around 5:30 p.m. local time, a large group of nearly stationary thunderstorms began forming just east of Estes Park. The storms grew quickly and ultimately produced roughly a foot of rainfall in the span of the next several hours: about five times the amount of precipitation that the area typically receives in an entire July.
Most of the precipitation fell during an even shorter time frame, a little over an hour. That sudden surge of water triggered a fast-moving flash flood along the Big Thompson River and steep adjoining canyon. The river rose upward of 20 feet in some locations and peak flow rate of more than 31,000 cubic feet per second was over four times as fast as the river’s previous maximum.
The devastation was tremendous: Hundreds of homes and businesses were destroyed, sections of Highway 34 were washed away and, tragically, 144 people lost their lives. There has not been a deadlier flash flood in the U.S. since that event, and it remains one of the deadliest weather disasters in Colorado’s history.
The ingredients
One way that atmospheric scientists examine flash flood potential is using an “ingredients-based” approach, which involves examining the characteristics of several atmospheric variables. For flash flood-producing rainfall, the key factors we consider are: rain rate, precipitation duration and surface conditions.
The Big Thompson Flood had numerous ingredients come together to support thunderstorms with very heavy rain rates. First, a cold front pushed westward across Colorado’s eastern plains, which brought moisture-rich air into the Front Range Foothills. The cold front also provided a “cap” atmosphere: bottling up very unstable air in the atmosphere above.
As the front continued to move west, air was forced upwards as the elevation of the terrain continued to increase. This upward motion helped the atmosphere to destabilize, eroding the cap and unleashing plenty of instability for thunderstorms to grow. This localized lift combined with larger-scale upward motion forced the moist, unstable air to cool and condense into thunderstorms.
The ingredients of the Big Thompson Flood (Courtesy of USGS, adapted from UCAR).
As the ingredients were in place for very high rainfall rates, the atmosphere also had very weak “steering currents,” or the layer of winds in the atmosphere that move storm systems. Those weak winds meant that the thunderstorms forming at the mouth of the canyon were nearly stationary, allowing the very high precipitation rates to persist over the same area.
This extreme-rain-producing, slow moving thunderstorm set up near the mouth of the Big Thompson Canyon, a high-risk area for flooding due to its pervasive steep, rocky terrain and susceptibility to rapid runoff. These environmental ingredients coupled with social vulnerability factors all combined to create a disaster that evening.
Damage during the September 2013 flood on U.S. 34 leading up to Estes Park. (Courtesy of the town of Estes Park)
The future
The 2013 Front Range Flood was a reminder that the Big Thompson Canyon continues to be a flash flood-prone area. And throughout Colorado, flash floods have always been and will always be a part of our climate, though climate change could potentially make them worse.
Research suggests that in a future, warmer climate, flash flood-producing rainfall will likely become more extreme. The reason behind this expected trend is that as temperatures warm, water is more eager to exist as vapor rather than liquid — allowing storms to tap into more moisture. Wildfire burn scars, which enhance flash flood risk by making soils repellent to water and cause debris flows, are expected to have an even more profound effect on flash flooding. Climate change is expected to increase wildfire risk in Colorado, leading to more widespread burn scar areas (and thus greater flash flood potential).
CSU research has helped contribute to the knowledge on the Big Thompson event and continues to advance research on heavy precipitation and flooding. The Colorado Climate Center, located in the Department of Atmospheric Science at CSU, serves as a conduit for conducting and disseminating such research to stakeholders and the public.
We’re now nearly a couple weeks past the 50th Anniversary of the Big Thompson Flood, one of the deadliest weather-related disasters in our state’s history. There were several commemorative events on July 31st that stretched from Loveland to Estes Park, including our symposium that we hosted. We heard great feedback from several of the ~100 folks who attended, and we hope to do more public events like these in the future. If you were able to make it, thank you for joining us!
We thought we’d use our blog as a medium to highlight some of the content that was covered during our event. If you’re interested in learning even more, we published an article in CSU Source, summarizing the key atmospheric ingredients that triggered the flood that day. And lastly, we’d like to highlight that the Loveland Museum has an exhibit for the flood that will be showing through the end of November. (Several folks from our team are planning to check it out)!
And while we’re on the subject of flooding, we’ll go ahead and remind you that this time of year is peak flash flood season in Colorado. As precipitation looms in the forecast, check the weather before you recreate, never drive through flooded roadways, and have ways to receive flash flood warnings.
The Colorado Climate Center’s Dr. Russ Schumacher presented first, summarizing the meteorological factors that contributed to the Big Thompson Flood. He also shared his output from a high-resolution model simulation of the event, showing that it successfully captured the extreme rainfall rates but displaced the location of the storm. Credit: Colorado Climate Center
Patricia Rettig, archivist for the CSU Water Resources Archive, transported the audience back to the year 1976. She shared a series of harrowing photos of the aftermath of the Big Thompson Flood, detailing how the flood altered communications and reshaped lives. Photo courtesy of Theresa Barosh.
Mike Nelson, former chief meteorologist at Denver7 News, shared local news clips from the day after the Big Thompson Flood.
Dr. Lori Hodges, Director of the Larimer County Office of Emergency Management, has done extensive research on the Big Thompson Flood. She detailed the complexities of the recovery efforts that took place after the flood and described how communications have improved since. She also engaged with participants on the topic of the lack of cellular service in the canyon, explaining that that infrastructure would need to be put in place by service providers. Photo courtesy of Keil Neff.
The National Weather Service Boulder’s Jennifer Stark and Greg Heavener further detailed how the flash flood-producing storm evolved. They also explained that warning systems and collaboration between meteorologists and emergency responders have improved immensely in the last several decades. Photos courtesy of Ken Langford.
Dr. Robert Jarrett, formerly with the USGS, helped conduct post-flood surveys in the Big Thompson. The goal of these surveys was to determine where the flood waters went and how they reshaped the canyon. He also discussed USGS research on determining flash flood potential in Colorado’s canyons, including his own work on “paleoflood hydrology”–the assesment of historic environmental flood markers used to inform future flood risk. Photo courtesy of Keil Neff.
Dr. John England, Lead Civil Engineer at the US Army Corps of Engineers Risk Management Center, discussed flash flood research that has been used to inform risks surrounding dam safety, including the Olympus Dam in the Big Thompson.
Dr. Kelly Mahoney (NOAA Physical Sciences Lab) details NOAA’s initiatives to better understand and predict extreme precipitation, including their work on probable maximum precipitation–or determining the maximum amount of precipitation that is possible over a given area. Photo courtesy of Ken Langford.
CSU Department of Atmospheric Science PhD Candidate Lexi Sherman presented some of her dissertation research. Lexi’s work examines how heavy rainfall and flash flooding in Colorado is expected to change in a future warmer climate. Photo courtesy of Keil Neff.
Our final presenter was Dr. Kristen Rasmussen, an Assistant Professor of Atmospheric Science at Colorado State University. She provided information on ingredients-based flood forecasting, illustrating how that approach can apply to both floods in the US and abroad. Credit: Colorado Climate Center
Drs. John England and Robert Jarrett convene the flood tour at Viestenz-Smith Mountain Park. The field trip covered several topics including paleoflood evidence, differences between the 1976 and 2013 Big Thompson floods, and how peak discharges were determined. Photo courtesy of Keil Neff.
Robert Jarrett stands near the remnants of Loveland’s former hydroelectric power plant, which was destroyed during the flood. Credit: Colorado Climate Center
Thank you again to all who attended! Credit: Colorado Climate Center
On its surface, Sloan’s Lake is a beautiful oasis that offers a refuge from city life. Part of one of the largest parks in Denver, it features glistening water, mountain views and plenty of paved paths to walk a dog, catch up with a friend or train for a race. But just beneath its gentle waves is a murky, sometimes smelly truth. The [North] Denver lake is slowly filling in with stormwater sludge. The surprisingly shallow water is often quite warm, making it a difficult environment for fish to survive and an easy place for dangerous algae blooms to thrive. If the accumulating muck isn’t addressed soon, the lake is at risk of becoming fully stagnant and bereft of life. On Wednesday, Denver Mayor Mike Johnston stood alongside members of the City Council and advocates for the lake’s future to announce a plan to invest tens of millions of dollars to prevent that from happening.
“A lake that used to be 12 feet deep is in some places only 4 feet deep. It affects the lake’s health. It affects algae blooms. It affects our most beloved events,” Johnston said from the lake’s shore. “We think there’s nothing more important for the long-term health of this neighborhood than to support the long-term health of this lake.”
Dragon boat practice at Sloan’s Lake August 29, 2026.
To raise more money for the cleanup effort, Johnston’s administration will ask the Denver Urban Renewal Authority to add the lake to a nearby urban renewal district south of the park. That would allow it to benefit from money raised through an already-approved tax incentive in the area…The 177-acre lake, which plays host to the annual Colorado Dragon Boat Festival, is only 3 feet deep on average…Swaths of neighborhoods in Denver, Edgewater, Lakewood and Wheat Ridge drain into the lake, bringing sand, sediment and street crud. Over time, that has built up and begun filling in the bottom of the lake. The cleanup project will include dredging sediment out of the bottom of the lake and disposing of it. Crews will also work on ways to prevent more sediment from building up in the lake. Kurt Weaver, the executive director of the Sloan’s Lake Park Foundation, asked the community to keep advocating for the project throughout the entire construction process to ensure it’s completed.
“To be able to have an opportunity to write a new future for the lake is massive for us, the community around it and everyone who spends time here at the lake,” he said.
Cormorants on old pier pilings at Sloans Lake April 12, 2026.
The Berthoud Pass Ditch is now owned by the City of Northglenn. Photo credit: Clear Creek County
Click the link to read the article on The Denver Post website (Elise Schmelzer). Here’s an excerpt:
August 28, 2026
The Colorado Attorney General’s Office and the 14th District Attorney’s Office this week charged Fabrizio Lorenzin, 65, with four felonies in connection with repeated sabotage of the Berthoud Pass Watershed Ditch and its security cameras over several years. The remote ditch system begins at 11,200 feet high on its namesake pass in the mountains and helps funnel water to Northglenn and Golden. The ditch’s water is stored…in Standley Lake in Adams County. Lorenzin allegedly forced open headgates on the system’s ditches, damaging the infrastructure and diverting millions of dollars’ worth of drinking water from its intended destination downstream. Prosecutors allege that he also stole cameras meant to watch the district’s property…
Law enforcement first began investigating the possible tampering with the headgates in August 2019, according to an arrest affidavit documenting the investigation. That’s when four of the gates that control the direction of the flow of water were vandalized, diverting water worth approximately $1.3 million, the affidavit says…Headgates were damaged again in 2022, diverting $4.3 million in water, the affidavit says. Trail cameras again photographed the same man with the same backpack. Another headgate was damaged in 2023 when it was forced open and propped up with rocks. This time, the trail cameras were also stolen. In 2024, the affidavit says, federal investigators with the U.S. Environmental Protection Agency installed three cameras with Apple AirTags attached. More images from the area showed the same man with the same backpack. In August 2024, the AirTags on the stolen cameras pinged from inside Lorenzin’s home, the affidavit says, and investigators searched it on two occasions, finding the disassembled EPA cameras and a laptop that contained images from other stolen cameras. A review of the search history on the laptop found multiple searches for information related to sabotage on the Berthoud Pass system as well as information about trail cameras and headgates, the documents says.
Denver Water’s collection and service areas continue to face severe drought conditions, with historically high temperatures, low streamflows and reservoir storage far below normal. As a result, at its meeting today, the Denver Board of Water Commissioners amended its Stage 1 drought resolution to prohibit lawn watering as of Oct. 1.
Until that time, Denver Water customers are still required to follow mandatory watering restrictions of two assigned days per week through Sept. 30, per the current Stage 1 drought restrictions that remain in place.
A group of visitors walks down the boat ramp at Williams Fork Reservoir on July 20. The ramp was closed this summer due to low water levels caused by drought. Photo credit: Denver Water.
“The drought afflicting the Denver region and its water supply system has only worsened over the course of the summer, making it clear that we need to take additional steps in response,” said Tyrone Gant, president of the Denver Board of Water Commissioners. “Formally ending lawn watering Oct. 1 will help stretch our supplies, as we will be entering next spring with storage levels far below normal.”
While the board’s Stage 1 drought declaration set a target for system-wide reduction of 20% below the five-year average in water consumption, prolonged hot and dry conditions have led to many customers using more water during their permitted irrigation days to keep trees, shrubs and landscapes alive, making the conservation target difficult to achieve. With drought conditions ongoing, Denver Water staff project storage supplies could drop to 60% before the 2027 runoff season.
“Despite the blistering conditions, customers overall have reduced their water use this summer. But with a lack of precipitation and the hottest first seven months in the Denver region we’ve recorded, we must take this additional step,” said Denver Water CEO/Manager Alan Salazar. “It’s critical that our customers turn sprinklers off Oct. 1, so that we can extend our water supply.”
Lawn watering and all spray irrigation must stop after Sept. 30, 2026, as part of an amendment to the Stage 1 drought declaration originally approved March 25. Trees, plants and gardens may be watered any day by hand if needed. Photo credit: Denver Water.
The resolution includes additional details outlining the kind of watering still permitted after the shutdown date.
High-traffic, active-use grass areas, such as parks and school fields, may only be watered after Sept. 30, under a Denver Water-approved water budget or variance. Additionally, recycled water users can continue to irrigate any day of the week, following the standard watering rules, as they are relying on reused water supply.
Trees, shrubs and perennials may be watered any day with a hand-held hose with a shutoff nozzle or low-volume, non-spray irrigation (such as a drip system). They may not be watered by spray irrigation.
Annuals and vegetables may be watered any day with a hand-held hose with a shutoff nozzle or low-volume, non-spray irrigation, until the first frost. They may not be watered by spray irrigation.
Grass establishment is not allowed after Sept. 30, except under special circumstances outlined under an approved variance.
An irrigation system may be operated for installation, repair or reasonable maintenance, so long as the system is attended throughout the period of operation and water waste does not occur.
Placing a soaker hose around the tree along the drip line is an effective way to water trees without wasting water. Reminder: Don’t water established trees too close to the trunk. Photo credit: Denver Water.
Conditions in Denver Water’s service and collection areas continue to worsen. The amended resolution outlines specific factors driving the additional board action.
Denver Water’s water collection system watersheds remain in various levels of drought as defined by the U.S. Drought Monitor.
Natural streamflow in the areas that flow into Denver Water’s storage reservoirs for the period of April to July was 95,000 acre-feet, which is 22% of normal and marks the lowest level observed since recordkeeping began 110 years ago.
The Denver metro area is experiencing the hottest year on record (through July) with average daily high temperatures five degrees above normal and four inches below normal precipitation.
As of Aug. 24, 2026, storage in Denver Water’s supply reservoirs is at 72% full, which is significantly lower than the historic median of 94% full for this time of year.
“If you are the only one on your block with a lush green lawn, you might want to revisit your watering practices, as your overuse is compounding the impacts of this historic drought on our water storage supplies,” said Greg Fisher, Denver Water’s manager of demand planning.
“We’re asking everyone to care more and water less, so we don’t have to take more drastic steps in the future, which could create more damaging impacts to our landscapes.”
With reservoir levels continuing to drop, Denver Water is asking customers to Use Only What You Need. Every drop saved, both indoors and outdoors, makes a difference. Photo credit: Denver Water.
Watering season typically runs from May 1 to Oct.1, during which Denver Water’s annual watering rules are in place. In a non-drought year, the start and end dates are general guidance for customers to turn on and off their irrigation systems. With this amendment to its March 25 drought resolution, the board has made the Oct. 1 date mandatory this year, prohibiting lawn watering as of that date.
In addition, the lawn watering ban remains in effect until the board determines how and when lawn watering can resume. That means sprinklers need to remain off in spring of 2027, pending an official resolution from the Board of Water Commissioners. [ed. emphasis mine]
Climate change will almost certainly feature prominently in any multi-state litigation over the Colorado River. A court case over an almost-finished dam expansion may decide how.
Is climate change enough justification to stop the expansion of a reservoir that will take more water from the dwindling Colorado River?
That’s the central question in a lawsuit pitting the U.S. Army Corps of Engineers and Colorado’s largest water utility against a consortium of environmental nonprofits. The environmentalists say the Colorado River has no more water to give, while Denver Water, the utility whose Gross Reservoir would nearly triple in capacity, argues it is ensuring its customers can withstand droughts. The Corps contends it is not required to consider climate change or the downstream effects of its expansion of a dam to grow the reservoir.
The case in the 10th U.S. Circuit Court of Appeals has the potential to ripple through Western water management as states, tribes, cities and the federal government struggle to find a compromise on how to steeply cut water use. Some see history repeating itself, with the Gross Dam expansion emblematic of the kind of thinking that helped put the West into the very water crisis the project is meant to buffer the region against.
“Does it make sense for major water projects like this to continue to move forward?” asked Sarah Matsumoto, an associate professor of clinical law at the University of Colorado, Boulder, and director of the Getches-Green Natural Resources, Energy, and Environmental Law Clinic. “I just don’t think it does anymore, without at minimum considering impacts of climate and impacts of overappropriation on the river.”
The Corps and Denver Water appealed that decision, arguing that construction of the dam expansion is nearly complete, and topping off the reservoir behind it is in the public’s best interest. There are no other alternatives to consider, the utility asserts. The National Environmental Policy Act (NEPA), which requires evaluating the impacts of projects that need federal approval, does not require the assessment of climate change, they contend.
“We believe that considering potential climate impacts to a project goes beyond the scope of any guidelines, practicability, or NEPA reasonableness analysis,” said U.S. Department of Justice attorney Kyle Glynn, representing the Army Corps, during oral arguments for the case before the 10th Circuit Court of Appeals.
The expansion of Denver Water’s Gross Reservoir would hold an additional 77,000 acre feet of water diverted from the declining Colorado River, enough water for roughly 150,000 homes. Denver Water would get that water incrementally from an unused 1945 water right of 18,000 annual acre feet to ensure it can supply the growing metropolis of Denver and protect its water supplies during droughts.
The utility plans to only use its water right during wet years when it can stockpile water from excess supply. Of the 77,000 acre feet in diversions, 5,000 would be sequestered in an “environmental pool” that would enhance streamflows on South Boulder Creek and serve as additional storage for the cities of Boulder and Lafayette.
But environmentalists are not convinced there will be enough surplus water in the future for the utility to fill the reservoir. If the state is required to cut back its water use to address system-wide shortages on the Colorado River, reductions the seven states that depend on the river are currently negotiating, what happens to the over $800 million project, they wonder.
Those are the concerns driving the environmental groups, which sued over what they called an inadequate NEPA process and a failure to properly examine alternatives to the project. Natural resource professors watching the case share their concerns. The court’s decision, both say, could have far-reaching consequences for Southwestern states and nearly 40 million people who rely on the Colorado River, and could determine how climate change is considered in any future litigation.
Denver Water’s position is in direct contradiction with what Colorado is arguing in the current negotiations about how much water from the river states must give up, said Gary Wockner, founder of Save the Colorado, the environmental group that’s led the push against the Gross Reservoir expansion.
Colorado has maintained that it and other states close to the river’s headwaters should not have to make mandatory cuts because climate change is already limiting their supply by reducing river and stream flows. Should the negotiations over cuts to allocations from the river devolve so completely that states in the upper and lower halves of the Colorado River Basin sue one another, some water law experts believe climate change would figure prominently in the litigation.
“If the court supports Denver Water and says that Denver Water did not have to account for climate change to prove that they could operate the project, it sets a very difficult and perhaps powerful precedent, potentially undermining the state of Colorado’s position in the entire Colorado River negotiations,” Wockner said.
Roller-compacted concrete will be placed on top of the existing dam to raise it to a new height of 471 feet. A total of 118 new steps will make up the new dam. Image credit: Denver Water.
Can a Dam’s Progress Block Climate Considerations?
On the last day of July, attorneys for the environmental groups, Denver Water and U.S. Army Corps of Engineers gathered before three justices on the 10th Circuit Court of Appeals in a courtroom in Santa Fe, New Mexico. Their oral arguments came nearly two years after senior federal judge Christine Arguello ruled in favor of the environmentalists, saying that “the cracked foundation of the Colorado River’s management system all but demands skepticism over any proposal that will affect the hydrology of the Colorado River basin.”
Arguello’s decision didn’t stop construction to expand the dam, but forced the parties to meet and agree on remedies. Those discussions failed, however, leading Arguello to issue an injunction to stop construction in April 2025. That was lifted due to safety concerns about the dam being left incomplete, but an injunction remained preventing the clearing of the forest below to make room for the additional water, or filling the added space behind the dam.
The Gross Reservoir expansion solves a problem Denver Water has been trying to address for 23 years, said Jessica Brody, general counsel for the utility, in the 10th Circuit last month.
Denver Water has a water storage imbalance between its two collection systems with 90% of its reservoir storage located in the utility’s South System compared to 10% in its North System. This storage imbalance creates vulnerability if there is a drought, mechanical issue or emergency that affects the South System. The storage imbalance is one of the reasons Denver Water is expanding Gross Reservoir. Image credit: Denver Water.
Denver Water’s storage and delivery network is divided into north and south systems, which are unconnected and imbalanced. The south system provides 80 percent of the utility’s water supply, and if it were to go down, the north system, which includes Gross Reservoir, could run out of water in just one year. That leaves the utility’s system vulnerable in times of severe drought, wildfires or other emergencies.
Despite construction being nearly done, Brody said, Denver Water has a dam it cannot fill because of the lower court’s opinion.
That decision was an “abuse” of the court’s power, she said, as the water rights at stake are under the jurisdiction of the state, not federal agencies. Plaintiffs never sought a preliminary injunction to stop construction, although they did when later mediation failed. Jurisdiction over the cutting of trees to make room for the expanded reservoir lies with the U.S. Forest Service and the Federal Energy Regulatory Commission, not the Corps, she said.
The arguments from Denver Water and the Corps seemed to resonate with the three justices presiding over the case, largely due to the fact the dam is nearly complete.
“Poor pun: It’s water over the dam, because it’s built,” said Judge Timothy Tymkovich. “So costs, and I think climate change, are off the table now.”
William Eubanks, the attorney representing the environmental groups, disagreed. The dam expansion is part of Denver Water’s Moffat Collection System project, which requires work in addition to the Gross Reservoir project, such as felling the trees.
And there is still the question of where the water will come from.
A central point for the lawsuit, he said, is that under the Clean Water Act, water infrastructure developers have to show a project can be built and fulfill the expected need—in this case, a reservoir with more water. That wasn’t done here, Eubanks said.
“With the Moffat Collection System project, Denver Water and the Army Corps have recklessly gambled with over $800 million of ratepayer money,” Eubanks said before the court. Neither the Corps nor the utility forecasted whether there would be enough surplus water in the Colorado River for Denver Water to fill its reservoir, he argued. “In effect, they’re building a giant bathtub, even though there’s likely no water to ever fill it.”
CU Boulder professor Matsumoto is one of 11 natural resource law experts who submitted an amicus brief to the court asking it to affirm the lower court’s decision.
This case, they wrote, is a “classic example of why we need NEPA”—illustrating the consequences of an agency permitting and approving a project without a full evaluation of other alternatives and whether the project was even feasible. The foundational U.S. environmental law was designed to push agencies to “fully appreciate the consequences of their actions before they move forward with those actions,” they wrote.
The Corps violated NEPA by limiting the number of alternatives it considered for the project and only examining impacts up to 50 miles downstream, not along the full course of the river, the brief noted.
“It just doesn’t make any sense for the amount of water that they’re getting,” said Mark Squillace, a natural resources law professor at the University of Colorado in Boulder, and another one of the professors part of the amicus brief. “It’s insane.”
Udall/Overpeck 4-panel Figure Colorado River temperature/precipitation/natural flows with trend. Lake Mead and Lake Powell storage. Updated through Water Year 2025. Note the tiny points on the annual data so that you can flyspeck the individual years. Credit: Brad Udall
A Complicating Compact
Since 1922, the Colorado River has been governed by its eponymous compact, which is now widely acknowledged to have overallocated the river by millions of acre feet of water. Under the compact, both the Upper Colorado River Basin, made up of Colorado, New Mexico, Utah and Wyoming, and the Lower Basin states of Arizona, California and Nevada, are entitled to 7.5 million acre feet of water, with another 1.5 million acre feet going to Mexico. But the river has averaged closer to 11 million acre feet since 2020—more than 6 million acre feet less than the total that has been allocated, according to the most recent federal data.
