What is the Best Material for a Rainwater Tank in New Zealand?

Rainwater Harvesting

Rainwater harvesting using rainwater tanks is the third-largest supply of water in New Zealand, with billions of litres of rainwater being harvested annually.  Rainwater harvesting and storage provides water conservation, better infrastructure for water delivery, and an overall resolution to the management of stormwater.  The New Zealand rainwater tank supplier Think Water is committed to helping you install the most efficient rainwater tank with the options of building materials; polyethylene or steel.

What are polyethylene and steel?

The two most reputable materials requested from water tank suppliers of New Zealand are polyethylene and steel.  Polyethylene water tanks are formed from UV protected plastic to prevent damage from the sun.  Steel rainwater tanks are sheets of metal, welded and bolted together at joints to structure the rainwater tank.  Like polyethylene, they are equipped with a protective agent that prevents steel material from environmental corrosion.

Steel: The Pro’s and Con’s

Steel material has many benefits.  The strength of steel enables rainwater tanks to encompass the greatest amounts of water, which are necessary for bulk industries such as fire departments, agriculture and irrigation. Because steel is heat resistant and strong, it is the longest lasting material for a rainwater tank.  This metal form is protected from extreme heat and fires as well as extreme cold and freezing.  Steel rainwater tanks offer durability and increased protection due to their strength.

While steel is of great benefit, it does have some drawbacks.  Because steel is of such heavyweight and confined material, these rainwater tanks are not ideal for movement and require increased labour for installation. Care must be taken to ensure steel tanks are installed on a pad which meets the tank manufacturers specifications. The durability of the material comes with a much higher price both with the cost of material and installation.  Lastly, while steel is protected with an anti-corroding agent to prevent decomposition of the rainwater tank, it is still susceptible to overtime corrosion from longtime use. Often sacrificial anodes are used to reduce the likelihood of corrosion.

Polyethylene: The Pro’s and Con’s

In comparison to steel rainwater tanks, polyethylene rainwater tanks are also a good choice for rainwater harvesting in New Zealand.  Polyethylene rainwater tanks are optimised for outdoor use with an ultraviolet ray stabilizer embedded in its coating, thus further protecting the quality of harvested water and the overall structure of the rainwater tank from the sun.  These rainwater tanks are also the most affordable option, and they are also the easiest to install.  Because of their lightweight material, they pose as a non-permanent rainwater harvesting option, that can be relocated and easily fixed in case of minor damage.  Polyethylene rainwater tanks allow for customization in colour and shape as the material is easily adaptable and able to be tinted. 

However, polythene tanks also have downsides.  Because the material is not heat resistant, they are susceptible to damage from the sun over time.  The polythene material also means that in case of a fire or any extensive heat, these rainwater tanks are not considered heavy duty and would not withstand some variations of extreme weather.

Choosing Between the Two:

Polyethylene rainwater tanks and steel rainwater tanks are both considerable options for rainwater harvesting in New Zealand.  Polyethylene tanks are the best solution for customers who are looking for an affordable option with a smaller need for water capacity.  They also are the best option for customization and the ability to be moved,  whereas steel rainwater tanks are ideal for those who seek a more permanent, heavy-duty rainwater storage, protected from extreme conditions and capable of holding mass amounts of water.  Choose the right rainwater tank for the harvesting and storage of your water supply today and enjoy all the rewards this integrated water system has to offer!

Think Water has been supplying rainwater tanks for rainwater harvesting to New Zealand properties for many years and are happy to provide you with expert advice about the best choice of tank for you.

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