Water Supply Outlook for Alberta

July 2010

Water Supply Forecast as of July 1, 2010 - Oldman River Basin (Natural Flows)

Volume Forecast for July 1 to September 30, 2010 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-June 2010 Volume as a % of Average Ranking (lowest to highest)
St. Mary River 227,000** 96 84-125 74 49/91 116*** 69/91
Belly River 78,100* 95 79-105 70 43/91 104*** 50/91
Waterton River 147,000* 90 81-124 64 42/91 100*** 45/91
Oldman River near Brocket 223,000* 87 69-119 58 43/91 89*** 38/91
Oldman River at Lethbridge 704,000* 86 71-117 59 40/91 101*** 48/91

*NOTE: The forecast shown is the March to September 2010 forecast minus the recorded volume to date

** - This value is the natural volume and includes the U.S. share
*** - Recorded 2010 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