Though both basins get an equal share of the river, Article III(d) of the compact specifies that the Upper Basin “will not cause the flow of the river” to be depleted below an average of 7.5 million acre feet per year over any 10-year period downstream.
Failing to meet that requirement could trigger the Lower Basin to demand more water from the Upper Basin in what is known as a “compact call.” That unprecedented action could force severe water usage curtailments in the Upper Basin, and how that would affect users like Denver Water is unclear. The system is dangerously close to the hydrological conditions that could trigger a compact call.
It’s a known risk for this project, the professors say, but one that was ignored during permitting.
Gross Reservoir is far from the only new diversion proposed in the Upper Basin, which has never used its full allocation from the river, but sees that water as key to the region’s continued economic growth and prosperity. Over 1 million acre feet of diversions have been proposed across 30 projects in the Upper Basin. Many of those may not be developed, but they have become a sticking point in negotiations over the river’s future.
“Repeating the Same Mistakes”
As the lawyers argued in Santa Fe, news of a short-term federal proposalfor managing the Colorado River rippled across the basin. In the absence of a new consensus among the states over how to allocate the water, the federal government stepped in to manage the crisis.
Its track record on the Colorado River is deeply checkered.
The compact has served as the bedrock for a web of dams, reservoirs, canals and ditches built largely with federal funding and engineering prowess to distribute water across arid Western lands. The magnitude of this diffuse system and its overreliance on diverting and impounding water, experts say, is at least partially responsible for the severity of the West’s water crisis.
Building the Gross Reservoir Dam in the 1950s. Photo credit: Denver Water.
Some believed not everyone has learned the lesson. “We’re just repeating the same mistakes,” Squillace said. “A lot of it just results from a lack of imagination about a better way to do things.”
As water supplies shift, water utilities across the West are squeezing every last drop out of their systems through a range of modifications and adjustments to their infrastructure.
After the first of the West’s deep 21st-century droughts in 2002, Denver Water, which serves 1.5 million people across Colorado’s Front Range, decided it needed to act. The utility convinced the Army Corps of Engineers, which completed the original Gross Reservoir in the 1950s, that raising the dam to triple the amount of water it could impound would be the best course of action to combat drought.
Since then, Denver Water has also invested in water efficiency, which allowed it to better endure droughts from 2002 to 2026. Despite a growing population, water use is below the benchmarks from the 1970s, said Jeff Martin, Denver Water’s program manager for the reservoir expansion.
“We’ve really capitalized on most of our customer savings at this point,” he said. “Now, we need to shore up the rest of our need with the expanded reservoir.”
But a drier future is precisely what should preclude Denver Water and the Corps from seeing this project through, said Wockner with Save the Colorado.
“It’s nonsensical to be diverting more water out of rivers anywhere in the Southwest United States,” he said. “Because in many ways the climate change bullseye in the United States is on the Southwest and Colorado River Basin.”
The Colorado River, Wockner said, has no more water to give. But Martin sees room for more improvement in how the river is managed.
“I would be the first to say something needs to change there on how we use the river for all stakeholders, including some type of cuts throughout the system,” said Martin. “I’m not that decision maker though.”
Graphic credit: RogerWendell.com
The state, he said, controls Denver Water’s rights to the river. The utility has the right to use the water that may one day fill Gross Reservoir, he said, and has been planning to do so for decades.
Despite arguments that the water isn’t available, Martin has no doubt Denver Water will be able to one day fill the reservoir—if the courts allow it.
What Comes Next
The justices have given no indication of when a ruling on the Gross Reservoir Expansion Project will land.
If Denver Water loses its current appeal, the utility claims it will be unable to ensure a reliable water supply during times of drought, and the decision may deter developers from pursuing other ambitious projects to solve the West’s water problems, from new dams to expensive desalination plants.
In the Santa Fe courtroom, Teagen Blakey sat on a wooden bench watching the lawyers argue over a project that has loomed over more years of her life than it hasn’t.
President of The Environmental Group, a nonprofit from Colorado’s Front Range and one of the lawsuit’s plaintiffs, Blakey grew up in the area around Gross Reservoir. She remembers sitting in community meetings as a teenager when the project was being permitted.
Despite the project’s impacts on Boulder County, the water won’t serve residents there, she pointed out. But the dam and reservoir expansions’ impacts will fall on the local population. At the site where Denver Water will clear the forest is a hike featuring a waterfall that would be submerged.
“It’s something you can’t quantify as a value,” she said.
With such a high cost to something so special, Blakey said, there must be certainty about the benefit it will provide.
South Platte River Basin via Wikipedia
Map of the Colorado River drainage basin, created using USGS data. By Shannon1 Creative Commons Attribution-Share Alike 4.0
Denver Water’s 1.5 million customers are using less water than usual, but it’s still not enough to meet the utility’s goal of reducing water consumption by 20% amid this year’s drought.
“We’d need to be at 10,300 acre-feet of savings. Instead, we are at 1,300 acre-feet of savings, so behind where we want to be,” said utility spokesperson Todd Hartman.
That means the utility, which serves residents in Denver and many surrounding communities, has achieved barely a tenth of its target.
In Aurora, water officials said locals have made progress toward that utility’s 20% goal, but did not provide exact statistics.
While the utilities aren’t hitting their goals, they’re not ringing alarms yet. Both utilities have implemented Stage I water restrictions, and neither plans to move to the more severe restrictions of Stage II.
But that could change depending on how water levels look for the rest of the year — and Aurora Mayor Mike Coffman said it could be soon. In a Facebook post, Coffman wrote that the city is “now teetering on having to move to Stage II drought restrictions that, if enacted, will reduce all outdoor irrigation from two waterings a week down to one, killing off most lawns completely. According to [Kirby] Shedlowski, however, Stage II restrictions are not yet on the table. She said Aurora Water staff would have to recommend that shift to the Aurora City Council, which hasn’t happened yet.
From Tishana ‘Tish’ Cano at the Greeley Water & Sewer Department:
“Here is a land where life is written in water.” Thomas Hornsby Ferril, named Colorado’s poet laureate in 1979, could not have composed a better description of the agricultural community founded at the confluence of the Cache la Poudre and South Platte Rivers. In April 1870, a group of far-seeking settlers after a long four-day train ride from New York City and other points back East. Their goal was to create a new way of life on the dry and desolate plains of northern Colorado. Water was the key – and in 1874, a conflict with upstream irrigators of the agricultural community of Fort Collins created a flashpoint in Colorado water law and the American West. Both sides met “half-way” near present-day Windsor and launched an iconic, heated debate over western water rights. With guns used in the Civil War at the ready, the parley led to the birth of western water law – the Doctrine of Prior Appropriation.
Authors Gregory J. Hobbs, Jr. and Michael Welsh describe the triumphs and challenges of Greeley’s water history, from its 1884 artesian well in City Park to its 1907 mountain water system. The book chronicles the Colorado-Big Thompson Project of the 1930s and the Milton Seaman Dam and Reservoir construction in the 1940s. Hobbs and Welsh describe the foresight and tenacity of creative men – David Boyd, Henry C. Watson, Delph Carpenter, W.D. Farr, Harold Evans, and others – who shouldered the work and pointed the way to identify, acquire, and deliver affordable water to Greeley for more than a century. “Plan for others as they have planned for you” guides and unites the actions of our story of Greeley Water.
From the Rocky Mountain American Water Works Association:
Public works agencies rarely have time to reflect on their accomplishments and lessons learned, as they pursue on a daily basis their operations, maintenance, and plans for future growth. Yet that retrospective is what the City of Greeley Water Utilities Department, with its century and one-half of service to the community, decided to engage with the research and publication of Confluence: The Story of Greeley Water (2020).
Harold Evans, chairman of the Greeley Water and Sewer Board for the past two decades, believed that those whom the utility served would benefit from a comprehensive analysis of the origins and development of an organization that began before Colorado statehood, and one that has grown over time by addressing the cycles of abundance and scarcity of water that define the Headwaters State.
Joining the team of researchers and writers in 2015 were Gregory J. Hobbs, Junior, a retired associate justice of the Colorado State Supreme Court, often considered the most knowledgeable member of the high court in matters of water law and policy, and Michael Welsh, a professor of history at the University of Northern Colorado, whose decades of teaching and scholarship included studies of the U.S. Army Corps of Engineers in the Southwest and on the West Coast.
This team explored the range of issues and tasks of a municipal water system that began in the summer of 1870 with a single irrigation ditch on the Cache la Poudre River that conveyed water to the fledgling Union Colony (later to become the town of Greeley). As the population increased and the economy evolved, the Greeley water utility added a community artesian well (1884); a mountain water treatment facility above Fort Collins at Bellvue (1907); and a storage facility on the North Fork of the
Poudre River known as Milton Seaman Reservoir (1945); the latter two remaining operational over a century later. Residents of the Colony, and their policies and regulations, also played an important role in the development of statewide and interstate water law. One example would be the enshrining in Colorado’s 1876 constitution of the “prior-appropriation doctrine.” In addition, a Greeley native, Delph Carpenter, who had been employed as a youth inspecting the community’s ditch system to guard against violation of its rules, became an authority on the collaborative features of western water law. Carpenter would be tasked by the U.S. Commerce Secretary, Herbert Clark Hoover, with a key role in the drafting of the Colorado River Compact.
That agreement would permit a group of Greeley and Colorado water professionals a decade later to approach the U.S. Bureau of Reclamation to confront the severity of the Great Depression and the Dust Bowl by means of the Colorado-Big Thompson Project; a multipurpose facility that secured the future for farmers and ranchers of the South Platte River basin, and later the urban growth of the Front Range.
The Greeley Water & Sewer Board, originating in 1958 from the idea that local decisions in water belong with the people, and guided by those who understood and appreciated what water meant to Greeley, established the nonpartisan principles that inform the acquisition and development of water facilities. From the leadership of water pioneer W.D. Farr to today, with Harold Evans, who has a background in Civil Engineering, the Board has possessed expertise and foresight that contributes to Greeley’s good fortune with its most precious resource.
What began with that first ditch has now become a network of multiple reservoirs in four river basins, and prize-winning water pollution-control facilities. The City of Greeley also has taken the lead in water efficiency & quality, working with state and federal partners to replace aging lead pipes, and to institute an advanced metering system and residential and commercial “water budgets” that keep utility customers informed of their use patterns and the value of conservation in times of drought. Once the first volume on the story of Greeley water appeared, the water utility continued to provide domestic water and wastewater treatment to its network of communities. The City also pursued regional cooperation with the municipalities of Fort Collins, Loveland, Windsor, and Evans. Greeley maintained its partnership with the Northern Water district, in particular its Chimney Hollow Reservoir, which will store additional supplies for a dozen water organizations that own water rights in the CBT system that are not reliably accessible in times of need.
From that recognition in 2020 that the story of Greeley water had not ended came a new edition in the summer of 2026, written to incorporate the purchase of water rights to the vast underground aquifer in far northern Colorado known as the Terry Ranch Project. Other dimensions of the utility’s operations addressed in the second edition of Confluence are the expansion of the “non-potable” water system for use in public and private spaces; the application of sophisticated information technology; and the advanced-planning functions of the “Integrated Water Resources Program,” which identifies scenarios and options for a wide variety of challenges and opportunities in water-resource management decades into the future.
It is our hope that this new look at an old story helps residents and businesses of Greeley and surrounding communities realize how important their water supplies are to their security and prosperity. In 1941, in the midst of a world at war, and as the decade of the Dust Bowl neared an end, Greeley’s leaders embraced a simple but compelling idea: “To plan for others as others have planned for you.” Wise words for their time, and wise words for ours now.
Aurora Water doesn’t much care which two days in a week you water your lawn, amid this historic drought.
But if your irrigation system starts up on a third day in the same week, the water world equivalent of a Flock camera is watching. The “smart” meters on every Aurora property automatically sense a spike in water use, and alert Aurora Water to confirm the violation and send out a warning or fine.
With updates at 15-minute intervals, the meters also detect irrigation watering during hot daytime hours when that’s against the rules.
The water surveillance, which Aurora Water officials acknowledge many of their customers might not realize exists, is one key to Colorado’s third-largest city so far achieving its water-saving goals in a year with record-low snowpack and abysmal streamflows into mountain reservoirs. Aurora says its 400,000 residents are using 27% less lawn water than in 2025, and managed a 9% cut from combined indoor and outdoor use.
Maintaining or even improving those savings is crucial as Aurora Water’s reservoir system sits at 49% full at a time when it should be above 80%.
Denver Water, meanwhile, has seen only about a 5% cut of water use compared with its previous five-year average among 1.5 million city and suburban customers. When Denver Water enacted twice-a-week watering restrictions in the spring, it set a target of a 20% cut from five-year average use.
Denver’s customers are doing better when using Aurora’s comparison with 2025 only, Denver officials said.
“Versus 2025, total water use is currently down about 7% and outdoor use is down about 16%,” said Travis Thompson, Denver Water communications manager.
The state’s largest water agency says it is encouraged by other statistics showing customers are using 21% less lawn water than they would have expected in the run of 95- to 100-degree days the Front Range experienced in July. In a summer that sits in the top 1% hottest and driest on record, the agency says, that’s a laudable savings mark.
One difference: Aurora Water spent millions of dollars in capital getting smart meters on every customer tap, while Denver Water chose to spend more of its capital speeding up replacement of aging, dangerous lead water delivery lines. Denver’s enforcement of drought restrictions to date has relied on thousands of neighbor complaints about properties watering more than twice a week, during restricted daytime hours or other violations.
“We have a far bigger tool than they have for being able to detect when people are using water irrigation water when they’re not supposed to,” said Shonnie Cline, Aurora Water’s deputy director of water internal and external relations.
Watchdog groups such as the American Civil Liberties Union in the past have raised questions about privacy invasions from smart home devices, including electric and water meters monitored by utilities. Especially by combining information from multiple meters, hackers or other bad actors could watch patterns and learn when people are home or away, are cooking, taking showers or other personal habits.
Cline said a better analogy than a controversial Flock camera is to see a smart water meter as a personal fitness tracker. “It gives you data and you are able to identify patterns that can improve your overall health if you make changes,” Cline said.
Aurora points out the smart meters for every customer work both ways, as a protection from leaks and potential property damage. Customers are able to log on and track their own use at the same time the city sees it, and could recognize a home leak while away on vacation, for example. During droughts, the meters will be one key to helping maintain reservoir storage for the benefit of the whole community, Cline said.
“There is a definite footprint that goes along with the data that indicates irrigation is taking place,” Cline said. “We have that pretty locked in where we can see when somebody’s irrigating, and so that’s why it’s interesting, because even when we send a warning, people are like, ‘But I didn’t!’ And then we’ll show them the data, and they’re like, ‘OK, I can’t argue with you, right?’ “
Denver Water, while enjoying higher water storage rates at its mountain reservoirs that have seen better snowpack, is not satisfied with customer savings rates and is now shifting somewhat from “education” to “enforcement” mode.
Denver had sent out nearly 3,600 warning letters but only five fines by the beginning of August. Fines will ramp up now that customers know what the rules are and Denver Water knows more about where the problem customers are, officials said.
Aurora Water, by contrast, has issued 234 fines after sending out more than 2,500 warning letters, including 10 of the highest $2,000 fines to businesses and large irrigation consumers. Only three customers were issued a second fine at the $250 residential level, Aurora Water said, and none had been issued a third fine. Aurora’s fines total more than $70,000.
Now that Denver Water has weeks of data on actual water use during drought restrictions, the agency can focus its communications on suburban areas with bigger lawns that haven’t cut back, said Greg Fisher, the utility’s manager of demand planning. Some of those suburban customers have no idea it’s Denver Water that collects their mountain runoff and delivers it to their local water utilities.
With only 5,000 advanced meters installed for 250,000 taps, Fisher said, word of mouth enforcement confirmed by onsite visits from Denver Water employees will continue to be the standard for warnings and fines.
“We continue to rely on, and I think it’s a pretty inventive idea, of letting our customers report water waste violations,” he said. “Even with the water people out on the street, we can’t be everywhere. So giving our customers the ability to report has been pretty powerful and I think effective for us.”
Denver Water officials do not anticipate asking their board this season to approve the next drought stage that would take lawn watering down to one day a week and add other restrictions. Denver Water would have to change its rate structure again to charge more for lawn watering that does occur to make up for loss of revenue from restrictions.
Plus, the utility thinks it’s a longer-term challenge to convince customers to change habits and stay “on board” with drought restrictions in the middle of what could be a multiyear crisis, Fisher said.
“We have a long game,” Fisher said. “This thing’s going to last a minimum of 12 more months, in my opinion, save for some sort of record-breaking snowfall this winter. So we’re in it for the long haul. I think we need to continue to up the message as we see conditions change. But at the same time, we really need to support our customers and have them stick with us for that extended period.”
People are capable of change, Denver Water officials said. The last drought this severe for Front Range customers was 2002.
“Our customers are using 100 million gallons less per day this year than they did in 2002, which is just stunning,” Fisher said. “And that translates to being actually 14% higher in our reservoir storage now than we were in 2002, because of our customers’ efficiency efforts over the last quarter century. We’re feeling really good about that. And that’s with significantly more population … 200 to 250,000 more people.”
Big Thompson Flood, Colorado. Cabin lodged on a private bridge just below Drake, looking upstream. Photo by W. R. Hansen, August 13, 1976. Photo via the USGS.
Re-upping this post for July 31, 2026. The flood remains Colorado’s deadliest. Here’s a link to Coyote Gulch coverage mentioning the Big Thompson Flood.
July 31, 1976, Steamboat Springs: I had been wandering around the Flat Tops Wilderness for a week or so with Mrs. Gulch. Drizzle in between downpours during the monsoon. We were holed-up in a hotel to dry out and I phoned my mother to check in.
She asked, “Johnny are you anywhere near the Big Thompson Canyon? There’s been a terrible flood.”
And it was a terrible flood. After the September 2013 floods Allen Best wrote about being part of the disaster response in The Denver Post. It’s a good read on this 40th anniversary. Here’s one passage:
I was at the Big Thompson disaster. I was living in Fort Collins then and was among scores of young men (sorry, women, those were different times) with strong backs who could be summoned in case of forest fires. My only fire was at an old sawmill site in the foothills. The joke was that one of us had set the fire because we were so desperate for minimum-wage work.
Then came July 31. It was hot that night in Fort Collins. It hadn’t rained a drop.
I was living above Gene’s Tavern, just two blocks from the Larimer County Courthouse. When the call came, I was at the sheriff’s office almost immediately. It was 9 p.m.
Being among the first at the command center at the Dam Store west of Loveland, near the mouth of Big Thompson Canyon, I was assigned to a pickup dispatched to look for people in the water near the turnoff to Masonville. Already, the river was out of its banks. From the darkness emerged a figure, dripping and confused. “I went fishing at Horsetooth (Reservoir) and was driving home and then there was all this water,” he sputtered. He was befuddled. So were we.
Our leader decided we’d best get out of there. From what I saw the next morning, that was an excellent decision. Water later covered the road there, too. I spent the night at the Dam Store as the water rose. Helicopters were dispatched, but there was little that could be done. Our lights revealed picnic baskets, beach balls and propane bottles bobbing in the dark, roiling water that raced past us, but never any hands summoning help.
In the morning, we found those hands. The bodies were stripped of clothing and covered with mud. The first I saw was of a woman who we guessed was 18, not much younger than I was then. This thin margin between life and death was startling in my young eyes.
Eventually, 144 people were declared victims of the flooding that night (although one turned up alive in 2008 in Oklahoma).
Estes Park got some rain, but not all that much. The larger story was partway down the canyon, in the Glen Haven and Glen Comfort areas, where the thunderstorm hovered. In just a few hours, it dropped 10 to 14 inches of water.
Downstream in the canyon, just above the Narrows, some people were unaware that anything was amiss until they went outside their houses and saw the water rising in their yards. It hadn’t even rained there. One cabin I saw a few days later was stripped of doors and windows but stood on its foundations, a mound of mud 5 or 6 feet high in the interior. I seem to recall a dog barking as we approached, protecting that small part of the familiar in a world gone mad.
At the old hydroelectric plant where my family had once enjoyed Sunday picnics, the brick building had vanished. Only the turbines and concrete foundation remained. In a nearby tree, amid the branches maybe 10 or 15 feet off the ground, hung a lifeless body.
The river that night carried 32,000 cubic feet per second of water at the mouth of the canyon, near where I was stationed. It happened almost instantaneously — and then it was gone. It was a flash flood.
Here’s an excerpt from a look back forty years from Michelle Vendegna writing for the Longmont Times-Call.
Night on the ledge
“We, Terry Belair-Hassig and Connie Granath-Hays, graduated from Berthoud Jr. Sr. High School the month before, and were anxious to begin the summer. We spent the beautiful, sunny day of July 31, 1976, at a Hewlett-Packard company picnic at Hermit Park not far from Estes Park. After the picnic, we drove up to Estes Park and had dinner at Bob and Tony’s Pizza.
The clouds started moving in about 6 p.m., so we began the drive down to Loveland via U.S. 34. Within minutes, Connie had to pull her car over because the driving rain was causing zero visibility. We needed to get home, so she started out again, but we didn’t get too much farther before we were blocked by trees, boulders and debris washing down the canyon sides. We had just passed the Loveland Heights area — barely three miles since entering the canyon. The closest town, Drake, was miles away.
Connie pulled over to the side of the mountain as far as she could. There were a few other cars in this section doing the same, but we all sat in our cars — planning to wait out the storm. However, once the river began to rise and the water was hitting the tires, we decided to leave the car and start climbing. Connie’s dad had taught her to always ‘be prepared,’ so she had a tarp and a few extra jackets stored in her trunk. We grabbed them before climbing. It was a dark, treacherous climb.
A small group of people scrambled up the mountain near us. Connie gave one of the men her extra jacket. She also had a flashlight which came in handy later in the evening when the lightning wasn’t lighting up the canyon. The other people were lucky enough to find an overhang of rocks to sit under. We tentatively settled on a ledge out in the open, and wrapped ourselves in the tarp. Of course, the tarp was just an old tarp, not waterproof like the ones are today. It protected us for a while, but with the downpour of rain and runoff from the hillside, it too became drenched.
After only a little while, we watched her car, during the lightning flashes, being lifted up and carried down the river. We decided at this point we should climb higher, so we found a ledge where we spent the long, cold night. We had spent many winters skiing and had never been as cold as we were that night.
We sat on that little ledge (3 foot by 1 foot) with our knees drawn up to keep us from sliding off. We sang, shivered, cussed and did anything we could to keep our minds off of how cold and achy we were. We heard and saw cars, houses and propane tanks floating down the river during flashes of lightning. We thought by now it must be about morning time, but looking at our watch, it was about 10 p.m. We had a long night ahead of us.
The next morning was another blue bird day and we were freezing and soaked to the bone. We decided it would be warmer to take our jackets off and left them on the ledge. The road below us had been washed away, but the river had receded enough that we could get off the ledge and move around a little on the steep mountainside. We heard the helicopters for a long time before we saw one. Finally, we were rescued off the side of the mountain by a four-seat helicopter,and dropped off up river on a section of the highway that had survived. There were several other people there. I remember we were all surveying the canyon in a daze. There wasn’t much conversation. I leaned over and picked up a small piece of asphalt and put it in my pocket.
Click here to read the Fort Collins Coloradoan special about the flood.
On July 31, 1976, during the celebration of Colorado’s centennial, the Big Thompson Canyon was the site of a devastating flash flood that swept down the steep and narrow canyon, claiming the lives of 143 people, 5 of whom were never found. This flood was triggered by a nearly stationary thunderstorm near the upper section of the canyon that dumped 300 millimeters (12 inches) of rain in less than 4 hours (more than 3/4 of the average annual rainfall for the area). Little rain fell over the lower section of the canyon, where many of the victims were.
Around 9 p.m., a wall of water more than 6 meters (20 ft) high raced down the canyon at about 6 m/s (14 mph), destroying 400 cars, 418 houses and 52 businesses and washing out most of U.S. Route 34. This flood was more than 4 times as strong as any in the 112-year record available in 1976, with a discharge of 1,000 cubic meters per second (35,000 ft³/s).
Officials on Friday detailed how a Big Thompson River that was flowing at 30 cubic feet per second increased to 30,000 by the time it got to the narrows near Sylvan Ranch and the Dam Store.
The 2013 flood, by contrast was flowing at 16,000 cubic feet per second at the same point. But Bob Kimbrough, from the U.S. Geological Survey, said that number can be misleading. Just because it was flowing at less than half the rate, doesn’t mean the water was half as high as it was in 1976. It could have been a foot or two lower, Kimbrough said.
