Most people who follow the Colorado River crisis have never heard of the one agreement that decides whether the river reaches the sea at all. It runs out at the end of 2026. And almost no one has explained it in plain language — in English or in Spanish.
That agreement is called Minute 323. If you want to understand what happens to the Colorado River after 2026, you can't stop at the seven U.S. states. The river doesn't stop there either.
the short answer
Minute 323 is a 2017 binational agreement between the United States and Mexico that governs how the two countries share the Colorado River during shortage — including how much water Mexico gives up when reservoirs fall, how much it can store in Lake Mead, and how much flows to the drying river delta. It expires December 31, 2026, the same day the U.S. domestic rules expire.
the 1944 treaty: mexico's 1.5 million acre-feet
Start with the foundation. In 1944, the United States and Mexico signed a water treaty that guarantees Mexico 1.5 million acre-feet of Colorado River water per year — a little under 10% of the river's historical flow. (An acre-foot is about 326,000 gallons — roughly a year of water for two or three households.)
That number has been fixed for 80 years. The treaty made Mexico a permanent partner on the river, not an afterthought. What it didn't do was say what happens when there isn't enough water to go around. In 1944, no one was planning for a river running 20% below its old average.
what is a "minute"? the binational fine print
The treaty is administered by a joint agency called the International Boundary and Water Commission (IBWC) — known in Mexico as CILA (Comisión Internacional de Límites y Aguas). It has a U.S. section and a Mexican section, and together they issue formal amendments to the treaty called "Minutes."
A Minute is how the two countries update the 1944 treaty without renegotiating the whole thing. Each one is numbered, negotiated, and — critically — time-limited. It's the fine print that decides who gives up water in a bad year.
A Minute is not a new treaty. It is a binational handshake with an expiration date — which means the Colorado River delta's water gets renegotiated from scratch every few years.
minute 319 and the 2014 pulse flow: the river met the sea
For most of the last half-century, the Colorado River has not reached the ocean. It is drained dry by dams and diversions long before it gets to the Sea of Cortez. The delta — once nearly two million acres of wetlands and cottonwood forest — lost more than 90% of its habitat and became a cracked salt flat.
Minute 319, signed in 2012, was the first time the two countries wrote environmental water into the agreement. Its most famous result: the 2014 "pulse flow." In spring 2014, the U.S. and Mexico released about 105,000 acre-feet through Morelos Dam. For the first time in years, the Colorado River reconnected to the sea. Native cottonwoods and willows sprouted. Birds returned.
Minute 319 also let Mexico do something new — store some of its water in Lake Mead instead of taking delivery all at once, helping prop up the shared reservoir. That storage idea became a permanent tool.
minute 323: sharing the shortage, funding the delta
Minute 323, signed in 2017, is the current agreement. It did three things that matter for anyone tracking the post-2026 cliff.
1. Mexico shares the pain. When Lake Mead falls into shortage and U.S. states take cuts, Mexico now takes cuts too — on a tiered schedule that runs roughly parallel to the U.S. Lower Basin. At the first tier, Mexico's reduction is on the order of 5% (~80,000 acre-feet). This is the part most U.S. readers don't know: Mexico is a full, formal participant in Colorado River shortage, not a bystander.
2. Mexico keeps storing water in Lake Mead. Minute 323 continued and expanded Mexico's ability to leave water in the reservoir, which supports levels for everyone drawing on it.
3. It funded the delta. Minute 323 committed roughly 210,000 acre-feet of environmental water to the delta over its term, split three ways — the U.S., Mexico, and a coalition of nonprofits — plus money for restoration and scientific monitoring. That NGO coalition is Raise the River (in Spanish, Revive el Río Colorado), which includes the Sonoran Institute, Pronatura Noroeste, The Nature Conservancy, the National Audubon Society, and the Environmental Defense Fund. A 2021 addendum (Minute 330) reaffirmed those binational conservation and environmental-flow commitments.
The results are real but small: restoration sites like Laguna Grande have brought back more than a thousand acres of native forest, and bird abundance and diversity have climbed sharply where the water flows. It's proof that the delta responds fast when you give it even a little.
the deadline nobody's talking about
Here's the part that should make every water manager, funder, and border community pay attention: Minute 323 expires December 31, 2026 — the exact same day the 2007 U.S. interim guidelines and the 2019 drought plan expire.
