Hydrohistorian
Colorado River status
7.1 ft above 3,510 (2027-28 guidelines: operations aim to hold this)
13.7 ft above 1,025 (2007 guidelines tier 3 shortage)
The rule in force
- Post-2026 operations are settled for 2027-2036 under the Record of Decision signed 21 August 2026, which adopts a "Decision Framework" with guidelines reset every two years.
Decided 2026-08-21 · source · Reclamation states that consensus among the Basin States on long-term operations was not reached.
- Lake Powell for water years 2027-2028 is operated by projected 1 October elevation: above 3,565 ft is the normal band, 3,565 to 3,540 ft an intermediate band, and below 3,540 ft the "Low Elevation Infrastructure Protection Range", with operations aimed at holding 3,510 ft and protecting a critical 3,500 ft.
Decided 2026-08-21 · source · These bands replace the 2007 Interim Guidelines tiers for 2027-2028.
- Water year 2027 (October 2026 to September 2027): the August 2026 24-Month Study projects Powell below 3,540 ft on 1 October and falling below 3,510 ft, so Glen Canyon Dam releases 6.0 to 7.0 million acre-feet under the Low Elevation Infrastructure Protection Range.
Decided 2026-08-21 · source · Issued as two scenarios, 24Month_08_6.pdf and 24Month_08_7.pdf (6 versus 7 maf release).
- Lake Mead for calendar years 2027-2028 is in a Shortage Condition apportioning 6.25 million acre-feet to the Lower Basin (Arizona 2.04, California 3.96, Nevada 0.25), a 1.25 maf reduction, with consultation triggered below 1,010 ft or above 1,125 ft.
Decided 2026-08-21 · source · Section 5.3.A; section 5.3.B adds 700,000 af of system conservation for 2026-2028.
- Water year 2026 (the year now ending): Powell began in the 2007 Guidelines' Mid-Elevation Release Tier at 7.48 maf and the release was cut to 6.0 maf in April 2026 under section 6.E of the 2024 Supplemental EIS; Mead was in a Level 1 Shortage (Arizona 512,000 af, Nevada 21,000 af, Mexico 80,000 af).
Decided 2025-08-15 · source · The April 2026 reduction is Reclamation news release 5326 (2026-04-17).
Checked against the documents on 2026-09-08 by John Crawford, from the Reclamation documents linked below. A machine updates the numbers on this page every night; it never updates this box.
Lake Powell against its decision elevations
Last 365 days
Since 1963, end of each month
What each line means
| Elevation | Meaning | Where it comes from |
|---|---|---|
| 3,700 ft | Full pool | Reclamation, Glen Canyon Dam |
| 3,575 ft | Upper bound of the 2007 Mid-Elevation Release Tier | 2007 Interim Guidelines ROD |
| 3,565 ft | 2027-28 Guidelines: above this, normal band | 2027-2028 Operating Guidelines, post-2026 ROD |
| 3,540 ft | 2027-28 Guidelines: below this, Low Elevation Infrastructure Protection Range | 2027-2028 Operating Guidelines |
| 3,525 ft | DROA target: 35-ft buffer above minimum power pool | Drought Response Operations Agreement, 2019 |
| 3,510 ft | 2027-28 Guidelines: operations aim to hold this | 2027-2028 Operating Guidelines |
| 3,490 ft | Minimum power pool | Reclamation, Glen Canyon Dam |
| 3,370 ft | Dead pool | Reclamation news release 4294 |
Lake Mead against its decision elevations
Last 365 days
Since 1935, end of each month
What each line means
| Elevation | Meaning | Where it comes from |
|---|---|---|
| 1,229 ft | Full pool (spillway crest) | Reclamation, Hoover Dam |
| 1,125 ft | 2027-28 Guidelines: consultation trigger, high | 2027-2028 Operating Guidelines |
| 1,075 ft | 2007 Guidelines Tier 1 shortage | 2007 Interim Guidelines ROD |
| 1,050 ft | 2007 Guidelines Tier 2 shortage | 2007 Interim Guidelines ROD |
| 1,025 ft | 2007 Guidelines Tier 3 shortage | 2007 Interim Guidelines ROD |
| 1,010 ft | 2027-28 Guidelines: consultation trigger, low | 2027-2028 Operating Guidelines |
| 950 ft | Hoover loses hydropower | 2027-2028 Operating Guidelines |
| 895 ft | Dead pool | Reclamation, Hoover Dam |
Glen Canyon Dam, last 90 days
Inflow to Powell, cfs
Release from Glen Canyon Dam, cfs
Release above inflow draws the reservoir down; Reclamation sets the release by the operating determination above, not by the inflow of the week.
The other CRSP reservoirs
Flaming Gorge, Blue Mesa and Navajo are the reservoirs the Drought Response Operations Agreement can draw on to prop up Powell; Blue Mesa is the one in Colorado.
Water past Lee Ferry, and the Compact's ten-year test
Article III(d) of the 1922 Compact says the Upper Basin "will not cause the flow of the river at Lee Ferry to be depleted below an aggregate of 75,000,000 acre-feet for any period of ten consecutive years." Measured flow at the compact point (the Lees Ferry gage plus the Paria) over the most recent ten complete water years, WY2016–2025, was 84.4 maf. The Upper Colorado River Commission's own accounting for WY2016–2025 put the ten-year total at 84.38 maf. Both are measurements of what passed, not findings about depletion, which is a different calculation under the compact's own rules.
The full record, decade by decade, is on the compacts page.
Read the documents
- Latest 24-Month Study (Upper Colorado)
- Weekly Hydrologic Update, one page (Lower Colorado)
- Daily system levels (Lower Colorado)
- Post-2026 process and decision documents
- 2007 Interim Guidelines Record of Decision
- 2019 Drought Contingency Plans
- Upper Colorado River Commission annual reports (Lee Ferry accounting)
- Reclamation HydroData (the series on this page)
Reservoir series: Reclamation Upper Colorado HydroData, marked provisional and subject to revision by Reclamation; capacities are Reclamation's live capacities (Powell reflects the 2017–18 resurvey). Fetched nightly; summary built 2026-09-13T11:24 UTC. Lee Ferry: USGS 09380000 and 09382000. This page reads decision documents; it does not model operations or forecast elevations. Report a problem →