Is there something in the water…?
Lake Wakatipu's water is now under the spotlight with a recent report showing a drop in quality from ‘excellent’ to ‘high’, amid concerns untreated sewage could be seeping into the lake.
While Queenstown Lakes District Council (QLDC) is under the gun about discharge from its Shotover Waste Water Treatment into the Kawarau River downstream from the lake, the water in the lake itself is potentially being degraded from 'cross connections'.
That's when plumbers and contractors unwittingly connect pipes from new developments into the storm water system, rather than the council's sewage system.
There's also concern from local business leaders about how problems with water quality in the lake are communicated, with alarming pollution warning signs put up around New Year, turning out to only be precautionary.
Otago Regional councillor Alexa Forbes says she’s had reports about cross connections.
“This is not the only cause of degradation but is one that should not be happening,” she says. “It’s a very expensive and difficult problem to fix once you start to have any degradation in the lake, especially as it’s so deep and can absorb so much trouble before it shows.
“The lake is our greatest asset and needs a lot more care and attention."
A NIWA report presented to a December 2024 ORC committee meeting showed a slight drop in water quality in both Lakes Wakatipu and Wānaka.
A QLDC spokesperson says cross connections are rare, but do occur occasionally and are rectified as soon as the problem is discovered. Fixing the issue is paid for by the homeowners.
Otago Regional Council regularly tests water quality, including E.coli levels, at popular local swimming spots, posting the results on the LAWA website (Land Air Water Aotearoa – lawa.org.nz), and notifying QLDC.
So there was a good deal of concern among locals and visitors when a 'Temporary Health Warning' sign was erected in Frankton just after New Year, stating that 'this waterbody is polluted', and not to swim or collect food.
Frankton Road five-star hotelier Mark Rose, of The Rees, says he contacted both councils after upset American guests had noticed the warning not to enter our supposed pristine waters.
"Naturally our guests come here to enjoy our clean, clear waters so it was of grave concern when we hadn’t been notified at all and there was nothing displayed on the LAWA website,” Rose says.
He spent some time trying to establish if there were heightened E. coli levels in the lake in the area, and what had happened.
The QLDC spokesperson says the signs were put up as a precaution while work was carried out by contractors on a private property. Council was made aware of the work, and followed its normal process, also informing ORC.
But despite the signs, "there were no significant E. coli levels in Frankton Bay”, the QLDC spokesperson says.
That's confirmed by ORC’s scientist, water quality Helen Trotter, who says there have been “no exceedances recorded at ORC’s monitored sites”. ORC staff did receive some public enquiries about the warning signs along Frankton Track, directing further enquiries back to QLDC.
Rose says he wants to see better communication between the parties involved if contractors are going to be erecting council signage like that.