Further, the 2013 flood lasted longer. Where the 1976 flood dissipated nearly as quickly as it rose, the 2013 flood flowed over saturated ground for days, causing foundation failures and greater erosion than the 1976 flood.
Click here to read the extensive coverage from The Estes Park Trail-Gazette.
Denver Water’s Gross Reservoir Expansion Project reached a milestone in June as workers completed major construction on raising the dam.
On June 3, 2026, workers placed the final load of roller-compacted concrete on the top of the dam, bringing Gross Dam to a height of 470 feet. Roller-compacted concrete is the type of concrete put in place to raise, thicken and lengthen the dam over the past three years.
The project is designed to nearly triple the capacity of Gross Reservoir, increase Denver Water’s reservoir storage capacity by 11%, and provide balance, resiliency and flexibility to the utility’s water collection system.
Additional work to complete the dam will take place over the next year, including adding one more foot of conventional, protective concrete to the top of the dam, which will bring it to its final height of 471 feet above the valley floor below.
At this point, dam is taller and also has a new shape.
“We have fundamentally changed how this dam works. The old Gross Dam was a gravity dam that held back the water by its sheer weight. We’ve now transformed this into an arch dam which holds the water back by its weight and also transfers the loads laterally like a Roman arch. This is the first time that we know that this dam transformation has ever been done in the world.”
Gross Dam on June 2, 2026, on the final day of roller-compacted concrete placement work. Photo credit: Denver Water.
In the video above, you can see new images of the dam and hear from Jeff Martin, Denver Water’s program manager for the project.
“We’re excited and proud of this accomplishment,” Martin said.
“Hundreds of people helped us reach this milestone, which will provide a secure water future to Denver and the surrounding communities.”
Roller-compacted concrete will be placed on top of the existing dam to raise it to a new height of 471 feet. A total of 118 new steps will make up the new dam. Image credit: Denver Water.
Below is the Precipitation Accumulation in South Platte graph from the NRCS for July 27, 2026. This morning precipitation is at 76% of the median (up 4% one week), and 65% of the water year median (up 5% one week). There are 65 days left in the water year.
Thunderstorrms are likely today through Wednesday, there is a chance for thunderstorms Thursday, a slight chance for thunderstorms Friday, with a chance for showers/thunderstorms Saturday and Sunday, in the central mountains. Light rain is currently falling and thunderstorms are likely today, there is a slight chance for showers then thunderstorms are likely Tuesday and Wednesday, with a chance for thunderstorms Thursday and Friday, and a slight chance for showers/thunderstorms Friday and Saturday in the northern mountains. There is a chance for thunderstorms today, thunderstorms are likely Tuesday and Wednesday, with a slight chance for thunderstorms Thursday and Friday, and a slight chance for showers/thunderstorms Sunday, down here, about 12 miles from Golden, where the Colorado Central Railroad was chartered February 9, 1865. From Wikipedia:
The railroad was chartered as the Colorado and Clear Creek Railroad Company on February 9, 1865, by Loveland and other entrepreneurs in the town of Golden, then the capital of the Colorado Territory. Loveland and his partners desired to build a 4 ft 8+1⁄2 in (1,435 mm) standard gauge railroad up Clear Creek Canyon to Central City and other mining centers, and to connect to nearby Denver and Boulder. During the three years before construction on the line began the company underwent several reorganizations. On January 20, 1866, the name of the railroad was changed to the Colorado Central & Pacific Railroad. The following year, in June 1867, the company was reorganized; Union Pacific investors were in control, but provided no funds for construction. That year, the seat of territorial government for Colorado was relocated from Golden to Denver…In May 1871 local interests regained control of the railroad from Union Pacific investors. By the following September, 150 men were at work in the mountains west of Golden to extend the line to the mining communities. In the spring of 1872 the company acquired critical right-of-way along Clear Creek to extend its line. West of Golden, the line built as 3 ft (914 mm) narrow gauge. In late August, the company took delivery of its first two locomotives (both 0-4-0T), the General Sherman, No. 2, followed a week later by General Sheridan, No. 1. On September 1, the track was completed 13.3 miles to Forks Creek. By mid-December, the line had been extended 7.7 miles further to Black Hawk. By February 24, 1873, a second line from Forks Creek had been extended 3.3 miles to Floyd Hill. In September, the company’s shop in Golden produced the first passenger car in Colorado. On May 11, 1874, the company took delivery of an 18-ton Mogul locomotive from Dawson & Baily. The new locomotive replaced the “Sheridan” as the #1 locomotive.
Here’s a look at the 7-Day Colorado precipitation map through July 26, 2026 from the High Plains Regional Climate Center. Precipitation in the South Platte Basin along the Continental Divide of the Americas ranged from 0.10” to 1.90”.
Here’s the 7-Day percent of normal precipitation map through July 26, 2026 from the High Plains Regional Climate Center. Precipitation in the South Platte River Basin along the Continental Divide of the Americas ranged from 50% to 400% of normal.
Below is the 7-day Quantitative Precipitation Forecast for the week of July 27, 2026. Precipitation is anticipated for the mountains of the South Platte River Basin and may total up to 1.50″.
Below are the 8-14 day outlooks from the Climate Prediction Center, issued July 26, 2026, for temperature and precipitation, for the week starting July 27, 2026. The CPC expects above normal temperatures and near normal to below normal precipitation for the mountains of the South Platte River Basin.
Below is the Colorado Drought Monitor map from June 21, 2026. There were one class degradations in Douglas, Elbert, Arapahoe, Adams, Denver, Jefferson, Clear Creek, Gilpin, Boulder, Weld, Morgan, and Larimer counties, in the South Platte River Basin. Drought and abnormal dryness covers 97.14% of Colorado. The South Platte Basin is experiencing Abnormally Dry, Moderate, Severe, Extreme, and Exceptional drought conditions.
Below is the Colorado Drought Monitor one week change map ending July 21, 2026.
Here’s the US Drought Monitor Map from last week along with the one week U.S. change map.
In the spring of 2026, anomalously low snow conditions in the western United States threatened winter recreation and water supplies. Here, we investigate: to what extent was this snow drought attributable to the climate change that has occurred since the pre-industrial period? We find that a snow drought this severe across the western United States was approximately 4.4 [95% CI: 2.6, 9.4] times more likely in the current climate than in the preindustrial period. In the Upper Colorado River Basin, the snow drought was approximately 14 times more likely [0.09, 4,300]. Given a projected increase in the frequency of snow droughts at least this severe in a moderately high emissions warming scenario, the lived experience of this event may help scientists, resource managers, and the public consider what western US snow might look like if greenhouse gas emissions are not aggressively reduced.
As we enter the thick of watering season in mid-July, it’s a good time to assess how Denver Water customers are doing in cutting water use amid a drought.
The early verdict: Good but needs to be even better.
Denver’s Board of Water Commissioners, in its drought declaration of March 25, called for a 20% reduction in water use over the coming year.
By one important measure, the 1.5 million people Denver Water serves are meeting that goal. Customers are using about 20% less than projected — when the record-setting hot and dry weather we’ve experienced in 2026 is factored in.
By another measure, against the five-year average, customers are conserving water — but have a ways to go to hit the goal. Using the five-year average sets a tough bar, however, as those years were not generally as hot and dry as what the Denver region has seen so far this year.
Get tips for helping your lawn survive the summer on mandatory drought restrictions that allow residential water only on two assigned days per week. Photo credit: Denver Water.
Overall, when you consider the conditions, the high temperatures and lack of precipitation, we think customers are doing well,” said Greg Fisher, manager of demand planning for Denver Water. “They are showing restraint even as the spring and early summer continued the record-breaking drought numbers we saw last fall and winter, combined with extremely high temperatures.”
In fact, tracking at Denver Water’s three weather stations, spaced out west to east across the metro area, shows January through June of 2026 experienced the highest daily average temperature ever, at 67 degrees, compared to an average of 62 degrees.
9News meteorologist Chris Bianchi’s July 9 post on Twitter noted that Colorado has just experienced the hottest opening half of the year on record, “and it wasn’t even close.” Image credit: Chris Bianchi via Twitter.
Colorado as a whole is seeing the same trend, with 9News meteorologist Chris Bianchi reporting that it was the hottest opening half of the year on record, “and it wasn’t even close,” he noted on Twitter July 9.
The average temperature of 46.2 degrees beat the previous mark by a full degree. “The impact of a warming climate is clear,” Bianchi noted.
The weather has taken a toll, putting water supplies and landscapes in a major water deficit, Fisher said. Even so, customers have heard the call for conservation.
Overall, they adhered to Denver Water’s call to hold off on activating sprinkler systems until mid-to-late May or even June.
But as spring rains retreated and temperatures rose, watering season hit its stride and the hot weather predictably drove up use to levels similar to the five-year average recorded from 2021-2025.
Now, as we enter the heat of July and August, Denver Water should get a better sense of how well customers continue to keep water use in check and hold to mandatory two-day-a-week watering schedules.
Suggested watering times that comply with Denver Water’s mandatory drought restrictions that limit outdoor watering to two days per week. Image credit: Denver Water.
Mother Nature may help, with some climate models suggesting the potential for a rainier summer that could reduce the need to turn on sprinklers, cut demand and keep water in Denver Water reservoirs.
“It’s so important for customers to pay attention to the weather, and keep irrigation systems off around rain events,” Fisher said. “A good rainstorm should allow you to take your watering day off and, in some cases a rainy week means you can skip watering on both designated days.”
Preserving water supplies in Denver Water’s reservoirs is key.
Overall reservoir levels, as of July 13, are currently around 78% percent full (compared to percentage levels usually in the high-90s at this time of year), but levels are dropping as summer watering hits full stride.
The more Denver Water customers can stretch those supplies, the quicker the storage levels can begin to recover after a year — or more likely years — of better winter snowpack.
Too much drawing down of precious water supplies stored in reservoirs could be consequential for water users.
Antero Reservoir in 2026, after its water was moved to Cheesman Reservoir to reduce the amount of water lost to evaporation. Photo credit: Denver Water.
Should supplies drop too low this summer, water planners would potentially consider reducing outdoor watering to one day a week to further ease pressure on supplies and avoid an even larger storage deficit next spring. So now is the time to pay close attention to water use outdoors — and indoors.
Every bit you save, whether it’s while you shave, shower or water the lawn improves the chances we can avoid even tougher restrictions and look with hope for a stronger winter to come and begin recovering storage supplies.
“We need people to be thinking bigger than this week or this year when they think about water,” Fisher said.
“Even with watering restrictions in place now, we’ll enter next year with a water deficit due to the record snow-drought last winter. Recovering from that requires not only some good snow years, but thoughtful conservation from our customers.”
Click the link to read the article on The Denver Post website (Elise Schmelzer). Here’s an excerpt:
July 15, 2026
Even in the driest of years — like this one — powerful Western Slope water rights on the mainstem of the Colorado River draw water downstream, making boating on the state’s major water artery possible.
“For mainstem floating, we should still have pretty darn good flows for the rest of the season for as long as people want to be boating,” said Sam Calahan, a water resources specialist for the Colorado River District. The taxpayer-funded agency is based in Glenwood Springs and works to protect Western Slope water…
On Wednesday, Browns Canyon — a popular section of the Arkansas River near Buena Vista — was flowing at the lowest level in 55 years of data and at 16% of its median flow for that date. Clear Creek near Idaho Springs was flowing at 61 cubic feet per second on Wednesday, also a record low for the date in 72 years of data. The median flow for the date is 347 cfs, or more than five times as much water…But flows on much of the Colorado River were high enough for rafts and kayaks this week. Flows on a popular section near Kremmling were near normal, as were water levels farther downstream in Glenwood Canyon. Two major factors keep water flowing down the Colorado River during drought: large senior water rights owned by farmers in Mesa County’s Grand Valley and the water rights connected to the Shoshone Power Plant, a hydroelectric facility in Glenwood Canyon owned by Xcel Energy. Irrigators and power plant operators can call water to their facilities from upstream reservoirs, like Green Mountain Reservoir, which is on the Blue River — a tributary of the Colorado River — north of Silverthorne. This year, the irrigators began calling down water on July 1, boosting flows in the Colorado River.
The Northern Water Board of Directors has unanimously approved a change to Colorado-Big Thompson Project accounting procedures concerning C-BT water tracking.
During a rule-making hearing at the June 11 Board meeting, Directors heard about the changes to the rules surrounding the tracking of water from the Project. The new accounting procedures will require accounting of tracking data to be provided in a manner to allow for the administration of C-BT Project water return flows, which will help Northern Water protect them as described in the District’s Repayment Contract with the Bureau of Reclamation, the Water Conservancy Act and contracts with allottees.
The modifications affect only domestic and municipal users, and Northern Water staff met or contacted 26 municipalities, water districts and treatment plants in the months before the rule change was approved.
Map of the Colorado-Big Thompson Project via Northern Water
The Roaring Fork River in Aspen on July 8. Pitkin County Commissioners gave initial approval to buying more shares of Twin Lakes water to boost low flows on the Fork. CREDIT: HEATHER SACKETT/ASPEN JOURNALISM
Against the recommendation of an advisory board, Pitkin County commissioners on Wednesday gave preliminary approval to buy more water to boost flows in the often-depleted Roaring Fork River.
Commissioners approved on first reading a resolution and ordinance to spend $442,500 to buy 4.68 shares from the Twin Lakes Reservoir & Canal Co., which is about 3.5 acre-feet of water, according to a staff memo. The deal is in addition to the $6.5 million Pitkin County already agreed to spend earlier this year for about 71 acre-feet from Twin Lakes and another ditch company.
Twin Lakes collection system
The water is currently taken across the Continental Divide to the Arkansas River basin to be used by entities on the Front Range. The deal would allow the water to be released out of Grizzly Reservoir to Lincoln Creek and could help boost the Roaring Fork through Aspen and upstream, which suffers from low flows in dry years.
“I think it’s really critical that we purchase water rights when we can, and this is an opportunity that we can, and we should,” District 1 Commissioner Patti Clapper said.
Pitkin County has long had a goal of increasing the amount of water in the Roaring Fork, a river that has about 40% of its headwaters diverted to the eastern side of the state through the Independence Pass Transmountain Diversion System to be used by Colorado Springs, Pueblo and Aurora. These diversions can often contribute to the depletion of the Roaring Fork through Aspen, and purchasing Twin Lakes water represents a rare opportunity to return water to the Western Slope.
Commissioner Greg Poschman said he supports acquiring the water shares.
“I think it’s great that we are doing this,” he said. “I know it’s expensive; there are some raised eyebrows about that, but I think this is something we have to do.”
Poschman added that he was concerned that the Healthy Rivers board members recommended against buying more water and said he would like to fully understand their reasons. County staff said they were trying to schedule a joint meeting with the Board of County Commissioners and the Healthy Rivers board in August.
Members of the county’s Healthy Rivers board, which advises the BOCC, are concerned that the water will have a small impact on river health but a big impact on the program’s budget. The board held a special meeting June 25 to consider acquiring the shares and approved a motion saying the water yield would potentially be only 1 additional cubic feet per second for two days.
“Additionally, the deleterious effects of the purchase price on the long-term fund balance of the Healthy Rivers Fund will reduce the Healthy Rivers Program’s ability to support programs to address other ballot measure mandates, including water quality, ecological health, recreation opportunities, wildlife and riparian habitat, and promoting water conservation,” the motion reads.
The motion goes on to say that in the future, the county should implement a framework for evaluating the true value of water shares to the Roaring Fork.
At Wednesday’s meeting, County Budget Director Connie Baker told the BOCC that the Healthy Rivers board will have to trim or reallocate about $500,000 from next year’s budget to account for the combined impact of this year’s two water purchases.
Healthy Rivers board member Ned Andrews said he is against the purchase, citing the impact that it will have on the program’s budget.
“None of the analysis or details that would justify such a purchase or a strategy going forward has been done,” Andrews told Aspen Journalism. “I think before you commit essentially a quarter of your budget for the next 15 years, you’d want to have an analysis that shows you what could be accomplished. My gut feeling is that it wouldn’t really accomplish much.”
Andrews also opposed the earlier, larger water share purchase, although the rest of the Healthy Rivers board was supportive.
At their regular June meeting, Healthy Rivers board members went through the budget line by line and considered where they could trim, although those cuts have not yet been finalized.
Spending big bucks in an effort to rescue rivers is not new for Pitkin County, which has spent at least $3.5 million on the Roaring Fork River Park in Basalt, including a water court battle to secure the water right for recreation, several redesigns of problematic waves, and improvements to the riverbank and boat launch.
Grizzly Reservoir, a forebay that collects water to send through the Twin Lakes Tunnel to the Front Range, sits in the middle of the Lincoln Creek watershed and connects water users on both sides of the Continental Divide. Pitkin County commissioners gave initial approval to a deal that would allow more water to be released from Grizzly for the benefit of the Roaring Fork. CREDIT: HEATHER SACKETT/ASPEN JOURNALISM
Bond for original purchase approved
The BOCC at Wednesday’s meeting also approved issuing a bond for the original purchase of Twin Lakes shares. That deal cost the county $6.5 million, although only 45 of those acre-feet represent Western Slope water that is currently diverted to the Front Range. The county plans to sell or trade the other 26 acre-feet, which is owned by the Fountain Mutual Ditch Co. in El Paso County and decreed for use on the east side of the divide.
The 45 acre-feet of water can be released down the Roaring Fork during the irrigation season when flows are low, and it must be used by a downstream water user on the Colorado River before the town of DeBeque. Instream flow for the benefit of the environment is not a decreed use of the water.
This year, according to Colorado Water Resources Division 5 Engineer Tyler Benton, at least some of Pitkin County’s Twin Lakes water was released as part of the Colorado River Water Conservation District’s emergency substitute water supply plan, which the district enacted in response to this year’s historic drought. Benton said he expects the River District to provide a full accounting of how much Pitkin County water has been released Friday.
Grizzly Reservoir is currently drained for dam maintenance, which may have affected how much water could be released under the River District’s plan.
At a time when drought impacts are being acutely felt across the state and climate change continues to rob rivers of their flows, for some, the unique opportunity to put water back into a depleted stream is worth the cost.
“This is expensive water, but it’s the only water you can get up at the headwaters of the Roaring Fork,” said Pitkin County Deputy Attorney Anne Marie McPhee. “So that scarcity makes it more valuable.”
The issue is scheduled for a public hearing and second reading July 22.
The full impact of this past winter’s record-low snowpack is rearing its ugly head in the form of:
Record-low spring stream flows.
Low reservoir storage levels.
An empty reservoir.
And one incredibly rare statistic.
On June 17, Denver Water’s reservoir system hit its peak storage level following a diminished spring runoff.
Water levels in the utility’s reservoirs collectively hit 81% of the system’s storage capacity — the second-lowest peak storage level on records dating back to 1983, considered the beginning of the modern Denver Water collection system.
“Peak storage” is the moment, or day, when the utility’s collection system holds the most water it will hold for the next year. It’s akin to topping off a swimming pool once a year in June to carry the pool through the next year of use.
Typically, the “peak storage” moment happens in mid-June, after the spring runoff.
But in 2026, due to the record-low winter snowpack and low spring runoff, Denver Water’s collection system held more water on Jan. 1 — 83% of capacity — than on June 17, as the runoff dwindled and storage levels inched to 81% of capacity.
There’s only one other year since 1983, when the Strontia Springs Dam was completed, that Denver Water’s storage was higher in the dead of winter than the dawn of summer — the drought year of 2002.
“Having our highest amount of water happen in January is incredibly rare. It speaks to how little snow we saw this winter and the impact of the record-setting warm weather,” said Nathan Elder, Denver Water’s manager of water supply.
“We’ve seen many records fall this year, and unfortunately, they were not good ones.”
Dillon Reservoir reached 80% capacity on June 17, the highest elevation it is expected to see in 2026. Dillon is the largest reservoir in Denver Water’s collection system, storing roughly 38% of the utility’s water supply. Photo credit: Denver Water.
During the spring peak, the amount of water stored in Denver Water’s reservoirs typically hits an average of 97.5% of capacity.
And since 1983, the utility’s peak storage levels have hit at least 95% of capacity (considered sufficient for normal operating conditions) in all but six years.
“Ideally, we like to top off our mountain reservoirs during the spring runoff, but this year our storage levels came up well short,” Elder said.
Record low ‘paycheck’
Why do water managers focus on peak storage numbers?
The peak reservoir storage figure is critical to determining how much water is available until next year’s spring runoff. It’s comparable to a family determining how much money they have to pay the bills until the next paycheck comes through.
“The spring runoff is our annual paycheck from Mother Nature,” Elder said. “The water filling our reservoirs is the cash that fills our bank account. But in our case, that paycheck only comes once a year — and this year we didn’t get anywhere close to the normal amount.”
Tenmile Creek in Frisco, as it enters Dillon Reservoir on June 12. Denver Water saw record low flows into the reservoir in 2026. Photo credit: Denver Water.
This year’s meager paycheck was reflected in the record-low peak flows on the rivers and streams that feed Denver Water’s reservoirs.
Mountain snowmelt accounts for 90% of Denver Water’s supply, which provides water to 1.5 million people in metro Denver.
In Summit County, Denver Water recorded this year’s peak stream runoff into Dillon Reservoir at just 404 cubic feet per second, or cfs, on May 29. That’s a record-low “peak inflow” and less than a quarter of the normal peak inflow into the reservoir of 1,750 cfs, which typically happens on June 7.
In Park County, the South Fork of the South Platte River experienced a double-whammy, with record-low flows that occurred abnormally early in the season.
Flows on the South Fork peaked on March 25 at a record-low flow of just 18 cfs. That’s 15% of the normal peak flow of 120 cfs, which usually happens on June 10.
The South Fork of the South Platte River south of Fairplay on May 22. The river peaked at a record low flow of just 18 cfs in 2026. Photo credit: Denver Water.
“In a typical year, the rivers and streams start rising in late-April as the snow starts to melt, then they peak in early June, and then they start to ease back to normal flows throughout the summer,” Elder said.
“This year the runoff started about six weeks early in March, and the normal spring surge of water we usually see was basically nonexistent.”
Reservoir impact
The results of the record-low spring flows are having a significant impact on three of Denver Water’s most popular reservoirs.
Dillon Reservoir in Summit County topped off on June 17 at 80% of capacity, with water levels about 18 feet below normal for this time of year. Water levels are expected to drop over the next year until the 2027 spring runoff — hopefully more boisterous than this year’s meager flow — begins.
Dillon Reservoir in Summit County reached 80% capacity on June 17. This picture shows the low levels at the Snake Inlet on the southeast corner of the reservoir on June 12. Photo credit: Denver Water.
In Grand County, Williams Fork Reservoir topped off June 21 at merely 53% of capacity, about 35 feet below normal for this time of year and forcing the closure of the reservoir’s boat ramp.
At the Williams Fork Reservoir in Grand County, the boat ramp will be closed all summer due to low snowpack and record-low runoff. Photo credit: Denver Water.
Because of the low snowpack, Denver Water also dipped into its emergency water supply at Antero Reservoir in Park County.
Using water from Antero Reservoir is only done in extremely dry years. It’s comparable to someone having to dip into their 401(k) savings to pay bills until their next paycheck.
Denver Water moved water out of Antero this spring and sent it downstream to Cheesman Reservoir to avoid losing water in shallow Antero due to evaporation.
Denver Water moved water from Antero to Cheesman reservoir in 2026 to reduce losses from evaporation. The water in Antero Reservoir, pictured above, is only used in extreme dry years. Photo credit: Denver Water.
Early forecasts for the abysmal spring runoff and low peak storage were two factors that led Denver Water to issue a Stage 1 drought declaration in March.
The declaration, which calls on customers to reduce water use by 20% and includes mandatory watering restrictions of two assigned days per week, seeks to stretch existing water supplies until next spring’s paycheck is deposited in the reservoirs.
“While the reservoirs are low this year, they are doing what they were built for, which is to help us get us through a dry year,” Elder said.
“We hope customers notice the low reservoir levels and take steps to conserve water at home so we can stretch our water supplies over the coming months.”
Governor Clarence J. Morley signing Colorado River compact and South Platte River compact bills, Delph Carpenter standing center. Unidentified photographer. Date 1925. From the CSU Water Archives
Click the link to read the article on The Denver Post website (Elise Schmelzer). Here’s an excerpt:
June 29, 2026
The U.S. Supreme Court will weigh in on a legal battle over one of Colorado’s critical water sources as a neighboring state seeks to use more water from the South Platte River. The nation’s highest court on Monday announced it would hear the case, in which Nebraska officials claim Colorado water administrators are violating a century-old water compact by failing to send enough of the river’s water across the border. They also say Colorado officials are interfering in the neighboring state’s efforts to build a canal that would allow it to take more of the river’s water. Colorado Attorney General Phil Weiser on Monday denied Nebraska officials’ allegations that the Centennial State was violating the 1923 South Platte River Compact.
