Water Supply Outlook for Alberta

July 2015

Water Supply Forecast as of July 1, 2015 - Oldman River Basin (Natural Flows)

Volume Forecast for July 1 to September 30, 2015 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 2015 Volume as a % of Average Ranking (lowest to highest)
St. Mary River 149,000** 73 57-89 43 17/99 91*** 30/99
Belly River 60,000* 78 67-90 57 21/99 95*** 37/99
Waterton River 106,000* 74 57-95 41 23/99 91*** 26/99
Oldman River near Brocket 183,000* 77 60-109 44 37/99 86*** 27/99
Oldman River at Lethbridge 572,000* 75 59-90 46 30/99 81*** 26/99

*NOTE: The forecast shown is the March to September 2015 forecast minus the recorded volume to date

** - This value is the natural volume and includes the U.S. share
*** - Recorded 2015 natural volumes are preliminary and subject to change
Average is calculated for the March 1 to September 30 period 1981 to 2009

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