The Head-to-Head: Which Post-2026 Plan Actually Wins?
Two plans stand out for different reasons — Supply Driven for lake recovery, Max Operational Flexibility for worst-case protection. Which to pick depends on what you value.
Imagine if, starting in 1996, we had released just 5% less water each year. Lake Powell would be about 97 feet higher today. (Read the math →)
That is what's possible. This article asks which post-2026 plan on the table gets us closest.
A quick note on the baseline. The April 2026 federal plan — release cuts plus a Flaming Gorge transfer — commits to keeping Powell above 3,500 ft by April 2027. That is 10 ft above minimum power pool. It is the short-term floor the plan defends. The long-term plans below pick up after Sep 30, 2026, starting from wherever that short-term floor leaves the lake.
We ran the five federal plans and the current 2007 Guidelines through the same stress test. We sampled inflows from the last ten years — the driest decade on record. Each plan ran 2,000 times over 40 years. The starting point is Lake Powell on October 1, 2026. That is the end of the reduced-release window. By then, the states and feds will have picked a long-term operating rule, and the new plan takes over. The April 2026 federal plan may keep sending Flaming Gorge water past Sep 30, but that is not certain. So the long-run test starts from the Sep 30 mark. Everything stays the same except the operating rule.
Here is what each plan produced.
Median (p50) trajectory under the driest decade on record. Same starting point, same inflow sampling, only the operating rule changes.
Forty years is a long horizon. Here is the same chart zoomed to the first five years so the near-term choices are easier to see.
Zoomed in to the first 5 years so the near-term differences between plans are easier to read. Same data as the chart above.
The full scorecard — four axes, and the winner depends on what you value
These numbers look 40 years out, under the driest inflows on record. The one-letter "overall" grade is handy shorthand. But it hides the real story. Different plans win on different axes. Click any plan name for its full article.
| Plan | Recovery lake fills (40yr median) | Floor worst-case low point | Bad-case End 40yr p10 ending | Speed 10yr gain | Overall |
|---|---|---|---|---|---|
| Max Operational Flexibility → Strongest worst-case protection — floor holds closest to the Oct 1, 2026 baseline | B 3599 ft | A 3507 ft | B 3551 ft | A +89 ft | A |
| Supply Driven → Best recovery — highest median elevation at every long horizon | A 3678 ft | B 3433 ft | A 3641 ft | A +113 ft | A |
| Enhanced Coordination → Balanced fallback — middling on every axis, no major weakness | B 3593 ft | B 3469 ft | B 3532 ft | A +102 ft | B+ |
| Basic Coordination → Not recommended — median stays below min power; floor reaches dead pool | C 3530 ft | F 3370 ft | D 3415 ft | B +26 ft | D+ |
| 2007 Guidelines (status quo) Not recommended — structural deficit persists; floor reaches dead pool | C 3535 ft | F 3370 ft | D 3411 ft | B +28 ft | D+ |
| No Action → Not recommended — lowest median of any plan; floor reaches dead pool | D 3482 ft | F 3370 ft | F 3370 ft | F -21 ft | D- |
Reading the grid
- Recovery — median ending elevation at 40 years. How full does the lake get? Supply Driven wins at 3677.6 ft.
- Floor — the single lowest point hit in the worst 10% of futures. It can be brief. How bad can it get at any moment? Max Operational Flexibility wins at 3507.2 ft. That is only 10 ft below the Oct 1, 2026 start. Every other plan dips 84+ ft further in bad luck.
- Bad-case End — where the lake ends up at year 40 in the worst 10% of futures. This is different from Floor. A plan can dip low early and climb back by the end. Supply Driven wins at 3641 ft. In the bad-luck case, SD still ends above MOF's bad-case end of 3551 ft. SD's low dip is brief; MOF's bad case stays flatter.
- Speed — median elevation gain in the first 10 years. Near-term climb from the Oct 1, 2026 start. SD wins at +113 ft, just ahead of MOF at +88.8 ft.
No plan wins every axis. MOF and SD split the top spots. MOF takes Floor. SD takes Recovery and Speed. At 40 years, SD's median is 78 ft higher. MOF's floor is 74 ft higher. Both are real outcomes. The grid lets you weigh them side by side, not squished into one grade.
Note on grades: the Monte Carlo starts on Oct 1, 2026 — the end of the federal reduced-release window — with Powell at about 3517 ft. The Overall grade is a weighted GPA of the four axes with Floor counted 2×. Worst-case outcomes (dead pool, lost power, closed marinas) have lasting costs that recovery can't undo, so they weigh more. Supply Driven (A on Recovery, Bad-case End, and Speed) and MOF (A on Floor and Speed) both earn A Overall through different paths. SD climbs highest in typical years. MOF holds the line in bad luck.
