In our company story, Together Making A Difference Today To Sustain Life Tomorrow, we set out some facts that are equal parts fascinating and concerning. They all point the same way: there is less rain falling on New Zealand than there used to be, and the case for catching what does fall gets stronger every year.
What the rainfall numbers say
According to Stats NZ, the average annual rainfall for the five years to 2020 was 3.1% below the previous five-year average, and 10.7% below the five-year average for 1996 to 2000. Between 2016 and 2020, New Zealand's average precipitation, including rain, snow and hail, was 504,988 million cubic metres. Compare that to 520,890 million cubic metres in the previous five years, and 565,691 million cubic metres between 1996 and 2000. Three consecutive five-year blocks, each one drier than the last. That is not a bad season. That is a direction of travel.
The regional picture is sharper still
National averages soften what individual regions actually lived through. Seven of the nine North Island regions endured drought-like conditions in 2019, recording their lowest precipitation over the 25 years to June 2020. Northland, the home of Promax, recorded only 64% of the region's average annual rainfall in the year to June 2019. That is barely two-thirds of normal, in one year, in one region. Averages spread that kind of shortfall thin. The people living through it do not get to average it out, and neither does a garden, a herd or a tank that has run dry.
Climate change is not a future event
Promax does not see climate change as a future event to be debated and planned around. It is here, and it is happening. There is less rain and more drought. No matter where you live in New Zealand, that is the current reality, and our dry country will only become drier. When we examine the importance of rain harvesting, we only have to look at statistics like those above to appreciate the need to collect every drop we can. The argument does not rest on a projection. It rests on what has already been measured.
Free water the council cannot charge you for
Harvesting the rain lets you use this most precious natural resource as you see fit. Why wouldn't you? The council cannot charge you for the water you capture. It is free. We think it is an enormous waste for rain to fall on a roof and just sit there before evaporating, when the roof has already done the collecting work for you. The catchment is built. The water arrives whether you use it or not. All that is missing is somewhere to put it, and if you are unsure what size that needs to be, our guide to sizing a water tank is the place to start.
Restrictions hit you less hard
When local authorities impose water use restrictions, which is now seen as an annual inevitability in most regions, you will not be as severely affected. You will be able to access the water you have harvested and use it to keep your garden alive over summer, or carry out other household activities that restrictions would usually curtail. This is the part people tend to appreciate only once a restriction is already in force. A tank installed in March is worth a great deal in January. One ordered in January is worth nothing that summer. Our article on water restrictions and their causes covers how they come about.
What we do with our own roof
Our company's actions back up our thoughts on rain harvesting. We use 100% of the rainwater collected on our 1,500 square metre roof in Kerikeri for factory and office drinking water and ablutions. Not some of it, and not for the garden only. All of it, including what we drink. We are not asking anyone to do something we have not done ourselves at full scale, and the fact that a working factory can run its drinking water off its own roof says something about what the resource is actually capable of when you commit to it properly.
You do not have to be big
We know that not everyone has a building of that size. We also know you can catch an awful lot of water on an average size property. You do not have to be big to boost your sustainability. The maths is in your favour more than most people expect, because every square metre of roof is already a catchment, and a modest house has more of them than it looks like from the driveway. The rainwater tank size calculator will put a number on what your own roof can do.
The benefit extends past your own tap
The advantages of rain harvesting go beyond collecting water for use later. The more water we collect and use, the less reliant we are on water treatment plants. Less demand means those plants reduce their power consumption and emit fewer greenhouse gases. If more of us used our own water, treatment plants would continue to reduce their emissions. Tell us that isn't a good thing. It is the rare decision that pays the person making it and everyone downstream of them at the same time, which is a large part of why we keep making the case.
The time to act is now
Rain harvesting is important today. Will it be a necessity tomorrow? There should be no such thing as a long term plan for installing water storage tanks. The time to act is now. After installing a Promax plastic storage tank you have ready access to the water you need for irrigation, cleaning and drinking, and you stop being wholly dependent on a supply someone else meters and restricts. If the household economics interest you, our piece on reducing your water rates bill goes further. Call Promax on 0800 77 66 29 for advice on the right decision for your property.