New South Wales based water investigation and solutions company Photon Water has been awarded a two-year extension to its contract for monitoring water quality at Valley Lake/Ketla Malpi, continuing its vital work to support recreational use and environmental health.
Since 2022, Photon Water has deployed two water quality monitoring floats alongside quarterly physical sampling to assess and improve lake conditions. These efforts have focused on understanding the lake's dynamics and mitigating seasonal algal blooms that have historically impacted recreational activities.
"The first step in improving water quality was to understand the lake's behaviour," City of Mount Gambier Environmental Sustainability Business Partner Aaron Izzard said.
"The floats measure temperature, dissolved oxygen, turbidity, algae and other water quality parameters across the lake depth profile. Continuous 24-hour monitoring combined with regular sampling over the past three years has enabled us to confidently characterise the lake's conditions."
During warmer months in the past, Valley Lake/Ketla Malpi experienced algal blooms triggered by elevated temperatures and increased light exposure. These blooms, primarily composed of green algae and cyanobacteria, can reduce water clarity and pose health risks.
To combat this, Photon Water introduced ultrasonic technology via two specialised floats. These devices emit short ultrasonic pulses that disrupt the structural integrity of algae and cyanobacteria cells, causing them to sink and halting their growth and reproduction.
"Since implementing Photon's ultrasonic floats, cyanobacteria and algae counts have remained below the thresholds outlined in the National Health and Medical Research Council's guidelines for recreational water," Mr Izzard said.
This treatment has led to a healthier lake ecosystem, benefiting not only recreational users but also the fish and invertebrate species that inhabit the lake. - City of Mount Gambier Environmental Sustainability Business Partner Aaron Izzard
"Together we share a commitment to environmental management grounded in data-driven, scientifically verified measurement and control solutions. It's important to measure improvement in the lake's water quality over time and proactively manage this into the future," Photon Water General Manager Ian Phillipps said.
"We look forward to continuing our stewardship in partnership with the City of Mount Gambier. We also value the interest and support received when working on the lake from council staff members, and the local community."
The ongoing monitoring has confirmed that Valley Lake/Ketla Malpi is safe for recreational activities, with water quality consistently meeting national standards.
Photon Water will collaborate with local water experts Water Dynamics to continue regular sampling and data analysis as part of the extended water quality monitoring program.
"The Valley Lake/Ketla Malpi precinct is an important location to our community. We look forward to playing our role in the long-term health of the lake to allow the community to enjoy this natural wonder for generations to come," Water Dynamics Mount Gambier Branch Manager Sam Work said.
