Water Supply Outlook for Alberta

May 2003

Table 3a - Water Supply Forecast as of May 1, 2003 - Oldman River Basin (Natural Flows)

Volume Forecast for March 1 to September 30, 2003
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 2002 Volume as a % of Average
St. Mary River 591,000* 79 65-97 62 16/85 152
Belly River 202,000 82 61-108 64 20/85 150
Waterton River 508,000 77 64-108 62 17/85 143
Oldman River near Brocket 896,000 81 63-105 53 26/85 145
Oldman River at Lethbridge 2,273,000 76 59-104 54 20/85 149

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.

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