Lake Mead ended August 2026 at 1,038.83 feet above sea level, according to the Bureau of Reclamation's own table of end-of-month elevations. That is below the 1,040.92 feet of July 2022, until now the lowest month-end reading since the reservoir first filled, and lower than any month-end level since March 1937, when Lake Mead was still rising behind the newly completed Hoover Dam. The lake fell 2.27 feet in August after 3.48 feet in July, and Reclamation's September 24-Month Study projects 1,038.40 feet at the end of September.
Reclamation published that September study on 15 September the way it published August's: twice, as two official Most Probable reports, one assuming that Lake Powell releases 6.0 million acre-feet in water year 2027 and one assuming 7.0 maf. Both narratives repeat August's formula — the expected release "will be in the range between 6.00 million acre-feet (maf) to 7.00 maf" — and neither names a single figure.
They again disagree about the one clause in the new 2027-2028 guidelines that reads Lake Mead's elevation. Section 5.3.A.4 requires the Secretary of the Interior to consult the Basin States and Basin Tribes if the Most Probable projection of any 24-Month Study shows Lake Mead "falling below 1,010 feet at any time in the subsequent 12-month period". In the twelve months from October 2026, the 6.0 maf run takes the reservoir below that line at three month-ends: 1,008.13 feet in June 2027, 1,007.38 feet in July and 1,009.66 feet in August. The 7.0 maf run's lowest point in the same window is 1,015.54 feet, in June.
Compared with August, both runs are slightly better for the summer of 2027 — the 6.0 maf low is 1.75 feet higher and the 7.0 maf low 1.62 feet higher — and slightly worse for the winter. The projected elevation on 1 January 2027, identical in both runs, is 1,034.18 feet, down from 1,034.74 in the August studies, which this publication reported was already the lowest 1-January figure printed in any August study since 2010.
The tables run past the clause's window, and there the 6.0 maf run goes much further than its headline figures suggest. It has Lake Mead below 1,010 feet again from May 2028, and below 1,000 feet at the end of June, July and August 2028, reaching 996.96 feet in July. The August 6.0 maf run went lower still, to 991.68 feet in July 2028. Even the 7.0 maf runs dip below 1,010 feet in the summer of 2028: to 1,009.07 feet in the September edition and 1,004.62 feet in August's.
That last figure corrects this publication. On 25 August we wrote that the August 7.0 maf study "never falls below 1,013.92 feet" and that it bottoms there. Within the 12-month window that the consultation clause reads, 1,013.92 feet is its lowest point, and that story's account of the clause is unaffected; but the study's full table does go lower, to 1,004.62 feet in June 2028. The correction is logged in our corrections log.
Reclamation's April 2027 determination will fix the water-year release and, with it, which of the two runs describes the river. Until then, Section 5.3.A of the guidelines already sets a flat 1.25 million acre-foot reduction in Lower Basin water for 2027, whatever the lake's elevation.