Water Supply Outlook for Alberta

June 2015

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

Volume Forecast for June 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-May 2015 Volume as a % of Average Ranking (lowest to highest)
St. Mary River 340,000** 78 69-87 61 19/99 111*** 59/99
Belly River 126,000* 83 73-94 63 23/99 99*** 54/99
Waterton River 267,000* 78 64-99 52 20/99 108*** 53/99
Oldman River near Brocket 471,000* 81 67-115 56 34/99 105*** 43/99
Oldman River at Lethbridge 1,371,000* 76 62-89 50 31/99 102*** 41/99

*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