Going into the Victoria Day long weekend, MNRF has, as of Tuesday afternoon, removed all Food Watch / Warning notifications for our watershed. Water levels are approaching normal for this time of year. Lake Muskoka could reach summer target by the weekend. Lakes Rosseau and Joseph could reach normal Spring levels by the weekend. Drawdown in Bala Bay suggests that Bala Reach water levels will recede below flood level by week’s end. Please appreciate these are educated guesses; are very rough, and for general guidance only. Events such as the predicted 25mm of rain in the watershed on Sunday will have a negative impact on our water levels. As freshet is now past, this will be the last weekly newsletter for this year.
Spring Freshet is not over. Heavy rainfall at the end of last week has partially reversed recent lake level reductions for Lake Muskoka and completely reversed them for Lakes Rosseau and Joseph. Levels are again at or above Spring high and projected to rise significantly again with major 40 to 70mm rainfall forecast for Friday. MNRF has issued a Flood Warning for entire Muskoka River watershed in advance of this rain.
Since last Sunday a number of dry days has allowed lake levels to crest and start declining. The drawdown rate is slow and ranging from 1 to 2 cm per day for Lakes Muskoka, Rosseau and Joseph. Significant rainfall forecast for this weekend has the potential to erase part of the drainage gain made this week.
A persistent series of rain events has moved the Muskoka Lakes up to flood level over the past week. All except the highest docks are now underwater. With significant rain falling and predicted for the balance of today - April 20th, levels will increase again. A long stretch of dry days are now needed to allow levels to peak and then begin to diminish. As of today – April 20th- the Ministry of Natural Resources and Forestry [MNRF] reiterated its Flood Watch for the District of Muskoka and extended its Flood Warning for the Moon River/Bala Reach to include the North and South Branches of the Muskoka River. Members are advised to act to mitigate damage from submergence and wave action.
Moving into the second half of April, extreme rainfall remains the sole risk for flooding of the Muskoka Lakes. Lake levels remain normal for this time of year but are rising in response to a 40mm rainfall and runoff from earlier this week. Levels above Spring normal are possible by next week due to predicted 25mm rainfall this weekend. The snow is gone, except in Algonquin Park, and the ground is thawing. Ice is mostly out in the lakes. Longer term prediction of precipitation effects remains difficult. As of yesterday the Ministry of Natural Resources and Forestry [MNRF] has a Flood Warning in effect for the Moon River/Bala Reach. Members continue to be advised to be prepared for high water due to potential rain and Bala Reach is advised to prepare for imminent flooding.
Moving into the second week of April, extreme rainfall remains the sole risk for flooding and Environment Canada has just issued a rainfall alert for this Thursday. Total rainfall amounts of 20 to 35 mm are now expected in the watershed by Friday night. Last week’s rain and melt has now reduced the snow pack to below normal levels, so the risk of flooding from snow melt is further reduced from last week. Lake levels are now normal for this time of year but are rising rapidly in response to rainfall and runoff from earlier this week. Predictions of precipitation effects remain difficult. The Ministry of Natural Resources and Forestry [MNRF] has posted Flood Outlooks for rivers in the watershed including the Muskoka River and the Moon River/Bala Reach. Members at these locations continue to be advised to be prepared for high water due to potential rain.
Entering April, the recent rain and melt has reduced the snow pack to near normal levels, so drawdown requirements and risk of flooding from snow melt are reduced from last week. Lake levels are now approximately 10 to 15 cm [4 to 6”] higher than the target low water level but significantly below normal summer water levels. Slightly warmer temperatures will contribute to gradual melting of the remaining snow, and could pave the way for a normal Spring freshet. However, precipitation amounts remain the major risk factor over the next week with significant rainfalls predicted.
Very aggressive drawdown of lake levels by MNRF is producing significantly lower water levels but these levels are still higher than the required drawdown level for this time of year and snow conditions. As we near the end of March, weather systems are volatile and even the weather forecasters are challenged with predictions. Rain is predicted over the next few days posing an additional risk to the melting snow from warmer air temperatures over the next week which we expect will result in the lake levels rising again before they reach the target. Members are advised to be prepared for high water.
Cooler weather and continued water level drawdown by MNRF have reduced the risk of flooding for this week…. water levels are still above the required drawdown level for this time of year but long term weather forecast - daytime highs just above freezing but overnight below freezing - should allow for continued drawdown of the water levels.
Your MLA Water Level Task Force has been keeping a close eye on precipitation and lake water levels all winter long, as well as lobbying the MNRF for needed change.