Auckland’s water crisis not the first

I was on holiday in August 1994 in Auckland with my brother. We were staying at the house of a mate who had his first years of life just up the road from myself and my brother.

Despite my memory of that holiday being distinctly of passing showers, at times heavy, every single day we were there Auckland was officially in drought. The reservoirs in the Hunua and Waitakere Ranges were low, with their bell mouth spillways well and truly high and dry. And the mother of my mate had to go warm up buckets of water to put in the bath when we needed a wash as showers were not recommended.

Fast forward 22 years to March-April 2017 and here we are again. Auckland coming out of another major crisis where people were forced to ration water. This one was a bit different though because the water supply is actually quite plentiful and the reservoirs were near brimming. The problem was that the sheer volume of run off into the reservoirs from several huge downpours, each one being many days worth of rain landing in the space of a couple hours – thunderstorms being a major source of the trouble – dumped a huge volume of sediment in the catchments of the dam, thus significantly increasing the volume of sediment being processed at Auckland’s treatment plant.

Whilst the rain fall was not stoppable, I wonder how much of the silt content in the run off had from excess felling of stabilising vegetation in that catchment. In a sort of sub tropical climate surrounded by water both north and south of the isthmus, with substantial hills to the west, Auckland is our wettest city with 1200mm on average per annum (currently at 531mm for the Shelley Park gauge in Howick for the year to date).

But Auckland has a water supply issue both in terms of volume and water quality. Many kilometres of pipe needs replacing as a matter of urgency. The volume of water leaking out of them is unknown, which makes metering a problem. And it is compounded by the need to replace or upgrade the treatment plant itself in the near future, as it is old and cannot cope with cyanobacteria and algae problems.

In the future, the current infrastructure is expected to be servicing another 700,00 people in the next 30 years according to one report. Pipes feeding Auckland from the treatment station are going to require significant additional investment. Being able to fund the large investment will create issues with Aucklanders rates.

So it will be interesting to see how Auckland copes with these significant challenges. But you cannot blame the weather for all of their water issues.

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