Toronto Islands erosion problems
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Toronto Islands erosion problems


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Toronto Islands slipping into Lake Ontario through erosion
How the Islands are being eaten by the Spit

From Wednesday's Globe and Mail

August 8, 2007 at 5:04 AM EDT

The islands are one of Toronto's most bucolic places - a beautiful waterfront park in Lake Ontario formed out of an archipelago of sandbars.

But here at their southwestern tip, the scene is anything but breathtaking. Erosion caused by the pounding action of waves from Lake Ontario is chewing away at the islands. It's not a pretty sight.

Mature cottonwood trees are tumbling into the lake, as are the islands' dunes, considered an ecological rarity because there aren't any others in this area of Canada for more than 100 kilometres. So much of the islands has been washed away that old water and gas mains buried decades ago, thought to be safely away from the then-existing shoreline, now lie exposed in open water. Even the city's popular nude beach at Hanlan's Point, once a wide expanse of buff-coloured sand, is beginning to be stripped away.

"It's sad. It's valuable real estate washing away," observed Warren Hoselton, Toronto Islands park supervisor, who has been watching with increasing alarm as the lake claims parts of his park. He is concerned that the erosion is set to worsen. "We're at the tipping point now."

The problem of disappearing real estate at one of Toronto's local landmarks has an unusual cause. In Toronto parlance, the islands are being eaten by the spit.

For decades, Toronto has been dumping construction waste from downtown building sites into Lake Ontario.

The rubble has been shaped into a five-kilometre-long peninsula jutting into the lake near the islands and known locally as the Leslie Street Spit.

The spit is blocking the lake currents that, in the past, built up the islands from sand washed off the Scarborough Bluffs.

Now, whenever storms blow across the lake from the south, their large, rolling waves cut away at the exposed southwesterly tip of the islands. With no fresh sediment from the bluffs to replenish what is washed away, the islands are slowly losing ground to the lake.

The rate of erosion has been estimated at about eight metres a year, a relatively sedate pace but one that is still worrisome, given that the islands are only a few hundred metres wide at many points and, in some areas, trees that previously resisted the waves have toppled over. Once tree cover is lost, exposed sand is no match for waves, and is quickly washed away.

According to an estimate by the Toronto and Region Conservation Authority, up to about a sixth of the park could be lost over the next century if no solutions are found. But the problem could easily worsen. A pickup in the pace of erosion would occur should the high water levels existing in the mid-1990s return and coincide with big winter storms.

"All we need is one high-water year and we're really in trouble," said Joanna Kidd, a spokeswoman for the Toronto Bay Initiative, an organization that tried to preserve the islands' rare dunes but was running a losing battle with the erosion.

The worst damage on the islands is around Gibraltar Point, where the entire near-shore area is suffering.

The point lies more than a kilometre to the west of the park's most popular picnic area at Centre Island, and about 3
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