Water Supply Outlook for Alberta

April 2005

Table 3b - Water Supply Forecast as of April 1, 2005 - Oldman River Basin (Natural Flows)

Volume Forecast for April 1 to September 30, 2005 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 2005 Volume as a % of Average Ranking (lowest to highest)
St. Mary River 518,000** 71 59-101 51 17/91 55*** 22/91
Belly River 188,000* 79 61-102 54 18/91 107*** 66/91
Waterton River 434,000* 74 60-100 50 18/91 86*** 44/91
Oldman River near Brocket 752,000* 71 55-103 50 21/91 111*** 67/91
Oldman River at Lethbridge 1,958,000* 68 53-99 46 18/91 69*** 36/91

*NOTE: The forecast shown is the March to September 2005 forecast minus the recorded volume to date

Click on the site Location to see the Water Supply Forecast graphically

** - This value is the natural volume and includes the U.S. share
*** - Recorded 2005 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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