Sam Judd: Auckland's water threatened by poo?

Photo / Thinkstock

Recently I was having some friendly banter with a mate who lives in Hamilton. He rebuked my criticism of his hometown by telling me that we in Auckland are drinking Hamilton's poo.

I had to investigate this and found that to a certain degree it is true. Treated sewage from Hamilton is discharged into the Waikato River near Hamilton, and much further down, Auckland City is taking water. One day, we may actually want Hamilton's poo - a study by a group of experts recently said that waste from one million Americans could contain as much as US$13 million (A$16.47 million) worth of precious metals.

But it turns out that the human discharge is not of big concern as it is properly treated - we can thank Hamilton for that. What is more worrying is the dairy conversions. Cow poo is of course not treated. I was told that nationwide, our dairy herd excretes the equivalent of 70 million peoples' worth of untreated effluent into our waterways.

The problems are becoming so big that many farming leaders are starting to see that we simply can't sustain cows everywhere. Martin Bennett, chairman of the Dairy Environment Leaders Forum of the country's top 60 farmers has called for a halt to big conversions, saying that "reckless, large-scale conversions are undermining farmers' efforts and costly investments to make their farms sustainable."

Even Federated Farmers' Waikato President Chris Lewis has called for a moratorium on dairy conversions - a move that seems to show that farmers own lobby groups are now understanding that there is a limit to how much water can be polluted by nutrients.

With more conversions proposed in the Waikato catchment and elsewhere around the country - our water supply is seriously threatened.

Watercare has stated in a submission a while back that discharges from just one industrial dairy development in the Waikato catchment involving Landcorp could mean "the nitrate increase and increased risk of protozoa would cause a decline in water quality", and "if irrigation was allowed for this one project, summer low flows in the Waikato would reduce by a further 13 percent and river nutrient concentrations could go up by 120 percent."

Under medium growth predictions, the population of Auckland is expected to increase by over 800,000 people in the next 35 years.

The booming construction sector is so busy preparing for this that I can't even find a building contractor with spare time at the moment (any builders out there - please drop me a line if you have some spare time!).

But while construction, education and many other sectors will benefit from this growth, there is inevitable pressure put onto our city services. Put simply, more people need more water to survive.

Auckland currently gets water from five water storage dams in the Waitakere Ranges, four water storage dams in the Hunua Ranges, a groundwater take from an aquifer in Onehunga and the Waikato River.

But as this will not be enough in the future, Watercare has applied for Resource Consent to take an additional 200,000 cubic metres of water per day on top of the 150,000 taken currently.

So we are starting to see industry have a direct impact on humans' ability to get clean water. Who out there thinks that this will start to make some change to our sick waterways? Should the human need for clean water come first?