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Toronto Islands slipping into Lake Ontario through erosion

how does sediment from the bluffs end up on the west shores of the islands??

wouldn't it build up on the eastern shores? the erosion is happening on the west shores.
The changes to the shoreline are a result of both erosion (mainly from the winter storms) and sand deposition, where the sand erodes from the Scarborough Bluffs and is deposited along the southern length of the Islands shoreline, especially at the southwestern tip (this deposition is what has been nearly eliminated, due mainly to the Leslie Street Spit).

The Gibraltar Point area had been growing to the west in the past, since deposition had been exceeding erosion, while the shoreline to the east of that had been slowly receding, with the net effect being that the Islands had been slowly moving to the west.

Sands has always been deposited along the shoreline between the Bluffs and the Islands, but never for long, since it is always remobilised by the west-flowing shore currents. It only is 'permanently' deposited in areas shielded from the currents (such as the western, lee shores of the Islands), where it will not be immediately remobilised.

Currently, the sand is no doubt settling in the stretch of lake bed between the Leslie Street Spit and the Islands, where the water is mostly undisturbed by the current.

Waves eroding tip of Toronto Islands
$14M project proposed to keep Gibraltar Point from turning into a nub
Jan 14, 2008 04:30 AM
Paul Moloney

Gibraltar Point, the southwestern tip of the Toronto Islands, is disappearing from the map.

Exposure to Lake Ontario's wave action is causing the sandy shoreline to wash away, and beachfront will continue to be lost if nothing is done, warns the Toronto and Region Conservation Authority.

An environmental assessment is nearing completion and a report on the project – estimated to cost $14.2 million – will go before the city's public works and infrastructure committee this spring.

The vanishing shoreline "hasn't had too much attention and is receding to the point where some of the infrastructure is starting to be threatened," said Brian Denney, the conservation authority's chief administrative officer.

"There's a park building there – a little washroom building – that needs to be protected, not to mention a lot of valuable open space."

A possible fix would be to build an offshore breakwater 750 to 900 metres long, possibly submerged so it wouldn't be visible while still calming the currents. Sand would probably have to be brought in to replace shoreline lost to the waves.

Action is long overdue, said Councillor Pam McConnell, whose ward includes the islands.

"Year after year, the lake gets closer and closer and the beach gets narrower and narrower. It's about time we fixed this problem that we've known about for 20 years."

A water treatment plant, one of four supplying the city, is not far from Gibraltar Point. It isn't under imminent threat, but the water department is working with the conservation authority nonetheless.

Ironically, Gibraltar Point was named by John Graves Simcoe, Ontario's first lieutenant-governor, because he believed it could be as impregnable as the Rock of Gibraltar.

However, the islands were formed as a buildup of sand from the Scarborough Bluffs, Denney said. Over thousands of years, sand, silt and clay were carried west by storms and currents. The amount of sand taken from the bluffs diminished over time and basically ran out by the 1850s, when storms cut a channel through the outcropping to form the Eastern Gap.

The harbour was upgraded by dredging and concrete breakwaters were put in place to control erosion, along with seawalls along the eastern and western gaps.

"Now we're looking at what to do with Gibraltar Point," Denney said. "This is a project that we think really needs to be addressed in the next two to five years."

I never realized that the island used to be that much bigger...
From the diagram, it appears the official Hanlans Point Beach has actually widened at some points since 1988. The area that appears to be significantly eroded is the more bushy, treed area that resembles an eroded landscape... and that's also where the more risque nudity appears to happen.
In the '70s and early '80s the ... ahem ... "busiest" part of the nude beach was just behind the airport. The shrubbery was periodically clearcut by the forces of decency and spoilsportishness.