City eyes a breakwall to halt erosion of Islands

Conservation authority plans to construct a lake barrier to keep lands from fading away

Thestar.com
May 1, 2016
By Dan Taekema

The Toronto and Region Conservation Authority is betting on a breakwater to stop one of the city’s most popular summer destinations from washing away.

The Toronto Islands have long been victim to erosion caused by waves and winter storms, but in recent years the problem has gotten worse - stabilization of the Scarborough Bluffs and the creation of the Leslie Street Spit have limited the amount of sand and soil carried by the current to feed the island.

“We essentially started to starve the islands of a source of sediment to sustain itself,” said Ethan Griesbach, a project manager with the TRCA.

According to a report from the conservation authority titled the “Gibraltar Point Erosion Control Project,” erosion on the islands has been documented in the area since 1879.

Significant storm damage in the ’70s led to several possible solutions, but only short-term attempts to solidify the shoreline were used.

“If it’s not stopped we’ll lose more real estate,” said Warren Hoselton, the island’s park supervisor. “The trees are what bind the soil. Once you get beyond them to pure sand, erosion happens even faster.”

Hoselton said a severe storm in 2004 nearly caused a washroom on Gibraltar Point to tumble into the lake and some “limestone boulders” were placed there to act as “armour” from erosion.

While the amount of land that’s washed away varies each year, Griesbach said some studies the TRCA has done show if the damage isn’t stopped, Gibraltar Point could be severed in two sometime in the next 20 years.

To make sure that doesn’t happen, the TRCA has teamed up with the city to build a 550-metre long breakwater that will stand about 2.5 metres above water level.

Griesbach said the project’s dimensions might change slightly after consultation from stakeholders and the public, but he added that great effort has gone into making the underwater wall almost unnoticeable.

“We want this to blend into its surroundings and almost not be seen at all,” he said. “When people are along the shoreline we don’t want them to see just a wall ... We want them to still have that natural feel where they can still see the lake.”

Andrew Simpson has watched the island wash away for years from his kayak.

Last year, he estimates, he paddled around the island 65 times. During one of his first days on the water this season, he took pictures of significant damage to the shoreline.

“There’s a dune that’s almost eaten away until it’s a bit of a cliff face,” he said, describing a scene with fallen trees and pipes that have been exposed.

“Over the last couple of years you can see the shoreline rapidly receding.”

Simpson said he has concerns about a breakwater ruining the look of one of the island’s “few natural beaches,” but agrees the problem needs to be solved soon.

“The islands are pretty precious for the city, a pretty unique kind of public space, and if it’s melting back into the lake that’s a cause for concern,” he said.

Griesbach said the TRCA plans to start building the breakwater next year and added he’s proud to play a part in stopping the islands from losing ground to the lake once and for all.

“I’m pretty happy we have some funding to move forward and build something that’s going to protect these islands for future generations.”