Canberrans and territory newcomers coughing up cash to secure real estate along Tuggeranong's lakefront are being shut in by blue-green algae, and shafted by people using the lake as a dumping ground.
Lead University of Canberra researcher Dr Fiona Dyer, who is looking into solutions to kill off algae in the lake, said her team found several dead cats in stormwater drains while surveying the water.
She suspected the animals had been dumped there by people who didn't want them, although blue-green algae could release potentially fatal nerve tissue-destroying neurotoxins. Humans who come into contact with "cyanobacteria" can also be struck by skin irritations, flu-like symptoms and gastrointestinal illness.
It was unclear whether Lake Tuggeranong's blue-green algae had released neurotoxins.
"It's just bizarre behavior," Dr Dyer said.
"If you want to have good water quality, it matters what you put in stormwater drains."
An ACT government spokeswoman said they had received no reports of dead cats in stormwater drains. They are inspected after every 25 millimetre rainfall event and cleaned at least twice a year.
The H20K campaign, as part of the $93.5 million ACT Healthy Waterways project, was educating Canberrans about the importance of having "only rain down the stormwater drain".
"This campaign encourages Canberrans to think long term about improving water quality in ACT lakes and waterways by taking action now and highlighting the important role everyone plays in reducing nutrients and pollution that flows into the stormwater system," the spokeswoman said.
Greenway's Essence apartments residents, lured to the lakeside by advertisers' lauding in November, say they have been house-bound since, warned off the lake by the algae's threat and foul stench.
"I want to be able to pull my kayak out of my garage, put it in down there and actually not have to worry about my child taking a swim," Kristen Murray said.
"When your kid is going off and prodding dead birds next to the water, or he just wants to get in and have a splash but he can't, [it's not good]."
No cyanobacteria measurements had been taken in upstream Tuggeranong Creek where Ms Murray spotted the dead birds.
Dr Dyer said she was surprised that no dogs had died because of last summer's plague, but took it as a sign that pet owners had heeded warnings.
Essence resident Shell Koegh said she had stopped taking her dogs anywhere near the lake because "it's just too poisonous". She also used to take her friend Chantelle Hayes' dog kayaking, but wouldn't risk it getting splashed and sick.
"The few times that [Tuggeranong Creek] has been drained ... it smelt so bad and you could see how much rubbish was at the bottom of it," Ms Hayes, who lives in the nearby Southport apartments, said.
"It was just like, oh my god, this is such a new area with new development, so why is it so disgusting?"
Ms Koegh said she had seen people drag carp out of Lake Tuggeranong, kill them, and leave their stinking bodies on its banks. Like other residents, she had stopped leaving her windows open at night when the lake's smell became unbearable.
"What annoys me the most is when the algae is really bad I can't have a window or a door open as the smell just comes into my home," Grounds Crescent resident Tracey Anne said.