Water Management Update – Low Water Levels

Parks Canada Issues a Water Management Update for the Trent-Severn Basin

On November 17th the Parks Canada posted a Water Management Update for the entire Trent – Severn watershed (click here) noting low water levels across the reservoir area and the risk that levels may decline further. The Update confirms that all of the reservoir dams have been at their winter set levels since the first of October. However lake levels have continued to fall because of the lack of normal fall rainfall. The flow in both the Gull and Burnt Rivers is also very low. The Update further notes that lake levels may continue to fall and residents should be aware of the risk of very low water levels this winter unless we begin to see significant rainfall. 

The extreme drought conditions that persisted throughout the summer have now continued through the fall. Haliburton has received only 170mm of precipitation since the first of September compared to a normal of 316mm. 44mm of that total fell on one day in mid-October so in fact the drought is even more severe than the totals show. So far through three weeks of November we have received only 18mm of precipitation compared to a normal of 87mm. In a normal year we expect the reservoirs to reach their lowest levels in mid to late October and then stabilize or recover somewhat in late fall into winter. This year we have experienced a continuing decline in levels on most reservoirs and in some cases levels are approaching the 30 year minimum levels. This situation is a threat to the lake trout spawn and may result in levels that will impact water intakes in shallow water. Because there is very little or no inflow to the system there is no action which can be taken to stop the decline.

The Weather Network Winter Forecast

On November 21, The Weather Network posted their long range forecast for the next three months (click here). The forecast is for below normal temperatures and above normal precipitation for central Ontario. Unless we get significant rainfall in the early winter we may not see the reservoir levels rebound until the spring melt. The Great Lakes are warmer than normal and as a result lake effect rainfall and particularly snowfall events may extend from Georgian Bay across the reservoir areas this fall and winter depending on wind direction. We definitely need above average precipitation this winter to restore the water balance across the Trent basin and then allow the reservoirs to be replenished in the spring runoff.