Think about your morning routine — the coffee maker, the shower, the lawn sprinkler. In Denver, most of that water traces back to the Colorado River basin through a complex system of tunnels, reservoirs, and treatment plants. Denver Water, one of the nation's largest utilities, draws heavily on Colorado River basin supplies. When researchers at the University of Colorado Boulder say the basin's storage system is at risk of crashing, that's not abstract policy language. It's about your tap, your food supply, and your utility bill.

The study, presented Thursday at CU Boulder's Getches-Wilkinson Center, is blunt: one more dry winter — similar to the droughts Colorado has already seen — could leave Lake Powell and Lake Mead so depleted that the massive dams can no longer generate electricity or deliver reliable water allocations to anyone downstream. Researchers call this a 'system crash.' It doesn't mean Denver runs dry tomorrow. But it means the safety net disappears.

Your Household Water Risk

Two Futures for the Colorado River

Another Dry Winter

• 2.59M acre-ft Shortfall Gap between supply and demand
• Lake Powell and Lake Mead near-depleted
• Dams risk infrastructure damage
• Agriculture across 7 states severely curtailed
• Urban areas forced into emergency backup supplies
• No buffer remaining — next drought is catastrophic

A Very Wet Year (Like 2023)

• ~2 years Buffer Gained Temporary relief only
• Reservoirs recover somewhat — not fully
• Electricity generation stabilized short-term
• Farm water allocations partially restored
• Cities gain breathing room — but not security
• Without use cuts, crisis returns in 2 years

How the Colorado River Crisis Unfolded

• 1922 — Colorado River Compact signed — divides water among 7 states based on flows that scientists now know were historically high
• 2000 — Lake Mead begins its long decline as a two-decade 'megadrought' takes hold across the West
• 2021 — Bureau of Reclamation declares first-ever Tier 1 water shortage on the Colorado River — Arizona, Nevada, Mexico take cuts
• 2022 — Lake Powell drops to 24% capacity — Glen Canyon Dam nearly loses power generation ability
• 2023 — Massive snowpack year partially refills reservoirs — but researchers warn this is a brief reprieve, not a recovery
• 2024–25 — Bureau of Reclamation releases 1M acre-feet from Flaming Gorge to prop up Lake Powell; reduces releases from Glen Canyon Dam
• Oct 2026 — Current interstate water-sharing agreements expire — states have not reached a replacement deal

We have to be looking at how we use water in agriculture, for cities, for industry, for ecosystems — and make some very difficult decisions about how to reduce use overall.Anne Castle, former U.S. Commissioner for the Upper Colorado River Commission

How Much Do You Know About Colorado's Water?

Five questions. The answers might surprise you.

Where does most of Denver's water actually come from?

• The South Platte River — The South Platte is part of the picture, but the majority of Denver Water's supply originates from the Colorado River basin via tunnels through the Continental Divide — the Moffat Tunnel system being the most important.
• The Colorado River basin — Correct. Denver Water imports water from the Western Slope via the Moffat Tunnel and other infrastructure. When researchers warn about a Colorado River system crash, Denver is directly in the impact zone.
• Rocky Mountain snowmelt stored locally — Snowmelt is the source — but it originates on the Western Slope and must be physically transported through the mountains to reach Denver. The infrastructure that does that work depends on healthy Colorado River basin hydrology.
• Groundwater and aquifers — Groundwater is a backup source, and Denver Water has diversified its portfolio. But the primary supply is surface water from the Colorado River basin. Groundwater is what utilities fall back on in a crisis — exactly the scenario researchers are warning about.

What does a 'system crash' actually mean for Lake Powell and Lake Mead?

