Glen Canyon Dam · Colorado River · AZ–UT
Lake Powell
The second-largest US reservoir, gaged by both USGS (15-minute) and Reclamation (daily) — the two records cross-check each other on this page.
Water surface elevation
3,517.8 ft
USGS gage, 15-minute · Sep 2, 4:45 AM MST
Water in storage
5.14 million acre-feet
Bureau of Reclamation, daily · daily value, Aug 31
Share of capacity
20.4% full
against the 2018 survey capacity figure (USGS-USBR 2017-18 bathymetric survey)
Below full pool
182.2 ft
full pool at 3,700.0 ft
This month in the record
lower than 97% of the 63 Septembers on record
monthly mean storage; record low 436,433 acre-feet (1963), record high 24.57 million acre-feet (1983)
30-day trend
-8,269 af/day
storage, 2026-07-30 → 2026-08-29; over the year -5,076 af/day. Measured change, not a forecast.
Drought at the dam
D2 — Severe drought
US Drought Monitor at the dam's coordinates, released 2026-08-27; the feeding basin can differ.
Water flowing out
7,729 cfs
operator's daily release, 2026-08-29 — powerplant release only; river-outlet bypass excluded
20.4% full
of capacity, by storage (2018 survey figure, USGS-USBR 2017-18 bathymetric survey). Sedimentation slowly shrinks real capacity.
The water line is elevation (NGVD29); the percentage is storage ÷ capacity. They are different measures — a reservoir's volume is not linear in its depth, so the line's height in this column is not the percentage.
Snowpack in the feeding basin
Measured across the Upper Colorado basin snowpack that feeds the whole Colorado system.
Snow season
typically Oct 12 – Jun 12
0 in on the ground, 2026-09-01; median peak 19.7 in around May 3
Last winter's verdict
47% of median peak
water year 2026 — the snow that fed this year's pool
5 highest active SNOTEL stations in the basin (Black Mesa, Slumgullion, Castle Peak, …), NRCS AWDB REST (SNOTEL), station set pinned 2026-08-31. Daily snow-water equivalent against the stations' own 30-year medians; off season the percent is withheld rather than divided by zero.
The last 119 days
Daily water-surface elevation in feet. The axis hugs the data — it does not start at zero. Source: USGS NWIS daily values.
See the numbers as a table
| Date | Elevation (ft) |
|---|---|
| Aug 31 | 3517.70 |
| Aug 30 | 3517.80 |
| Aug 29 | 3517.80 |
| Aug 28 | 3517.90 |
| Aug 27 | 3518.10 |
| Aug 26 | 3518.30 |
| Aug 25 | 3518.40 |
| Aug 24 | 3518.50 |
| Aug 23 | 3518.60 |
| Aug 22 | 3518.80 |
| Aug 21 | 3519.00 |
| Aug 20 | 3519.10 |
| Aug 19 | 3519.30 |
| Aug 18 | 3519.40 |
| Aug 17 | 3519.60 |
| Aug 16 | 3519.70 |
| Aug 15 | 3519.80 |
| Aug 14 | 3519.90 |
| Aug 13 | 3520.10 |
| Aug 12 | 3520.20 |
| Aug 11 | 3520.40 |
| Aug 10 | 3520.60 |
| Aug 9 | 3520.80 |
| Aug 8 | 3520.90 |
| Aug 7 | 3521.10 |
| Aug 6 | 3521.30 |
| Aug 5 | 3521.40 |
| Aug 4 | 3521.60 |
| Aug 3 | 3521.70 |
| Aug 2 | 3521.90 |
Most recent 30 days shown.
The whole record
Monthly mean elevation, Jan 1964 to Aug 2026. The axis spans the pools, not zero; elevations in NGVD29. Months with fewer than 15 gaged days are dropped, and gaps in the record break the line. Source: USBR RISE, retrieved 2026-08-31.
See the numbers as a table
| Month | Mean elevation (ft) | Days gaged |
|---|---|---|
| Aug 2026 | 3520.0 | 29 |
| Jul 2026 | 3523.9 | 31 |
| Jun 2026 | 3527.4 | 30 |
| May 2026 | 3527.0 | 31 |
| Apr 2026 | 3527.4 | 30 |
| Mar 2026 | 3529.4 | 31 |
| Feb 2026 | 3532.9 | 28 |
| Jan 2026 | 3537.7 | 31 |
| Dec 2025 | 3541.7 | 31 |
| Nov 2025 | 3544.4 | 30 |
| Oct 2025 | 3545.0 | 31 |
| Sep 2025 | 3546.3 | 30 |
| Aug 2025 | 3551.6 | 31 |
| Jul 2025 | 3558.4 | 31 |
| Jun 2025 | 3561.1 | 30 |
| May 2025 | 3558.3 | 31 |
| Apr 2025 | 3558.5 | 30 |
| Mar 2025 | 3560.9 | 31 |
| Feb 2025 | 3564.7 | 28 |
| Jan 2025 | 3569.4 | 31 |
| Dec 2024 | 3573.5 | 31 |
| Nov 2024 | 3576.1 | 30 |
| Oct 2024 | 3577.3 | 31 |
| Sep 2024 | 3579.4 | 30 |
Most recent 24 months shown; the full monthly series is in the page's API response.
Storage against capacity
Monthly mean storage in acre-feet, zero baseline. The dashed line is the 2018 survey capacity figure (USGS-USBR 2017-18 bathymetric survey) — sedimentation slowly shrinks real capacity. Storage can legitimately rise past a conservation-pool line when the flood pool is in use.
See the numbers as a table
| Month | Mean storage (acre-feet) | Days gaged |
|---|---|---|
| Aug 2026 | 5,262,878 | 29 |
| Jul 2026 | 5,483,459 | 31 |
| Jun 2026 | 5,681,823 | 30 |
| May 2026 | 5,659,361 | 31 |
| Apr 2026 | 5,683,179 | 30 |
| Mar 2026 | 5,803,544 | 31 |
| Feb 2026 | 6,012,822 | 28 |
| Jan 2026 | 6,303,905 | 31 |
| Dec 2025 | 6,555,523 | 31 |
| Nov 2025 | 6,731,020 | 30 |
| Oct 2025 | 6,769,910 | 31 |
| Sep 2025 | 6,851,344 | 30 |
| Aug 2025 | 7,205,334 | 31 |
| Jul 2025 | 7,672,823 | 31 |
| Jun 2025 | 7,867,169 | 30 |
| May 2025 | 7,668,056 | 31 |
| Apr 2025 | 7,681,130 | 30 |
| Mar 2025 | 7,849,603 | 31 |
| Feb 2025 | 8,126,894 | 28 |
| Jan 2025 | 8,471,238 | 31 |
| Dec 2024 | 8,785,751 | 31 |
| Nov 2024 | 8,983,318 | 30 |
| Oct 2024 | 9,076,031 | 31 |
| Sep 2024 | 9,247,156 | 30 |
Most recent 24 months shown.
Where these numbers come from
Readings at Lake Powell are the measuring agencies' own: each value above names its source (USGS gage, Bureau of Reclamation daily record, Army Corps project data, or this desk's committed copy) and its observation time in the reservoir's own time zone. The capacity figure is the 2018 survey USGS-USBR 2017-18 bathymetric survey number; sedimentation slowly shrinks real capacity, so the vintage travels with the percent.