Bala Reach/ Moon River Update:
With significant rain since March 25th and significant rain now predicted by Environment Canada flows through Bala are now increasing and will likely exceed the flows experienced earlier in the year if current trends continue. Natural flow restrictions between the main part of Lake Muskoka and Bala Bay [at Wallis Cut, Jannocks narrows and Coulter Narrows] continue to cause a level difference of 20 cm [ 8“] or more. Lake levels in Muskoka are now increasing rapidly in response to rain earlier this week and further increases are expected following the significant rain currently predicted by Environment Canada. Increased flows though the spillways will occur as a result. Members are advised to keep aware of weather conditions and to be prepared for flooding.
Snow Core information
Snow core data contained in the April 3rd MNRF Watershed Conditions statement shows average snow water content is now below normal. This amount of snow water content indicates that normal drawdown levels are likely sufficient to absorb the melting ice and snow. Rainfall amounts now far outweigh snowmelt considerations.
ALERT! Environment Canada has just issued a Special Weather Statement regarding rainfall. “Significant widespread rainfall amounts of 20 to 30 mm are likely by Thursday night [April 6th]. Some area may exceed 40 mm. Rainfall warnings [issued when over 50 mm is expected] may be required.” Temperature-wise, the current weather forecast calls for daytime highs over the next week ranging between 4oC to 19oC and overnight lows between -5oC to 9oC.
On Monday, April 3rd MNRF issued a “Water Conditions Statement – Water Safety” for the Muskoka River Watershed which applies until April 7th. In part this statement says “A Flood Outlook is in effect for the Muskoka River Watershed including the South Branch of the Muskoka River, the North Branch of the Muskoka River, the Big East River and the Moon River/ Bala Reach.” “The North and South Muskoka Rivers, the Big East River and the Moon River/Bala Reach are expected to react quickly to the influx of water from precipitation expected over the coming week.”
Several instances of boathouse/dock damage have been reported this year, following days when rapid temperature rise has caused the clear, uninsulated ice to expand and shove. The forces involved [on the order of 5 tons per lineal foot] far exceed the strength of normal shoreline structures. Ice expansion is dependent on the unusual coincidence of rapid temperature rise, clear ice without insulating snow cover and ice adhesion to the shoreline. Frequent thaws and rains have made these conditions more common this year. The damage has occurred at structures which did not have bubblers in place to provide a protective gap of open water beside the cribbing. Alternatively, cutting a trench in the ice beside the structure can also relieve forces from ice expansion. Members are advised to be aware of this damaging phenomenon which is unrelated to any wind or water level changes at the reported locations.