Water Supply Outlook for Alberta

April 2009

Water Supply Forecast as of April 1, 2009 - Oldman River Basin (Natural Flows)

Volume Forecast for April 1 to September 30, 2009 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 2009 Volume as a % of Average Ranking (lowest to highest)
St. Mary River 597,000** 82 68-103 56 23/91 35*** 6/91
Belly River 205,000* 86 74-105 67 25/91 62*** 13/91
Waterton River 503,000* 85 64-104 55 25/91 47*** 8/91
Oldman River near Brocket 902,000* 85 70-109 56 31/91 51*** 9/91
Oldman River at Lethbridge 2,365,000* 83 63-106 52 31/91 36*** 5/91

*NOTE: The forecast shown is the March to September 2009 forecast minus the recorded volume to date

** - This value is the natural volume and includes the U.S. share
*** - Recorded 2009 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.

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