“Colorado is complying with the South Platte River Compact and not interfering with Nebraska’s efforts to build the Perkins County Canal,” Weiser said in a statement. “Today’s court decision merely opens the door for Nebraska to bring its claims against Colorado. Nebraska’s burden to prove those claims is incredibly high and we will vigorously defend Colorado’s full entitlements under the compact.”
Perkins County Canal Project Area. Credit: Nebraska Department of Natural Resources
Nebraska officials last year surprised Colorado leaders by taking their allegations to the Supreme Court. The two states had been meeting for months to discuss the proposed canal project. The Supreme Court asked the Office of the Solicitor General to weigh in on whether it should take the case. In May, the federal office — tasked with representing federal interests at the Supreme Court — argued that the court should decide Nebraska’s claim that Colorado is not sending enough water over the state border, but deny consideration of Nebraska’s other issues…Controversy over compact-obligated water deliveries between two states is a “quintessential” Supreme Court question, the brief states. The solicitor general’s office suggested appointing a special master — a subject-matter expert outside of the nine justices — to handle the issue. The solicitor general’s brief argues that the Supreme Court should not hear Nebraska’s arguments that Colorado is obstructing its efforts to build the Perkins County Canal because, the office said, Nebraska has not identified any actions by Colorado officials that have substantially interfered in the project. Other potential canal-related problems identified by Nebraska are hypothetical, the solicitor general said, as the state has just begun the permitting process and, therefore, is not ready for Supreme Court consideration. It’s unclear which issues the Supreme Court will consider as it hears the case. The order Monday allows Nebraska to file its complaint against Colorado.
The South Platte River Basin is shaded in yellow. Source: Tom Cech, One World One Water Center, Metropolitan State University of Denver.
The new conveyor system moved concrete across the gap where the spillway channel will be to the far side of the dam. Photo credit: Denver Water.
Click the link to read the article on The Denver Post website (Elise Schmelzer). Here’s an excerpt:
June 14, 2026
…it remains unclear whether Denver Water will ever be able to fill the reservoir to its new full capacity as a yearslong court battle lumbers on between the utility and environmentalists. Months of mediation between the parties have failed. Denver Water is now asking a federal appeals court to reverse a lower court judge’s 2025 order barring the utility from filling the expanded reservoir and ordering the yearslong federal permitting process to be redone. A panel of three judges for the 10th U.S. Circuit Court of Appeals is scheduled to hear arguments in the case on July 31 in Santa Fe…
U.S. District Court Judge Christine Arguello in 2024 found that federal regulators violated environmental protection laws when they failed to properly analyze the environmental impact of the project or consider reasonable alternatives to the dam expansion that would be less harmful. She later issued the order against filling the reservoir. Environmental groups argued in court, and in their filings, that regulators failed to evaluate how siphoning more water from the drought-stricken Colorado River would impact the basin as a whole. And the groups charged that they failed to weigh other project options that wouldn’t require the clear-cutting of a half-million trees or risk damage to wetlands. The case has drawn the attention of other Front Range water providers, lawyers from across the county and the U.S. Chamber of Commerce — all of which have filed briefs in the appeals case…
While the dam structure itself is complete, at least a year of work remains to fully finish the project, Martin said. Construction crews must finish the spillway and place the final topper foot of concrete on the completed dam structure. Divers will place a gate between the reservoir’s water and the dam’s intake tubes. But the crews on site will diminish in the coming months, from up to 500 workers a day to closer to 100. On the morning of June 3, crane operators already worked to remove from the dam crest the heavy machinery that was necessary to build the main structure.
Roller-compacted concrete will be placed on top of the existing dam to raise it to a new height of 471 feet. A total of 118 new steps will make up the new dam. Image credit: Denver Water.
A reservoir built to serve nearly a million Northern Coloradans started filling this spring. But Chimney Hollow’s future is still murky weeks after the initial fill. Chimney Hollow will eventually pull water from the Colorado River near its headwaters in Grand County to serve a dozen fast growing cities on the Front Range from Broomfield to Greeley…Chimney Hollow is holding just 2% of its total volume today because there’s a problem. Northern Water discovered that some of the rocks it used to build the massive dam at the reservoir contained radioactive uranium. It was naturally occurring, but it set the project back at least a year. Northern Water is still coming up with a mitigation plan.
“Really, the best way to kind of move that uranium out is to draw down the water and force that out,” spokesperson Rachel Stevens said. “But before we make any of those decisions, we really want to see what the levels of uranium are.”
So every week, crews are taking water samples from the small pool and sending it to a lab to see how much radioactive material is really in the water. The results are expected soon. Northern Water has only been able to test how uranium leaches out of the rocks in a laboratory setting. Filling the reservoir just slightly will help reveal the extent of the problem.
Map from Northern Water via the Fort Collins Coloradan.
Each stage of a big construction project has its own challenges and puzzles to solve along the way. Raising Gross Dam is no different.
Denver Water is raising the height of the dam by 131 feet, with the final 22 feet going up this spring in two sections that are separated by a giant gap. The Gross Reservoir Expansion Project, which began construction in 2022, is designed to nearly triple the reservoir’s storage capacity. Major construction work resumed in April following a winter break.
And this year’s construction puzzles included:
How to move concrete across a 160-foot gap between where the concrete is made and where it’s placed?
And, how do you move construction vehicles across that same gap when work on the first section is finished?
“We are building the top of the dam in two sections because we need to leave a 160-foot gap in the middle of the dam for the spillway channel,” said Casey Dick, Denver Water’s deputy program manager for the Gross Reservoir Expansion Project.
Denver Water is building the last 22 feet of Gross Dam in two sections. The photo shows the left side at its new height. The right side’s last 22 feet will be finished in June. Photo credit: Denver Water.
Spillway channels are safety features on dams that allow water to safely flow out of a reservoir if needed due to flooding rains or exceptionally high and rapid snowmelt.
Raising the dam’s last two major sections, while leaving a 160-foot gap between them, meant coming up with a new way to move concrete across the construction site.
On the lower portion of the dam, crews worked on one continuous structure, which allowed trucks and equipment to easily move from one side of the dam to the other, and to move concrete from the batch plant down a large chute to where it was put into place.
However, with the final 22 feet going up in two sections, construction crews had to find a way to deliver concrete from the batch plant and across the 160-foot spillway gap as the first section went up.
The solution to this puzzle? A series of conveyors positioned in the middle of the dam that tilted higher as the first section rose higher.
“Building the new conveyor system is just another example of all the ingenuity we go through out here to build the dam,” Dick said. “With each new phase, there are new challenges that our team has to figure out.”
The new conveyor system moved concrete across the gap where the spillway channel will be to the far side of the dam. Photo credit: Denver Water.
Construction crews finished placing roller-compacted concrete on the dam’s left side on May 12.
But once that was done, crews faced the second challenge: How do you move the equipment off the finished, 22-foot higher section of the dam, across the spillway gap, down to where they are needed to complete the second section?
Short answer: If you can’t go over, go around.
Cranes lifted equipment off the higher section of the dam to the road, where the machines convoyed about 4.5 miles around to the other side using the dam’s access road.
A crane lifts a piece of equipment off the dam. Because of the new spillway gap, equipment was driven across the dam’s access road to get into position on the other side of the dam. Photo credit: Denver Water.
Construction on the final 22 feet of the second side of the dam began at the end of May and is expected to be completed in June.
Once the second section is done this summer, a year’s worth of remaining work includes: finishing the top of the dam, building safety walls; constructing the actual spillway; building a bridge over the spillway and completing the stilling basin at the bottom of the dam.
This view from the bottom of the dam shows the new baffle blocks on the bottom of the stilling basin. The baffle blocks reduce the energy of the water that flows down the spillway. Photo credit: Denver Water.
Full construction on the dam raising project is expected to wrap up in mid-2027.
“There are hundreds of logistical challenges throughout this project, but our team has been able to meet every one of them along the way,” Dick said. “We’re making good progress so far in 2026 and are looking forward to getting a lot of work done in the coming months.”
The Gross Reservoir Expansion Project involves raising the height of the existing dam by 131 feet. The dam will be built out and will have “steps” made of roller-compacted concrete to reach the new height. Image credit: Denver Water
This USGS map shows the number of PFAS detected in tap water samples from select sites across the nation. The findings are based on a USGS study of samples taken between 2016 and 2021 from private and public supplies at 716 locations. The map does not represent the only locations in the U.S. with PFAS. Sources/Usage: Public Domain. Visit Media to see details.
EPA aims to end federal regulation of four PFAS in drinking water and give utilities more time to comply with existing rules.
FEMA reopens applications for a climate-resilient infrastructure grant program that the agency had cancelled.
Bureau of Reclamation announces $52 million for three new Hoover Dam turbines that will generate hydropower at lower Lake Mead levels.
A House FY27 budget bill will cut the federal government’s primary water infrastructure funds by 24 percent.
NOAA forecasts fewer Atlantic hurricanes this season.
EPA water office leader commits to investigate groundwater pollution in Georgia from Meta data center construction.
The Trump administration recommends that the U.S. Supreme Court take up Nebraska’s claim that Colorado has violated a river-sharing compact.
And lastly, the Bureau of Reclamation’s acting commissioner informs a House subcommittee about the status of Colorado River negotiations.
“Several weeks ago, I met with the 14 senators from the Colorado River basin and on a bipartisan basis, several of them said, ‘Look, we have a real crisis on the Colorado and we need to get things done and if there are any environmental statutes that are slowing things down, tell us what they are and maybe we can legislate to clear out some of the unhelpful bureaucratic paperwork.’” – Scott Cameron, acting Bureau of Reclamation commissioner, speaking at a House Natural Resources subcommittee hearing. Cameron said his office has not yet followed up on the offer but “looked forward” to conferring with the senators about “waiving or streamlining certain environmental statutes on the Colorado.”
Udall/Overpeck 4-panel Figure Colorado River temperature/precipitation/natural flows with trend. Lake Mead and Lake Powell storage. Updated through Water Year 2025. Note the tiny points on the annual data so that you can flyspeck the individual years. Credit: Brad Udall
As for the status of Colorado River negotiations, Cameron said, “Frankly, the seven states are not in a position where they could agree today, right now, to a four-year deal, let alone a 20-year deal, because of the uncertainties we’re dealing with.”
By the Numbers
$1 Billion: Funding now available from FEMA’s Building Resilient Infrastructure and Communities program, a grant opportunity to reduce risk from climate and weather hazards. A federal judge ordered the agency to reinstate the program, which the Trump administration had cancelled. Applications are due July 23.
$52 Million: Funding announced by the Bureau of Reclamation for three new low-head turbines at Hoover Dam. Only five of the dam’s 17 turbines are designed to operate when Lake Mead drops below elevation 1,035 feet, a threshold that the shrinking reservoir is fast approaching and could breach in the next 12 months, if not sooner.
Not So PFAS The EPA is proposing to repeal federal regulation of four PFAS in drinking water, partially undoing a Biden-era rule that set first-ever limits on six of the “forever chemicals.”
Three of the chemicals – PFHxS, PFNA, and Gen X – were regulated individually. Together with PFBS, they were also regulated as a mixture.
The EPA will retain standards for PFOA and PFOS, the two most-studied of the chemicals. However, in a separate rule-making, the agency is proposing to give water utilities more time to comply, extending the deadline by two years, until 2031. The agency says the move will “ease the implementation burden” financially and administratively for water systems and might allow for cheaper treatment technologies to come to market.
Water utilities must apply for an extension. One of the considerations is whether an extension would pose an “unreasonable risk to health.” The EPA is proposing that PFOA and PFOS levels below 12 parts per trillion would not be unreasonable. (The federal standard for both is 4 ppt.)
The EPA wants public comment on whether interim utility actions during a compliance extension – point-of-use treatment, filtration pitchers, education, alternative water sources – can mitigate health risks above 12 ppt.
Water Infrastructure Funding Cuts A House spending bill cuts the two main federal sources of water infrastructure funding by about 24 percent in fiscal year 2027. The bill passed out of subcommittee last week.
The bill provides $1.2 billion for the Clean Water State Revolving Fund (27 percent cut) and $911 million for the Drinking Water State Revolving Fund (19 percent cut).
Following a recent trend, about half of the appropriation comes in the form of earmarks. This money will go directly to specific projects and will not enter the revolving fund. Water industry advocates argue that continuing to take earmarks out of the revolving fund appropriation threatens the viability of the program.
Studies and Reports
The South Platte River Basin is shaded in yellow. Source: Tom Cech, One World One Water Center, Metropolitan State University of Denver.
Great Plains Water Fight The federal government’s top lawyer recommended that the U.S. Supreme Court take up one of Nebraska’s claims that Colorado is violating the South Platte River Compact, which divides the river’s water between the two states.
Nebraska argues that Colorado is breaking three articles of the compact. The U.S. solicitor general says that the high court, through a special master, should pursue only one of them: that Colorado is allowing irrigators to take too much water.
“A claim that one State has deprived another of water to which it is entitled under an interstate compact is a quintessential case for this Court’s original jurisdiction,” the brief states.
Atlantic Hurricanes NOAA is forecasting a less active Atlantic hurricane season. The agency estimates that one to three major hurricanes (Category 3 or higher) will form.
The category ratings can be misleading. They measure wind speed, not precipitation. Tropical storms and minor hurricanes can still inflict serious flood damage.
Air Conditioning Estimates The U.S. Census Bureau published data estimating how many homes use air conditioning.
States with the lowest air conditioning use are in New England and the West.
On the Radar
EPA on Data Centers and Household Wells Under oath at a House subcommittee oversight hearing, Jessica Kramer, head of the EPA Office of Water, committed to investigate impacts to drinking water quality from data center construction.
“Whatever type of construction it is, it’s a priority to ensure that water quality standards established by EPA are being met. So we’ll be looking into that certainly,” Kramer said.
Kramer’s commitment at the House Energy and Commerce hearing was prompted by Rep. Alexandria Ocasio-Cortez (D-NY) who asked about water pollution from data center construction.
Ocasio-Cortez visited Morgan County, Georgia, a few weeks ago. She returned with jars of brown water from household wells near the construction site of a Meta data center. She displayed those at the hearing.
“This is what the drinking water now looks like, next to that data center,” Ocasio-Cortez said.
“As soon as I get back to the office, I will be looking into exactly what you just talked about,” Kramer replied.
Army Corps Deauthorized Projects The Army Corps published a list of water projects that it intends to deauthorize.
These are projects that were authorized years ago but either haven’t ever received funding or haven’t recently received funding.
Public comment on the proposal runs through August 19. Submit comments at http://www.regulations.gov using docket number COE-2026-0034.
Federal Water Tap is a weekly digest spotting trends in U.S. government water policy. To get more water news, follow Circle of Blue on Twitter and sign up for our newsletter.
Here’s the release from the St. Vrain and Left Hand Water Conservancy District (Sean Cronin):
April 20, 2026
Agreement affirms no new on-river dam while preserving valuable water rights for communitybenefit
The St. Vrain and Left Hand Water Conservancy District has reached an agreement with Save the World’s Rivers that reaffirms a new path forward for its Coffintop Reservoir water rights—one that does not include construction of a large on-river dam.
The District was created in 1971, in part, to build Coffintop Reservoir on South St. Vrain Creek west of Longmont and upstream of Lyons, through a planned partnership with the U.S. Bureau of Reclamation. While the reservoir itself was never built, two water storage rights associated with the Coffintop Reservoir project remain legally valid today.
As a governmental entity, the District holds the Coffintop Reservoir water rights not for its own benefit but for the community’s. In 2024, as required under Colorado water law, the District filed a routine six-year diligence application in water court to maintain those rights. The filing prompted an environmental group, Save the World’s Rivers, to submit a statement of opposition, opening discussions between the two organizations about the future use of the Coffintop water rights.
“The Water Court process is complex, and at the onset we were uncertain what Save the World’s Rivers hoped to achieve through it,” said Sean Cronin, the District’s Executive Director.
“We are always watching proponents of dams,” said Gary Wockner, Executive Director of Save the World’s Rivers. “At the appropriate time, we seek to identify ways proponents can achieve their mission while not creating a new dam. We were generally aware of the good work being done by the District, but concerned about their plan to build Coffintop Reservoir and dam.”
Through dialogue, the District and Save the World’s Rivers found common ground. Cronin noted, “I met with Gary several times, and I gained respect for his organization’s objectives, and I appreciated his willingness to come to the table and talk through complicated issues.” Save the World’s Rivers learned that the District had been working for more than 10 years with the City of Longmont, Town of Lyons, Boulder County Parks and Open Space, local environmental organizations, and food producers to develop a strategy to best utilize the Coffintop Reservoir water rights – without building the actual reservoir.
The District and Save the World’s Rivers reached an agreement through the court process, under which the District agreed to forgo using the Coffintop Reservoir water rights for any new on-river reservoir, including Coffintop Reservoir, and for the expansion of any existing on-river reservoir. Instead, the District will return to water court with plans to use the water rights at alternative locations and in ways that align with community needs, and environmental and water management goals.
“It became clear through discussions that the District shared values around avoiding a new on-river dam while still meeting its mission,” said Wockner. “That made an agreement possible,” Wockner said.
District leaders emphasized that the water rights are held for public benefit and that the original Coffintop Reservoir concept no longer reflects the highest and best use of the resource.
“This is something we and our communities have contemplated for decades,” said Christopher Smith, President of the District’s Board of Directors. “The Coffintop project, as envisioned more than 50 years ago, no longer fits today’s needs or values.”
For more than a decade, the District has worked with community partners to explore alternatives that could use the Coffintop water rights, while also supporting increased stream flows during low-flow periods. The District’s development and implementation of these alternatives is moving forward with engagement from important partners, including the Town of Lyons and City of Longmont.
Town of Lyons Mayor Hollie Rogan welcomed the agreement. “St. Vrain Creek is the lifeblood of our town, and a large dam upstream was never embraced by our community,” she said. “We’re pleased the District will not pursue Coffintop Reservoir and look forward to continued collaboration.”
Longmont Director of Water and Waste Service Chris Huffer noted the long history between the City and the District. “The challenges around water have only grown more complex over the last 50 years,” he said. “The District has a solid water plan, and the City is an eager partner in realizing the greatest potential of these water rights.”
The South Platte River Basin is shaded in yellow. Source: Tom Cech, One World One Water Center, Metropolitan State University of Denver.
The initial fill of Chimney Hollow Reservoir has concluded, and the reservoir currently has about 1,500 acre-feet of water—less than 2 percent of the reservoir's full capacity of 90,000 acre-feet. Read more about the initial fill at https://t.co/WaxdbfiFWz. pic.twitter.com/ndlN3Y6zoV
— Chimney Hollow Reservoir (@ChimneyHollow) May 5, 2026
“By taking voluntary measures now to reduce water use, Utilities customers can actively help lower the chance of mandatory water restrictions if conditions worsen,” the news release stated.
Fort Collins Utilities and East Larimer County Water District, or ELCO, which are two of the city’s three major water providers, are asking customers to:
Limit lawn watering to no more than two days per week.
Avoid watering between 10 a.m. and 6 p.m.
The West Fort Collins Water District is required to follow city-issued water rationing and restrictions, according to its website. Sunset Water District is managed by ELCO.
When Donald Trump was elected president for the second time, we all knew what was coming to the nation’s public lands: The administration would favor extractive uses by eviscerating environmental protections, rolling back regulations, and leasing out as much land as possible while handing out drilling permits like Shriners throwing candy at a parade.
Yet there was one realm where I figured the administration couldn’t bestow any more deregulatory gifts, namely public lands grazing. It’s not that I thought Trump would clamp down on the destructive practice, it’s just that I figured the status quo was about as permissive as it could get. Past administrations, be they Democratic or Republican, have generally shied away from updating or reforming public lands grazing policies out of fear of inflaming the West’s cowboy culture — even if it is based largely on myth.
But Trump, his Interior Secretary Doug Burgum, and Agriculture Secretary Brooke Rollins are intrepidly going where previous administrations did not dare: grazing reform. Well, sort of, though maybe not in the way public lands lovers might have hoped. In fact, they are doing their best to make grazing policy even more lax with a goal of getting more cattle out there to trample public lands, cryptobiotic soils, and cultural sites.
Last month, Burgum and Rollins announced an MOU between the two agencies designed to “boost the supply of American born, raised, and harvested beef” by cutting “bureaucratic red tape” and giving the livestock industry more control. The MOU has a goal of “maintaining grazing capacity wherever possible, including no net loss of Animal Unit Months within allotments,” even if those allotments are degraded or in poor health. In Burgum’s words, one goal is to “preserve America’s ranching heritage for generations to come.” Forgive me for getting anxious whenever I see “heritage” used in conjunction with public lands.
“Today’s signing sends a clear message: the Trump administration is putting America’s farmers and ranchers first,” said Secretary of Agriculture Brooke Rollins. Which brings up the question of what message the administration was sending in February when Trump signed an executive order to quadruple beef imports from Argentina in an effort to keep Big Macs affordable.
🗺️ Messing with Maps 🧭
To help it carry out its mission, the Bureau of Land Management has released an interactive map aimed at putting more cattle and sheep back on public lands. The “federal grazing lands potentially available” map shows allotments that have been vacated, often as a result of deals brokered by environmentalists, with the intent of peddling the tracts to livestock operators. While there’s no guarantee that the BLM would lease out all of the vacant tracts, the presence on the map of the ones vacated for environmental purposes is enough to set off alarm bells.
Grazing allotments listed as “potentially available” for leasing on the BLM’s new map. The five parcels closest to Silverton were retired in 2023 to protect bighorn sheep. Source: BLM
For example, the map includes 10 allotments in the high country around Silverton, Colorado, totaling about 70,000 acres. In 2023, the National Wildlife Federation paid the Etchart Sheep Ranch to vacate five of these allotments in an effort to give Rocky Mountain bighorn sheep more breathing room and protect them from diseases transmitted by domestic sheep. The deal was made with the hope that the leases would be retired permanently. Yet the inclusion on the map indicates they could see domestic sheep once again, emphasizing the need for legislation that would make such retirements perpetual.
Also on the map are the Flodine Park and Yellowjacket allotments in Canyon of the Ancients National Monument near the Colorado-Utah border. In 2005, a rancher gave up the allotments, north and south of McElmo Canyon, respectively, and sold 4,500 acres of adjacent private land to the BLM to add to the national monument. Both allotments and the private land contain a number of intermittent streams, shallow canyons, and numerous cultural sites. They had been grazed relentlessly for decades prior, and showed the wear and tear—much of the cryptobiotic soil had long before been trampled and destroyed and invasive cheat grass had infiltrated the grazed areas. An archaeological assessment conducted later found grazing had damaged dozens of sensitive and cultural sites in the areas.
The Yellowjacket and Flodine Park allotments in Canyons of the Ancients National Monument. They have been vacant since 2005, and a previous effort to lease them out again was halted. Now it looks like they may be back on the block. Source: BLM
In 2010, the BLM, which manages the monument, issued a new resource management plan, which allowed for continued grazing, but also opened the door to permanently retiring vacant grazing allotments if they fail to meet BLM rangeland health standards or when grazing is negatively impacting cultural sites. Five of the 28 allotments in the most heavily visited areas—including Sand Canyon—were cancelled, but not the Flodine Park and Yellow Jacket allotments, which were still in retirement at the time.
Instead, the local county commissioners and a group of ranchers pressured the BLM to reauthorize grazing on both allotments—to bring them out of retirement, if you will. The BLM acquiesced, but environmentalists and tribes with roots in the area fought back, forcing the agency to do a more thorough environmental analysis of the proposal. The opposition was enough to prompt the agency at least to delay issuing any leases, and the allotments remain in limbo.
Meanwhile, a team of scientists assessed the healing process on the Flodine Park and Yellow Jacket allotments, which by then had been cow-free for 11 years (though feral horses had grazed there). They compared biocrusts on those allotments to a fenced enclosure that hadn’t seen grazing for 53 years and a plot that was being actively grazed. What they found was both predictable and remarkable: The longer a plot went without cows, the healthier it was, as summed up by these graphs.
Source: Grazing, Rest, and Biological Soil Crust in Canyons of the Ancients National Monument Marc Coles-Ritchie, Lior Gross and Mary O’Brien, Grand Canyon Trust.
