Standing Message - Lake Erie & Lake St. Clair - High Static Water Level

Date: Tuesday, October 4, 2022

Issued to: Municipal Flood Coordinators of Municipalities, Media

Issued by: Lower Thames Valley Conservation Authority

Highlights:

• Current water levels are down from where they were at this time of the year from 2017 through 2021, but are still well above average.
• With the drop in water levels, near gale force or stronger winds are now required to create the waves that cause flooding along much of the LTVCA shoreline. 
• However, strong sustained wind speeds can still create waves that cause flooding, erosion, and shoreline damage in the Erie Shore Drive area.
• There is still a risk of erosion and damage to shoreline protection works, including erosion along the high bluffs.

Message:

Average daily water levels on Lake Erie at the beginning of October were around 174.4 m (I.G.L.D.). This is down about 47 cm from last year’s peak daily average water level record set on July 21st.  The all-time record high monthly average for October was 174.94 m, set in 1986. Water levels at the beginning of October were still 31 cm above what would be considered normal for the month of October. Water levels on Lake Erie peaked in June and are now well into their seasonal decline.  Forecasts suggest water levels could drop around 13 cm by the beginning of November.   

Average daily water levels on Lake St. Clair at the beginning of October were around 175.4 m (I.G.L.D.). This is down about 41 cm from last year’s peak daily average water level record set on July 17th. The all-time record high monthly average for October was 175.96, set in 1986. Water levels at the beginning of October were 38 cm above what would be considered normal for the month of October.  Water levels on Lake St. Clair peaked in June and are now well into their seasonal decline.  Forecasts suggest water levels could drop around 13 cm by the beginning of November.   

While current water levels on the lakes are still around 30 to 40 cm above average for this time of the year, water levels on both Lake Erie and Lake St. Clair have fallen back down below October water levels seen from 2017 to 2021.   

With lower water levels, the risk of shoreline flooding has decreased.  Along the Lake St. Clair shoreline in the LTVCA, it is expected that sustained gale force winds (above 60 km/hr) would now be needed to produce shoreline flooding. Along most of the Lake Erie shoreline conditions have also improved.  Some areas along the shoreline are also now looking at wind speeds closer to gale force before flooding would occur.  While significant flooding has not been seen for several months now down on Erie Shore Drive, this may have more to do with the lighter winds seen over the last few months.  The Fall and Winter seasons typically see higher winds.  Current water levels on Lake Erie are still fairly close to 2017 Fall/Winter water levels when flooding was being seen in the area.  Flooding along Erie Shore Drive could still occur with sustained winds over 35 km/hr from a southerly (southwest through southeast) direction.       

Erosion and shoreline damage are still concerns along the Great Lakes shorelines. The same waves that cause flooding can damage shoreline protection works and cause erosion in unprotected areas. The bluff areas all along the Lake Erie shoreline are also at a greater risk of erosion due to the high lake levels, especially when there are onshore winds and waves. Along the bluffs, the erosion can cause the bluffs to fail and there have been times over the last few years when many metres of land have fallen into the lake all at one time. Such failures do not necessarily happen during a high wind and wave event, and exactly when the bluff may fail is not something that can be predicted.

Shoreline residents need to pay attention to local conditions and prepare accordingly.  Should an event occur, people should be extra careful and avoid the shoreline and any waterways with high water levels. The waves on the lakes can be strong, and the shoreline and the banks of waterways can be slippery and unstable. There could also be hazardous debris within the waves and water which could be thrown onto the shoreline. Standing water can also present unseen hazards. Children and animals should be kept away from the water.

Please contact your local municipality should flooding and/or erosion events occur, or should events occur that could impact roadways and other public infrastructure. If there is an urgent risk to personal safety, call 911.

This is a standing message issued for the month of October.  Should weather forecasts suggest a sustained wind event likely to cause shoreline issues, this message will be upgraded.

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