NIAGARA-ON-THE-LAKE, Ont. — Jason Rosso distinctly remembers the moment he realized it was good to be the chef. He was a student in culinary management at Humber College in Toronto.

A Canadian 14-year-old completed a nearly 27-hour, 31.6-mile solo swim across Lake Ontario on Sunday, becoming the youngest person ever to make the trek.

About 80% of Ontario’s inflow comes from its sibling Lake Erie, cascading over Niagara Falls and coursing down the Niagara River. The twin deluges of 2017 and 2019 have given way to the drought ...