Bow River Basin - Water Supply Forecasts

As of April 1, 2006, natural runoff volumes for the March to September 2006 period are forecast to range from below average to average in the Bow River basin. Natural runoff volumes are expected to be below average at Banff, Calgary and into the Spray Lakes and Cascade Reservoirs, and below average to average for the Kananaskis, Elbow and Highwood Rivers (Table 5a). Current natural runoff volume forecasts range from 85 to 95% of average in the basin. Current forecasts have dropped 2 to 4% of average since the March 1 forecasts, except for the Kananaskis River forecast which rose 1%. The current forecasted volume for the Bow River at Calgary would rank 30th lowest in 91-years of record (1912-2001).

The first month of the forecast period has been completed, with March 2006 recorded natural runoff volumes ranging from 90 to 126 % of average. Banff, Calgary, the Kananaskis and Elbow Rivers, and the Spray Reservoir recorded above to much above average runoff during March, while the Highwood River and Cascade Reservoir recorded near average runoff. Recorded volume data is preliminary, due to ice effects, and is subject to change. March volumes typically comprise a small portion of the March to September total. The remaining volume forecast, which is the March to September 2006 forecast minus the recorded volume to date, is available in Table 5b.