Rainwater falling on your roof is the cheapest water you will ever have access to, and a Promax storage tank is a reliable way to capture and store it. That is good for the environment, and it can help you reduce your water bills for a lifetime. A tank does not change what you are charged per unit of water. It changes how many units you have to buy.
What happened to Auckland's water rates in 2023
In July 2023, Auckland's water rates were set to rise by 9.5%. That figure is now several years old and should not be read as a current rate. It is useful as a marker of direction rather than as a number to plan against: when inflationary pressures and challenging weather conditions land on a metered supply, the bill is where they surface. Rather than track each increase, the more useful question is a different one. What proportion of the water you are paying for could have come off your own roof instead? For everything you do not need to drink, the answer is usually most of it. Rain harvesting is the mechanism.
Why a tank changes the maths
All Promax storage tanks are reliable ways to capture and store rainwater, which is good for the environment and can help you reduce your water bills for a lifetime. The economics are unusual in one respect: the saving does not depend on the rate staying where it is. A tank installed once keeps taking demand off the metered supply for as long as it stands, so a rising rate makes it work harder rather than making it redundant. The capital goes in once and the offset continues. Our Slimline tanks, in particular, are designed to fit into New Zealand's shrinking residential sections.
Sections are shrinking
The traditional quarter-acre section, which measures about 1,000 square metres, is being consigned to the history books. In our metropolitan centres, houses are now built on blocks half that area, or less. In Auckland, new section sizes have reduced by a third in the past 30 years. Auckland's new build sections now have a median size of less than 500 square metres, with the average section about 120 square metres smaller than in the rest of New Zealand. The consequence for tanks is straightforward. A round tank needs a diameter and a clear circle around it, and on those sections there is nowhere to put one. This is the problem slimline tanks on new builds exist to solve.
The 1,000 litre Slimline
Our Slimline range includes our 1,000 litre Slimline tank. At 1.8 metres high it is the same height as the fence, 2.25 metres long and only 31 centimetres wide, and this diminutive tank is the least visually intrusive tank on the New Zealand market. You can hide it behind the house or along a fence. Those three dimensions are the entire argument: a tank that is fence height and roughly a third of a metre deep does not consume section at all, it occupies the strip of ground along the boundary you were never going to use for anything else. There are more reasons the Slimline range gets specified.
Still stormwater compliant
Being small and hidden does not mean stepping outside the rules. The tank is still stormwater compliant, making it easy to satisfy council requirements. This matters more than it first appears, because on a modern small section the tank is often not purely a saving. It is frequently part of what the consent requires in the first place. A tank that meets the stormwater requirement and reduces your metered use is doing two jobs for one footprint, and on a small site doing two jobs for one footprint is the only way the numbers work.
Built-in seismic restraint and PS1
Every tank in our Slimline range includes a built-in seismic restraint, which is the simplest to install, by simply bolting it to the concrete slab with four bolts. Our PS1 covers the seismic restraint detail to make it compliant, so there are no consenting issues. This is the part that quietly saves the most time on a build. Restraint details are a common source of back-and-forth with a council, and having the detail already covered means the tank is not the item holding up the paperwork. If the concept is new to you, start with what a seismic restraint is and why you need one.
Two problems, one tank
Sections are shrinking, but water rates bills are not, and a Slimline tank is the way to resolve both issues at once. It fits where nothing else fits, it satisfies the stormwater requirement, it arrives with its restraint detail already handled, and it keeps taking water off your meter for as long as it stands. For great pricing, excellent service, and long-lasting, durable tanks, contact Promax. We'll make it easy to save water and money. Call Promax on 0800 77 66 29.