Adelaide’s River Torrens, one of the city’s most recognisable waterways, has become the centre of a debate over how authorities should respond to recurring water-quality problems. On 9 September 2026, In Daily reported that Adelaide City Councillors had voted against a proposal to introduce a six-month trial of nanobubble oxygenation and controlled ozone technology at Torrens Lake.

The proposal was put forward by Deputy Lord Mayor Carmel Noon, who argued that the council should take a stronger leadership role in addressing the lake’s ongoing health problems. The suggested trial would have cost about $300,000 and was intended to test whether the technology could improve water conditions during the summer period.

Nanobubble technology works by introducing extremely small gas bubbles into water. Supporters say the process can increase oxygen levels and potentially help reduce contaminants without relying on harsh chemical treatments. The technology has previously been trialled at Lake Albert in Wagga Wagga, New South Wales, where it was used as part of efforts to address water-quality and algae problems.

The debate comes after a difficult year for Torrens Lake. The waterway has experienced several closures because of elevated bacterial levels. Earlier closures were associated with high levels of E. coli and enterococci, while heavy rainfall also contributed to large amounts of rubbish, litter and organic debris entering and accumulating in the lake.

The latest situation had improved by the time of the council debate. Testing confirmed that bacterial levels had returned to safe levels and Torrens Lake had reopened. However, significant debris remained along the waterway, prompting council staff to prepare a clean-up operation. The City of Adelaide said the initial stage would involve removing floating litter from the lake, with work scheduled to begin the following week.

Supporters of the proposed technology argued that repeated closures demonstrate the need for a longer-term solution. Noon pointed to the impact of water-quality warnings on rowing, dragon boating, tourism, the Popeye, businesses and recreational activities around the lake. She argued that authorities should investigate whether new technology could prevent repeated closures rather than continually responding after problems occur.

However, councillors opposing the trial said there was not enough scientific evidence to justify spending council money on the proposal. Councillor Janet Giles said the Torrens Lake is affected by many different environmental factors and warned against relying on technology without stronger evidence that it would work effectively in the specific conditions of the lake.

The River Torrens is also managed across multiple jurisdictions. The City of Adelaide is responsible for the central Torrens Lake area, while other councils, Green Adelaide and state government agencies have responsibilities elsewhere along the river and catchment. This makes the water-quality problem broader than the lake itself, particularly because pollutants and stormwater can enter the river upstream.

The state government has separately committed $4.06 million to revitalise and rewild the River Torrens, with an additional $1.1 million for stormwater infrastructure. The broader program includes restoring native aquatic plants, stabilising riverbanks, improving biodiversity and supporting the return of native species such as platypuses.

For Adelaide residents, the debate highlights a continuing challenge: keeping the Torrens Lake clean, safe and usable while addressing pollution and runoff throughout the wider catchment. Although the proposed technology trial has been rejected, authorities continue to pursue other environmental and infrastructure measures to improve the river’s long-term health.