• The reservoirs go completely empty — Not quite — a system crash doesn't mean bone-dry reservoirs. It means water levels drop so low that the dams can no longer function as designed: generating electricity for millions of homes or delivering reliable downstream allocations.
• The dams lose power generation and run as 'flow-through' facilities — Exactly right. Researchers define a crash as dams operating as 'run-of-the-river' facilities — water flows through without storage or control. That kills hydropower for millions and eliminates the regulated deliveries that cities and farms depend on.
• Water stops flowing to cities immediately — This is a common misconception. Most cities, including Denver, have backup supplies — groundwater, local rivers, reclaimed water. A crash hurts agriculture first and hardest. Urban taps don't run dry right away, but restrictions, cost increases, and food price spikes hit everyone.
• Federal emergency powers take over all water decisions — Federal intervention is possible in a crisis — the Bureau of Reclamation already has emergency authority. But the study's definition of a crash is specifically about reservoir infrastructure, not governance. That said, a physical crash would almost certainly trigger federal emergency action.

All seven Colorado River states had record warmth in March. What does that mean for river flows?

• Warmer temperatures melt snowpack faster, delivering more water sooner — True in the very short term — but the longer-term reality is darker. Rapid early snowmelt means less water available during the dry summer months when demand peaks. It also increases evaporation, so less of that water actually reaches the river.
• Higher evaporation and earlier snowmelt reduce how much water reaches the river — Right. Warming temperatures are a double hit: they increase evaporation from both snowpack and reservoir surfaces, and they shift melt timing so summer flows drop. CSU researcher Brad Udall calls this 'aridification' — the Colorado River basin is drying out structurally, not just cyclically.
• Temperature doesn't affect river flows — only precipitation does — Temperature is actually one of the biggest drivers of river flow decline. Even in years with average snowfall, warmer temperatures mean more water evaporates before it reaches the river. Researchers estimate that warming alone accounts for roughly 10-15% of recent flow decreases on the Colorado.
• It means more moisture from the Pacific — warmer air holds more water vapor — Warmer air does hold more moisture, and researchers hope that might bring stronger atmospheric rivers in some years. But climate models project the Colorado River basin gets drier overall, even accounting for more intense storm events. The dry spells between storms get longer and hotter.

The current interstate water-sharing agreements expire in October. What happens if states can't agree on new terms?

• The Supreme Court decides who gets what — Court intervention is possible but unlikely to be the first step. If states fail to agree, the federal government — specifically the Department of Interior and Bureau of Reclamation — has authority to impose operating rules. Litigation could follow, but federal action would come first.
• The federal government imposes interim rules and pressures states to keep negotiating — That's the most likely scenario. The Trump administration has already prodded states to keep negotiating. If no deal is reached by October, Interior could impose emergency guidelines — essentially a federally mandated water rationing plan that states didn't choose for themselves.
• The 1922 Colorado River Compact automatically remains in effect — The original 1922 compact doesn't expire — it's the more recent shortage-sharing guidelines (from 2007 and updated in 2019) that are expiring. Without new agreements, older rules would technically apply, but they were written for higher reservoir levels and more water than currently exists.
• Nothing changes — water keeps flowing as usual — If only. Without updated agreements, there's no legal framework for managing shortages at current reservoir levels. That creates enormous uncertainty for farms, cities, and utilities across all seven states — including Colorado's own agriculture and Front Range water providers.

The study says tribal communities must be included in future river negotiations. Why?

• Tribes have legally recognized water rights that predate state water law — Correct — and this is critical. Tribal water rights, known as Winters Doctrine rights, are among the most senior on the river. They were largely excluded from the 1922 compact and subsequent agreements. Daryl Vigil of the Water & Tribes Initiative argues that any lasting solution must include tribal voices and honor those rights.
• Tribes control most of the river's source water on reservations — Some tribal lands do include important headwaters and tributaries, but the bigger issue is legal rights. Tribal water rights are constitutionally senior to state allocations in many cases — and those rights have never been fully quantified or honored in river management agreements.
• Federal law requires tribal consultation before any water decisions — Consultation requirements exist, but advocates say consultation without inclusion isn't enough. The call from tribal leaders at Thursday's conference was for meaningful participation in decision-making — not just being informed after decisions are made.
• Tribes are the largest agricultural water users in the basin — Agriculture on tribal lands is significant, but tribes aren't the dominant agricultural users basin-wide. The more important point is legal and moral: tribal sovereign rights to water were largely ignored in the 1922 compact, and researchers and advocates argue that a sustainable future for the river requires correcting that.

