Shotover River E. coli reading hits eight times the consented limit and Queenstown community group demands answers

A Queenstown community group is demanding more transparency from local authorities after monitoring data from the Shotover River showed E. coli concentrations eight times the consented annual average and almost four times the level considered safe for swimming.

The reading of 2,100 colony forming units per 100 millilitres was recorded on 10 March at a sampling site just downstream of the Queenstown Lakes District Council wastewater treatment plant, which has been discharging treated effluent into the river for more than a year.

According to figures published by RNZ, the treated wastewater leaving the plant on the same day measured just 25 cfu, while upstream river samples taken across March ranged between 1 and 490 cfu. The Ministry for the Environment guideline for safe primary contact recreation is 550 cfu, which puts the downstream result well into the unsafe range.

The Otago Regional Council has opened a formal investigation into the spike and conducted supplementary sampling on seventeen separate days through March. A council spokesperson told reporters the body could not comment on what may have caused the elevated reading because the inquiry was still under way.

Queenstown Lakes Community Action, an incorporated group that has been tracking water quality monitoring in the basin, said the result was alarming and that residents and visitors deserved a clearer explanation. Member Nikki McFarlane described the figure as strange and substantial and said the community wanted the district council to be far more open when contaminant levels rose sharply.

“We’d like to see QLDC much more proactive in giving explanations for when there’s high levels or of contaminants,” she told 1News.

She added that the group had repeatedly asked the district council to install warning signage near the plant outfall and to publish real-time alerts on its website when readings exceeded the safe swimming threshold, but no such system had yet been put in place.

The Queenstown Lakes District Council attributed the result to a compromised sample or an isolated contamination event upstream of the testing point, and emphasised that bacteria counts in any river fluctuate naturally with rainfall, wildlife and stock movements. The council told the Otago Daily Times that the section of riverbank in question is not a commonly used bathing area and that elevated readings would typically dissipate by the time laboratory results were returned.

In a statement provided to media the council said its priority was the quality of the treated wastewater leaving the plant, because that was the only part of the system entirely within its control.

Discharge into the Shotover began in early 2025 after the original disposal field on the Shotover Delta failed and ponded effluent on the surface, a problem that the council had previously addressed at a cost of about 1.8 million dollars in repairs and a further 600 thousand dollars in legal fees connected to compliance breaches. In March of this year, councillors voted to lodge an application for a 35-year consent that would allow continued discharge into the Kawarau River system while a long-term land-based disposal solution was scoped.

Queenstown Lakes Community Action has signalled that it intends to challenge the council’s retrospective consent application in the Environment Court. Ngāi Tahu, the South Island iwi with mana whenua status over the Whakatipu basin, has previously told councillors that the direct discharge of human waste into freshwater is abhorrent and runs counter to tikanga.

Water scientists not directly involved in the investigation note that a single high reading does not by itself prove a treatment failure, because faecal indicator bacteria can also enter rivers through stormwater runoff, waterfowl, livestock movement and sediment disturbance from heavy rain. However, the size of the 10 March anomaly, combined with its location immediately downstream of the discharge pipe and the comparatively low upstream readings on the same dates, has put the treatment plant under fresh scrutiny.

The Shotover is one of the headwater catchments of the Kawarau and ultimately the Clutha, and the basin draws hundreds of thousands of visitors a year for jet boating, rafting and swimming. The Whakatipu region has also been one of the fastest-growing parts of New Zealand for more than a decade, putting sustained pressure on three-waters infrastructure that was originally sized for a much smaller resident population.

Council officers are expected to return to the regulatory committee with a more detailed report on the March data once the regional council investigation concludes. Any infringement notice, abatement notice or prosecution would fall to the Otago Regional Council as the consent authority.

For Queenstown residents and the community group following the issue, the immediate ask is simpler. They want signs at the river when results exceed safe swimming thresholds, prompt online updates, and a clearer public account of what went wrong on 10 March before the next holiday weekend brings swimmers, paddlers and tourists back to the water.

What do you think the council should do next? Have you seen warning signage at your local swimming spot when readings have spiked? Share your thoughts in the comments below.