Water Supply Outlook for Alberta

April 2008

Mountain Water Supply Forecast Summary

As of April 1, 2008, below average natural runoff volumes are forecast for this year (March - September 2008) for the North Saskatchewan River basin and the Bow River at Banff and Calgary, and slightly below average volumes are forecast for the Highwood, Red Deer and Milk River basins. Near average natural runoff volumes are forecast for the Oldman River basin and the Kananaskis - Elbow River area (Table 1).

Forecasted volumes have decreased in most basins since the March 1 forecasts were issued, due to much below normal precipitation in most mountain areas during March.

Cooler than normal temperatures during March resulted in less than normal melting of snowpack in southern Alberta. Due to the delayed melt and much below normal precipitation, natural runoff volumes recorded for March ranged from below to much below average in most mountain areas except near average in the Kananaskis and Elbow River basins. Recorded volume data is preliminary, due to ice effects, and is subject to change. March volumes in the North Saskatchewan River basin have not yet been presented due to ice effects and other issues with the data. March - April natural volumes will be available in the May Water Supply Outlook. March volumes are typically a small portion of the yearly total.

Remaining snowpack is generally slightly below average in the upper Bow and North Saskatchewan River basins, and average to above average in the Oldman River basin. In the Red Deer River basin, despite snow accumulations that are third to ninth lowest in the past 25 to 30 years, runoff is forecast to be slightly below average for this year with normal rainfall this summer as soil moisture conditions in the basin are generally near average or better.

Forecasts assume that precipitation over the summer period will be normal. Precipitation will have a major impact on the summer water supply forecast between now and the end of September. Streamflow volume forecasts will be updated monthly until mid-summer. Check our Forecaster's Comments throughout the month for updated information regarding runoff conditions.

For technical enquires about this web page please contact Alberta Environment - Environmental Management Water Management Operations Branch at AENV-WebWS@gov.ab.ca