Which plan wins depends on what you value
Three plans are in real contention. They win on different axes of the grid. So picking between them is a question of priorities, not rank. Here is how to choose.
If you want the lake to fill back up — Supply Driven
SD has the highest median elevation at every long year mark. At 40 years, it reaches 3677.6 ft. That is a gain of about 161 feet from the post-Phase-1 start. That is near Hite territory. For anyone who cares how the lake looks on a summer weekend, this plan comes closest to "full." The tradeoff shows up in the grid. SD's worst-case floor (3432.8 ft) is 74 ft lower than MOF's. SD trades more downside risk for more upside.
Pick SD if your top concern is: "get the lake as high as possible over the long run, and accept more worst-case exposure to get there."
Full scorecard for Supply Driven →
If you want the strongest worst-case protection — Max Operational Flexibility
We start from the post-Phase-1 line of 3517 ft. MOF is the plan whose worst-case floor holds closest to that line: 3507.2 ft. That is only 10 ft below where the federal plan leaves us. Every other plan's worst 10% dips 84+ feet further. Supply Driven's worst case reaches 3432.8 ft. Enhanced Coordination hits 3468.5 ft. In plain terms: in a bad-luck decade, MOF is the plan least likely to make the drought much worse.
Pick MOF if your top concern is: "don't let the lake drop further than it already has."
Full scorecard for Max Operational Flexibility →
If you want a balanced fallback — Enhanced Coordination
Enhanced lands in the middle of the grid. It has a fair median (3592.6 ft) and a moderate floor (3468.5 ft), but does not lead on either axis. It stays inside the current Compact framework and avoids the worst outcomes. If neither MOF nor SD can pass politically, Enhanced is the safe pick.
Full scorecard for Enhanced Coordination →
Plans that don't meet the math
Three plans on the table don't clear the bar. Not on feelings — just on numbers.
- 2007 Guidelines (status quo) — 40-year median of 3534.9 ft. That is below minimum power pool. Floor reaches dead pool (3,370 ft) in the worst 10% of futures. The core shortfall does not change.
- Basic Coordination — a small bump above the status quo. 40-year median of 3530 ft, still below min power. Floor reaches dead pool.
- No Action — the lowest median of any plan (3481.5 ft). Floor reaches dead pool. The weakest option on the table.
These are not knocks; they are what the math shows. If any of these wins, Powell's worst-case path runs into dead pool over the 40-year stress test.
Where the Abundance Act fits
The Colorado River Abundance Act does not compete with the operating-rule plans. It stacks on top of them. Augmentation is new water delivered to Lake Mead. That means Powell does not have to release as much downstream. More water stays in Powell.
New water layered on the 2007 Guidelines. Buildout reaches peak around 2045 — new water is a long-run lift, not a short-run rescue.
Three things stand out in this chart.
- Augmentation takes 15-20 years to kick in. Phase 1 comes online around 2045. Full buildout is 2055+. In the first decade, the path barely moves.
- Long-run, the lift is large. 2007 Guidelines + Full buildout lifts the 40-year median from 3534.9 ft to 3606.8 ft. That is close to what Max Op Flex alone gives us, but by adding water rather than managing less.
- Augmentation alone cannot fix the worst case. Even with full buildout, the bad-luck 10% floor of the combined plan still hits dead pool. The new water is not online yet when back-to-back dry years hit.
The right mix is both: adopt Max Operational Flexibility (or Enhanced Coordination) for post-2026 operations, and back the Abundance Act for long-run capacity. Short-run, the operating rule protects the lake. Long-run, added water keeps us ahead as demand grows.
Full scorecard for the Abundance Act →
The bottom line
We built this site to make the post-2026 choice clear to the people who actually use Lake Powell. The math is plain: two plans stand out for different reasons, and the status quo is not one of them.
Both of our top picks are worth pushing for — they are the two plans that clear every bar, and they are strong in different ways. If you want the lake to fill back up over time, push for Supply Driven. If worst-case protection is your top priority, push for Max Operational Flexibility. If neither can pass politically, Enhanced Coordination is the safe fallback that still avoids the worst outcomes. Anything below those three runs Powell into dead pool in the worst 10% of futures.
Every number in this article comes from Monte Carlo runs you can redo on this site's simulator. Sources and methods are listed on the About page.