More soaking rains raise risk of flooding along Lake Ontario
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Meteorologist/Science Writer
Thursday, May 25, 2017, 2:28 PM - Lake Ontario water levels are the highest they've been in roughly a century, and with another soaking rainfall over the area on Wednesday and Thursday, the threats of lakeshore flooding and erosion are rising.
According to Environment Canada, southern Ontario has already seen between 10 and 20 mm of rainfall since the latest active weather system moved in to the area on Wednesday night, and before it finally taper off later this afternoon, another 20 to 30 mm of rain is expected to fall.
This would not normally be a problem, however, the waters of Lake Ontario have already been running high over the past month, and according to the Great Lakes Environmental Research Laboratory (GLERL) and the U.S. Army Core of Engineers, they are currently at 75.86 metres - the highest they've been since record keeping began in 1918.
With levels that high already, beaches along the shores of Lake Ontario have all but vanished under surging waters, and the latest account from Toronto Island say that it is roughly 40 per cent under water (with around half of the buildings at risk of flood damage).
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Adding another 30-50 mm of rainfall to waterways, along with winds driving storm surges and wave action into the western part of the lake, this has the potential to make an already precarious situation along some stretches of lakeshore even worse.
Backshore flooding, shoreline flooding and shoreline erosion are the primary concerns at this time.
As of May 24, 2017, a Provincial Flood Watch has been issued by the Ontario Ministry of Natural Resources and Forestry, while regional watersheds throughout southwestern, central and eastern Ontario either continue under previously issued statements, watches and warnings, or they have issued new alerts in response to this additional rainfall.
• Province of Ontario - Provincial Flood Watch
• Toronto and Region - Watershed Conditions Statement - Water Safety
• Niagara Peninsula - Flood Warning
• Hamilton - Flood Watch
• Central Lake Ontario - Flood Warning
• Ganaraska Region - Flood Warning
• Lower Trent - Flood Warning
• Quinte - Flood Warning
• Cataraqui Region - Flood Warning
• Lake Simcoe Region - Flood Warning
• Rideau Valley - Flood Warning
• South Nation - Flood Watch
• Otonabee - Watershed Conditions Statement – Water Safety
Residents in these areas are advised that shorelines of the lake, as well as the banks of streams and rivers, could be slippery and unstable. Extreme caution should be exercised around all waterways and bodies of water.
KEEP UP TO DATE ON ONTARIO'S FLOOD ALERTS: Check the Ontario's Flood Forecasting and Warning Program site
Sources: GLERL | U.S. Army Core of Engineers | Ontario Ministry of Natural Resources and Forestry | CBC
