Water Supply Outlook for Alberta

August 2010

Water Supply Forecast as of August 1, 2010 - Oldman River Basin (Natural Flows)

Volume Forecast for August 1 to September 30, 2010 Year to date
Locations Volume in dam3 Volume as a % of Average Probable Range as a % of Average Reasonable Minimum as % of Average Forecast Ranking (lowest to highest) Recorded March-July 2010 Volume as a % of Average Ranking (lowest to highest)
St. Mary River 97,000** 99 92-118 82 50/91 117*** 69/91
Belly River 34,800* 96 82-106 70 47/91 104*** 51/91
Waterton River 56,700* 92 80-110 65 46/91 103*** 52/91
Oldman River near Brocket 90,000* 83 67-100 62 42/91 89*** 39/91
Oldman River at Lethbridge 293,000* 88 73-109 65 47/91 113*** 64/91

*NOTE: The forecast shown is the March to September 2010 forecast minus the recorded volume to date

** - This value is the natural volume and includes the U.S. share
*** - Recorded 2010 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.


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