LOW WATER LEVELS – AN EXPAINER Nov 4 2024
Lack of Rain has caused Reservoir Lakes to be below average levels and Flow Through Lakes and connecting Rivers to be extremely low.
From April through to August the precipitation levels across the reservoir area were well above the normal average levels. It required active water management by TSW to avoid high water and then to manage the normal fall drawdown. The logs in all reservoir dams were gradually removed such that all dams were at winter settings by the first week of October. This is normal practice to ensure levels stabilize to annual lows before the lake trout spawn later in October.
However this year saw very little rainfall in September and October. At Haliburton the totals were only 54% of normal in September and only 29% in October. This meant that as the reservoir water levels stabilized at winter levels there was less inflow than normal from the lake drainage areas and from upstream reservoirs. The result is that almost all reservoir lakes are below normal by up to 15 cms or more (6 inches +) for the end of October and the flows over dams are low leaving connecting rivers and flow through lakes at exceptionally low levels.
By the end of October most reservoirs levels had stabilized but TSW can not further lower reservoirs without possible impact on the trout spawn. We desperately need fall rainfall to return to gradually bring all levels back closer to normal and increase downstream flows to the connecting rivers and flow through lakes. We have seen some rainfall in the first days of November and the forecast is for more in the next couple of weeks. But so far there are no major rainfall events forecast.