<!-- canonical: https://the-waterline.com/basin/colorado-lower -->
<!-- Machine-readable Markdown for agents. Append .md to any page URL; index at https://the-waterline.com/llms.txt -->

# Colorado (Lower) basin

Reservoir storage across Arizona / California / Nevada

_Data through Aug 12, 2026 · source last checked Aug 13, 2026 · page revised Aug 13, 2026_

> Now 9.25M af, 15% below the 5-yr median.

Lower Colorado basin storage at 9.28M af, down 9.7% from last year and 14% below the 5-year median. Storage has declined 2.3% this month.

## The numbers

| Period | Current | Prior | Change |
| --- | --- | --- | --- |
| Week over week | 9.25M af | 9.31M af | -0.6% |
| Month over month | 9.25M af | 9.45M af | -2.1% |
| Year over year | 9.25M af | 10.28M af | -10.0% |
| vs 5-yr median | 9.25M af | 10.86M af | -14.8% |

## About this data

- Source: US Bureau of Reclamation RISE; California reservoirs via CA DWR CDEC
- Series: Reservoir storage summed across the basin
- Geography: Colorado (Lower) basin
- Unit: acre-feet
- Calculation period: Daily reading
- Last observation: Aug 12, 2026
- Update frequency: Daily

---
Cite: Colorado (Lower) basin storage is 15% below its 5-yr median. The Waterline, data through Aug 12, 2026. https://the-waterline.com/basin/colorado-lower
Canonical URL: https://the-waterline.com/basin/colorado-lower