Lake Tuggeranong Rowing Club's membership is at a low ebb, while strollers past Mimi's Pit Stop have been more likely to sprint for their coffee to avoid the lake's stink.
Lake Tuggeranong Sea Scouts, meantime, have been anything but, resigned to land activities for the most part of the peak season in a huge disappointment to children and their parents.
"We have to keep a back-up program, so in case the lake is open, we'll get on the water; if it's not open, we've got to do something else," group leader Michelle Taylor said.
"We've sold all our windsurfers because it's no use keeping them if we can only use them once or twice a season."
In February, blue-green algae or "cyanobacteria" concentrations in Lake Tuggeranong measured more than 100 times the levels recommended for safe swimming.
The lake, closed to primary contact activities such as swimming and water skiing since December 2018, was only reopened on May 3.
Ms Taylor says the sea scouts have been able to use the lake for about six weeks in the past six months. Even secondary activities, like canoeing and sailing, are too risky for junior members as they tend to fall in the water.
The majority self-funded organisation stops doing water activities from April to September because of dropping temperatures.
"Some parents get nervous. The studies are showing that there's links [between blue-green algae and] motor neurone disease," she said.
"We've just picked up two sponsors ... they've put their names on our boats, so we want to get them on the water.
"If you don't get seen, you don't get sponsorships, and we don't pick up numbers."
Tuggeranong rowing club's community liaison officer and former president, Lyndon Langdon, says the club has about 30 regular members as opposed to their high-point of 70, as people opt to row in Lake Burley Griffin instead.
Lake Burley Griffin had partial closures because of blue-green algae over summer, but there was significantly fewer cyanobacteria than in Lake Tuggeranong.
"I was talking to someone who said they were reluctant to row [in Lake Tuggeranong] when it was really smelly because they were all starting to feel unwell," Mr Langdon said.
"A lot of people say, 'You just need sprinklers, bubblers, and stirrers', but this lake is that bad that it wouldn't even have a dint on the water quality.
"They've really got to look at some aggressive treatments."
University of Canberra researchers have been testing four blue-green algae treatment methods in "mesocosms", or big plastic tubes, in Lake Tuggeranong.
A report on their results would be handed to the ACT government in June, with the tests funded as part of the $93.5 million healthy waterways project.
Owner of Mimi's Pit Stop, Vicki Eveille, said the winning solution better be implemented soon to avoid customers being further turned off by the algae and bacteria-emitted stench.
"[People will] get their coffee and keep moving because it's like, 'Ew, I'll get away from the smell'. When we were having those 38-degree days, oh man that was bad," she said.
"If people can't sit around and use the facilities, then absolutely my business would be affected."