Toronto Islands have taken a beating with ongoing deluges of rain and higher than normal lake levels in the last three weeks, with city officials saying Thursday's downpour is the "worst [they've] seen yet."

"We could not keep up with the water level today," the city's manager of Water Front Parks James Dann told CP24 this afternoon.

As of 2:30 p.m., Environment Canada reported the island had been pounded by 55 millimetres of rain.

Earlier, city officials estimated that 40 per cent of the island is underwater and more than 50 per cent of the buildings are at a risk of flooding.

Now they say, closer to 50 per cent of the island has been replaced by water from Lake Ontario.

"The rain has really compounded the existing flooding problems, especially in the residential areas," Dann said.

He says Gibraltar Point has been washed out completely and that wave action today took the lake over Centre Road, the main roadway on the island. On Ward's Island, between 30 and 50 centimetres of water has pooled on the road from the Royal Canadian Yacht Club and the Toronto Fire Station.

Toronto and Region Conservation Authority have been working overtime this month to offload 500,000 litres of water from the island each hour to help water levels recede.

The city also retricted accesss to the island to residents-only after two weeks of consistent rainfall, which caused Lake Ontario to swell to dangerous levels.

Though an emergency evacuation of the island's 700 residents was never deemed necessary, ferry service was suspended and businesses shuttered until June 1.

Dann says it's unlikely the island will reopen to the public by then.

More than 20,000 sandbags have been placed along the shorelines to mitigate rising waters.

City crews are still stationed on the island and are continuing to tackle ongoing flood concerns.

"They’re monitoring the conditions very closely," city spokesperson Wynna Brown said Thursday. "We do know that lake levels are very high this year so we’re keeping a close eye over there."

Lake Ontario, which has risen nearly 30 centimetres since May 1, according to data from Fisheries and Oceans Canada, is the primary culprit for the current state of the beach.

But this doesn’t include last month’s extreme wet weather, which the International Lake Ontario-St. Lawrence River Board told CP24 was “well about normal.” In that time, Lake Ontario rose 45 centimetres.

Dann expects the water levels will continue to rise for at least the next month.

"We're going through a time of extreme weather where we're seeing more and more stormwater events and every year another flood," Coun. Mike Layton told CTV News Toronto at city hall today.