Status: Updated Dec 21, 2016
CEWF has been monitoring reservoir and flow-through lake water levels and regional precipitation amounts closely throughout 2016. Our most recent website posting was a November 17th TSW Water Management Update along with our commentary. CEWF believes that TSW did an outstanding job of managing the water levels throughout the summer drought. Likewise this fall, the drawdown was normal with all of the reservoir dams at their winter set log levels by the first of October.
RLCA is a member of CEWF
But the lack of rainfall since then has resulted in minimal inflow to the system, low water levels and the likelihood that levels may decline further unless there is significant rainfall. Residents depending on water from shallow wells are already facing problems, as are shoreline residents dependent on shallow water intakes. Both are likely to face continuing difficulties.
After the rains in late August, water levels were close to seasonal norms and were drawn down to establish the normal winter-set condition in October as is standard practice in order to protect the lake trout spawn. Normally rains in October and November cause the lake levels to rise slightly and to stabilize at levels similar to those achieved in mid-September to mid-October (the timing varies from lake to lake). However, this year many lake levels have not stabilized but have continued to fall, and in some cases, are approaching the 30-year minimum levels. The flow in both the Gull and Burnt Rivers is also very low. The accumulative impact of these very dry conditions has depleted the water table and the base flow in both rivers.
The attached table documents the precipitation amounts over the Trent River Basin for the period from May 1st until November 28th and the overall shortfall in precipitation.
We need major rainfall events before freeze up if there is any chance of seeing lakes rise closer to seasonal levels. The TSW remains ready to manage flows if a runoff event occurs, but it is not possible to adjust levels without increased inflow to the system.
Given that the long range forecast is for a ‘colder than normal’ and ‘wetter than normal’ winter, prospects are good that the reservoirs will fill in the spring. But a cold winter will mean little relief in water levels until then, as inflow to the system will remain low. This situation is a threat to the lake trout spawn, and may result in lake levels that will affect an increasing number of shallow water intakes.