What’s changed since Version 1.0: the first version of this paper set out a simple frame — two paths forward, one preserving the 1922 Compact and one replacing its core formula. Every version since has been an effort to earn that frame through primary-source research rather than just assert it.
This version reflects the largest expansion yet. It adds the complete public archive of the research group known as the Traveling Wilburys of the Colorado River, and the Upper Colorado River Commission’s own annual reports and technical resolutions. It also draws on a rigorous 2012 legal history of the Compact’s delivery-obligation question and extensive Aspen Journalism reporting on Upper Basin negotiations — material this paper had previously underweighted.
Two corrections deserve to be named directly, because they change what the paper argues, not just what it cites. The core registry mechanism is now stated precisely as a hard aggregate cap with every individual allocation fully tradable beneath it, replacing an earlier, less accurate description. The legal debate over whether the Upper Basin owes the Lower Basin an actual water delivery is also now presented in full. An earlier version of this paper leaned on a citation that turned out to represent a historical minority position, and that’s been corrected.
This version also adds a new proposed mechanism for trading water directly across the Upper and Lower Basin divide. A leading researcher on this exact question says the gap remains entirely unsolved. Two current legal precedents place real, honest limits on how that mechanism would actually work.
The arithmetic was wrong from the start, and not by accident
The Colorado River Compact of 1922, plus the later treaty with Mexico, promises 17.5 million acre-feet of water a year. The best current reconstruction of the river’s true long-run average is closer to 14 million acre-feet — and the last six years have averaged only 10.8 million.
USGS hydrologist E.C. LaRue testified directly to Congress in 1925 that the river couldn’t support the promised volume. As water historian John Fleck put it: “None of the senators followed up.” Every crisis since traces back to a choice made with eyes open, not an honest data error.
A debate this paper now presents in full
Whether the Upper Basin owes the Lower Basin an actual water delivery, or merely a promise not to actively deplete the river, has divided the Upper Basin’s own historical leadership since the Compact’s earliest years. It deserves real space on both sides, not a one-line citation.
Colorado’s own 1948 commissioner, Clifford Stone, described a real delivery obligation directly, with the Upper Basin’s own share treated as what’s left over. New Mexico Senator Clinton Anderson made the strongest case for the opposite reading: if the Lower Basin’s delivery simply trumps the Upper Basin’s own apportionment, the Compact’s stated equal apportionment would have been pointless to write in the first place. A 2012 legal history from the University of Colorado’s own law school found the non-depletion reading was actually a minority position within Colorado’s own delegation at the time. That history’s own conclusion is the honest one to carry forward: either interpretation, or some compromise position, could conceivably prevail.
The Upper Basin’s own exposure isn’t new to this year’s crisis
A 2018 report found Lake Powell had already dropped 94 feet since 2000, despite Upper Basin water use staying comfortably within its legal entitlement the whole time. As of September 2025, the running ten-year Lee Ferry total stood at 84.4 million acre-feet, per the Upper Colorado River Commission’s own record. That’s still above the disputed threshold of roughly 82 million, though a later 2026 projection puts it falling below that line within the year.
Not all “voluntary” conservation is the same
A 2004 study of the 2002 drought found mandatory restrictions cut water use by up to 56 percent, while appeals to civic duty achieved only about 12 percent. This paper’s proposal is built on a sharper distinction than “mandate versus market”: a single hard cap on total basin-wide use, with every individual’s share of meeting that cap fully tradable beneath it.
An honest limitation deserves equal billing here. A registry lease reallocates conserved water to a new user — it doesn’t by itself shrink total demand, since someone still ends up using it. A 2025 proposal argues the federal government specifically, not a city or another farmer, should fund permanent retirement of low-value, high-water land. That’s not a new idea for American policy — it echoes the 1937 Bankhead-Jones Farm Tenant Act’s own retirement of unproductive Dust Bowl-era farmland. This paper treats leasing and a targeted federal buyout as complements, not substitutes.
This is a commons problem, and commons problems have a known fix
Roughly three-quarters of the river’s consumptive use goes to agriculture, priced in many districts at a small fraction of what municipal users pay. The largest remaining pool of unrealized value is very likely reallocation within agriculture itself, from low-value forage toward high-value food crops.
What a working solution requires:
A hard aggregate cap, fully tradable beneath it — no personal non-tradable minimum for any single user.
