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Protecting our water . . . Cromwell and Pisa Moorings lie on the shores of Lake Dunstan. Alexandra man Gavin Dann says councils are still not doing enough to protect lake and river quality. PHOTO: STEPHEN JAQUIERY, OTAGO DAILY TIMES

Alexandra man Gavin Dann’s three-part series about water in the Central Otago and Queenstown-Lakes district started our Protecting our Water series at the beginning of the year. Midway through the year-long series, he contributes more thoughts on water in our district.

Rampant urban development in Wanaka has already resulted in adverse stormwater events causing sediment to flow into Lake Wanaka.

Councils see development as a cash cow, so are not interested in slowing it, and the Queenstown Lakes District Council (QLDC) has shown little interest in prosecuting the polluters.

Under its Project Pure scheme years ago, the Otago Regional Council (ORC), which grants consents for such matters, made the QLDC discharge liquid waste water from the Wanaka wastewater treatment plant on to land near the Wanaka airport rather than have it discharged into the CluthaRiver.

This saved the river from an additional burden of waste – a stance for which the ORC should be congratulated.

I would like to know why the Central Otago District Council (CODC) is not also looking to discharge its liquid waste to land when sewage from Clyde is added to the Alexandra wastewater plant, rather than discharge it into a river already burdened with “treated” human liquid waste from Queenstown and Cromwell.

It seems the horse has bolted when it comes to the new source of Alexandra’s drinking water from Lake Dunstan. Pumps are in and the pipeline is being laid.

I am surprised it is best practice to put a drinking water main only a metre away from a sewer main over an 8km distance.

I am sure it is not best practice to site a new bore field near an old Ministry of Works industrial tip 350m “downstream” from the intake pipes which will deliver Lake Dunstan water to Alexandra homes.

I could not believe it when I had it confirmed that this is the case above the Clyde dam, from where Alexandra’s drinking water will be sourced.

I hope the design engineers have factored in the expected alpine fault rupture.

In the meantime, we can add party pill chemicals to the smorgasbord of stormwater toxins, lake snow and treated sewage effluent served up from the Lake Dunstan soup when that pipe gets connected.

I was intrigued to read recently how authorities monitor drug use in this modern age.

They take samples from the town or city’s wastewater plants and analyse them for various narcotics.

These, and other medicinal compounds flushed down toilets, are all part of our liquid effluent discharges.

Queenstown – our party town – must contribute nicely to the toxicity of the Kawarau River downstream of the Shotover wastewater treatment plant.

There are, after all, very good bore fields between the golf course and Dunstan High School.

Yes, they contain some lime; but if lime was the major reason to shift the bore field, the Earnscleugh aquifer has much lower levels, similar to Lake Dunstan.

It is my personal view that Lake Dunstan water will be a much less safe source of drinking water than an underground aquifer.