That knowledge gap — the distance between what's happening to the Colorado River and what Front Range residents understand about it — is exactly what researchers at Thursday's conference said must close. Anne Castle, who spent years negotiating water policy at the federal level, told the Colorado River Collaborative that incremental tweaks won't be enough. The math simply doesn't work. The basin uses more water than the river produces, and a warming climate is making that gap wider every decade.

Colorado State University water scientist Brad Udall put it bluntly to the assembled experts: climate change will force a rewrite of more than 100 years of water policy. He called on water managers to 'pull straws out of this glass' — meaning real, significant reductions in consumption, not accounting tricks or optimistic modeling. The Bureau of Reclamation's own projections, the study argues, are 'too optimistic' about how much water the basin will reliably produce.

How Dependent Is Colorado on the River?

Even in the best-case scenario — a repeat of the record-wet 2023 water year — the study says the basin would only buy about two years of cushion before returning to the same crisis point. The recovery would be real, but brief. Without permanent, basin-wide reductions in how much water is consumed, the math always catches up. Every household, every farm, every city is part of that equation.

For Denver-area residents, the most immediate impact of a system crash wouldn't be empty taps — Denver Water has invested heavily in backup sources, including groundwater and reclaimed water. But those backups cost more to operate, and that cost gets passed to ratepayers. Beyond the utility bill, a system crash would devastate Western agriculture, driving up grocery prices for every household in Colorado and across the country.

Who Uses the Colorado River's Water?

What Denver Residents Can Do Right Now

1. Get a free water audit from Denver Water — Denver Water offers free indoor and outdoor water use audits that identify where your household can save the most. Visit denverwater.org or call 303-893-2444.
2. Replace thirsty landscaping with xeriscape — Outdoor irrigation accounts for roughly 50% of Denver residential water use. Denver Water offers rebates for replacing grass with drought-tolerant plants. Every square foot of grass you remove counts.
3. Check for leaks inside your home — A dripping faucet wastes up to 20 gallons per day. A running toilet can waste 200. Fix leaks now — and report them to your landlord if you rent. The EPA's WaterSense calculator can help you find your biggest sources of waste.
4. Contact your elected representatives — Colorado's water future is a political decision. The river compact negotiations involve your U.S. senators, your state legislature, and the Governor's office. Let them know water matters to Front Range voters.
5. Know where your water comes from — Ask your water utility for their latest Consumer Confidence Report — it's required by law and tells you exactly what sources your water comes from and how supply is managed. Knowledge is the first step.

What's True — and What's Overstated

Denver's taps will run dry if the Colorado River crashes.

Verdict: mostly false

A system crash is serious, but Denver Water has diversified its portfolio — groundwater, South Platte water, reclaimed water, and storage reserves. Taps won't go dry immediately. The real risks are rising costs, mandatory restrictions, and dependence on backup supplies that are more expensive to operate.

Agriculture would be devastated by a system crash.

Verdict: true

Eighty percent of Colorado River water goes to agriculture. A crash that eliminates reliable reservoir storage and deliveries would force farms across seven states to drastically reduce or abandon irrigated fields. Western states like California and Arizona are major food producers for the entire country — this hits grocery prices nationwide.

The Bureau of Reclamation has the situation under control.

Verdict: mostly false

BuRec's deputy director for the Colorado River acknowledged at Thursday's conference that 'it doesn't look good' and warned the crowd to prepare for another dry winter. The agency has already resorted to emergency water releases and dam output cuts — signs of crisis management, not stability. Researchers say federal projections are 'too optimistic.'

One good wet year would solve the problem.

