Highlights:

• Rainfall totals in the 5 to 25 mm range have fallen in the last 24 hours, with the potential for a further 5 to 15 mm for the rest of the day.
• As we didn’t receive as much rain as previously predicted, the LTVCA no longer expects to operate the Diversion Channel, nor will the Thames River get as high as previously expected.
• Ponding and localized flooding may still occur in areas of poor drainage and some local watercourses could still rise and each bank full conditions or spill their banks

Message:

The Lower Thames watershed did not receive the amount of rainfall that was previously predicted. The weather system predicted to bring all that rain remained mostly to our west. Much of the region has received between 5 and 15 mm of rainfall in the last 24 hours. However, thunderstorms associated with the system have dropped in excess of 25 m of rain in certain areas. Forecasts are calling for rain to continue throughout the day dropping an additional 5 to 15 mm of rain, with the possibility of greater amounts in certain areas due to thunderstorm activity. Strong east to northeast winds are still predicted to last through tomorrow and are the subject of separate Flood Watches and Warnings.

The amount of the rain still in the forecast could lead to ponding and localized flooding in areas with poor drainage. Local ditches, creeks and streams have begun rising and some could still reach bank full conditions or spill their banks. The LTVCA no longer expects to operate the McGregor Creek Diversion Channel. The Thames River has also begun rising. However, without the widespread rain, the river is not expected to rise up and flood the river flats, except perhaps in the most low lying areas.

The rains still could have a larger impact in shoreline areas affected by high lake levels. Due to the high lake levels, the groundwater table is high and storm water sewer systems and local watercourses are full with lake water. As a result, rainwater is not draining properly from these areas. Combined with the potential for shoreline flooding on Lake Erie, there could be additional ponding and localized flooding in shoreline communities.

People should take extra caution and avoid the river, ditches, and streams. The combination of slippery banks and fast moving water can be dangerous. Standing water can also present unseen hazards. Children and animals should be kept away from the water.

Officials will continue to monitor the situation and update this advisory if necessary.

This message will be in effect until May 20, 2020.

Message Contact: Jason Wintermute (jason.wintermute@ltvca.ca)