Waiheke Stormwater Re-use

Water is quickly becoming one of the world’s most valuable resources, yet in New Zealand because of its apparent availability we are very wasteful with its use. So much so that New Zealand is the second largest consumer of water per capita in the world.

An average family home in Auckland pays over $1000 per year in water supply and waste water. Why are we paying for and treating water to a drinking standard only to flush it down the toilet or put it on the garden? Furthermore, industrial sites typically have large impervious areas and often require large amounts of process water to carry out their operation. In countries such as Australia and the USA, water shortages have driven research and development of technology to make the most out of the stormwater re-use.

In these countries stormwater re-use (alternatively called rainwater harvesting), water banking and trading are becoming an intrinsic part of good low impact and sustainable design, however the benefits of stormwater re-use should not be limited to these water scarce places.

This paper talks about an innovative underground water storage system installed on Waiheke Island, New Zealand and subsequent monitoring. The paper will look at the quality of the water, how it was re-used, demand analysis and discuss why designers of stormwater management systems in water plentiful New Zealand should be considering re-use more, and some of the barriers to uptake in New Zealand.