Verified measurement — satellite evapotranspiration data already unanimously adopted by the Upper Colorado River Commission and by Reclamation itself for official federal accounting. This paper extends an existing standard, not an unproven one.
A real joint authority — one commission able to coordinate both major reservoirs as a single hydraulic system, correcting for Colorado’s own documented, repeated institutional delays in building a real conservation program.
Anti-concentration rules without a single buyer — ownership caps without routing every trade through one state monopsony.
Tribal water as a full right, on tribes’ own terms — grounded in the Upper Basin tribes’ own stated framework: unused, undeveloped, uncompensated, and unquantified rights.
A mechanism to cross the Lee Ferry divide — discussed below, with its real legal limits named directly.
Community and basic-needs protection — including direct payment to tenant farmers, not just landowners.
The biggest new idea, honestly limited
Every cross-basin mechanism already operating today stays within one basin. Nothing lets an individual Upper Basin water-right holder sell directly to an individual Lower Basin buyer. Eric Kuhn names the gap explicitly: “Where we haven’t made any progress is what I would call the crossing of the Lee Ferry divide.” This paper offers a concrete mechanism for it — but not without naming two real legal obstacles standing in the way today.
The first is “shepherding”: Colorado currently lacks clear legal authority to protect conserved water from being picked up by other users as it moves toward its destination, except in narrow circumstances that have never actually occurred. The second is a live court decision — Water Horse v. Wilhelmsen, decided by the Utah Supreme Court in October 2025 — establishing that a water exporter must also satisfy the receiving state’s own legal process before the water can be used there. A Colorado-to-Arizona trade would need both states’ legal machinery in place, not just Colorado’s willingness to sell.
Two paths, and a third worth naming
Option A — Preserve the Compact, build the market. Faster, less politically explosive — but it leaves the underlying 17.5-million-acre-foot promise unrepaired.
Option B — Replace the formula. Not a foreign import: the 1948 Upper Basin Compact already allocates by percentage among its own four states. The Upper Division States’ own March 2024 proposal to Reclamation ties Powell releases to Powell’s own storage and ties Mead releases to combined storage. It includes a real concession worth quoting: it “reflects the reality of annual hydrologic shortages across the Upper Division States.” That’s the Upper Basin’s own formal proposal acknowledging its own exposure.
A grand bargain. Mutual mandatory reductions in both basins, paired with a negotiated shield against Compact litigation for the life of the agreement.
A diagnosis failing in real time
Anne Castle and John Fleck’s own 2021 paper argued crisis conditions plus federal deadlines reliably force compromise. By early 2026, both were present in full, and no deal resulted. Castle’s own words, testing her prior thesis against reality: “we have all those underlying conditions, and we don’t have a compromise.”
Fleck’s own diagnosis is worth sitting with: “What we have seen in the last few years is a shift to a leadership that is made up of people who are solely looking out for the interests of their own community.” His own statement of the alternative is among the most direct in this whole research effort: “I would not be at all happy to win the litigation and see the Central Arizona Project shut down. I would see that as a failure even though my community’s water supply might be protected.”
The recommendation
Pursue Option A now, built as a hard aggregate cap with a fully tradable registry beneath it, and build it as shared infrastructure. Because the cap can be tied to trailing river flow rather than fixed by negotiation, relaxing it when conditions improve becomes arithmetic, not a fresh political fight nobody wants to start.
Five limits are worth stating plainly. It doesn’t replace emergency authority in an acute crisis, it doesn’t manufacture water that doesn’t exist, it doesn’t fully solve groundwater depletion, and it doesn’t resolve the Salton Sea’s exposure on its own. And the interbasin trading mechanism proposed here isn’t yet fully executable under current law — a real gap this paper names honestly rather than assumes away.
The full white paper has grown substantially again with this version. It now includes the full delivery-obligation debate on its own terms, and two current legal precedents affecting how the paper’s own proposals would work. It also gives a much fuller accounting of Upper Basin perspectives across negotiators, elected officials, water managers, and internal critics alike. It makes the case for the harder options as fairly as the case for the easier one, and flags plainly where this proposal rests on extension rather than precedent.
This paper was produced through an iterative research and drafting process with Claude (Anthropic), working from primary sources — federal agency documents, court filings, peer-reviewed studies, congressional testimony, tribal vision statements, and named-attribution reporting — verified throughout. Comments and corrections welcome; further updates will follow as developments in the basin warrant them.