While the natural landscape can eventually heal itself, livestock’s damage to the cultural landscape is irreversible. BLM surveys identified 266 cultural sites on the two allotments, including 35 with “standing architecture.” At least 43% of those had been damaged by livestock.
Now what’s left may be in danger, too, at least if those allotments’ presence on the new map is any indication. And guess what? Packing these allotments isn’t going to make that steak any cheaper. Only about 1% of American beef is grazed on public lands.
Mt. Blue Sky at 14,130 feet in elevation on April 22, 2026. Jonathan P. Thompson photo.
⛈️ Wacky Weather Watch ⚡️
If you were to get all of your information about the West’s climate from daily weather reports and road condition websites, you might think that April snow showers and deep freezes had ended the snow drought and would lead to big May streamflows. After all, it snowed enough in Colorado to turn roads to slip-and-slides and causing a 75-car pileup on I-70 near the Eisenhower Tunnel. The temperatures dropped low enough to wipe out most of the fruit blossoms the March heat wave tricked into blooming early. Only the farmers who used extraordinary measures — starting fires or smudge pots in the orchards, running wind machines, etc. — could save some of their summer harvest.
Sunset over the San Juans. Jonathan P. Thompson photo.
Sure, the snow that did fall in April helped, but only enough to elevate snowpack levels to, well, the lowest on record (only by a slightly smaller margin than before). And the freeze was deep, which helped extend the spring runoff in the few areas where there was any snow left. But even there, I suspect that peak runoff has already come and gone (though I’m not calling the Predict the Peak contest yet!).
I flew over Colorado’s mountains the other day and was rather shocked at the dearth of snow, even on the highest peaks. Mt. Blue Sky, formerly Mt. Evans, had only a few patches of white left — at 14,130 feet in elevation. Everything below 10,000 feet appeared to be snowless. While the San Juan Mountains appeared to be in slightly better shape, it was still looking pretty dry. The Animas River watershed’s snowpack remains lower than it was on 2002 on this date.
Water starts to fill Chimney Hollow Reservoir in Larimer County on Tuesday, April 21. Scott Franz/KUNC
Click the link to read the article on the KUNC website (Scott Franz):
April 22, 2026
At 8 a.m. Tuesday, there was only silence and the occasional crunch of rocks as a dozen people in orange vests waited in a moonlike landscape beneath a 350-foot-tall dam near Loveland.
“Ninetey seconds,” a worker called out.
Moments later, it sounded like a waterfall suddenly roared to life as Northern Water started filling Colorado’s newest reservoir, Chimney Hollow.
“It’s pretty cool, I mean it’s something we’ve been working on for a long time, so just to see it for real, it’s pretty cool,” Chris Manley, a water quality specialist with Northern Water, said as he watched water gush from a 40-foot-tall concrete tower at the bottom of the reservoir.
By the end of the week, the initial release of 1,500-acre feet of water will rise about 30 feet above the spot Manley and a gaggle of journalists were standing on Tuesday morning.
Engineers will make sure the pipes that will funnel Colorado River water to the reservoir are functioning correctly. It will also give Northern Water a chance to study an issue with the water supply.
The reservoir’s future became murky last year after officials announced that naturally occurring uranium was found in the rock used to build the dam for the reservoir.
Manley said the uranium discovery has set the project back roughly a year. But he said it is an issue Northern Water can manage long term.
Water from Chimney Hollow Reservoir is projected to serve almost a million people on the Front Range. Scott Franz/KUNC
“But we’ve got to really understand the situation a lot better before we can move forward,” he said.
This week’s initial fill will provide Northern Water with a real-world test of the water quality that was only previously done in laboratories.
None of the water coming into the reservoir will be released to taps at this point. The reservoir is only being filled to about 2% of its total capacity in the coming days.
“We’ll be measuring it actually pretty frequently, to see just what is (the water) picking up as it goes up and touches the dam and starts to move some of the sediments around here,” Northern Water spokesperson Jeff Stahla said.
Northern Water officials could not provide a timeline for when water will begin reaching the dozen water suppliers who have signed up to receive it.
Map from Northern Water
The reservoir project cost an estimated $500 million and has been in the planning stages for more than two decades.
Conservation groups have raised concerns about the reservoir.
“You can have a bunch of buckets, and you can build more buckets to put water on the front range,” Pelz said. “But the reality is, if the projected climate change impacts come to fruition — which all indications are, they’re coming to fruition quicker than we even thought — there’s going to be no water to fill those buckets.”
The reservoir is seeing its initial fill during historic drought conditions in the Colorado River basin.
“It’s definitely very ironic that we’re filling the reservoir in these historic drought conditions, but we’re fortunate that we had a little bit of supply left from last year,” Northern Water Operations Director Jerry Gibbens said. “It really showcases why storage is so important for our region.
Northern Water officials say the reservoir is a way to boost water security on the Front Range.
“As we’ve seen this year, water storage is such a key element of our overall water supply in northern Colorado, and this just adds another increment of that supply to a region where our water demands continue to grow,” Stahla said.
The South Platte River Basin is shaded in yellow. Source: Tom Cech, One World One Water Center, Metropolitan State University of Denver.
Denver Water’s collection and service areas continue to face severe drought conditions, with historically low snowpack. Denver Water depends on mountain snowpack for its water supply, which serves 1.5 million people in Denver and surrounding suburbs.
As a result, on March 25, 2026, the Denver Board of Water Commissioners declared a Stage 1 drought, seeking a 20% reduction in water use to preserve water levels and avoid even stricter mandatory restrictions later this summer. On April 8, 2026, the board approved the implementation of temporary drought pricing, starting with May water use and reflected in June bills, to signal the premium value of water during droughts and help incentivize customers to save water.
Customers are urged not to turn on automatic sprinkler systems until at least mid- to late-May, or later if possible. It is not necessary to water grass two days per week in April and the beginning of May; keeping automatic systems off will help save water. Occasional hand-watering may be necessary for trees and shrubs during this time. Keep an eye on the weather and let Mother Nature do the watering when she delivers spring rains.
Comment from Nathan Elder, Denver Water’s manager of water supply:
“The snow we saw last week brought marginal improvement to snowpack, but it’s still the worst on record, which is doubly concerning as this week is typically our spring peak when the snow levels are the highest. We need our customers to reduce their water use by 20% and help stretch the water we have stored in our reservoirs. Hopefully, working together, we can save water across our service area and avoid increasing restrictions later this summer.”
In Denver Water’s collection system, snowpack as of April 20, 2026, remained at the lowest levels observed in the past 40 years:
Colorado River Basin: 36% of normal, worst on record.
South Platte River Basin: 7% of normal, worst on record.
Snowpack and melting conditions are unprecedented, with accelerated melting seen since mid-March. Customers need to save water to protect the supply we have right now.
Streamflow forecasts are calling for runoff levels to be 10-40% of normal in 2026.
Reservoir storage conditions are below average; while in reasonably good shape for the time being, far less snowpack is available to help refill them. As of April 20, 2026, reservoirs were 80% full, versus an average of 85% full for this time.
Customers are urged not to turn on automatic sprinkler systems until at least mid- to late-May, or later if possible. When watering season begins, Denver Water will require customers in single-family residential properties to limit watering to no more than two days per week on a set schedule based on their address.
Addresses ending in even numbers: Sunday and Thursday.
Addresses ending in odd numbers: Wednesday and Saturday.
All other customers, including multifamily properties, commercial properties, homeowners associations and government properties, may water only on Tuesdays and Fridays.
Water only during cooler times of the day, between 6 p.m. and 10 a.m.
Do not allow water to pool in gutters, streets and alleys.
Do not waste water by letting it spray on concrete and asphalt.
Repair leaking sprinkler systems within 10 days.
Do not irrigate while it is raining or during high winds.
Use a hose nozzle with a shut-off valve when washing your car.
For its part, Denver Water has proactively reduced its spending, taking steps that include enacting a hiring freeze and reviewing maintenance and other projects to see which ones could be deferred. We are also looking into other ways to increase supply by activating agreements that allow us to capture additional water that is typically unavailable during normal conditions.
This year marks the fifth time since 2000 that Denver Water has issued a Stage 1 drought, and the first since 2013. Prior to 2013, the board declared a Stage 1 drought in 2002, 2003 and 2004.
Denver Water has many resources for homeowners looking for inspiration and information about landscapes that fit naturally into our dry climate. Click here for conservation and efficiency tips for outdoor irrigation and to get more details on ways to ColoradoScape your property, including through rebates for turf removal and a DIY guide for landscape changes, among many other potential water-saving steps.
Updates about Denver Water’s reservoir levels, customer water use and snowpack can be found in the Water Watch Report, which is updated weekly in the spring and summer.
This chart shows the cumulative snowpack on April 20, 2026, in the area of the Colorado River Basin where Denver Water captures its water supply. The snowpack is 36% of normal, which ranks as the lowest on record for April 20. Image credit: Denver Water.
This chart shows the cumulative snowpack on April 20, 2026, in the area of the South Platte River Basin where Denver Water captures its water supply. The snowpack is 7% of normal, which ranks as the lowest on record for April 20. Image credit: Denver Water.
Water from Antero Reservoir (pictured) will be moved to Cheesman Reservoir in 2026 to help with drought response. This measure was last taken in 2002. Photo credit: Denver Water.
In the coming weeks, Denver Water will begin moving water from Antero Reservoirto Cheesman Reservoir,as part of the utility’s drought response.
Antero Reservoir has the highest ratio of evaporation to storage of any of Denver Water’s reservoirs, and moving the water to Cheesman Reservoir will prevent about 5,000 acre-feet of water (about 25% of the reservoir’s storage capacity) from evaporating. One acre-foot of water equals the annual water use of about three to four single-family households a year.
“A lot of forethought and planning went into our collection system and reservoirs,” said Nathan Elder, manager of water supply for Denver Water. “Antero is a drought reservoir, designed to provide water to our customers during a severe drought. Consolidating this water into Cheesman will help us make the most of the water we have.”
Denver Water is working closely with Colorado Parks and Wildlife to minimize the loss of fish during this process and to allow the public to use the reservoir for a brief period before it eventually closes. Following the fish relocation process, there will be no recreation, including camping, allowed at Antero Reservoir in 2026. More details about this plan will be announced when it is finalized.
The decision also allows Denver Water to use more water from its South Platte River Basin supplies, reducing the need to pull as much water from sources west of the Continental Divide, which are also below normal levels following an abysmal snowpack and runoff season.
In a standard year, the water lost to evaporation is recovered by the next runoff season. Because of the historically low snowpack levels in 2026, the water lost this year would not have been recovered.
Drought conditions will determine when the reservoir can be refilled. The reservoir was also drained to assist with water management during the 2002 drought. There were plans to drain the reservoir as a drought response in 2013, though a series of late-season snowstorms allowed Denver Water to continue storing water in the reservoir. The last time Antero Reservoir was emptied was in 2015 for a dam rehabilitation project.
The South Platte River Basin is shaded in yellow. Source: Tom Cech, One World One Water Center, Metropolitan State University of Denver.
Denver Water’s collection and service areas continue to face severe drought conditions, with historically low snowpack and concerns about the diminished spring runoff that will be available to meet customer’s water needs in the future.
As a result, at its meeting today, the Denver Board of Water Commissioners adopted a resolution approving the implementation of temporary drought pricing on outdoor water use. The drought pricing will apply starting with May water use (reflected in June bills) and will be in effect through April 30, 2027, or until further action by the board.
Under the temporary drought pricing, residential customers will see a drought charge on Tier 2 water use of $1.10 per 1,000 gallons. Tier 3 will have a drought charge of $2.20 per 1,000 gallons. The temporary drought charges will be added on top of the customer’s existing 2026 water rates.
Tier 1, which covers essential indoor water use, is exempt from drought pricing.
“Implementing temporary drought pricing is not a step we take lightly. It is one of many tools Denver Water has available — when needed — to respond to drought conditions, encourage customers to conserve our water supply, and ensure our ongoing ability to operate and maintain the system that delivers clean, safe water to 1.5 million people,” said Alan Salazar, Denver Water’s CEO/Manager.
“Drought charges signal to our customers the premium value of water in a drought, while exempting essential indoor water use. We haven’t needed to use this tool in more than 20 years — since the historic drought of 2002-04 — and conditions surrounding this year’s snowpack and potential runoff are shaping up to rival, and possibly be worse than, those years,” Salazar said.
Please keep sprinklers OFF until mid-to-late May, or later if it rains, to help stretch the water supplies we have. Hand water trees and shrubs if needed. It’s a drought. Use Only What You Need. Photo credit: Denver Water.
Under the temporary drought pricing approved by the board, for Denver Water residential customers in Denver and the suburbs:
e first tier will be exempt from the temporary drought charge. This tier is charged at the lowest rate and covers essential indoor water use for bathing, cooking and flushing toilets. Each customer has their individual first tier determined by the average of their monthly water use as listed on bills that arrive in January, February and March — when there is very little or no outdoor watering.
The second tier will have a temporary drought charge of $1.10 per 1,000 gallons added on top of their 2026 water rates. This tier is for water consumption, typically used for outdoor watering, that is above the customer’s first tier and up to 15,000 gallons of water per month. Water use in this tier is considered to be an efficient use of water outdoors.
The third tier will have a temporary drought charge of $2.20 per 1,000 gallons of water added on top of their 2026 water rates. Tier 3 is for water use above the second tier each month. It is priced at the highest level to signal potentially excessive water use and encourage conservation efforts by larger-lot customers.
The board’s decision to impose temporary drought charges on outdoor water use follows its March 25 declaration of Stage 1 drought. The declaration seeks a 20% reduction in water use effective immediately, with the goal of preserving water supplies and to help avoid the need for Denver Water to take further actions later this summer if conditions don’t improve. Read the March 25, 2026, drought declaration.
The snowpack, which supplies the water Denver Water captures, stores, treats and delivers to customers, is at historically low levels despite recent storms that brought some much-needed precipitation to the mountains and city last week.
It’s a drought. Image credit: Denver Water.
“We welcome the storms that do come, while knowing that this year’s snowpack is at historically low levels and hopes for a Miracle May snowstorm are dimming. And Denver Water has made a number of tools available to help customers reduce their water use — whether it’s a normal year or a drought year. We encourage our customers to take steps to conserve water for this drought and be better prepared to manage through future dry times,” Greg Fisher, Denver Water’s manager of demand planning and efficiency.
Denver Water’s temporary drought pricing charges a premium for outdoor water use and covers several classes of customers, including residential, large irrigation, wholesale and raw water customers. (See the chart at the bottom of this story for additional information on nonresidential customers.)
An individual residential customer’s monthly water bill will vary depending on where they live in Denver Water’s service area (in Denver or in one of the utility’s suburban distributor districts) and how much water they use. Drought charges are expected to incentivize customers to reduce outdoor water use.
The following two charts illustrate the potential impact of the temporary drought charges on an annual water bill for residential customers living inside the city of Denver and, below that, in a Total Service suburban distributor district.
Examples of the impact of temporary drought charges on an annual water bill for Denver Water customers living inside Denver. In this example, “super conservers” will see their bills increase by roughly $7 annually. High users who do not conserve will see their bills increase by roughly $76 in one year. Individual bills will vary. Image credit: Denver Water.
In these charts, the categories are:
“Super conserver”: A customer who has very little outdoor water use, maybe only watering trees and shrubs throughout the year.
“Good conserver”: An average customer who reduces their annual water use by 20%, from 104,000 gallons (the average use by residential customers in an average year) to 82,000 gallons.
“Non-conserver”: An average Denver Water residential customer who uses 104,000 gallons of water over the course of the year (the average use by residential customers in an average year) and doesn’t respond to Denver Water’s call to reduce water use by 20%.
“High user”: A customer in the top 25% of residential water users.
The following chart illustrates temporary drought charges impacts for residential customers who live in one of Denver Water’s Total Service distributor districts in the suburbs. (Learn more about Denver Water’s suburban customers.)
Examples of the impact of the temporary drought charges on an annual water bill for Denver Water customers living in one of Denver Water’s Total Service suburban distributor districts. “Super conservers” will see their bills increase by roughly $8 annually. High users who do not conserve will see their bills increase by roughly $76 in one year. Individual bills will vary. Image credit: Denver Water.
“This is not Denver Water’s first drought. We know our customers strive to be efficient in their water use, and we know we are asking them to use less to stretch the water supplies we have in this drought. We also know that success in reducing water use will result in reduced revenue for our organization. We have tools to address reduced revenue and ensure the organization maintains its financial foundation for when this drought is over,” said Angela Bricmont, Denver Water’s chief financial officer.
If customers comply with Denver Water’s request to reduce water use by 20%, the utility estimates 2026 revenue to fall by a commensurate amount. While drought pricing can offset a portion of that reduction, the utility will rely on cash reserves and budget reductions to cover the majority of the gap.
Denver Water has proactively reduced its spending, taking steps that include enacting a hiring freeze and reviewing maintenance and other projects to see which ones could be deferred.
Now is the time to replace non-native plants with with drought-tolerant plants. Photo credit: Denver Water
To help customers Use Only What They Need indoors and outdoors, Denver Water offers a range of tools, including:
Watering restrictions take effect on April 15. Courtesy of City of Arvada
Click the link to read the article on the Arvada Press website (Rylee Dunn). Here’s an excerpt:
April 7, 2026
After one of the driest winters on record in Colorado, the City of Arvada has declared a Stage 1 drought and will begin implementing mandatory watering restrictions on April 15. Starting April 15, all Arvada water customers — including residents, businesses and city-managed properties — will have to start following a mandatory two-day per week watering schedule. Outdoor watering is prohibited from 10 a.m. to 6 p.m. Amy Willhite, Arvada’s Water Resources Administrator, said the watering restrictions will help Arvada preserve its water supply amid rising temperatures and historically low snowpack levels.
“Maintaining a reliable water supply is a public health and safety priority for the City of Arvada,” Willhite said. “Restricting outdoor watering ensures we can continue to have the supply needed for drinking, cooking, cleaning, and other essential needs this year and in the future.
“These conservation measures protect our water supply through the current drought, and unknown future conditions,” Willhite continued. “In a significant drought, it becomes the responsibility of our entire community to conserve water.”
The city’s goal with the restrictions is to reduce water use across the city by 20%. Once the restrictions take effect, single-family residential homes with even-numbered addresses will be permitted to water on Sundays and Thursdays. Homes with odd-numbered addresses will be allowed to water on Wednesdays and Saturdays. Apartment buildings and commercial buildings will be permitted to water on Tuesdays and Fridays unless otherwise instructed. Trees, shrubs, vegetable gardens, and flowers can be watered using a handheld hose or drip irrigation outside of 10 a.m. to 6 p.m.
The record-breaking hot and dry winter and early spring has continued through March in Colorado’s mountains and plains. Snow gauges and weather stations throughout Northern Water’s collection and distribution areas have collected data showing the lack of precipitation in the region this year.
On April 9, the Northern Water Board of Directors will use the data collected this year and more to determine the annual quota for allottees of Colorado-Big Thompson Project water. Unlike many irrigation systems, the C-BT Project is designed to provide water to supplement the native supplies available in a given year, using water collected in previous seasons. If there is a bright spot this season, it’s that C-BT Project reserves are above their average levels over the life of the project for this time of year.
If you would like to provide comment on the quota send an email to quota@northernwater.org or offer a comment at the April 9 Board meeting.
Colorado-Big Thompson Project map. Courtesy of Northern Water.
Today, Governor Polis and Colorado Parks and Wildlife (CPW) announced the first round of wildlife and habitat projects funded through Senate Bill 24-230, which created new production fees on oil and gas development to mitigate the adverse impacts of oil and gas operations on wildlife and habitats.
CPW’s initial allocation of SB24-230 revenue will fund seven wildlife and habitat initiatives designed to address the impacts of habitat fragmentation, climate change and ecosystem degradation.
“Colorado is known for our iconic outdoor spaces, recreation, and wildlife viewing. Greenhouse gas emissions have a direct impact on our environment and all who call Colorado home. By investing in protecting habitats for Colorado’s wildlife, we are decreasing our carbon footprint, protecting native species, and keeping Colorado beautiful for generations to come,” said Governor Polis.
“SB24-230 provides an important new tool to invest directly in the health of Colorado’s wildlife and habitat,” said CPW Director Laura Clellan. “These initial projects demonstrate how funding generated from oil and gas operations can help restore habitat, improve ecosystem resilience and support wildlife across the state.”
Senate Bill 24-230 established two fees on oil and gas production in Colorado. One fee is administered by the Clean Transit Enterprise, and the other by Colorado Parks and Wildlife to support wildlife and land remediation.
The legislation recognizes that oil and gas development is a significant source of greenhouse gas emissions and habitat degradation, and it directs new investments toward mitigating those impacts and strengthening wildlife and ecosystem resilience.
Under the law, the CPW Director is authorized to set production fees within statutory ranges based on quarterly oil and gas spot prices published by the Colorado Energy and Carbon Management Commission.
The initial CPW production fee was established in October 2025 and generated $5,477,765 in revenue from oil and gas production between July 1 and Sept. 30, 2025.
To put the new revenue to work immediately in order to mitigate the impacts of oil and gas operations, CPW’s Executive Management Team identified seven projects and programs for early investment during fiscal year 2026.
The first round of funding will support:
Barr Lake State Park Habitat Enhancements ($1,500,000)
Beaver Restoration Program Implementation – Initial Phase ($1,174,111)
Operating Increase for Park Pollinator Gardens ($300,000)
Operating Increase for Wildlife Movement Coordination ($100,000)
Wildlife TRACKER Hosting and Maintenance ($125,000)
Together, these projects provide remediation services, including habitat restoration, wildlife monitoring, species conservation and strategic land and water protection efforts across Colorado.
CPW will continue to work closely with industry partners, conservation organizations and local communities to ensure that funds generated through SB24-230 are invested in projects that deliver measurable remediation services that mitigate the impacts of oil and gas operations.
“As Coloradans, we all value the outdoors and the wildlife that makes our state so special. When responsible oil and natural gas production can help support these kinds of projects, protecting the wildlife and habitat we all care about, that’s a huge win for all of Colorado,” said Dan Haley, Executive Director, Coloradans for Responsible Energy Development.
“The science is clear that climate change is negatively impacting Colorado’s wildlife and the ecosystems on which they rely,” said Tarn Udall, senior attorney at Western Resource Advocates. “That’s why the state created the oil and gas production fee in 2024, requiring the industry to partially cover the cost of its emissions and impacts through habitat protection and restoration. It’s rewarding to see Colorado Parks and Wildlife put the first tranche of those dollars to good use, and the agency is just getting started.”
Additional projects funded through the program will be evaluated and announced as future revenue is collected.
American beaver, he was happily sitting back and munching on something. and munching, and munching. By Steve from washington, dc, usa – American Beaver, CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=3963858
Colorado is in a severe drought, and simple indoor water conservation measures can lead to big savings when everyone pitches in.
Free and easy
Turn the water off while brushing your teeth or washing your face.
Limit showers to 5 minutes (or try to shorten them by 1-2 minutes).
Only run your dishwasher and washing machine with a full load.
Turn off the kitchen faucet when handwashing dishes.
“A drought is a great time to teach kids, or anyone, about the importance of conserving water,” said Greg Fisher, Denver Water’s manager of demand planning. “Simple lifestyle changes can become lifelong habits.”
Fixing leaks
Across the U.S., Americans waste about 1 trillion gallons of water every year through water leaks and spend about 10% of their water bill on wasted water, according to the EPA.
The biggest water waster in the home is the toilet. The EPA reports that an average leaking toilet can waste about 200 gallons of water every day.
This toilet has a small, almost undetectable leak through its pink, circular flapper on the bottom of the tank. Some leaks can be detected by listening to hear if water is coming into the tank after it’s done filling. Faulty flappers are a leading cause of toilet leaks. Photo credit: Denver Water. Photo credit: Denver Water.
In addition to checking for toilet leaks, inspect all water sources in your home, including faucets, showers, water supply lines for dishwashers, washing machines, swamp coolers and ice machines.
Small leaks can add up over days and weeks. A small leak of 10 drops per minute can waste 300 gallons of water per year. Not only can these leaks add to your water bill, but they can also damage your home.
Denver Water offers rebates to help customers replace old toilets with newer, more efficient models that can save thousands of gallons of water every year. Image credit: Denver Water.
When buying new appliances and fixtures, purchase products that carry an Energy Star or WaterSense label, an indication that the product uses less energy or water compared to products that don’t carry those labels.
Replacing faucet aerators is an easy way to save water. New aerators slightly reduce the flow of water without impacting the performance of the faucet. Photo credit: Denver Water.
