Water Supply Outlook for Alberta

May 2002

Table 3a - Water Supply Forecast as of May 1, 2002 - Oldman River Basin (Natural Flows)

Volume Forecast for March 1 to September 30
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-September 2001 Volume as a % of Average
St. Mary River 726,000* 97 74-116 64 40/84 53
Belly River 224,000 91 69-113 65 28/84 70
Waterton River 608,000 92 66-109 53 34/84 60
Oldman River near Brocket 873,000 79 56-112 50 25/84 47
Oldman River at Lethbridge 2,516,000 85 60-112 52 27/84 49

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

Click here to see the table containing the remaining forecast for the season along with the recorded volume to date

* - This value is the natural volume and includes the U.S. share
Average is calculated for the March 1 to September 30 period from 1912 to 1995

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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