There is a stark contrast between how Lake Burley Griffin is viewed inside and the triathlon community, Steve Hough believes.
"If I mention that I swim in the lake to someone outside, I'll get told 'ew," Triathlon ACT board member Mr Hough said.
"Unfortunately Canberra got a very bad reputation for a while and people kind of got brainwashed into thinking you couldn't swim there."
Canberra triathletes and rowers say the public's misconception around the lake's water quality has impacted local take-up of their sports over the years. They say it's time people stopped being afraid to jump in.
Mr Hough has participated in triathlon events in several Australian cities and said the National Capital Authority, which manages the lake, had high standards for its weekly water testing.
"The levels of bacteria the NCA warns about are quite conservative," Mr Hough said.
"In some waterways in Australia there is no testing at all. I competed in Port Macquarie two years ago and and the week prior it rained suddenly and pushed dead animals down into the water and we swam in there."
Mr Hough said Triathlon ACT was bouncing back from a difficult period, having recently outsourced its events to save the group from going under financially.
He dated the lake's negative reputation among both interstate and local triathletes back to the 2010-11 season, which saw 50 per cent of events as duathlons (run/ride/run) because algae blooms caused the lake to close for long periods.
This perception had stuck, he said, despite only one event in each season since being affected by lake closures.
Other recreational groups who use Lake Burley Griffin pointed to pollution caused by flowing stormwater occasionally impacting events. But most agreed the ACT government's new $11 million stormwater system for Lake Burley Griffin was a good place to start addressing the issue.
Rowing ACT's president David Bagnell said his members had also suffered over periods in recent years due to the "myth" that you couldn't swim in Canberra's lakes.
While the sport involved less contact than swimming, he said some people were turned off by the fact they still had to spend time in the water, especially during training.
"I would actually argue the National Capital Authority has contributed to this perception by being so protective of people's health," Mr Bagnell said.
"I think they are very risk-averse and overly cautious in terms of blue-algae levels which is turning people off."
"I've been involved with the lake since 1974 when the testing wasn't so stringent and swimming on the lake beachside was a very popular activity and the lake really wasn't much worse."
While not denying there were fewer swimmers the lake these days, the National Capital Authority reported a rise in the number of people taking part in recreational events in recent years.
"We are hoping the increase in numbers of people on top of the lake will help more people to to tell other people about their experience," Head Malcolm Snow said.
"We do err on the side of caution with our testing. But we also need to keep promoting the lake and the many events that take place."