USBR 24-Month Study Projections
Reclamation's September 2026 published projections for Lake Mead and Lake Powell - transcribed, dated, and linked to the source PDFs. Reclamation has since published its October 2026 24-Month Study; the figures below remain the September 2026 study until the newer one is transcribed from the source PDF.
Western Reservoir Conditions·Daily·No. 91·
- Reclamation's September 2026 Most Probable 24-Month Study projects Lake Mead at 1,034.18 feet and Lake Powell at 3,513.51 feet on December 31, 2026.
- That Lake Mead projection is 6.40 feet below the July 2022 record low of 1,040.58 feet - the study projects new record-low territory by the end of 2026.
- In the Probable Minimum scenario, Lake Powell falls below its 3,490-foot minimum power pool at end-September 2027 and reaches 3,475.21 feet at end-February 2028, and Lake Mead ends the study window at 978.22 feet in June 2028.
- Actual levels as of : Lake Mead 1,037.19 ft, Lake Powell 3,521.76 ft.
What these numbers are
The 24-Month Study is the Bureau of Reclamation's monthly operational projection for the Colorado River system: one model run under Most Probable inflow, and (in most months) companion runs under Probable Minimum and Probable Maximum inflow. Reservoir Bench does not model or predict anything - this page transcribes Reclamation's published end-of-month elevations, names the study month, and links the source PDFs. No Probable Maximum study was published for September 2026.
Sources: September 2026 Most Probable study, 6 maf Powell release (PDF) · 7 maf release run (PDF) · Probable Minimum study (PDF), both released September 15, 2026.
Lake Mead projected end-of-month elevation (ft)
| Date | Most Probable | Probable Minimum | Most Probable vs today (1,037.19 ft) |
|---|---|---|---|
| December 31, 2026 | 1,034.18 | 1,033.58 | -3.01 ft |
| December 31, 2027 | 1,013.89 | 1,002.60 | -23.30 ft |
| June 30, 2028 | 998.42 | 978.22 | -38.77 ft |
Lake Mead context: the record low is 1,040.58 ft (July 28, 2022); minimum power pool is 950 ft and dead pool is 895 ft - see minimum power pool and dead pool. Live daily readings: Lake Mead water level.
Lake Powell projected end-of-month elevation (ft)
| Date | Most Probable | Probable Minimum | Most Probable vs today (3,521.76 ft) |
|---|---|---|---|
| December 31, 2026 | 3,513.51 | 3,511.82 | -8.25 ft |
| December 31, 2027 | 3,527.62 | 3,477.17 | +5.86 ft |
| June 30, 2028 | 3,558.44 | 3,506.09 | +36.68 ft |
Lake Powell context: minimum power pool is 3,490 ft, dead pool 3,370 ft. The lowest projected end-of-month elevation is 3,511.43 ft (February 28, 2027) in the Most Probable run and 3,475.21 ft (February 29, 2028) in the Probable Minimum run. Live daily readings: Lake Powell water level.
Operational notes from the study
- Water year 2027 is the first operated under the 2027-2028 Operating Guidelines issued under the 2026 Record of Decision. The August 2026 study projected Lake Powell below 3,540 feet on October 1, 2026, so Powell's WY 2027 release falls in the Low Elevation Infrastructure Protection Range, expected between 6.00 and 7.00 million acre-feet.
- With a 7.00 maf WY 2027 Powell release instead of 6.00 maf, the September 2026 Most Probable run puts Lake Mead at 1,025.13 feet and Lake Powell at 3,515.35 feet on December 31, 2027.
- A shortage condition under Section 5.3.A of the 2027-2028 Operating Guidelines governs Lake Mead for calendar year 2027; the 2027 determinations will be documented in the 2027 Annual Operating Plan, which Reclamation says is in development.
Projections policy: these are Reclamation's published figures, not this site's. Projections change every month; the study month is stated on every number above, and this page is refreshed when a new study is transcribed. The August study sets the following year's operating conditions. Actual elevations on this site come from the daily gauge record and are updated daily regardless.