Water Supply Outlook for Alberta

July 2009

Water Supply Forecast as of July 1, 2009 - Oldman River Basin (Natural Flows)

Volume Forecast for July 1 to September 30, 2009 Year to date
Locations Volume in dam3 Volume as a % of Average Probable Range as a % of Average Potential Minimum as % of Average Forecast Ranking (lowest to highest) Recorded March-June 2009 Volume as a % of Average Ranking (lowest to highest)
St. Mary River 156,000** 66 56-100 36 18/91 69*** 14/91
Belly River 59,200* 72 60-102 50 16/91 78*** 15/91
Waterton River 103,000* 63 48-99 39 17/91 72*** 16/91
Oldman River near Brocket 148,000* 58 44-96 36 15/91 54*** 9/91
Oldman River at Lethbridge 486,000* 60 46-96 34 17/91 60*** 12/91

*NOTE: The forecast shown is the March to September 2009 forecast minus the recorded volume to date

** - This value is the natural volume and includes the U.S. share
*** - Recorded 2009 natural volumes are preliminary and subject to change Average is calculated for the period 1912 to 2001

NOTE: There is: a 50% chance that the actual natural flow will fall within the probable range given; a 25% chance that the actual flow will be less than the lower bound of the probable range given; and a 10% chance that the actual natural flow will be less than the reasonable minimum. Actual day to day streamflow conditions may vary throughout the season as a result of the effects of streamflow diversion and reservoir storage.

For technical enquires about this web page please contact Alberta Environment - Environmental Management Water Management Operations Branch at AENV-WebWS@gov.ab.ca