Interior Secretary Doug Burgum signed the Record of Decision and 2027–2028 Operating Guidelines for the Colorado River on Aug. 21, closing the federal environmental review of post-2026 operations and replacing the interim rules that expire at the end of 2026.
The guidelines require the three Lower Basin states — California, Arizona and Nevada — to reduce deliveries by 1.25 million acre-feet in each of 2027 and 2028, more than double the maximum cuts under the expiring 2007 rules, plus at least 700,000 acre-feet of voluntary conservation and storage across the two years. Under the states’ proposed split, Arizona takes 760,000 acre-feet, California 440,000 and Nevada 50,000. The Upper Basin states are encouraged but not required to conserve. Interior framed the decision as a 10-year framework with rules written in two-year increments, leaving room for a negotiated seven-state agreement to replace it.
Reclamation’s August 24-Month Study projects Lake Powell will enter water year 2027 between 3,510 and 3,540 feet, inside what the agency calls its infrastructure protection range; releases will be managed to hold the reservoir at or above 3,510 feet, with the final 2027 release set in April. The combined contents of Powell and Mead are at their lowest since Powell began filling in 1963.
JB Hamby, an Imperial Irrigation District director speaking as chairman of the Colorado River Board of California, called the decision “a bridge, not a permanent solution” and said three states cannot carry the responsibility of all seven. The federal decision sets California’s total but does not allocate it among California agencies. The Imperial Irrigation District holds the largest senior entitlement in the Lower Basin and has consistently opposed shifting a disproportionate share onto Imperial Valley agriculture; that negotiation is where the question now sits. Nevada filed a federal court challenge to the rules on Aug. 25.
The same district is also in court over whether a proposed data center can convert leased farmland into an industrial water right. Producers and markets in the valley are listed on the Imperial County page; the farmers market directory covers all ten counties.
Why this matters for SoCal: Roughly 470,000 acres of Imperial Valley farmland run on this river, and the number that determines what gets planted there next winter — IID’s share of 440,000 — has not been set.
Update, Sept. 22, 2026: The Imperial Irrigation District’s share of California’s 440,000 acre-foot cut is still unset. Meanwhile a judge has overturned county approval of the data center whose farmland-to-cooling water claim sits before the same district.
Source: Interior Department finalizes New Colorado River Operating Rules for 2027-2028 — The Desert Review, Aug. 21, 2026