Wastewater is aerated as it flows over steps at Aurora’s Prairie Waters Project, which treats wastewater to drinking water standards. Credit: Jerd Smith
Colorado homeowners and businesses are already planning for a brutally dry summer. They should also be planning for an expensive one, as Denver and other cities prepare to impose drought fees to encourage conservation and to buffer their budgets against millions of dollars in lost water sales as customers cut back.
Denver Water, which announced Stage 1 drought restrictions last week, said its preliminary estimates suggest $30 million to $70 million may be lost as a result of restrictions. It has annual revenue of $488.5 million. Denver Water is Colorado’s largest water utility, serving more than 1.5 million people in the city of Denver and across the southern and western suburbs.
The agency said its surcharges will be designed to penalize high-volume outdoor water use, while keeping the price for drinking, cooking and bathing water unchanged.
ts surcharge prices, if approved by the board this month, will vary depending on how homeowners and businesses use water indoors and outside. A low surcharge for a conservation-minded homeowner who doesn’t do much, if any, outdoor watering might be just $7 per bill, according to the agency, but the drought fee could rise to $76 a month on a residential bill where outdoor water use is high.
Denver Water spokesperson Todd Hartman said via email that the agency will use a portion of its cash reserves to offset the lower water sales and other costs associated with the drought. It has also taken steps to reduce other costs, such as leaving job vacancies open longer.
Colorado experienced record-low mountain snows this year and a scorching hot spring, which has the thin snowpack melting sooner than normal. Reservoir storage is stable for this year, at roughly 80% of average across the state. But heavy water use could drain those reservoirs too quickly, potentially causing major shortages next year if this winter is as dry as last winter’s was, officials have said.
To protect reservoir storage, cities want customers to reduce water use by 10% to 20%.
They’re hoping the surcharges will help them reach those goals.
Chris Goemans, a professor in the agricultural and resource economics department at Colorado State University, said the drought fees are an important tool in water conservation, and can have a lasting impact on water use if they go on for a long period of time.
For several years after the deep drought Colorado experienced in 2002, for instance, water providers saw a lingering “drought shadow” where users continued to tighten their spigots, even after the drought fees were removed, according to research by Goemans, and others.
“They can promote lasting change,” he said.
Not every city will use the fees. Colorado Springs has permanent three-day-per-week watering rules and does not plan to impose a surcharge, at least not this year, spokesperson Jennifer Jordan said. She said the city’s drought plan allows surcharges only when reservoir storage is below 1.5 years on April 1. Right now, the system has three years of storage available.
And Aurora has only used them once before, in 2023, but took them off almost immediately when big rains came, according to Aurora Water spokesperson Shonnie Cline.
Cline said the severity of this drought is forcing the city to gear up for unprecedented times.
“We always thought that 2002 was the worst possible year, but we are expecting something worse this year,” she said.
Castle Rock will impose surcharges, if its council approves them in the coming weeks, but it is taking a different approach because its customers live with a water system based on what are known as water budgets, according to Mark Marlowe, director of Castle Rock Water.
Its customers already are limited every year in how much water they can use during the lawn-watering season, an amount that is based on home and lot size. A small home with a small yard is allocated less water each year and typically has a smaller bill than a large home with a large yard, which is given more water and pays a larger bill.
This year, Castle Rock will reduce everyone’s water budget. If homeowners exceed those lower budgets, they will be hit with a higher fee than normal.
To help offset that and keep its conservation message top of mind, Castle Rock envisions drought surcharges of $6.91 per thousand gallons initially and rising to $10.31 if the drought deepens, Marlowe said.
Is there any good news here? Maybe. City officials said if customers cut back as much as they are being asked to, say 10% to 20%, their bills might not change at all because they are using less water.
Colorado’s top-25 March heat waves since 1951, defined as 4-day averaged statewide temperatures. Colorado’s warmest heat wave (set last week, March 18-21) eclipsed its previous warmest heat wave (March 23-26, 2004) by nearly 5°F. Data from NCEI nclimgrid via the Colorado Climate Center
Click the link to read the article on the Big Pivots website (Allen Best):
March 30, 2026
It was weird, it was wacky. This string of summer days in Colorado that arrived around the first day of spring was extraordinary. Will it change us in some fundamental way?
It’s not like 9/11, the day we saw people jumping from the skyscrapers in New York City to escape an even more cruel death by fire. We knew instantly that the world was different and in a very big way.
But doesn’t this anomaly deserve more than a shrug of the shoulders? As summer arrived in the last days of winter, I heard several people say, “Well, enjoy this nice weather” as you passed through their doors. A well-intentioned pleasantry but detached from a vital truth. Nice weather for Arizona maybe, but this was Colorado.
Winter had altogether been very, very warm. November was the third warmest November on record across Colorado. December the warmest. February also broke records.
Then came March. Alamosa, a town at 7,543 feet in elevation in Colorado’s San Luis Valley, notched 11 record highs during March going into the last weekend. This included nine in a row from March 18-26. Of special note was the record high of 83 degrees recorded on March 21. It broke the old record by 7 degrees. It also was a higher temperature than has ever been recorded in Alamosa in April.
Crested Butte had a high temperature of 68, a full 10 degrees higher than the old record for that date.
Dates of first 90°F or warmer day in Fort Collins from 1895-present. The blue dashed line shows the 1991-2020 mean 90°F or warmer day, which is June 9. Data from ACIS.
Fort Collins got to 91 degrees, also 10 degrees more than the old record for that date. It was the highest ever mark for March — but also higher than anything ever recorded in April, whose record remains 89 degrees. The average first day for 90 degrees in Fort Collins is June 15.
Allie Mazurek, of the Colorado Climate Center staff, posted a report on Thursday morning that defines in numbers what she calls an event “impossible to ignore.” Included in her presentation is the chart atop this essay that shows how anomalous this four-day streak of heat was compared to others in Colorado during March.
This heat was nearly uniform across Colorado. “There were far more stations in the state that broke all-time monthly high records for March than did not,” wrote Mazurek. “To see monthly records shattered by more than 5 degrees F across numerous stations is truly remarkable. The kind of heat that we saw last week across Colorado is more typical of June or even July.”
Remarkable about theheat in Colorado was not only its intensity but its longevity across four days (March 18-21). “Over that period, several locations set new monthly records every one of those days, with each day being warmer than the last.”
March maximum temperature records at various long-term weather stations throughout Colorado. Data from ACIS.
This heat comes at a particularly bad time. The thin snowpack was already melting. The deepest snowpack in Colorado’s mountains has traditionally occurred in early May, because of accumulations at higher elevations.
That assumes a normal of some sort — although it is questionable whether “normal” has any true meaning given how fast the climate is now changing. So take this for what it’s worth: the statewide snowpack this past week sat at 38% of the 1991-2020 median. And what must be noted here — as with the temperature records that were broken — is that we have had an exceptional increase of heat in Colorado in the last 25 years.
Notable in the lifetimes of baby boomers in Colorado were the winters of 1976-77 and 1980-81. This year’s meager runoff will almost certainly surpass those dry years. New is the heat.
High-pressure heat domes can be predicted but are notoriously challenging to forecast weeks or months in advance. They also remain rare, but the warming atmosphere makes them more likely.
“We do have high pressures every year across the West,” said Mark Wankowski, a meteorologist at the Pueblo office of the National Weather Service. “This one was extremely early.”
Writing from Colorado Springs last weekend in an essay in The Atlantic titled “There’s No Way the West Will Have a Normal Summer,” Rebecca Boyle explained that the heat wave was created by a “a bizarrely strong ridge of high pressure in Earth’s atmosphere.” This ridge suppressed cloud formation and brought in warmer air. “Such atmospheric ridges are more common in the summer, but this one would be unusually intense even for that season.
Kaitlyn Trudeau, a senior researcher at the science nonprofit Climate Central, told Boyle this was the strongest ridge ever observed in March. Climate Central has developed a prediction model that assesses how much a warming trend or record high can be attributed to human-caused climate change. According to this model, the western high temps were five times more likely because of elevated greenhouse gas emissions.
I feel rattled by this heat. You may remember the high-pressure cooker that broiled the Pacific Northwest in June 2021. Temperatures spiked to 116 degrees in Portland. People in apartments that were not air conditioned died from the heat. In Multnomah County, the location of Portland, 72 deaths were attributed to heat. Farther north, in British Columbia, the town of Lytton went up in flames after several days of intense heat, including a temperature that reached 121 degrees Fahrenheit.
After that heat, the Colorado Public Utilities Commission asked Xcel to assess how well it could respond to somewhat similar heat in Colorado. The company concluded it had the resources.
But this week, in the wake of the intense spring heat, the PUC commissioners were clearly worried, part of a growing concern about “resource adequacy.” Will Xcel be able to meet critical electrical needs if another heat dome arrives in Colorado this summer? The commissioners asked Xcel to return with strategies for reducing demand from big industrial customers if demand for cooling spikes.
Colorado Drought Monitor map March 24, 2026.
Curious about an on-the-ground perspective from this heat and sparse snow, I called Paul Bonnifield in Yampa. A drought map colors that part of northwest Colorado mahogany, beyond extreme drought and in the realm of “exceptional.” What did exceptional drought look like to him?
Yampa lies at the headwaters of the Yampa River, between the Gore Range and the Flattops. It has a bucolic setting, a place of hay meadows and grazing cattle. Lying upstream are a couple of reservoirs on the edge of the Flattops.
It’s not uncommon for snow to remain on the ground at Yampa, elevation, 7,900 feet, in late March. Not this year. “The ground is hard, just dry, dry, dry,” said Bonnifield.
Bonnifield grew up a few miles away at Phippsburg, a railroad town, and he worked on the railroad himself in addition to spending time teaching and writing at a college in Oklahoma. He’s now in his late 80s and can put this year’s anomalous heat and drought into perspective.
“We are in serious trouble,” he said. “I’ve never seen it like this before.”
Less water will mean less hay production in Egeria Park, where this photo was taken about eight years ago. Photo/Allen Best
Unless a miracle arrives in the form of spring rain and snow, ranchers in Bonnifield’s area — called Egeria Park — will have to decide what to do with their cattle. There’s not enough water to grow grass. There will be wildfire smoke besotting the sky, dampening tourism. And as for river rafting downstream on the Yampa – not likely. Steamboat Spring has already imposed watering restrictions for lawns.
Denver Water this week adopted lawn-watering restrictions for its customers in Denver as well as those in surrounding jurisdictions. It has 1.5 million customers, directly and indirectly, in the metro area.
Nathan Elder, the utility’s manager of water supply, reported to board members on Wednesday that snowpack levels are at historic lows and melting earlier and more rapidly.
Denver Water diverts water from rivers and creeks on both sides of the Continental Divide. In Grand and Summit counties, at the headwaters of the Colorado River, the snowpack was 53% of normal and the lowest on record for the date, Elder said. The South Platte River has it even worse, just 40% of normal.
“These are really unprecedented snowpack conditions,” he said at the meeting on March 25. During the previous week — the week of the heat dome —Denver had lost 25% of its snowpack in the areas it collects water, he reported.
Denver Water is asking the 1.5 million households and businesses that get water from the utility to refrain from starting to irrigate lawns, including this one in southeast Denver, until mid-May. Photo credit: Allen Best/Big Pivots
Can it get worse? Well, yes, it could. “It’s well documented that, in part, due to climate change, the runoff generated from a given snowpack has declined when compared to the past,” said Elder. “So we can expect even less water from this already low snowpack.”
Might a miracle arrive? After the drought and heat of 2002, metro Denver was stressed. Then, on St. Patrick’s Day 2003, three feet of snow fell. In the San Luis Valley, monster rainfall last fall swelled the Rio Grande, leaving water in the soil that will help even now as farmers begin preparing their fields for early plantings.
NOAA projects continued likelihood of above normal temperatures and below-normal precipitation across Colorado, including Denver’s collection area, during April.
Denver aims to reduce water use 20% by its customers in Denver and in outlying suburbs. It will permit lawn watering two days per week and then after 6 p.m. or before 10 a.m. It is also urging customers to refrain from watering their lawns until mid-May. That’s not an easy ask when it feels like June in March. In April, Denver Water’s board members will be asked to approve “drought pricing.”
Russ Schumacher, the state climatologist in Colorado, is called upon frequently to give programs to water organizations and others. This past week he gave a presentation to the Fort Collins Chapter of the Colorado Renewable Energy Society.
“Wildfire certainly is top of mind,” he said while showing a time-lapse video of a wildfire called High Park Fire that occurred west of Fort Collins in 2012.
Dry and hot temperatures leave Russ Schumacher, the state climatologist, apprehensive about potential wildfires this year. Above photo is from the Longmont area in August 2020, a hot and smoky year when wildfires continued almost into November. Photo/Allen Best
Global warming is a simple proposition, he said.
“If you put a pot of water on your stove you’re not going to be able to predict all those individual bubbles or exactly when it’s going to start boiling,” he explained. “But you know that when you turn that heat on, the water’s going to get warmer and it’s going to continue to warm the more heat that you add. So the physics of climate change is actually rather similar in that regard.”
And, of course, adding greenhouse gases to the atmosphere traps heat, which heats the planet. “When you add heat to something, then it warms.”
Colorado has had outliers of heat before. The Dust Bowl during the mid-1930s was a time of heat and drought. More hot and dry arrived in the 1950s.
This chart shows snowpack in Colorado. The heat dome caused rapid melting of snow. In the San Luis Valley, heavy rains of last October may allow farmers to survive better than during 2002.
Dry has not changed. The hot has changed. What used to be an extremely hot year in Colorado is now a fairly average year or just slightly-above-average year, said Schumacher.
Citing NOAA data, Schumacher showed a sharp rise of almost 2.5 degrees Fahrenheit since 1980. The heat has been most acute in the summer and fall — although, obviously, recent months spoil that easy narrative.
With a moderate rate of emissions, we can expect another 2.5 to 3 degrees of warming by around 2050. That expectation comes with a disclaimer about uncertainty. It’s a best guess.
Precipitation has been more complicated than temperature in Colorado. As for the future, it remains a puzzle. Could be more, could be less. Either way, it will be impacted by temperatures.
“If it’s warmer, if it‘s windier, it’s less humid, the air is thirstier for water from the soils, crops, forests, reservoirs, wherever.” Schumacher said. “As it gets warmer, that evaporative demand goes up. The air is thirstier for water, and this has big implications for drought and water supply and water resources.”
Might warming occur more slowly? That’s possible, and a possibility tied strongly to whether global emissions of greenhouse gases can be abated. Given the current political climate in the United States, a key player in world politics, this low-emissions scenario looks highly unlikely. More likely are the heat domes.
Like the pot of water on the stove that Schumacher described, we’re certain to see more heat bubbles. Hard to tell where and when they will be, but there will be more of them. That leaves me distinctly uncomfortable. In Colorado I have felt 104 degrees. I cannot fathom the 118 degrees of Portland.
Colorado statewide annual temperature anomaly (°F) with respect to the 1901-2000 average. Graphic credit: Colorado Climate Center
Lake Dillon, a reservoir in Colorado’s Summit County, is owned and managed by Denver Water and supplies water to people living in Metro Denver. It is Denver Water’s largest reservoir and provides about 40% of Metro Denver water. A 23-mile-long trans-basin diversion pipeline, called the Harold D. Roberts Tunnel, carries water from the reservoir under the Continental Divide to Denver. Photo credit: Colorado State University
Each day during the winter and spring, one of the first things I look at is the U.S. Department of Agriculture’s website that shows the current status of the snowpack in Colorado’s mountains.
Maybe that sounds like the strange habit of a state climatologist, but I’m far from the only one. Why? Because the snow that falls in our state’s mountains will, when it melts in the spring and summer, become a large portion of the water supply for tens of millions of people.
Those people aren’t only here in Colorado, but are in other states, Tribal nations, and Mexico, drawing their water from the rivers that originate in Colorado. Mountain snow is essential for our winter recreation industry, for farms and ranches that grow our food, for drinking water, for ecosystem health, and much more.
It hasn’t been a pretty sight when I have opened that USDA website each morning this winter. In an average year, our mountains get a lot of snow: In places like the Park Range, the West Elk Mountains or the San Juans, a typical year brings hundreds of inches of snow, carrying more than 40 inches of liquid water. This year, we struggled to get half that. Now, after an unprecedented heat wave in March, the snow is already disappearing quickly.
Figure 1: Map of annual average precipitation over 1991-2020 in Colorado, with color scale matching the colors in the state flag. Data from the PRISM Climate Group. Credit: Colorado Climate Center
As of March 25, averaged across 115 stations in Colorado’s mountains, the snow water equivalent was just 38% of the 1991-2020 average. (The snow water equivalent is the amount of water stored in the snowpack.) This represents the lowest snowpack in more than 40 years – and possibly ever – in Colorado’s mountains. Conditions haven’t been any better along the Front Range and Eastern Plains, which have also lagged far behind the average amount of snowfall.
Figure 2: Statewide snow water equivalent from the SNOTEL network, as of March 25, 2026. The median over 1991-2020 is shown with the green line, the historical range is shown from red (low) to blue (high), and this year is shown in the black line. From USDA/NRCS.
There have been other major snow droughts in the past, notably the winters of 1976-1977 and 1980-1981, that threatened the ski industry and resulted in record-low streamflow on some of Colorado’s rivers. But this snow season has been unrivaled in its warmth. The first five months of the water year – from October through February – were Colorado’s warmest on record by a large margin. And it’s almost certain that we are in the midst of the warmest March on record as well.
The warmth has been remarkably persistent, as relentless ridges of high pressure have prevented the usual snowstorms from moving into the state. The Fort Collins weather station at Colorado State University recorded an astonishing 43 days with a high temperature of 60°F or above during climatological winter (December through February). The previous record, from records dating back to the late 19th century, was 22. Starting March 18, Fort Collins had temperatures higher than had ever been observed in March, four days in a row. This was capped by a high of 91°F on March 21; there had never previously been a 90-degree day in Fort Collins before May.
Figure 3: Number of winter days with high temperatures of 60°F or above at the official Fort Collins weather station on the CSU campus. Winter 2025-2026 had 43 days, far more than the previous record of 22 in 1980-1981. Credit: Colorado Climate Center
Records for March were smashed across the state and the western U.S., at both low and high elevations. One thing we do as state climatologists is put current conditions into historical context, as usually with some investigation, it’s possible to find a past analog to what we’re experiencing now. But the intense and prolonged heat has been unlike anything previously observed in March.
This, of course, is occurring in the context of a long-term trend toward warmer conditions, both globally and locally, largely attributable to increases in greenhouse gases. Per data from the National Oceanic and Atmospheric Administration, nine of the 11 warmest years in Colorado records have occurred since 2012, and Colorado has now warmed by 3°F since the 1890s. Droughts come and go, and they have always been a challenge in Colorado and the West. But warming is making them more likely and more intense. In other words, climate change is water change.
When above-average temperatures and precipitation deficits stack up over the course of months, we start to see drought conditions develop or worsen. The impacts of drought are wide-ranging and include economic and agricultural repercussions. Farmers and ranchers may face lower crop yields and higher costs of feeding livestock. A snow drought like this winter’s can reduce outdoor recreation opportunities and hurt the state’s tourism industry. Drought years also tend to be years with more and larger wildfires.
Drought impacts can be felt a long distance from where the precipitation deficits occur. For example, southeastern Colorado received decent precipitation this winter, but low snow in the mountains hundreds of miles away near Leadville means less water on the Arkansas River, an important source for farmers in southeastern Colorado.
As each winter progresses, even if the mountain snowpack isn’t looking great, we can always look ahead to March and April as the time when big storms are possible and the deficits can be made up. Unfortunately, this year has been just the opposite: Instead of much-needed snowstorms, we’re in an unprecedented March heat wave that is accelerating the melting of what little snow is there. The chances of getting back into the range of average have dwindled away, and if the weather pattern doesn’t turn around in April, we may be headed for uncharted territory for Colorado water.
Water stored in Colorado’s Denver Basin aquifers, which extend from Greeley to Colorado Springs, and from Golden to the Eastern Plains near Limon, does not naturally recharge from rain and snow and is therefore carefully regulated. Courtesy U.S. Geological Survey.
Water providers across Douglas County urge conservation this irrigation season
Three water providers in Douglas County are urging residents to conserve as irrigation season approaches. Following a warm, dry winter and below-average snowpack across Colorado, Castle Rock Water,… pic.twitter.com/b6pje2sx8L
Denver Water depends on mountain snowpack for 90% of its water supply, which serves 1.5 million people in Denver and surrounding suburbs.
Snowpack as of March 16, 2026, was at or near record lows: The Colorado River Basin within Denver Water’s collection system was at 71% of normal. The South Platte River Basin within Denver Water’s collection area was 54% of normal. In Denver Water’s decades of records for its watershed collection areas, as of March 16, Colorado River snowpack ranked the third-worst on record, and the South Platte River snowpack remains ranked at the worst.
No matter what, Denver Water’s annual summer watering rules will always be in place during the irrigation season. And, it is likely that we will need to implement additional drought response measures this year. Denver Water’s response to drought conditions uses a layered approach, including the potential for additional watering restrictions, in order to preserve water supplies. Denver Water is developing recommendations on a potential drought response for the Board of Water Commissioners to consider over the next several weeks.
Since 2000, Denver Water’s response to dry conditions in previous years included issuing a Drought Watch (voluntary restrictions) in 2002, 2003, 2004, 2012 and 2013. In some of those years (2002, 2003, 2004, 2013), Denver Water levied additional drought restrictions as part of declaring a Stage 1 level response, which required mandatory reductions in outdoor water use.
Denver Water snowpack update for March 16, 2026
Conditions remain highly concerning. Poor snowfall combined with warm temperatures have left us roughly 3 feet to 4 feet of snow short of where we’d prefer to be in the Denver Water collection area at this time. To reach the normal spring snowpack peak, which typically occurs in April, we need to see an additional 7 feet to 7.5 feet of snow this spring.
Reservoir storage conditions are below average, but in reasonably good shape: as of March 16, 2026, the reservoirs were 80% full versus an average of 85% full for this time. Those levels are also temporarily affected by the need to keep Gross Reservoir low during construction to raise the dam, a project designed to increase the storage capacity of the reservoir.
Denver Water has been here several times over roughly 50 years of reliable records. On the positive side, we have experienced years that started dry and conditions dramatically improved in March, April and May. This year, however, we are running out of time to build the snowpack.
No matter what, Denver Water’s annual summer watering rules will always be in place during the irrigation season. Additional drought restrictions, voluntary or mandatory, will depend in part on how the rest of the snow season shapes up and will be aimed at preserving water supplies in case this unusually dry stretch deepens into a multiyear drought.
Comment from Greg Fisher, Denver Water’s manager of demand planning:
“Another weekend snowstorm was welcome, though it mainly benefited lower elevations along the Front Range. Unfortunately, mountain regions didn’t receive significant snow. The good news is that moisture we get in the Denver region should give our yards and landscapes a good dose of moisture, limiting the need for any watering this week,” said Greg Fisher, Denver Water’s manager of demand planning.
“Overall, we’ve had an extremely dry winter, and that continues this week — the last week of winter — with unusually warm temperatures expected across the region. That could lead to snow melt even at high elevations and highlights the need to conserve water and limit the pull on our reservoir storage. We continue to emphasize the need to keep irrigation systems off until mid-to-late May at the earliest, and to be prepared for outdoor watering restrictions this spring.
“It’s a good time to consider landscape changes to your yard, with plants and grasses that require far less water and are far more adapted to Colorado’s dry stretches. Such landscapes, once established, can get through dry stretches like this far easier, and with far less water, and still give your yard a colorful and vibrant look.”
Denver Water has many resources for homeowners looking for inspiration and information about landscapes that fit naturally into our dry climate. Click here for conservation and efficiency tips for outdoor irrigation and to get more details on ways to ColoradoScape your property, including through rebates for turf removal and a DIY guide for landscape changes, among many other potential water-saving steps.
This chart shows the cumulative snowpack on March 16, 2026, in the area of the Colorado River Basin where Denver Water captures its water supply. The snowpack is 71% of normal, which ranks third-lowest on record for March 16. Image credit: Denver Water.
This chart shows the cumulative snowpack on March 16, 2026, in the area of the South Platte River Basin where Denver Water captures its water supply. The snowpack is 54% of normal, which ranks as the lowest on record for March 16. Image credit: Denver Water.
To learn more about the work Denver Water employees do to monitor the snowpack, read this TAP story about Denver Water employees snowshoeing into the forest near the top of Vail Pass in late February 2026 to conduct a monthly “snow survey.”
