Lake Wyangan remains on red alert as council continues trial of 'Diatomix' liquid to address toxic water

Griffith City Council is extending its trial of applying the product AlgaEnviro Diatomix – a liquid feed of micronutrients such as iron, zinc and copper – to improved water quality at Lake Wyangan.

The town’s main waterway is once again under a red alert, meaning the water quality is so poor that people should not swim there, fishing is not recommended and pets should stay clear.

Water samples have revealed the lake has dangerously high levels of blue-green algae – bacteria that can produce dangerous toxins.

The council has trialled various initiative to address this problem in recent years, but with limited success.

Its latest effort commenced in September 2024, when it started an 18-week trial of applying Diatomix to the water in the southern part of the lake, which continued until 10 January.

Due to available remaining supply of this product, council has decided to extend the trial for an additional 15 weeks.

If successful, the local government body plans to expand the initiative to include North Lake Wyangan.

Diatomix is said to produce “good algae”, which can compete with toxic bacteria and improve water quality.

“At this stage, we are cautiously optimistic about the potential of Diatomix to improve the condition of the lake by reducing blue-green algae,” Griffith Mayor Doug Curran said.

“I think the hardest thing is that we all need to be patient and allow time for the treatment to work before we can really assess its effectiveness.

“We’ve been advised that it could be up to 12 months before we know if this treatment is doing what we need it to do.”

Co-founder of AlgaEnviro, Simon Tannock, said Diatomix naturally created conditions in the water that promoted the ecosystem to become healthy.

“The data to date shows that the lake is responding to the treatment. As can sometimes be the case, the lake is looking worse before it gets better,” he said.

“The way the lake is changing is similar to the way other lakes have responded when first treated with Diatomix. The long-term outcome is expected to be very good for the lake, as it does not have problematic high nutrient inflows.”

Griffith’s Lake Wyangan was once the heartbeat of the town and a focal point for family picnics and aquatic sports.

However, frequent algal blooms have meant the lake has been largely out of action for the past two decades.

Local wetlands expert Geoff Sainty previously devised a plan to fix Lake Wyangan by creating a natural wetland habitat on the eastern shore to offset the blue-green algae. However, his proposal was rejected by Griffith Council in 2019. Mr Sainty has since died.

Wagga’s Lake Albert has faced similar problems, with the local council also trialling several approaches to combating algae in the lake in recent years, including a 2023 trial of Waterzyme, which uses enzymes to remove harmful bacteria.

However, an apparent lack of success in this approach resulted in council pivoting to Hydro2050, which uses an ozone-based treatment approach that is aimed at causing algae blooms to deteriorate by producing a consistent stream of ultrafine bubbles.