Rising water levels raise concerns in St. Clair Region

Shetland Conservation Area, Dawn-Euphemia

Alex Kurial
Local Journalism Initiative

Record water levels are being predicted and that could spell trouble for shoreline communities in the Sydenham River watershed.

While erosion along the Lake Huron shoreline has received a lot of attention and some of the areas have had emergency fixes, officials with the St. Clair Region Conservation Authority say high water levels will also affect inland communities.

Measurements taken in Lake Huron and Lake St. Clair have shown a steady increase in water rise throughout 2019 and continuing into 2020.

In Lake St. Clair especially, levels are predicted to equal or surpass even the record highs seen in 1986. 

Emily De Cloet, water resources specialist at the St. Clair Conservation Authority, says this is something that needs to be monitored carefully.

“This is something we’re really going to have to keep an eye on, because if these trends are consistent with these projections, and we do see these really high water levels, that’s going to mean that Wallaceburg is going to see high water because the water can’t get out of the Sydenham River into Lake St. Clair, and it’s actually going to push back,” De Cloet said.

“That’s what we saw last summer, and we had static high water levels.” 

The causes of high water levels in the area often originate well away from southern Ontario, with Lake Superior in particular playing a part. High precipitation and snow melt in Minnesota and northern Ontario causes water to rise in the westernmost Great Lake, which then flows eastward to Lake Huron and ultimately the St. Clair region.

De Cloet discussed several options that are available to combat these issues, but each one comes with its own restrictions. Water manipulation was one such option, where outflow from Lake Superior to Lake Huron would be regulated through the St. Marys River.

But De Cloet said on its own this would not be enough. 
“If we have lots of precipitation and runoff but not evaporation, that’s going to affect how much water there is. Controlling the outflow of Lake Superior can’t mitigate the fact we get a lot of precipitation.

“While there is some control via the St. Marys River, it’s not enough to change water levels significantly downstream where we are,” said De Cloet.

The McKeough Dam is another option to protect those along the Sydenham River from flooding, but each closing of the gates to send water back upstream results in the flooding of rural homes and farms. This option is therefore reserved for more extreme cases.

De Cloet also explained how shoreline armoring, where physical features like large rocks or fences are used to protect against coastal erosion, is also falling short.

Many of these structures were constructed in the 1980s, and are nearing the end of their lifespan. This has been accelerated by increased water activity, as well as wind storms.