With Lake Ontario at its highest point in decades and with heavy rain already falling, the City of Toronto is preparing for a possible evacuation of Toronto Island Park. 

But its residents have spent the day laying sandbags around low-lying areas in the hope they can stay in their homes. 

Between 40 and 90 millimetres of rain could fall on Toronto between Thursday evening and Saturday, according to Environment Canada — a figure the weather agency increased after the storm began.

That amount of rain doesn't usually pose a problem but with the ground already saturated and lake levels high, the residents and the city are preparing for flooding. 

The Willam Inglis, a ferry that usually docks on the downtown side of the harbour has been stationed at Ward's Dock in case of an "after-hours storm"  to provide "temporary shelter, if required," according to an email from the ferry's stakeholders.

Matthew Cutler, a spokesperson for Toronto Parks, said the move will help the city to react quickly if an evacuation is required. 

Also, residents on the Toronto Islands — who number about 700 and live on Ward's Island — will be notified via TOFerry@toronto.ca if the ferry is brought into service for storm evacuation.

The city also announced that it would limit ferry trips to residents, staff and emergency personnel. 

Toronto -island resident

Toronto Island resident Alan Tate has been dealing with flooding all week. (Lauren Pelley/CBC)

As of Thursday afternoon, some roads on the island became impassable and high water levels have also made some park buildings and beaches inaccessible, Cutler said.

Island resident Alan Tate said he's concerned about the flooding. 

"It's been a bit scary, but this whole area was just flooded with water a couple of days ago. It's a little bit nerve-wracking but hopefully it's OK." 

But most of the residents who spoke to CBC Toronto said that they've weathered other major storms — ones in '973 and 1992 also required sandbagging — and they expect to ride this one out in their homes as well. 

"It's kind of a phenomena that repeats itself every once in a while," resident Michael Page said as he shovelled sand into the orange sacks. 

'Not going anywhere'

While he's "a little nervous" about the high water level combined with the heavy rain in the forecast, Page said he has no plans to leave his home. 

"I'm not going anywhere," he said. "This talk about evacuation, I'm not leaving. I don't know why we'd do that."

Frank Sullivan has lived on the islands for roughly 70 years. He began by summering on Centre Island as a boy and moved to Ward's Island as an adult. 

Frank Sullivan

Frank Sullivan, 79, has lived on the Toronto Islands since he summered on Centre Island as a boy. He says the rain won't force him to leave. (CBC)

He remembers the sandbags going up both times before.

But the problem, he explained, is that the islands themselves are essentially a sandbar; while the bags can prevent waves from swamping the shoreline, the lake seeps up through the sandbar and creates "puddles" throughout the low-lying areas.

"It's been a real high-water year and all of a sudden we're going to get this almost torrential-type rain for a couple of days so that's not good."

Ken McAuliffe, however, took a lighter approach.

After floodwater created a pond at the front of his property, he chose to set up a table in the centre of it. A glass of wine — and years of stormy island weather — have fortified him for what's coming.

"This is bad, but I tend to be someone who makes light of everything," said McAuliffe, the co-owner of the island's Rectory Cafe. "We're adapters over here. It's a lake so ... there's not going to be a big tide here."

About 10 people, however, have already left the island.

Artists who had planned a short residency at Gibraltar's Point were moved to a new location Thursday afternoon, a spokesperson for the Artscape organization said. 

Ken McAuliffe

Ken McAuliffe, a resident of Ward's Island and the co-owner of the Rectory Cafe there, made the best of things and set up an alfresco lunch in the centre of the floodwater. (CBC)

Heavy rain in the forecast

The low elevation and multiple water features on the Toronto islands mean structures there could be vulnerable to flooding, according to Nancy Gaffney a waterfront specialist with the Toronto and Region Conservation Authority. Gaffney appeared today on CBC Radio's Metro Morning

Toronto - island flooding

Parts of Toronto Island Park are still underwater after a heavy rains fell earlier this week. Toronto could see up to 70 millimetres of new rainfall by Saturday. (Lauren Pelley/CBC)

"We do have to make sure we're prepared to get those people moved to a safer location," she said. "We're trying to make sure that we're monitoring things very closely."

Gaffney said the flooding will be worse if the rain is combined with high winds, which can drive waves over retaining walls designed to protect the shoreline.

"Most of our structures are built almost right at the level where the water is now, so any waves will start overtopping and pushing the water right onto land more than usual," she said.

Before the rain starts, the city is urging residents to make sure their catch basins are clear of debris and that their gutters are clear as well. Anyone who spots serious flooding should call 311.

The island's amusement park, Centreville, also announced that it plans to delay opening until May 13 rather than this Saturday. 

Toronto - island flood sand

City of Toronto crews have delivered loads of sand to the island should sandbags be needed. (Lauren Pelley/CBC)

With files from Chris Glover