An increase in extreme rainstorms brought on by climate change could set the stage for a return of cholera to North America, according to a world-renowned water scientist.

Cholera used to occur in Montreal, Boston and New York, but the advent of water purification wiped it out by 1900. However, the erratic weather of the 21st century worries Rita Colwell, a professor on water-related public health issues at the University of Maryland and Johns Hopkins University.

"Perhaps if we have a breakdown in sewage treatment plants with severe weather patterns that this can then bring us to a risk of cholera, which we haven't had for over a hundred years," said Colwell, one of the speakers at this week's Canadian Water Network's annual conference in Ottawa.

'Nobody's really standing up and saying, "I'll be the leader." '

— public health engineer Steve Hrudey

Colwell cited the July 2010 floods in Milwaukee, where the city's sewage system backed up and more than two billion gallons of untreated sewage and storm water poured into the streets.

Steve Hrudey, a University of Alberta public health engineer who is speaking at the Ottawa conference, couldn't agree more. But where Colwell is looking to the near future, Hrudey said he sees problems right now.

Hrudey, who recently authored a study for the Canadian public policy think-tank the CD Howe Institute, thinks the people who manage Canadian municipal water systems need to be better trained, better paid and given more resources — particularly in smaller communities.

"Drinking water — providing it safely, is a complex knowledge-based business and it's getting more complicated all the time," Hrudey said. "If you're in a community of 100, it's unlikely that you're a full-time water operator. You're probably responsible for snow removal and garbage removal and a few other things. What's the likelihood that you're going to be able to give the kind of attention to drinking water safety that it deserves?"

Fragmented jurisdictions

The main problem in Canada is the patchwork of water management rules and regulations across the country.

"Because of the fragmented jurisdiction in drinking water, nobody's really standing up and saying, 'I'll be the leader,'" Hrudey said.

But Rob de Loe, a University of Waterloo governance expert specializing in water issues, told CBC News he doesn't think showing that kind of leadership on this issue is that easy. Much of the difficulty lies in the push and pull of running a federation such as Canada, where competing levels of government don't give up their areas of management easily, he said.

"Half the battle seems to be trying to match up the natural units of water — like watersheds —with the administrative units that we've created — like countries and provinces and municipalities, and they don't match up," de Loe said.

The Canadian Water Network offers research and policy advice on water issues. Its annual conference continues until Mar. 3.