Greywater irrigation Solving the demand for a sustainable water supply

“Where resource conservation is required and in the absence of strong market mechanisms, regulations will be required to gain uptake of technologies which provide for water efficiency.” Beacon Pathways Report “It comes down to a question of do we want to put down more wells at about $1 million a shot to provide garden watering for one day a year or do we start to think about how we are using our water.” Council operations manager for water and wastewater “New Zealanders must move away from the attitude of thinking water should be freely available as of ‘right’ and start treating it as a valued and limited natural resource if we want to remain sustainable and prosperous.” The Institution of Professional Engineers New Zealand

THE ISSUE Internationally local bodies are investigating and using new ways to keep up with the increased demand for water caused by growing populations, changing rainfall patterns and ageing dams, reservoirs and treatment plants. They are finding it more cost-effective and sustainable to manage existing water supplies better, rather than spending money on finding and /or storing more of it - especially given current economic conditions. Trying to teach people to change their behavior hasn’t worked so regulations or restrictions are required to reduce demand but this management must be accepted by the community before it can be successful.

THE CAUSE Annual water use has a ‘spike’ during the summer months during which we use around twice as much water than usual. Gardening was the second most popular recreational activity in New Zealand last year, with over 1.4 million kiwis taking part. An average garden sprinkler uses 1000 litres an hour. We continue to pay for water to be stored, treated and supplied to a drinking-quality level, only for it to be used for watering our gardens.

THE SOLUTION Our washing machines and bathrooms produce more than enough water to provide a safe, sustainable and cost-effective supply with which to water our gardens.

THE RESULTS……..FOR ME Saves money on water, whether I’m being charged now or might be in the future. Lessens the burden water puts on my rates and helps keep rate rises in check. Means I can water my garden all year round – even through drought conditions and restrictions. Is 68% more effective in getting water to where plants really need it.

THE RESULTS……..FOR MY COMMUNITY Saves money by allowing spending on upgrading water infrastructure to be delayed. Meets objectives set out in the Water Demand Management Strategies required by the RMA. Allows for sustainable growth and development without burdening existing ratepayers.

THE RESULTS……..FOR MY PLANET Lessens impact on natural water systems caused by new infrastructure. Greywater spreads reclaimed nutrients, leading to improved soil quality. Encourages behaviour change resulting in less harmful chemicals entering environment through domestic water use.

“Now, while I’m having a shower, the garden is getting watered at the same time and it is really growing well. No more worries for me about droughts and water restrictions, not to mention doing my bit to save water.” Heather Tofts, Paraparaumu

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