Reservoirs
Near normalCanyon Ferry Lake level
Live reservoir storage and water level in Missouri basin, Montana
Data through Aug 12, 2026 · source last checked Aug 13, 2026 · page revised Aug 13, 2026
Cite
- Storage
About this data
- Source
- US Bureau of Reclamation RISE; California reservoirs via CA DWR CDEC
- Series
- End-of-day reservoir storage
- Geography
- Canyon Ferry Lake level
- Unit
- acre-feet
- Calculation
- Daily reading
- Last observation
- Aug 12, 2026
- Update frequency
- Daily
Now 1.62M af, 3% below the 5-yr median, 86% of capacity.
Canyon Ferry storage fell to 1.63M af on August 9, down 3.7% from a month earlier and 4% below the 5-year median. The reservoir sits at 86% of capacity. Storage is up 2.0% from a year ago.
| Period | Current | Prior | Change |
|---|---|---|---|
| Week over week | 1.62M af | 1.65M af | -1.7% |
| Month over month | 1.62M af | 1.69M af | -4.3% |
| Year over year | 1.62M af | 1.59M af | +1.9% |
| vs 5-yr median | 1.62M af | 1.68M af | -3.4% |
| Measure | Value | Source |
|---|---|---|
| Full pool elevation | 3,770 ft above sea level (top of active conservation pool) | USBR |
| Maximum depth at the dam | 172 ft | USBR |
| Surface area at full pool | 34,435 acres | USACE NID |
| Total capacity | 1,886,950 acre-feet | USBR |
About Canyon Ferry Lake
Canyon Ferry Dam impounds the Missouri River east of Helena, part of the Pick-Sloan Missouri Basin Program. Reclamation operates it for hydropower, irrigation, flood control, and recreation. Covering better than 33,000 acres, it is Montana's third-largest body of water and a heavily used recreation lake in the state's western valleys.
Total capacity is 1.89M af, over the past five years storage has ranged from 1.26M af to 1.89M af.
Those figures describe the reservoir at full pool, not today. The chart at the top of this page tracks storage in acre-feet rather than water depth, so read the current figure against total capacity for how full the reservoir is, and against the full pool elevation and maximum depth for the size of the water column behind the dam. The two do not move together one for one: a reservoir narrows as it deepens, so one holding half its capacity still stands more than half as deep.
Sources: full pool elevation and maximum depth from the Bureau of Reclamation; surface area from the Army Corps' National Inventory of Dams; total capacity from the Bureau of Reclamation.