Additional information on Denver Water’s drought planning can be found here. Additional information on Denver Water reservoir levels, customer water use and snowpack can be found in the Water Watch Report, which is updated regularly during winter, spring and summer.
Novedades de Denver Water sobre el deshielo de la montaña y el suministro de agua
Novedades sobre el deshielo de la montaña del 16 de marzo de 2026 para el área de recolección de agua de Denver Water.
Denver Water depende del deshielo de la montaña para el 90 % de su suministro de agua, el cual da servicio a 1.5 millones de personas en Denver y en los suburbios de alrededor.
En 16 de marzo de 2026, el deshielo de la montaña se encontraba cerca de niveles históricamente bajos: La cuenca del río Colorado dentro del sistema de recolección de Denver Water estaba al 71 % de lo normal. La cuenca del río South Platte dentro del área de recolección de agua de Denver Water estaba al 54 % de lo normal. En las décadas de registros de Denver Water sobre sus cuencas hidrográficas de recolección, al 16 de marzo el deshielo de la montaña en la cuenca del río Colorado ocupaba el tercer peor lugar y el deshielo de la montaña en la cuenca del río South Platte ocupaba el peor de todos.
Pase lo que pase, las reglas anuales de riego en verano de Denver Water siempre estarán vigentes durante la temporada de riego. Además, es probable que este año sea necesario implementar medidas adicionales de respuesta ante una sequía. La respuesta de Denver Water a condiciones de sequía utiliza un enfoque por niveles, que incluye la posibilidad de aplicar restricciones adicionales de riego para preservar el suministro de agua.
Denver Water está preparando recomendaciones para la Junta de Comisionados del Agua de Denver sobre una posible respuesta a la sequía en las siguientes semanas.
Desde 2000, la respuesta de Denver Water a condiciones secas en años anteriores incluyó la emisión de una alerta de sequía (restricciones voluntarias) en 2002, 2003, 2004, 2012 y 2013. En algunos de esos años (2002, 2003, 2004 y 2013), Denver Water impuso restricciones adicionales por sequía como parte de la declaración de una respuesta de Nivel 1, la cual exigía reducciones obligatorias en el uso de agua en exteriores.
Novedades sobre el deshielo de la montaña de Denver Water al 16 de marzo de 2026
Las condiciones siguen siendo motivo de gran preocupación. Las escasas nevadas, combinadas con temperaturas cálidas, han dejado aproximadamente entre 3 y 4 pies de nieve por debajo de lo que sería deseable en el área de recolección de Denver Water para esta época. Para alcanzar el pico normal de deshielo de la montaña en primavera, que por lo general se produce en abril, necesitamos ver entre 7 y 7.5 pies adicionales de nieve esta primavera.
Las condiciones de almacenamiento en los embalses están por debajo del promedio, pero razonablemente en buen estado: al 16 de marzo de 2026, los embalses estaban llenos al 80 %, frente a un promedio del 85 % para esta época. Estos niveles también se ven afectados temporalmente por la necesidad de mantener bajo el nivel del embalse Gross durante la construcción para elevar la presa, un proyecto diseñado para aumentar la capacidad de almacenamiento del embalse.
Pase lo que pase, las reglas anuales de riego en verano de Denver Water siempre estarán vigentes durante la temporada de riego. Las restricciones adicionales por sequía, voluntarias u obligatorias, dependerán en parte de cómo evolucione el resto de la temporada de nieve y estarán orientadas a preservar el suministro de agua en caso de que este período inusualmente seco se convierta en una sequía de varios años.
Comentario de Greg Fisher, gerente de planificación de la demanda de Denver Water:
“Le dimos la bienvenida a otra tormenta invernal este pasado fin de semana, aunque solo beneficiaron áreas con elevación bajas en el Front Range. Desafortunadamente, las regiones montañosas no recibieron cantidades de nieve significativas. Las buenas noticias es que la humedad que recibimos en la región de Denver le dio a nuestros jardines y paisajismos una buena dosis de humedad y así limitar el riego esta semana.
“Hemos tenido un invierno muy seco y estas condiciones continuaran esta semana, la última semana de invierno, con temperaturas inusualmente altas anticipadas a través de la región. Continuamos enfatizando la importancia de mantener sus sistemas de riego apagados hasta mediados o finales de mayo y estar preparados para posibles restricciones de riego esta primavera.”
Denver Water cuenta con muchos recursos para propietarios de viviendas que buscan inspiración e información sobre paisajes que se integren de forma natural en nuestro clima seco. Haga clic aquí para obtener consejos de conservación y eficiencia para el riego exterior y conocer más detalles sobre maneras de aplicar ColoradoScapes en su propiedad, lo que incluye reembolsos por la eliminación de césped y una guía para realizar cambios en el paisajismo por cuenta propia, entre muchas otras medidas para ahorrar agua.
Puede encontrar información adicional sobre la planificación ante sequías de Denver Water aquí (en inglés). Puede encontrar información adicional sobre los niveles de los embalses de Denver Water, el uso de agua de los clientes y el deshielo de la montaña en el informe Water Watch Report (en inglés), que se actualiza con regularidad durante el invierno, la primavera y el verano.
City water officials are sounding increasingly urgent alarms about Aurora’s water supply, warning that worsening drought conditions and poor snowpack could force early and potentially escalating restrictions this year. Aurora Water General Manager Marshall Brown told city leaders yesterday that the situation has deteriorated enough that staff will likely recommend a formal Stage 1 drought declaration as early as April 6, nearly a month ahead of the city’s typical seasonal watering restrictions. If approved by the City Council, new limits on water use would take effect April 7, officials said.
“Our water supply situation is actually bleak enough that, if things don’t improve, and we don’t get a community response that we need during a Stage 1 restriction, the forecast indicates we may be in a Stage 2 restriction by the end of the year,” Brown said. “That would be really dramatic.”
Aurora breaks water supply and restrictions into four categories:
Normal: Current permanent rules limit landscape irrigation from 10 a.m. – 6 p.m. for a maximum of three days per week.
Stage I: Considered when reservoir levels are lower, often reducing outdoor irrigation to two days per week.
Stage II: More stringent, potentially reducing irrigation to one day per week.
Stage III: Emergency conditions with severe restrictions, including no landscape irrigation.
The warning marks a notable shift from just weeks ago, when city leaders said conditions were concerning but not yet dire. Now, officials say a combination of record warmth, minimal precipitation and dwindling snowpack has pushed the system closer to critical thresholds. According to the latest Aurora Water report, conditions across Colorado remain deeply dry. More than 75% of the state is classified as abnormally dry, with over half in moderate drought and significant portions in severe to extreme drought. February and March so far have offered little relief, statewide water officials reported. Those trends are expected to continue. Long-range forecasts from federal agencies indicate warmer and drier-than-normal conditions through the spring, further reducing the likelihood of meaningful runoff to replenish reservoirs.
Click the link to read the article on The Denver Post website (John Aguilar). Here’s an excerpt:
March 15, 2026
Thornton is first to adopt restrictions; Denver Water, others prepare similar measures
When Thornton enacted a Stage 1 drought declaration last week, it became the first city in metro Denver to place a mandatory twice-weekly limit on outdoor watering for the upcoming hot season. But the northern suburb likely won’t be the last. Metro cities and utilities are starting to lay out various defensive strategies against what has become a crispy-dry 2026, starting with an alarmingly warm and dry winter in Colorado that’s been marked by one of the worst snowpacks in recorded state history. Denver Water, which serves 1.5 million people, could follow a similar track to Thornton’s by month’s end. Aurora Water, which is relied upon by 400,000 people, may be right behind with its own Stage 1 drought declaration in early April…Locally, that also translates to abysmal conditions in the Clear Creek basin, where Westminster gets most of its water. Last week, the Westminster City Council discussed enacting a drought watch — a less severe step than a Stage 1 declaration that would rely on voluntary cutbacks.
…the latest monthly bulletin from the National Weather Service painted a grim weather picture based on conditions in Denver. Last month was the third-warmest and second-driest February in the city, while it was the least-snowiest February on record for Denver, tying 2009’s equally snow-starved February…
What water managers can control sits on the demand side of the water ledger. Thornton gets the bulk of its water from the Upper South Platte River and Clear Creek watersheds, which are both at “record low levels,” according to a memo accompanying last Tuesday’s council meeting. Emily Hunt, Thornton’s interim infrastructure director, says the concern lies not so much with the summer ahead but with the summers to follow, assuming precipitation stays meager. Colorado’s sixth-largest city is presently at 83% of storage capacity across the 19 reservoirs that hold its water. It stores a large portion of the water it consumes in Standley Lake, which is also a water source for Westminster and Northglenn.
“We’re going into the summer with good storage, but with this snowpack, we’re not going to be able to top off our reservoirs the way we normally would,” Hunt said. “We’re basically trying to keep the year in balance so that if the drought continues into next year, we’ll be in pretty good shape.”
Colorado snowpack basin-filled map March 15, 2026.
More than a year after a landmark $100 million environmental settlement designed to improve the Poudre River was OK’d, little progress has been made to put the agreement into action.
The settlement, signed last February, came after Save The Poudre sued to stop the $2.7 billion Northern Integrated Supply Project (NISP). The deal was crafted to allow NISP to move forward while paying to improve the Poudre and protect it from any harm the project could cause.
The Northern Integrated Supply Project, currently estimated at $2 billion, would create two new reservoirs and a system of pipelines to capture more drinking water for 15 community water suppliers. An environmental group is now suing the Army Corps of Engineers over a key permit for Northern Water’s proposal. (Save the Poudre lawsuit, from Northern Water project pages)
NISP is designed to serve roughly one dozen fast-growing cities along the Northern Front Range and will include two reservoirs and a pipeline.
The Community Foundation of Northern Colorado is leading the effort to implement the settlement, which includes projects that will make the river healthier for fish and aquatic habitat, improve water flows and water quality, and increase recreational opportunities.
The foundation is overseeing a six-member committee that began meeting last August. The committee will decide how to implement the ambitious environmental projects outlined in the settlement.
“We are taking time to be intentional,” said Jodie Riesenberger, the foundation’s vice president for community impact.
But work has also been slow because key payments from NISP participants to the foundation are tied to benchmarks in building the massive reservoir and pipeline system. The committee received its first $5 million payment last year when the settlement was signed and is supposed to get its next $5 million payment when construction begins, something that could have happened later this year but has since been delayed. The full $100 million is to be paid out over a 20-year period, Riesenberger said.
Since the settlement was approved, though, the project’s largest customer, the Fort Collins-Loveland Water District, has dropped out of NISP. A handful of other cities, including Evans, have also dropped out, citing concerns about soaring design and construction costs, as well as the cost of the environmental settlement.
In response, Northern Water, which is overseeing project construction, temporarily halted design work as it re-examined NISP’s size.
Now, construction isn’t likely to begin until 2027 or later, according to Northern Water spokesman Jeff Stahla.
“We did slow things down,” Stahla said, “but there is still a chance we can start in mid-2027.”
Save The Poudre River President Gary Wockner said the delays aren’t surprising.
The committee has “been moving slow because there is a lot to learn. If you want to fix problems on the river, you have to understand the river and know what the problems are,” he said.
Since the river committee began meeting in August, Riesenberger said work has focused on analyzing what the issues are and trying to figure out how and whether to spend the money they have on hand now.
The delays “don’t impact what we’re doing yet, but it could if it drags on longer. The dream is that these dollars could do transformational things for the river,” Riesenberger said.
The only thing snow shovels have been gathering recently is dust as Metro-Denver finds itself more than a foot behind its normal snowfall total this winter. Boulder National Weather Service Meteorologist, Russell Danielson, said the normal snow total through the end of January for metro-Denver is 27 inches. This year, just 13.4 inches fell. That’s a sharp drop from 2025, when the region saw 38 inches of snow over the same time frame. In the mountains, it’s even starker. Breckenridge typically sees 101.7 inches by the end of January. This year? Just 34 inches. The lack of snow has largely been framed as a ski industry problem. But across the Front Range and into Colorado’s river corridors, it’s become something broader — and more immediate. From car washes in southwest Denver to rafting guides scanning snowpack data in the high country, the dry winter is rewriting balance sheets in real time…For other weather-dependent businesses, the impact is far more dramatic.
“We calculated that we’re about 70% down,” said Amy Campbell, office manager for Bear Creek Tree Service in Englewood. In a typical winter, her crews plow at least every other week — sometimes multiple times depending on the storm…
West Drought Monitor map March 3, 2026.
The economic ripple from a dry winter won’t stop when the season changes. And that has small business owners who rely on summer tourism also worried. In Kremmling, co-owner of Downstream Adventures, Jonathan Snodgrass, is already watching the snowpack charts — not for ski conditions, but for river levels.
“I’m feeling a little worried,” he said. “If it stays on this track, we’re looking at not a lot of water to work with for rafting. That could have some big impacts on the duration of our season and the quality of our product.”
Rafting on Clear Creek and the upper Colorado River depends heavily on snowmelt. In low years like 2018, Clear Creek trips ended around the third weekend of July. In stronger years, they run into late August — sometimes up to Labor Day. Those final weeks are critical.
Snowpack finally saw some above average gains last week. Snowpack across our Upper Colorado River basin monitoring sites now sits at 64 percent of median and South Platte sites are at 67 percent of median for this time of year (up from 54 and 58 percent respectively). #cowxpic.twitter.com/dunWiam1sx
Plans for the Wild Horse Reservoir have recently updated the location of the proposed water reserve in Hartsel based on Aurora Water’s evaluation of several alternative locations in preparation for the Bureau of Land Management (BLM)’s National Environmental Policy Act (NEPA) process. Located southwest of Spinney Mountain Reservoir, the site will be shifting to the Wild Horse South Reservoir, a move that representatives of Aurora Water describe as having significant advantages for construction. Aurora Water Assistant General Manager Sarah Young stated in a media briefing on the recent planning change that the NEPA process Aurora Water has been working through with the BLM, in collaboration with Park County government, aims to both clarify the need for the project and understand all available alternatives for meeting that need.
“We evaluated twenty different options,” Young said. “As we were evaluating these alternatives, what we found out is that the Wild Horse South Reservoir has a number of significant advantages.”
In addition to the initially proposed Wild Horse Reservoir Project, some of the alternatives included the Small Wild Horse Reservoir and Denver Basin Aquifer Storage and Recovery (ASR) Alternative, expanding existing capacities in Spinney Mountain Reservoir, a no-action alternative and the Wild Horse South Reservoir Alternative. Regarding the project’s need, the proposed reservoir undertaking aims to enhance the City of Aurora’s water management of supplies from the Arkansas and Colorado River basins. As the third-largest city in Colorado, Aurora serves over 400,000 residents, yet lacks access to an immediate water source. Projections in the statewide Colorado Water Plan indicate that a significant statewide water supply gap is anticipated by 2050 and the Wild Horse Reservoir was identified in Aurora’s 2017 Integrated Water Master Plan as a crucial step in meeting the growing need. The shift in plans comes during a record low snow pack year for Colorado, the lowest since 1987, which is projected to affect state water resources down the line.
“When we’re having a year like we’re having right now, [Wild Horse] will help us bridge these types of droughts by storing water that comes from times when the snowpack is much better,” Young said.
Denver Water depends on mountain snowpack for 90% of its water supply, which serves 1.5 million people in Denver and surrounding suburbs.
Snowpack as of Feb. 9, 2026, was near record lows: The Colorado River Basin within Denver Water’s collection system was at 55% of normal. The South Platte River Basin within Denver Water’s collection area was 42% of normal. In Denver Water’s decades of records for its watershed collection areas, as of Feb. 9, the Colorado River snowpack ranked among the worst, and the South Platte River snowpack ranked the worst.
No matter what, Denver Water’s annual summer watering rules will always be in place during the irrigation season. And, it is possible that we will need to implement additional drought response measures this year. Denver Water’s response to drought conditions uses a tiered approach, including the potential for additional watering restrictions, in order to preserve water supplies. Denver Water will move closer to developing recommendations for its Board of Water Commissioners on a potential drought response over the next couple of months.
Since 2000, Denver Water’s response to dry conditions in previous years included issuing a Drought Watch (voluntary restrictions) in 2002, 2003, 2004, 2012 and 2013. In some of those years (2002, 2003, 2004, 2013), Denver Water levied additional drought restrictions as part of declaring a Stage 1 level response, which required mandatory reductions in outdoor water use.
Denver Water snowpack update for Feb. 9, 2026
Conditions remain highly concerning. Poor snowfall combined with warm temperatures have left us roughly 4 feet of snow short of where we’d prefer to be in the Denver Water collection area.
Reservoir storage conditions are below average, but in reasonably good shape: 81% full versus an average of 85% full for this time. Those levels are also artificially affected by the need to keep Gross Reservoir low during construction to raise the dam, a project designed to increase the storage capacity of the reservoir.
Denver Water has been here several times over roughly 50 years of reliable records. On the positive side, we have experienced years that started dry and conditions dramatically improved in March, April and May. This year, however, we are running out of time to build a healthy winter base.
No matter what, Denver Water’s annual summer watering rules will always be in place during the irrigation season. Additional drought restrictions, voluntary or mandatory, will depend in part on how the rest of the snow season shapes up and will be aimed at preserving water supplies in case this unusually dry stretch deepens into a multiyear drought.
Comment from Nathan Elder, Denver Water’s manager of water supply:
“We are running out of winter. Conditions are highly concerning, and as we continue to hope for relief in the spring months, we also are preparing recommendations for our drought response. We encourage customers to think about conservation even now, with smart indoor use and potential changes in landscapes that would reduce outdoor use in the irrigation season.
“Water is a precious resource that supports our way of life across Colorado, from the mountains to the ski resorts to our communities on both sides of the Continental Divide. We all have a role to play in using water responsibly.
“If you’ve been up skiing, you’ve likely seen the low snowpack firsthand, and — if conditions don’t improve — when that snow melts, it won’t be enough to completely fill our reservoirs this spring and summer.”
This chart shows the cumulative snowpack on Feb. 9, 2026, in the area of the Colorado River Basin where Denver Water captures its water supply. The snowpack is 55% of normal, which ranks among the lowest on record for Feb. 9. Image credit: U.S.D.A., Natural Resources Conservation Service.
This chart shows the cumulative snowpack on Feb. 9, 2026, in the area of the South Platte River Basin where Denver Water captures its water supply. The snowpack is 42% of normal, which ranks as the lowest on record for Feb. 9. Image credit: U.S.D.A., Natural Resources Conservation Service.
To learn more about the work Denver Water employees do to monitor the snowpack, read this TAP story about Denver Water employees snowshoeing into the forest near the top of Vail Pass in late January 2026 to conduct a monthly “snow survey.”
Additional information on Denver Water’s drought planning can be found here. Additional information on Denver Water reservoir levels, customer water use and snowpack can be found in the Water Watch Report, which is updated regularly during winter, spring and summer.
Firefighting foam containing PFAS chemicals is responsible for contamination in Fountain Valley. Photo via USAF Air Combat Command
Click the link to read the article on The Denver Post website (Elliot Wenzler). Here’s an excerpt:
January 21, 2026
An Adams County water district filed a lawsuit against Denver on Tuesday [January 20, 2026], alleging that foam from the city’s fire training facility has contaminated its water for decades. The South Adams County Water and Sanitation District says the city’s Roslyn Fire Training Facility, near the Rocky Mountain Arsenal National Wildlife Refuge, has used firefighting foam containing a group of chemicals known as PFAS, also known as “forever chemicals,” since at least 1991…
“Denver has failed to eliminate or control releases of (the chemicals) at and from the fire training facility and those releases have contaminated and continue to contaminate the District’s drinking water supplies,” the lawsuit alleges.
The district serves about 75,000 residents in Commerce City and unincorporated Adams County. It first discovered the contamination in 2018. Since then, the district has spent tens of millions of dollars to mitigate the issue, according to the lawsuit. Officials there built another water treatment facility specifically to treat PFAS, and it purchased water from Denver Water to dilute the contaminated water…Even with state and federal funding, the lawsuit says, “there remains a huge deficit” from the costs associated with the firefighting foam. The district asks a U.S. District Court judge to rule that Denver is liable for the response costs and for the ongoing costs the district will incur. It notes that water district officials notified Denver city officials of this claim back in 2019. The amount that the city of Denver would have to pay, if found liable, would be determined in a trial.
Incorporating instream flow uses into municipal water supply planning efforts can provide numerous public benefits. This article discusses the framework and opportunity for collaborative instream flow protection in municipal water supply operations.
Colorado’s instream flow program is a dynamic approach to protecting the natural environment that encourages practical and creative solutions to evolving environmental concerns. While water rights typically involve diverting water from the stream, the instream flow program protects water in the stream. Environmental values associated with instream flow uses can work synergistically with municipal water supply operations to realize several public benefits, such as improved water quality, riparian health, urban cooling, resiliency, recreational opportunities, and aesthetic value. As illustrated by the examples discussed later in this article, the instream flow program can facilitate cooperative agreements with municipal water providers for shared beneficial use of our state’s most precious resource.
Water Rights and the Prior Appropriation Doctrine in Colorado
The prior appropriation doctrine governs the ownership and use of water and water rights in Colorado. In simple terms, the prior appropriation system is described as “first in time, first in right.” A water user that has demonstrated an intent to put water to beneficial use first has a vested and prior right to use water in that amount against subsequent water users. This system developed out of necessity during the colonial expansion westward and was influenced by Spanish settlers and early miners to allocate water in the arid environment of Colorado, as an alternative to the more common riparian system of water rights based on land ownership abutting water ways.1
The prior appropriation doctrine has been enshrined in the Colorado Constitution. Article XVI, § 5 dedicates water in Colorado as public property for use by the people, subject to appropriation, and § 6 gives the right to appropriate water for beneficial use in priority.2 The 1969 Water Rights Determination and Administration Act (1969 Act) provides the legal framework for surface and tributary ground water distribution and use under the prior appropriation doctrine.3
An appropriation of a water right under the 1969 Act, as originally codified, meant “the diversion of a certain portion of the waters of the state and the application of the same to a beneficial use.”4 Similarly, beneficial uses were limited to diversions of water from the stream system for extractive uses such as domestic or municipal, irrigation, and manufacturing or industrial activities.5 Environmental uses of water, including instream flows, were not initially addressed in the 1969 Act but were later incorporated through amendments.6
Colorado Instream Flow Program
The Colorado Water Conservation Board (CWCB) was first established by the Colorado legislature in 1937 to protect and develop Colorado’s water resources for the benefit of present and future generations.7 It was not until the national environmental movement in the late 1960s, however, that discussions regarding the value of instream flows and role of the CWCB in the protection of such flows began to garner serious attention and focus.8 In 1973, those discussions culminated in the passage of SB 97 to create the Colorado Instream Flow and Natural Lake Level Program.9 SB 97 was unprecedented at the time and amended the 1969 Act to define beneficial use of a water right to include use by the CWCB for protection of stream flows within a specified reach without a diversion of water from the stream.10
Under the instream flow program, the CWCB has exclusive authority to hold a water right for instream flow uses in Colorado and may appropriate water rights or acquire existing water rights for instream flow, provided that it determines that such water rights are necessary to preserve or improve the natural environment to a reasonable degree.11 Since the program’s inception, the CWCB has appropriated nearly 1,700 instream flow rights across 9,700 miles of stream and completed over 35 water acquisition transactions.12
The General Assembly has reinforced and expanded the CWCB’s ability to acquire water rights for instream flow purposes on several occasions.13 Acquiring and changing senior water rights for instream flows in over-appropriated systems can add great value by preserving the priority date, and therefore the availability, of the water for greater instream flow protection.14 Acquisitions can be donated to or purchased by the CWCB, and the statutory language specifically anticipates potential acquisitions from governmental entities, like municipalities.15 Other free-market developments to the Colorado instream flow program enacted by the state legislature over the years include streamlined processes for loans of water rights for instream flow use, instream flow protection for mitigation releases, and stream flow augmentation plans.16 These developments provide additional opportunities for water users, including municipalities, to participate in the program in support of instream flows.
