Water Supply Outlook for Alberta

July 2017

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

Volume Forecast for July 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-June 2017 Volume as a % of Average Ranking (lowest to highest)
St. Mary River 209,000** 102 82-123 63 48/99 137*** 83/99
Belly River 82,000* 106 95-118 84 57/99 114*** 70/99
Waterton River 158,000* 110 93-132 78 55/99 99*** 39/99
Oldman River near Brocket 208,000* 88 71-104 57 42/99 117*** 58/99
Oldman River at Lethbridge 746,000* 97 82-113 68 47/99 107*** 54/99

*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