Water Supply Forecast Summary

Significant precipitation is needed to improve the overall water supply outlook for Northern and Central Alberta. Most areas north of Calgary are extremely dry as a result of several consecutive months of much-below-normal precipitation. In fact, some areas have received record low precipitation. As a result, streams in the prairie region north of Calgary remain very low and are beginning to approach historical minimum values.

In Southern Alberta, however, the water supply forecast continues to improve as a result of record precipitation in June. A major storm system brought record high precipitation to some areas, and caused some minor flooding. The March to June recorded natural runoff volumes are near the highest on record in the Oldman and Milk River basins as a result of a very wet spring and early summer. Areas north of Calgary, which has not received significant precipitation in the past few months, remain very dry with prairie streams beginning to approach historical minimums.

Much-above-average natural runoff volumes as of July 1, 2002 are forecast for the Oldman and Milk River basins for the forecast period (March to September 2002 period) (Table 1) and for the remaining portion of the season (July to September). Natural runoff volumes are forecast to be above-average for the Elbow and Highwood Rivers, average for the Bow River basin and below-average for the Red Deer and North Saskatchewan River basins.

July 1 forecast volumes increased substantially from last month's forecast in southern areas of the province. Forecast volumes remained steady this month in the Bow River basin and decreased elsewhere in the province. Current forecasted runoff for this year remains higher than recorded runoff last year in most areas of the province.

These 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.