by Rachael Laurie
I grew up in the country drinking rainwater collected from the roof of our house and garage. It was delicious, and I much preferred it to the chlorinated water in town. Mum always told us we were safer – if ever there was a natural disaster we would still be able to access the water. This was important after the Kaikoura earthquake. The Raglan water supply was stirred up by the quake and was not potable for a week, but we were fine.
Living in the city now I am always confused by how all that good water is wasted down the drain. Over the past years, we have seen in New Zealand the weather move from flood to drought. It seems now every summer we have water restrictions in our towns and cities while at other times we struggle to cope with the deluge.
A solution: Private urban water collection.
Around the world, cities are beginning to implement urban water collection schemes. In Singapore, where around 86% of the population live in high-rise buildings water is collected from the roof tops and is kept in separate cisterns on the roofs for non-potable use. In Tokyo, rainwater is collected from private and public buildings. Rainwater collection and utilisation is promoted to mitigate water shortages, control floods, and secure water for emergencies. Rainwater collection was introduced in Berlin in 1998 to control urban flooding, save city water and create a better microclimate. Rainwater is collected in basement tanks and used for toilet flushing and watering gardens. Similar collection and utilisation schemes are used around the world in Thailand, Indonesia, the Philippines, Bangladesh, Gansu Province – China, Botswana, Togo, Mali, Malawi, South Africa, Namibia, Zimbabwe, Mozambique, Sierra Leone, Tanzania, Kenya, Brazil, US Virgin Islands, Bermuda, and Hawaii.
While rainwater in urban areas is not considered potable, it can be used for many other things such as watering the garden, flushing toilets, in washing machines and washing the car. The ORC recommends using “rain tanks to collect roof runoff (not for drinking water)”. You can have your water tested to see what contaminants are in it and so long as it is not polluted with chemicals or toxins in an emergency this water can be boiled or treated for drinking.
Collecting rainwater is environmentally friendly. Not only would it help to build your families resilience in emergency or drought situations it could help to build the resilience of your community as collecting the water from your roof could take pressure off drains during storms and help to prevent flooding.
Ideally, the council would be able to give rates rebates to households who collect their roof water in exchange the pressure they will then remove from the mains system. The issue of water was discussed in Blueskin Bay in 2004 – maybe it is time to revisit the topic with resilience in mind?