The Head-to-Head: Which Post-2026 Plan Actually Wins?
Max Operational Flexibility is the only plan that keeps Powell above minimum power pool in the worst 10% of futures.
Imagine if, starting in 1996, we had released just 5% less water every year. Lake Powell would be roughly 100 feet higher today. (Read the math →)
That is what's possible. This article is about which of the plans actually on the table for post-2026 operations gets us closest.
We ran the five federal-plan alternatives plus the current 2007 Guidelines through the same stress test: sampled inflows from the last ten years (the driest decade on record), 2,000 iterations, 40 years of projection, starting from today's lake level. Same everything, except the operating rule changes.
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.
The scorecard
At the 40-year horizon, under the worst inflow regime in the record:
| Plan | Median Ending | Worst-Case Floor | Grade |
|---|---|---|---|
| Max Operational Flexibility | 3585.7 ft | 3507.8 ft | A |
| Supply Driven | 3670.2 ft | 3474 ft | B |
| Enhanced Coordination | 3577.8 ft | 3442.3 ft | B |
| Basic Coordination | 3508.9 ft | 3370 ft | D |
| 2007 Guidelines (status quo) | 3514.8 ft | 3370 ft | D |
| No Action | 3430.1 ft | 3370 ft | F |
(Grades are based on ending elevation and worst-case floor; see each plan's article for the full 10/20/40 year breakdown.)
The winner: Max Operational Flexibility
Max Operational Flexibility is the only plan that earns an A at every horizon. Under the last-decade stress test, it keeps the median lake at 3585.7 ft over 40 years, and — crucially — the worst 10% of draws still floor at 3507.8 ft, which is above minimum power pool (3,490 ft). In plain terms: even in the bottom 10% of bad-luck futures, Glen Canyon Dam keeps generating power, and the lake does not break critical thresholds.
No other plan keeps the p10 floor above min power. That alone is the case for Max Op Flex.
Full scorecard for Max Operational Flexibility →
Runner-up: Supply Driven
Supply Driven produces the highest median elevation of any plan — 3670.2 ft at 40 years, a gain of roughly 144 feet from today. That is near Hite territory. For anyone who cares about what the lake actually looks like on a summer weekend, this is the plan that most closely resembles "full."
It earns an A at the 20-year and 40-year horizons. At 10 years it scores B because the 4.7 MAF minimum release floor can bite during consecutive dry years in the short run — but over time, the supply-tracking logic produces the strongest recovery of any plan.
Full scorecard for Supply Driven →
Third place: Enhanced Coordination
Enhanced Coordination earns B at every horizon. Its median (3577.8 ft) is lower than Supply Driven's, but its worst-case floor (3442.3 ft) is better than Supply Driven's (3474 ft). If you value downside protection above all else and Max Op Flex is politically out of reach, Enhanced Coordination is the conservative fallback.
Full scorecard for Enhanced Coordination →
What the status quo produces
Sticking with the 2007 Guidelines earns a D at every horizon. The median ends at 3514.8 ft, and in the worst 10% of draws, the lake hits dead pool (3,370 ft). No Action is worse — an F, with the median at 3430.1 ft. Doing nothing is not "safe"; it is actively the worst option on the board.
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 replacement water delivered to Lake Mead, which means Powell does not have to release as much downstream. More water stays in Powell.
Augmentation scenarios layered on the 2007 Guidelines. Note the delayed onset (buildout ~2045) — augmentation is a long-run lift, not a short-run rescue.
Three things are worth noticing in this chart:
- Augmentation takes 15-20 years to show up. Phase 1 comes online around 2045. Full buildout is 2055+. The short-run (first decade) trajectory barely moves.
- Long-run, the effect is large. 2007 Guidelines + Full buildout lifts the 40-year median from 3514.8 ft to 3593.9 ft — close to what Max Op Flex alone produces, but achieved through adding water rather than managing less.
- Augmentation alone cannot fix the worst-case. Even with full buildout, the p10 floor of the combined scenario still hits dead pool because the infrastructure is not online yet when bad runs of dry years happen.
The right combination is both: adopt Max Operational Flexibility (or Enhanced Coordination) for post-2026 operations, and support the Abundance Act framework for long-run capacity. Short-run, the operating rule protects the reservoir. Long-run, augmentation keeps us ahead as demand grows.
Full scorecard for the Abundance Act →
The bottom line
We built this site to make the post-2026 decisions legible to the people who actually use Lake Powell. The math is not subtle. Two plans clearly rise above the rest, and the status quo is a failing grade.
If you live near the lake, launch boats on it, run a business that depends on it, or just love the place — the plans worth pushing for are Max Operational Flexibility (best overall protection) and Supply Driven (best lake recovery). Enhanced Coordination is a solid third if neither of those is politically achievable. Anything less is mathematically worse.
Every number in this article comes from Monte Carlo simulations you can re-run on this site's simulator. Sources and methodology are documented on the About page.