Verdict: false

The study is explicit: even a repeat of the record-wet 2023 year would provide only about two years of cushion before returning to the current crisis — unless consumptive use decreases. Without structural cuts in how much water is used basin-wide, the math always catches up.

Tribes have been fairly included in Colorado River negotiations.

Verdict: false

Tribal representatives at Thursday's conference were unequivocal: sovereign tribes with legally senior water rights have been systematically excluded from major river decisions. The 1922 Colorado River Compact was negotiated entirely without tribal participation. Advocates say 'inclusion' — not just consultation — is essential to any lasting solution.

The 1922 Compact: A Century-Old Deal Coming Apart

The Colorado River Compact, signed in 1922, divided the river's water among seven states based on flow measurements from unusually wet years. Scientists now know those measurements dramatically overstated the river's long-term average flow — meaning the compact promised more water than the river reliably produces even without climate change.

The compact divided the basin into Upper (Colorado, Wyoming, Utah, New Mexico) and Lower (California, Arizona, Nevada) basins, each entitled to 7.5 million acre-feet per year. Add in the 1.5 MAF promised to Mexico under a 1944 treaty, and the total legal allocation is about 16.5 MAF/year — against a river that now averages closer to 12-13 MAF, and is trending lower.

Sovereign tribal nations were not included in the 1922 negotiations, despite having water rights that legally predate statehood. The Winters Doctrine, established by the Supreme Court in 1908, affirms that tribal reservations carry with them enough water rights to make the land livable — rights that are senior to virtually all state allocations. The full quantification of those rights has never been completed for Colorado River tribes, creating enormous legal uncertainty that hangs over any new agreement.

The more recent shortage-sharing guidelines — established in 2007 and updated in 2019 — are what expire in October 2026. These guidelines govern how cuts are distributed when reservoir levels fall below certain thresholds. Without replacement guidelines, the basin falls back on the original 1922 framework, which was never designed to manage shortages at anything close to current reservoir levels.

The Colorado River isn't just a policy debate happening somewhere else. It is the physical infrastructure underneath Denver's daily life — the reason water comes out of your tap every morning, the reason Colorado farms produce the food that fills the grocery stores on your street. What researchers presented Thursday in Boulder was not a doomsday prediction. It was an engineering assessment: the system is operating near its breaking point, the political agreements that govern it are expiring, and the climate is making everything worse.

The decisions that get made in the next 12 to 18 months — in negotiating rooms, in Congress, in state legislatures, in the Bureau of Reclamation — will shape what water looks like on the Front Range for the next century. The study's authors aren't asking for panic. They're asking for honesty about what the numbers say, and for the kind of difficult, permanent changes that match the scale of the problem. For Denver, that work starts at home — and it starts now.

Take Action on Colorado's Water Future

• Denver Water Conservation Programs: Free audits, xeriscape rebates, and water-smart resources for Denver-area households.
• Report a Water Leak or Waste: Denver Water's 24-hour leak reporting and wasteful use reporting line.
• Contact Your State Legislators: Colorado's water negotiating position is set by elected officials. Tell them water security matters to Front Range voters.
• Read the Full Study: The report was released at CU Boulder's Getches-Wilkinson Center for Natural Resources, Energy & the Environment.

Sources & References

• Primary source: local-news — Ben Winslow
• University of Colorado Boulder, Getches-Wilkinson Center — Study on Colorado River basin system crash scenarios, presented at the Colorado River conference, 2025
• U.S. Bureau of Reclamation — Colorado River reservoir operations data, Flaming Gorge emergency release records, Glen Canyon Dam output adjustments
• Colorado State University, Water Center — Long-term Colorado River flow trends and climate modeling data, Brad Udall research
• Colorado River Compact (1922) and Shortage Guidelines (2007/2019) — Basin allocation figures, shortage-sharing framework, expiration timeline
• Denver Water — Denver metro water source breakdown, conservation programs, and backup supply portfolio