Water Supply Outlook for Alberta

August 2017

Water Supply Forecast as of August 1, 2017 - Oldman River Basin (Natural Flows)

Volume Forecast for August 1 to September 30, 2017 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-July 2017 Volume as a % of Average Ranking (lowest to highest)
St. Mary River 67,000** 82 65-99 50 19/99 122*** 72/99
Belly River 31,000* 92 80-104 69 37/99 105*** 52/99
Waterton River 50,000* 92 76-121 63 45/99 93*** 30/99
Oldman River near Brocket 59,000* 58 41-76 25 11/99 107*** 49/99
Oldman River at Lethbridge 223,000* 71 56-86 42 26/99 96*** 43/99

*NOTE: The forecast shown is the March to September 2017 forecast minus the recorded volume to date

** - This value is the natural volume and includes the U.S. share
*** - Recorded 2017 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