Breakwater failed due to extreme storm surge from river, council told

·5 min read

The Balls Beach stone breakwater collapsed in March due to extreme weather caused by climate change and a design that wasn’t prepared to deal with those problems, according to a presentation by town irrigation and drainage superintendent Brett Ruck.

Soundings of the river bed showed the depth of the bed near the breakwater (called a groyne) had decreased by nearly seven metres from when it was installed last August to its partial collapse in March of this year, Jane Graham of Shoreplan Engineering told councillors.

Shoreplan Engineering designed the groyne, which was intended to prevent shoreline erosion.

The “scouring” of the river bed is believed to have been caused by near record-breaking flow rates recorded from the Niagara River due to storm surges and high water levels in Lake Erie, she said.

The maximum flow rate of the river in a 100-year average, as determined by Environment Canada's observational post at Fort Erie, is 9,800 cubic metres per second, Graham said.

On Nov. 15 and 16 last year, the flow rate reached 13,800 cubic metres per second, which coincided with a high water level recording of 3.04 metres in Lake Erie, just shy of the all-time high of 3.1 metres, according to data from the Canadian government.

“That’s a very significant increase in any situation,” GEI Consultants' Peter Ventin explained to council.

GEI Consultants is an environmental engineering consulting firm that deals with locations across the Great Lakes basin. Ventin said climate change-driven challenges such as the groyne’s collapse are becoming the norm.

“We are absolutely inundated, please pardon the pun. There is no end to projects and issues that are occurring around the Great Lakes,” Ventin said.

“These are not issues that we were referring to five to 10 years ago, these are new issues. We are in uncharted territory.”

Data for the river’s flow rate from March 12 to 13, 2021, is unavailable due to issues with the recording device the government uses, but a similar storm surge was recorded on Fort Erie at about 2.5 metres, right around the time the groyne collapsed, Graham said.

The increased intensity of these weather events is due to climate change and will continue at the current level or get worse, Ventin said.

“The conditions caused by climate change – changes in river levels, changes in water levels and changes in river flow are going to continue to create a very aggressive environment where the Niagara River hits Lake Ontario,” he said.

And while all this data points to possible natural reasons for the breakwater's collapse, councillors wanted to know why such events weren’t planned for.

Coun. Sandra O’Connor asked whether the groyne was designed with climate change in mind.

O’Connor pointed to reports from the National Research Council and Civil Engineering Society that stated decreasing lake ice due to climate change would open up shoreline structures such as the groyne to adverse effects from storm surges.

“We do look at climate change while we’re developing our designs. We consider the effects of storm surge and look at the data that’s available,” Graham said.

“It seems to me that we’ve been planning on the basis of past information and, with climate change, we have to plan for the future and not for the past,” O’Connor said.

When asked if the groyne was knowingly built on sand, Ruck responded, “Yes.”

Lord Mayor Betty Disero pushed the consultants to explain why the groyne was not anchored to the river bed and was instead built on sand that could shift when extreme weather occurs.

“The criteria is to go down until you find harder material,” Graham said.

The design dug into the sand until a firmer layer was found. The structure was then built on top of the firm layer and was surrounded by the loose sand.

A more costly construction involving the installation of steel piles drilled into the bedrock was passed over due to cost, Graham said.

The town set aside at least $400,000 for the work done at Balls Beach, according to a staff report from July 2020. That cost doesn't include consulting and temporary work done to stabilize the site, Coun. Gary Burroughs told The Lake Report.

The breakwater was repaired at the end of June. Shoreplan Engineering reviewed the state of the groyne and gave a written report to the town stating the temporary repairs are safe for public access, Ruck said.

Legal issues relating to the groyne have been discussed in closed sessions and councillors were not able to talk about it during the committee of the whole, with Coun. Allan Bisback warning fellow councillors to watch what they say.

But some councillors still pushed for answers.

“Who's at fault? And we can say nobody's at fault, that it was a 100-year storm event, but there’s a lot of money involved in either fixing it or in what we’ve already put in, and I don’t have that answer,” Burroughs said.

“You’ve heard a lot of good information,” replied the town's lawyer, Callum Shedden of Daniel & Partners LLP.

“I think you need to absorb some of that. My choice would be not to give you a legal opinion in open session. But, based on what I’ve heard, the opinion I gave you last time in closed session would still apply.”

An information report recommending actions for council is expected next month, chief administrator Marnie Cluckie said.

Evan Saunders, Local Journalism Initiative Reporter, The Lake Report

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