Water Supply Outlook for Alberta

May 2011

Water Supply Forecast as of May 1, 2011 - Oldman River Basin (Natural Flows)

Volume Forecast for March 1 to September 30, 2011
Locations Volume in dam3 Volume as a % of Average Probable Range as a % of Average Potential Minimum as % of Average Forecast Ranking (lowest to highest) Recorded March-September 2010 Volume as a % of Average
St. Mary River 760,000* 102 93-119 88 51/91 124
Belly River 250,000 102 84-112 77 50/91 109
Waterton River 634,000 104 83-113 77 56/91 85
Oldman River near Brocket 1,313,000 120 83-138 76 68/91 94
Oldman River at Lethbridge 3,206,000 107 77-123 72 55/91 114

 

* - 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 potential 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