Colorado River Brief — June 05, 2026
📅 Daily Colorado River Brief — Friday, June 5, 2026
🚨 Breaking / Most important
Nothing material broke in the last 24 hours — but we've crossed into the June inflection window everyone has been pointing at. Reclamation's Final EIS analysis for post-2026 operations is slated to begin this month, and Arizona has said it won't weigh legal action "until June at the earliest," pending Interior's read on the DEIS. The next four to ten weeks decide whether this stays an administrative process or becomes a Supreme Court original-jurisdiction case.
🏛️ Federal / Interior / Reclamation
The post-2026 schedule firmed up in recent reporting: Final EIS analysis expected to begin early June, the Final EIS notice of availability targeted for late July, and the Record of Decision aimed at roughly the same window — about ten weeks out, all ahead of the Oct. 1 expiry of the Interim Guidelines. Reclamation took more than 18,000 DEIS comments (period closed March 2). No new 24-Month Study since the May 15 release.
💧 Reservoir ops & hydrology
Per the May 15 24-Month Study (still the latest): Powell ended April at ~3,527 ft (~24% capacity); the most-probable WY2026 unregulated inflow is 3.27 MAF (34% of average), with the April–July forecast at just 0.800 MAF (13% of average) and May inflow at 0.180 MAF (9%). Powell is projected to finish WY2026 near 3,510.85 ft (~4.77 MAF, 20%). Spring runoff has effectively ended below forecast; the 6.0 MAF Powell release cap and Flaming Gorge augmentation remain the only things holding Powell off minimum power pool (3,490 ft) into fall.
⚖️ Policy, legal, post-2026 negotiations
The Upper Basin's late-April mediation call and the May 1 Lower Basin 3.2 MAF bridge proposal remain the live texts; no new state filing today. Analysts continue to frame June's Interior DEIS posture as the trigger that clarifies whether Arizona (Sullivan & Cromwell retained) sues the federal government or the Upper Basin under the 1922 Compact's 7.5 MAF delivery obligation — a dispute that would land in SCOTUS original jurisdiction. One expert reiterated litigation is likely "within the next 12 months." No new counsel retentions or fund movements surfaced publicly today.
🌾 Lower Basin / Imperial Valley specific
No new IID release today (the March 5 DEIS letter remains its anchor). New since the last brief: the Colorado River District (Western Slope, Upper Basin) launched a state-approved emergency water supply plan — borrowing from Wolford Mountain and Ruedi reservoirs to avoid triggering the Cameo call, and asking urban residents to limit lawn watering to once weekly.
📈 Significance for Imperial Valley
June is the hinge. The order Interior chooses in the Final EIS — and whether it honors the priority system protecting IID's senior 1901 rights — determines whether Imperial Valley's position is defended administratively or has to be litigated. The Upper Basin's own emergency rationing on the Western Slope strengthens the Lower Basin's argument that curtailment, not just CRSP repair, is unavoidable basin-wide — but it also hardens UB resolve against fixed cuts. Watch for the Interior DEIS signal: it sets Arizona's litigation clock, and IID rides with Arizona's timing whether it wants to or not.
📰 Further Reading
The big picture
Inside Climate News: Colorado River Faces 'Devastating Consequences' If Another Dry Winter Lands — June 2 framing of 2027 risk: a repeat of a WY2025-type year would overconsume natural flow by 2.59 MAF and push Mead and Powell to the edge of power-pool/structural minimums. Best single read on the stakes of next winter.
KNAU: About 40 million people use water from the Colorado River. Right? — June 1 explainer interrogating the most-cited basin statistic; useful for non-specialists and for anyone who quotes that number.
Negotiations & policy
Maven's Notebook: Post-2026 operations — Lower Basin proposal and next steps — Cleanest walkthrough of the May 1 LB proposal and the federal NEPA path to Oct. 1.
KJZZ: There's a new plan for managing the Colorado River. Here's what you should know — Lays out the FEIS-to-ROD timeline (early-June analysis, late-July notice).
Legal
Kilpatrick (KTS): Colorado River Developments and Potential Compact Litigation — Primary-style legal analysis of how additional LB cuts ripen into a Compact suit.
AZ Mirror: Arizona hires high-powered law firm, setting the stage for a legal battle — Background on the Sullivan & Cromwell retention and the SCOTUS scenario.
Imperial Valley & IID
- IID: Post-2026 Operations Must Comply with the Law of the River — IID's March 5 DEIS letter (priority system, Glen Canyon repair, Salton Sea scope); still the anchor IID position.
Hydrology
Reclamation: May 2026 Powell Elevation Projections (PDF) — Primary source for the 24-Month Study inflow scenarios.
Lower Colorado Weekly Hydrologic Update (PDF) — Standing tracker, refreshed weekly.
Lake Powell Water Data and Lake Powell Water Level — Real-time elevation trackers.
Infrastructure & federal money
- CPR: Colorado River District launches emergency water plan to protect Western Slope communities — Upper Basin rationing in action; relevant to the LB curtailment argument.
🎲 One More Thing
Colorado River trivia: When full, Lake Powell has nearly 2,000 miles of shoreline winding through Glen Canyon's side canyons — more coastline than the entire Pacific coast of the continental United States. At today's ~24% capacity, a huge share of that shoreline is exposed sandstone and "bathtub ring."
Imperial Valley / IID trivia: The Salton Sea wasn't born of a flood from the sky — it was an engineering accident. In 1905 the Colorado River breached a poorly built irrigation intake and poured almost its entire flow into the Salton Sink for roughly 18 months. It took the Southern Pacific Railroad dumping trainload after trainload of rock to finally plug the breach in 1907 — by which point the modern Salton Sea existed.
📅 Why does the calendar show "Jul 17"? Apple hardcoded that date into the emoji artwork when they launched iCal on July 17, 2002. It never changes. The date in the headline is correct.