Lake Diefenbaker Updates
Lake Diefenbaker Updates
Updated August 6, 2026
Current Conditions
- Most headwater stations are continuing to decline slowly. Flows on the Oldman and Red Deer rivers are near lower quartile levels for this time of year, while flows on the Bow River are generally between median and lower quartile levels.
- With the continued hot and dry weather, Alberta diversions have remained strong. Declining headwater flows and continued diversions are contributing to lower inflows into Lake Diefenbaker.
- Inflows into Lake Diefenbaker are currently near median levels for this time of year and are expected to remain between median and lower quartile levels into next week.
- Water levels on Lake Diefenbaker are currently near median levels for this time of year. Based on the current inflow and outflow forecast, the reservoir is expected to decline gradually over the next 10 days.
- Releases are planned to remain within the 200 to 250 m³/s range for the next while. The forecast indicates a gradual reduction in daily mean outflows to approximately 180 m³/s near the end of the forecast period.
- Conditions will continue to be monitored closely, and outflows may be adjusted as needed based on updated forecasts and observed basin conditions.
Forecast Overview
- Inflows into Lake Diefenbaker are expected to remain relatively steady over the next week.
- Daily mean outflows are expected to gradually decrease from approximately 250 m³/s to 180 m³/s over the forecast period.
- Lake Diefenbaker levels are expected to gradually decline from approximately 555.77 m to 555.51 m over the forecast period.
Note: Flows shown in the table above are mean (average) daily flows. Actual releases from Lake Diefenbaker may fluctuate throughout the day as SaskPower adjusts operations at Coteau Creek Hydro Station to meet the Province’s electricity demands.
Hydrologic / Weather Conditions
- Minimal precipitation was received across the South Saskatchewan River Basin headwaters this week.
- Approximately 5 to 15 mm of precipitation is forecast for the headwaters this weekend. This precipitation is not currently expected to result in a significant change in basin flows.
Below are the updated plots showing 2026 observed inflows and reservoir elevations compared to historical ranges.
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