Conservation Halton advises that the watershed has received upwards of 75mm of precipitation over the weekend due to the transit of the Low Pressure System through the Great Lakes. Much of this has fallen as freezing rain and ice pellets, and is running off quickly due to the continued addition of liquid precipitation. Environment Canada continues to have a Rainfall Warning in effect for our area, and advises that 20-30mm of additional precipitation is possible today before the system begins to taper off.
Given the large total depth of precipitation, soils are saturated and water levels in watercourses are rising rapidly into this evening and overnight.
With the observed rainfall, flooding of low lying areas and natural floodplains is expected. Municipalities, emergency services and individual landowners in flood-prone areas should be on alert. Regular inspection and removal of debris at culverts and drainage inlets is recommended.
Given the significant sustained winds and wind gusts, as well as the open-water surge waves into this morning in western Lake Ontario, there is a greater potential for erosion and shoreline flooding.
All watercourses and shoreline areas should be considered dangerous during this time. Conservation Halton is asking all residents to stay away from watercourses, shorelines and structures such as bridges, culverts, dams and breakwalls. Elevated water levels, fast flowing water, and slippery conditions along stream banks and shorelines make these locations extremely dangerous. Please alert children in your care of these imminent dangers.
Conservation Halton will continue to monitor weather reports and watershed conditions and will issue further messages as necessary. This Flood Watch will be in effect through to Wednesday, April 18th, 2018, at which point it will be either updated or terminated.