In addition to implementing the instream flow program, the CWCB is tasked with creating the Colorado Water Plan, which addresses the state’s water challenges through collaborative water planning, including expanded opportunities for instream flow protection.17
Case Studies Along the Front Range
The instream flow program provides reasonable protection of the environment for benefit of the public and is emphasized in the Colorado Water Plan as a balanced approach to addressing environmental needs in the face of climate change.18 Similarly, municipal water service providers, acting in the interest of their respective jurisdictions, must often balance water supply with other public interests. Municipal water projects and water supply planning efforts can be designed to address multiple needs and related uncertainties across a jurisdiction, informed by integrated planning efforts. The various public interests typically considered by municipalities may align with instream flow protection in many respects. The Colorado Water Plan includes several policy considerations that highlight this potential overlap between municipal water interests and instream flows.19
Fundamentally, the Colorado Water Plan encourages a holistic, collaborative approach to water management that balances multiple uses and benefits to meet water shortages throughout the state.20As competition for water resources in Colorado becomes more pronounced with increased demands and costs, the benefits of water sharing and collaboration will also likely increase.21 The Colorado Water Plan focuses on thriving watersheds as an action area to support stream health, recreational uses, resiliency, erosion control, and water quality, all of which provide tangible benefits to municipal water service providers.22 Accordingly, more water in the stream system for instream flows can be a natural complement to a municipality seeking to balance growing water demands with related public interests. The following examples demonstrate how instream flow uses can benefit municipal water supply, and vice versa, to realize this balance in a meaningful way.
Boulder Creek Instream Flow Project
The Boulder Creek instream flow project is a long-standing cooperative project that has been operating in Boulder County for almost 35 years. This project has operated successfully due in large part to the partnership between the City of Boulder and the CWCB and their collaboration with neighboring water users in Boulder County to support environmental stream flows and other uses in the creek.
In the early 1990s, Boulder donated a suite of valuable senior water rights to the CWCB to establish a year-round instream flow program on North Boulder and Boulder Creeks.23 The acquisition was memorialized in a series of donation agreements between Boulder and the CWCB pursuant to CRS § 37-92-102(3), following certain legislative amendments throughout the 1980s that clarified and enhanced the CWCB’s acquisition authority for instream flows.24 Boulder and the CWCB, as co-applicants, also received a water court decree to change the use of the donated rights to include instream flow uses for the project.25
Figure 1. Map depicting locations of instream flow protected reaches along Boulder Creek. Image created by the City of Boulder (Oct. 2018).
The Boulder Creek instream flow project protects three segments from below the Silver Lake Reservoir near the headwaters of North Boulder Creek down to 75th Street in Boulder County (see fig. 1). The donated rights include reservoir releases, bypassed diversions, and changed irrigation ditch shares to support instream flows throughout the year. As part of its donation to the CWCB, Boulder retained the right to use water available under the donated rights (1) for municipal purposes under certain conditions, including drought and emergency conditions in its municipal water supply operations; (2) for municipal purposes anytime they are not needed to meet instream flow amounts; and (3) for beneficial reuse downstream of the protected reaches.26This provides operational flexibility for the city’s municipal water supply while also supporting instream flow uses by the CWCB in most years. Its participation in the Boulder Creek instream flow program has also helped the city address US Forest Service regulatory requirements for bypasses related to its diversions from North Boulder Creek as part of federal permitting for one of its raw water pipelines.27
The City of Boulder has a long-standing environmental ethos that incorporates instream flows into its water supply planning and operations. Boulder’s water supply planning documents from the 1980s identified the goal of supporting instream flows in Boulder Creek to enhance aquatic and riparian ecosystems, reflecting city planners’ prediction that dry-up periods in the creek would become more severe and frequent with increased water demands.28 Subsequent Boulder water supply and land use planning documents have included similar goals focused on balancing instream flows and environmental preservation with municipal water demands and operations, and emphasizing the connection between stream health and reliable drinking water supplies.29
Because the protected stream segments run through the Boulder city limits, and extend both above and below the city, the project benefits water quality, riparian health, and resiliency in the Boulder municipal watershed and water system operations and provides additional environmental benefits to the larger Boulder County community.
Gross Reservoir Environmental Pool Project
The cities of Boulder and Lafayette entered into an intergovernmental agreement in 2010 with Denver Water to establish a 5,000 acre-foot environmental pool in an enlarged Gross Reservoir to augment stream flows in South Boulder Creek.30 Boulder recognized the need to address low flows on South Boulder Creek as a key goal in its planning documents and identified Denver Water’s planned expansion of Gross Reservoir as an opportunity to use upstream storage to establish a robust instream flow program. Lafayette similarly identified Gross Reservoir for potential water storage in its water rights decrees, providing both a water supply and environmental benefit to its operations. The parties proactively agreed to cooperate to mitigate the reservoir expansion’s impacts to aquatic resources in the South Boulder Creek basin by creating and operating the environmental pool.31
Coordinated with municipal water system operations, releases from the environmental pool will allow Boulder and Lafayette to store their decreed water rights for later release to meet specific target flows below Gross Reservoir in South Boulder Creek throughout the year. The segments identified for the target flows include Gross Reservoir to South Boulder Road (Upper Segment, depicted as segments 1 and 2 in fig. 2) and South Boulder Road to the confluence with Boulder Creek (Lower Segment, depicted as segment 3 in fig. 2).32 The agreement also includes provisions to address emergencies such as extended drought or an unexpected problem with water storage, conveyance, or treatment infrastructure to allow for flexibility in operations to meet both target flows and municipal needs.
Boulder’s releases from the environmental pool are protected as instream flows according to a Water Delivery Agreement with the CWCB dated September 9, 2019, and a water court decree entered for Boulder, Lafayette, and the CWCB.33 Water released by Boulder to meet the target flows will be protected for instream flow uses to the extent that such flows do not exceed the amounts that CWCB has determined to be appropriate to preserve the natural environment to a reasonable degree in South Boulder Creek. Boulder’s target flow releases will support CWCB’s existing appropriated instream flow rights up to the specified amounts (see fig. 2). Boulder may then redivert the water downstream of the protected reaches for its municipal uses.
The environmental pool will provide permanent, dedicated storage for water rights owned by Boulder and Lafayette to be released to enhance stream flows in South Boulder Creek prior to downstream uses for municipal purposes by the parties. These operations provide added flexibility, resiliency, and redundancy to the cities’ respective water supply systems. In turn, the enhanced stream flows will benefit 17.3 miles of South Boulder Creek, including Eldorado Canyon State Park, South Boulder Creek Natural Area, and City of Boulder open space lands, and will support native fish populations and riparian and wetland habitats.
Figure 2. Map depicting target flows and reaches for enhanced stream flows on South Boulder Creek. Image created by the City of Boulder (Aug. 7, 2018).
Poudre Flows Project
The Poudre Flows Project is the first stream flow augmentation plan developed pursuant to CRS § 37-92-102(4.5).34 It is a partnership amongst the CWCB; municipalities of Fort Collins, Thornton, and Greeley; Colorado Water Trust; Northern Colorado Water Conservancy District; Cache la Poudre Water Users Association; and Colorado Parks and Wildlife. The project will augment stream flows through a 52-mile reach of the Cache la Poudre River, with an overarching goal to improve river health (see fig. 3).35 The concept was first envisioned as part of the Poudre Runs Through It working group, a collaborative group of diverse partners and stakeholders in the Poudre River.36 The City of Fort Collins planning priorities incorporate similar goals, including to “[p]rotect community water systems in an integrated way to ensure resilient water resources and healthy watersheds.”37
The project anticipates that the CWCB, through agreements with water right owners, including Fort Collins and Greeley, will use previously changed and quantified water rights owned by these municipalities and potentially others to augment stream flows in six segments of the Poudre River spanning from Canyon Gage to the confluence with the South Platte River.38 Besides the instream flow protection of the environment to a reasonable degree, project partners have identified numerous additional benefits such as connectivity for fish passage and decreased temperatures and nutrient concentrations, all while avoiding impacts to existing water rights and operations.39
By integrating water supply planning with a holistic approach to water development and management that provides multiple public benefits, municipalities can become strong partners with the CWCB. Together, they can help protect instream flows and balance growing water demands and future uncertainties with the environmental values that make Colorado a beautiful place to live.
1. See generallyCoffin v. Left Hand Ditch Co., 6 Colo. 443, 447 (Colo. 1882).
2. Colo. Const. Art. XVI, §§ 5–6. See also Colo. River Water Conservation Dist. v. CWCB, 594 P.2d 570, 573 (Colo. 1979) (“The reason and thrust for this provision was to negate any thought that Colorado would follow the riparian doctrine in the acquisition and use of water.”).
9. SB 97, 49th Gen. Assemb., Reg. Sess. (Colo. 1973). See CRS § 37-92-102(3).
10. Bassi, supra note 6 at 398. See also Colo. River Water Conservation Dist., 594 P.2d at 576. SB 97 was carefully drafted to provide environmental protection through the CWCB, as a fiduciary to the public, without inviting riparian rights for adjacent landowners. Id. The Colorado Supreme Court reiterated this important distinction in St. Jude Co. v. Roaring Fork Club, LLC, 351 P. 3d 442 (Colo. 2015), ruling that a diversion from a steam for private instream flows is a “forbidden right” contrary to the prior appropriation doctrine; only the CWCB, with strict limitations identified by the general assembly, can hold an instream flow right for the benefit of the public. Id. at 451.
11. CRS § 37-92-102(3) (The CWCB is “vested with exclusive authority, on behalf of the people of the state of Colorado, to appropriate . . . such waters of natural streams . . . as the board determines may be required for minimum streamflows . . . to preserve the natural environment to a reasonable degree.” The board also may acquire water rights “in such amount as the board determines is appropriate for streamflows . . . to preserve or improve the natural environment to a reasonable degree.”). Legislation enacted in 2002 expanded the Colorado instream flow program to provide that water rights may also be used by the CWCB to improve the natural environment (and not just for preservation purposes). Bassi, supra note 6 at 391.
14. Id. at 406. The Colorado Water Trust was formed in 2001 to support Colorado’s instream flow program by promoting voluntary, market-based efforts to restore stream flows in Colorado’s rivers. The Water Trust has been instrumental in facilitating and streamlining the acquisition of water rights from willing partners for use by the CWCB. Seehttps://coloradowatertrust.org.
16. See generally CRS §§ 37-83-105, 37-92-102(8), 37-92-102(4.5).
17. The Colorado Water Plan was adopted by the CWCB in 2023 as a framework for decision-making to address water challenges and build resiliency in the state. The 2023 Water Plan is an update to the first iteration of the plan released in 2015. Seehttps://cwcb.colorado.gov/colorado-water-plan.
18. SeeSt. Jude Co., 351 P. 3d at 449 (in its use of water for instream flows, the CWCB has a “‘statutory fiduciary duty’ to the people . . . to both protect the environment and appropriate only the minimum amount of water necessary to do so . . . .”).
20. See id. at 217–19, 231, 233 (“All areas of the Water Plan are interconnected, and projects need to consider multi-purpose, multi-benefit solutions.”).
21. See id. at 217 (“Multi-purpose projects better address water supply challenges across municipal, agricultural, environmental, and recreation sectors as they occur.”).
22. See id. at 181, 204–07 (stream health and related environmental benefits can enhance municipal supply or improve the quality of life in urban areas).
23. See Decree, In re Application for Water Rts. of the Colo. Water Conservation Bd. on Behalf of the State of Colo. and Water Rts. of the City of Boulder, No. 90CW193 (Colo. Water Div. 1, Dec. 20, 1993).
30. See Decree, In re Application for Water Rts. of City of Lafayette, City of Boulder, and Colo. Water Conservation Bd. in Boulder Cnty., No. 17CW3212 (Colo. Water Div. 1, Feb. 11, 2021). The author represented the City of Boulder in Case No. 17CW3212 and was involved in prosecuting the case and negotiating the underlying agreement with CWCB.
31. Denver Water’s enlargement of Gross Reservoir is the subject of pending litigation.
32. The target flows and target reaches are based on previously collected data and analysis by Colorado Parks and Wildlife using the R2Cross method, which supported CWCB’s previous instream flow appropriations.
38. See Application, In reApplication for Water Rts. of Cache La Poudre Water Users Ass’n, City of Fort Collins, City of Greeley, Colo. Water Tr., N. Colo. Water Conservancy Dist., City of Thornton and Colo. Water Conservation Bd. in Larimer and Weld Cntys., No. 21CW3056 (Colo. Water Div. 1 Apr. 29, 2021).
Elder pointed to the team’s big win against the New York Giants on Oct. 19, 2025.
“I think most of us thought the Broncos were done in that game after going scoreless for three quarters, but then they had an amazing turnaround in the fourth quarter and came back to win at the last second,” said Nathan Elder, Denver Water’s manager of water supply.
“Let’s hope Mother Nature can do the same as Bo Nix and deliver a big comeback this winter.”
Snowmaking at Keystone Ski Resort on Dec. 31, 2025. Photo credit: Denver Water.
Record low start to the snowpack
Elder said the first three months of the 2025-26 snow season, from Oct. 1 to Dec. 31, 2025, ranked as the driest on record in Denver Water’s water collection area.
The records date back to the winter of 1979-80, when SNOTEL measuring gauges started being used to measure mountain snowpack.
Denver Water’s previous year-ending, record-low snowpack on Dec. 31 occurred during the winter of 1980-81.
This year, as of Dec. 31, 2025, the snowpack in the South Platte and Colorado river basins where Denver Water collects water stood at 51% and 49% of normal, respectively, according to SNOTEL measurements.
Snowpack in the South Platte River Basin at the end of December 2025 stood at 51% of normal. Image credit: U.S.D.A., Natural Resources Conservation Service.
Snowpack in the Colorado River Basin at the end of December 2025 stood at 49% of normal. Image credit: U.S.D.A., Natural Resources Conservation Service.
The lack of powder days is not only tough on Colorado’s ski resorts, but low snowpack also raises concerns about river levels and our water supply which comes primarily from mountain snow.
A skier navigates through early season conditions at Breckenridge on Dec. 23, 2025. Photo credit: Denver Water.
“We definitely prefer a snowier start to winter over a dry one,” Elder said.
“But we still have about four months left in the snow accumulation season. We will need a lot of snow to catch up to get back to normal.”
The first three months of the snow season typically account for about 20% of the annual snowpack. The good news is that the snowiest months of March and April are still ahead.
Loveland Pass in Summit County on Dec. 24, 2025. The lack of snow is clearly visible on the higher peaks. Photo credit: Denver Water.
Elder said that along with the low snowfall, strong winds and above-normal temperatures created windy and warm weather, which led to increased sublimation of the snowpack (think of sublimation like evaporation just for snow).
“In mid-December, we actually saw a noticeable drop in the snowpack in the South Platte River Basin, which is very rare for that time of year because it’s usually too cold for snow to melt,” Elder said.
What to expect in 2026?
While unfortunately there’s no crystal ball for snow forecasting, Elder pointed to other years that experienced similarly slow starts to the snowpack for a guess as to where this season could end up.
For Denver Water, snowpack typically peaks in mid-to-late April.
The lowest peak occurred during the winter of 2001-02, when snowpack peaked at just 56% of normal. The second-lowest peak was measured during the winter of 2011-12, when mountain snowpack peaked at 58% of normal.
Both of those seasons started slow and snowfall stayed below normal levels all winter long.
In contrast to those two dismal winters, Elder said the winter of 1999-2000 offers a glimmer of hope.
“That season started slow, but snow came on strong in April and May and we ended up right around normal in terms of peak snowpack by the end of the season,” he said.
Water managers also watch for a couple of big storms that could quickly bolster a lackluster snowpack.
Taking action
Denver Water’s reservoirs are currently at 83% of capacity, which is 4% below average for this time of year.
Dillon Reservoir in Summit County had open water on Dec. 24, 2025, due to warm conditions. The reservoir’s average “ice-in” date is Dec. 24. Photo credit: Denver Water.
Elder said that while the reservoir levels are expected to be in relatively good shape heading into summer, it’s too early to say if there will be any watering restrictions.
“We live in a dry climate with increasingly variable weather patterns, which means all of us need to pitch in to help conserve the precious water supplies that we have,” Elder said.
“Now is a good time to check your faucets and toilets for leaks, and fix any you find inside your home. It’s also a good time to start planning how to remodel your yard this summer to save water outside.”
Denver Water’s website has free tips, including a step-by-step DIY Guide that can help you replace thirsty Kentucky bluegrass with water-smart plants, available at denverwater.org/Conserve.
In 2026, the utility will again be offering customers a limited number of discounts on Resource Central’s popular, water-wise Garden In A Box kits and turf removal.
It’s important to water trees and plants during dry periods in the winter months. Soaker hoses are a great way to efficiently water a tree. Photo credit: Denver Water.
Colorado State University researcher Perry Cabot talks to a group about forage crops at the Fruita field station. Cabot studies the effects of irrigation withdrawal and forage crops that use less water. CREDIT: HEATHER SACKETT/ASPEN JOURNALISM
The findings of recent water-conservation studies on the Western Slope could have implications for lawmakers and water managers as they plan for a future with less water.
Researchers from Colorado State University have found that removing irrigation water from high-elevation grass pastures for an entire season could have long-lasting effects and may not conserve much water compared with lower-elevation crops. Western Slope water users prefer conservation programs that don’t require them to withhold water for the entire irrigation season, and having the Front Range simultaneously reduce its water use may persuade more people to participate. Researchers also found that water users who are resistant to conservation programs don’t feel much individual responsibility to contribute to what is a Colorado River basinwide water shortage.
“It’s not a simple economic calculus to get somebody to the table and get them to sign a contract for a conservation agreement,” said Seth Mason, a Carbondale-based hydrologist and one of the researchers. “It involves a lot of nuance. It involves a lot of thinking about tradeoffs.”
Udall/Overpeck 4-panel Figure Colorado River temperature/precipitation/natural flows with trend. Lake Mead and Lake Powell storage. Updated through Water Year 2025. Note the tiny points on the annual data so that you can flyspeck the individual years. Credit: Brad Udall
Over the past 25 years, a historic drought and the effects of climate change have robbed the Colorado River of its flows, meaning there is increasing competition for a dwindling resource. In 2022, water levels in Lake Powell fell to their lowest point ever, prompting federal officials to call on the seven states that share the river for unprecedented levels of water conservation.
The Upper Basin states (Colorado, New Mexico, Utah and Wyoming) have experimented for the past decade with pilot programs that pay agricultural water users to voluntarily and temporarily cut back by not irrigating some of their fields for a season or part of a season.
The most recent program was the federally funded System Conservation Pilot Program, which ran in the Upper Basin in 2023 and 2024, and saved about 100,000 acre-feet of water at a cost of $45 million. The Upper Basin has been facing mounting pressure to cut back on its use, and although some type of future conservation program seems certain, Upper Basin officials say conservation must be voluntary, not mandatory.
Despite dabbling in these pilot conservation programs, Upper Basin water managers have resisted calls for cuts, saying their water users already suffer shortages in dry years and blaming the plummeting reservoirs on the Lower Basin states (California, Nevada and Arizona). Plus, the Upper Basin has never used its entire allocation of 7.5 million acre-feet a year promised to it under the 1922 Colorado River Compact, while the Lower Basin uses more than its fair share.
Sketches by Floyd Dominy show the way he’d end the Glen Canyon Dam. From the article “Floyd Dominy built the Glen Canyon Dam, then he sketched its end on a napkin” on the Salt Lake Tribune website
But as climate change continues to fuel shortages, makes a mockery of century-old agreements and pushes Colorado River management into crisis mode, the Upper Basin can no longer avoid scrutiny about how it uses water.
“We need a stable system in order to protect rivers,” said Matt Rice, director of the Southwest region at environmental group American Rivers, which helped fund and conduct the research. “(Upper Basin conservation) is not a silver bullet. But it’s an important contributing factor, it’s politically important and it’s inevitable.”
Researchers from Colorado State University used this monitoring station to track water use on fields near Kremmling. Researchers have found that Western Slope water users are more likely to participate in conservation programs if there is a corresponding Front Range match in water use reduction. CREDIT: HEATHER SACKETT/ASPEN JOURNALISM
Findings
Papers by the researchers outline how water savings on Colorado’s high-elevation grass pastures — which represent the majority of irrigated acres on the Western Slope — are much less than on lower-elevation fields with other annual crops. Elevation can be thought of as a proxy for temperature; fewer frost-free days means a shorter growing season and less water use by the plants.
“Our results suggest that to get the equivalent conserved consumptive-use benefit that you might achieve on one acre of cornfield in Delta would require five acres of grass pasture if you were up near Granby, for example,” said Mason, who is a doctoral candidate at CSU. “This is a pretty important constraint as we’re thinking about what it means to do conservation in different locations across the West Slope.”
In addition to the science of water savings, Mason’s research also looked at the social aspects of how water users decide to participate in conservation programs. He surveyed 573 agricultural water users across the Western Slope and found that attitudes toward conservation and tendencies toward risk aversion — not just how much money was offered — played a role in participation.
Many who said they would not participate had a low sense of individual responsibility to act and a limited sense of agency that they could meaningfully contribute to a basinwide problem.
If you don’t pay attention to the attitudes of water users, you could end up with an overly rosy picture of the likelihood of participation, Mason said.
“It may do well to think less about how you optimize conservation contracts on price and do more thinking about how you might structure public outreach campaigns to change hearts and minds, how you might shift language as a policymaker,” he said. “A lot of the commentary that we hear around us is that maybe this isn’t our problem, that this is the Lower Basin’s problem. [ed. emphasis mine] The more you hear that, the less likely you are to internalize a notion of responsibility.”
Mason also found that a corresponding reduction in Front Range water use may boost participation by Western Slope water users. The fact that Front Range water providers take about 500,000 acre-feet annually from the headwaters of the Colorado River is a sore spot for many on the Western Slope, who feel the growth of Front Range cities has come at their expense. These transmountain diversions can leave Western Slope streams depleted.
Western Slope water users often describe feeling as if they have a target on their back as the quickest and easiest place to find water savings.
“I think they tend to be appreciative of notions that have some element of burden sharing built into them,” Mason said. “So they aren’t the only ones being looked at to contribute as part of a solution to a problem.”
Perry Cabot, a CSU researcher who studies the effects of irrigation withdrawal and forage crops that use less water, headed up a study on fields near Kremmling to see what happens when they aren’t irrigated for a full season or part of a season. The findings showed that fields where irrigation water was removed for the entire season produced less hay, even several years after full irrigation was resumed. Fields where water was removed for only part of the season had minimal yield loss and faster recovery.
“In the full season, you can have a three-year legacy effect, so that’s where the risk really comes in if you’re a producer participating in these programs,” Cabot said. “For three years after, you’re not getting paid even though you’ve diminished that yield.”
At the CSU research station in Fruita, Cabot is studying a legume called sainfoin, a forage crop and potentially an alternative to grass or alfalfa. He said sainfoin shows promise as a drought-tolerant crop that can be cut early in the season, allowing producers to have their cake and eat it too: They could maintain the income from growing a crop, avoid some of the worst impacts of a full-season fallowing, and still participate in a partial-season conservation program.
“I’d like to see flexible options that allow us to think about conservation happening on fields that still have green stuff out there,” Cabot said.
This field near Kremmling participated in an early study on the effects of removing irrigation water. Researchers found the effects of full-season fallowing can have lasting impacts. CREDIT: HEATHER SACKETT/ASPEN JOURNALISM
Part of the solution
The Glenwood Springs-based Colorado River Water Conservation District has been one of the loudest voices weighing in on conservation in recent years, helping to fund Cabot’s and Mason’s studies, as well as conducting its own. The River District, which represents 15 counties on the Western Slope, is not a fan of conservation programs, but it has long accepted their inevitability. It has advocated for local control and strict guidelines around a program’s implementation to avoid negative impacts to rural agricultural communities.
River District General Manager Andy Mueller said there is still a lot of resistance to a conservation program in Colorado — especially if the saved water is being used downstream to fuel the growth of residential subdivisions, computer-chip factories and data centers in Arizona. In addition to wanting the Front Range to share their pain, Western Slope water users don’t want to make sacrifices for the benefit of the Lower Basin. [ed. emphasis mine]
“They want to be part of the solution, but they don’t want to suffer so that others can thrive,” Mueller said. “That’s what I keep hearing over and over again from our producers on the ground: They are willing to step up, but they want everybody to step up with them.”
Water experts agree Upper Basin conservation is not a quick solution that will keep the system from crashing. Complicated questions remain about how to make sure the conserved water gets to Lake Powell and how a program would be funded.
And as recent studies show, the tricky social issues that influence program participation, multiseason impacts to fields when water is removed and the scant water savings from high-elevation pastures mean the state may struggle to contribute a meaningful amount of water to the Colorado River system through a conservation program.
“If the dry conditions continue, it’s hard to produce the volumes of water that make a difference in that system,” Mueller said. “But are we willing to try? Absolutely. It has to be done really carefully.”
Map of the Colorado River drainage basin, created using USGS data. By Shannon1 Creative Commons Attribution-Share Alike 4.0
