Water Supply Outlook for Alberta

May 2006

Table 4a - Water Supply Forecast as of May 1, 2006 - Oldman River Basin (Natural Flows)

Volume Forecast for March 1 to September 30, 2006
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 2005 Volume as a % of Average
St. Mary River 685,000* 92 80-113 71 35/91 77
Belly River 235,000 96 85-110 78 39/91 90
Waterton River 589,000 97 81-111 76 44/91 85
Oldman River near Brocket 1,067,000 98 83-119 71 47/91 132
Oldman River at Lethbridge 2,762,000 93 74-111 66 44/91 106

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 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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