Highlights:

• Record high water levels on both Lake Erie and Lake St. Clair
• Risk of shoreline flooding on both lakes
• Risk of erosion and damage to shoreline protection works
• Strong sustained winds, as well as thunderstorm related winds and heavy rains, could cause flooding, erosion and shoreline damage

Message:

Daily average water levels on Lake Erie peaked on June 22nd at an elevation of 175.19 m (I.G.L.D.) and have since fallen by about 28 cm. The all-time monthly average record for Lake Erie set in June of 1986 of 175.04 m was broken from May through July, reaching an elevation of 175.14 m in June. While monthly average water levels for this August on Lake Erie fell below the June 1986 record they were only 2 cm below that record. This August’s average monthly water levels still broke the previous August 1986 record by 8 cm. Current water level forecasts for Lake Erie suggest that by the end of September, water levels are most likely to fall by another 15 cm. However, this is still likely to leave the monthly average September water level above the previous September 1986 record.

Daily average water levels on Lake St. Clair peaked on July 7/8th at an elevation of 176.08 m (I.G.L.D.) and have since fallen by about 21 cm. The all-time monthly average record for Lake St. Clair set in October of 1986 of 175.96 m was broken in both June and July, and matched in August, reaching an elevation of 176.04 m in July. Current water level forecasts for Lake St. Clair suggest that by the end of September, water levels are most likely to fall by another 12 cm, bringing monthly average water levels back below the record highs of 1986.

With such high water levels, shoreline areas are highly vulnerable to shoreline damage, flooding and erosion. There are currently low lying shoreline areas in the Lower Thames Valley Conservation Authority jurisdiction that are constantly under water. Several roads in the region have been closed due to flooding and/or erosion. The most significant of these closures include Talbot Trail (between Coatsworth Road and Stevenson Road), Erie Shore Drive and Rose Beach Line (east of Antrim Road), all in Chatham-Kent. People should try to avoid these areas if possible.

Sustained winds can lead to water level changes and waves that cause shoreline issues. Strong winds out of any direction will have an impact on some area along our local shorelines. Wind conditions over the lakes can change quickly and with little warning. This is especially true during the summer when thunderstorms are more frequent. Onshore winds forecasted above 25 km/hr could start causing problems and by 30 km/hr flooding can be expected in some low lying areas. The areas most frequently impacted include: Lighthouse Cove when winds are out of the north or west; Erie Shore Drive when winds are out of the south (WSW through ESE); the bay side of Erieau when winds are out of the east or north; Shrewsbury when winds are out of the east (NNE through ESE); and Rose Beach Line when winds are out of the east (NNE through S). Of course, other shoreline areas are also susceptible. 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 land several metres deep to fall into the lake all at one time.

Summer thunderstorm activity has also proven to be an issue in these shoreline areas. Pop-up thundershowers are not always forecasted and the sudden strong winds associated with them can produce unpredicted waves and water level changes that impact shoreline communities. Heavy rains associated with thundershowers could also cause flooding in low lying shoreline areas. 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. Any water from upstream making its way downstream on these watercourses into these shoreline areas could cause additional flooding.

Shoreline residents need to pay attention as local conditions change and prepare accordingly.

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

Most importantly, people need to keep themselves safe. Should an event occur, people should take extra caution and avoid the shoreline and any waterways with elevated 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.

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

Message Contact: Jason Wintermute (519-354-7310 x227) ([email protected])