That alignment was intentional. It was meant to let the whole system — U.S. and Mexico — be renegotiated together. But as of now, no successor agreement is signed. If the U.S. states remain deadlocked and the federal process slips, the binational piece slips with it. And the most fragile line item in the whole arrangement — the water that keeps the delta alive — is also the easiest to cut when negotiators are fighting over cities and farms.
the turn: the delta's value shouldn't expire with a treaty
Remember the 2014 pulse flow? Here's what it really proved — and it's not what most people took from it.
It proved the delta is a shared-source investment. The birds that returned use the entire Pacific Flyway. The carbon and habitat benefit both countries. The tourism, the fisheries at the river's mouth, the cultural life of the Cocopah people whose homeland the delta is — all of it recovers when water arrives. The delta isn't Mexico's problem or America's charity. It's a piece of natural infrastructure that two nations, dozens of nonprofits, and millions of downstream people quietly depend on.
And right now, the funding for it is hostage to the treaty renewal cycle. Every few years the water has to be argued for again. A restoration site that takes a decade to mature is fed by an agreement that has to be re-won every few years. That mismatch is the trap.
The delta's water is renegotiated every few years; the delta's recovery takes decades. Protection that expires can't fund a forest that doesn't.
This is the gap ensurance is built to close. Ensurance is a way to fund the protection of a specific natural place upfront and hold it as a durable investment — not a grant that runs on a treaty clock. A few plain-language terms:
- an agent is an onchain account that represents a specific place — here, the Colorado River delta — and can hold funds and route them to the people doing the restoration.
- a certificate is a direct-funding instrument tied to that place: you fund the delta's restoration and hold proof of it, and the money reaches the stewards on the ground.
- a coin funds protection indirectly, through ongoing market activity rather than a one-time check.
The point isn't the mechanism. The point is persistence. A binational Minute can lapse in 2027; a funded delta agent doesn't. Instead of the delta's water being the first thing sacrificed in the next round of negotiations, its value gets priced directly and funded by the people and institutions — foundations, downstream utilities, binational collaboratives — who already know what it's worth.
future pacing: the delta in 2036
Picture the delta ten years from now. The Minutes have been renegotiated twice, and each time the environmental water survived the cut — because it was no longer the only thing without a dedicated funding source. A binational delta agent has pooled money from a U.S. foundation, a Mexican water district, and an Audubon-led coalition. Laguna Grande has doubled. The river reaches the sea in more years than it doesn't. None of it depended on winning the same argument every renewal cycle.
That's the difference between funding that expires and funding that persists.
frequently asked questions
what is minute 323 in simple terms?
It's the current U.S.–Mexico agreement (signed 2017) that sets how the two countries share Colorado River water during shortage — Mexico's cutbacks, its ability to store water in Lake Mead, and the water dedicated to restoring the river delta. It expires December 31, 2026.
how much Colorado River water does Mexico get?
Under the 1944 water treaty, Mexico is guaranteed 1.5 million acre-feet per year — a little under 10% of the river's historical flow. During shortage, that amount is reduced on a tiered schedule under Minute 323, starting around 5% at the first tier.
does Mexico take Colorado River cuts?
Yes. This surprises many people. Under Minute 323, Mexico shares in shortages alongside U.S. states, giving up roughly 5% (about 80,000 acre-feet) at the first tier and more as reservoirs fall further.
what happens to the Colorado River delta after 2026?
The environmental water that keeps the delta's restoration sites alive is written into Minute 323, which expires at the end of 2026. If a successor agreement isn't negotiated, that water — the smallest and most vulnerable share — is at risk.
what is the difference between a treaty and a minute?
The 1944 treaty is the permanent foundation. A "Minute" is a time-limited amendment issued by the International Boundary and Water Commission (IBWC / CILA) that updates how the treaty works — for example, how shortage is shared. Minutes expire and must be renewed.
read next
- what happens to the colorado river after 2026 — the full picture of every rule expiring at once.
- how upstream land decides downstream water — why protecting the source, not just dividing the flow, is the only move that adds water.
- will lake mead hit dead pool — the reservoir where Mexico stores its water, and the levels that trigger the cuts above.
If you're a government, foundation, or binational collaborative thinking about how to fund the delta beyond the next treaty cycle, start a conversation — or see how direct, place-based funding works with specific ensurance.