Water Tank Sizes

What size water tank do I need?

When looking at a water tank, and determining what size rainwater tank you need, you must first determine a few factors that will influence the size of your water tank. While everyone has a budget, if you aren’t on mains water a water tank loses its usefulness if it doesn’t hold enough water storage for your drinking water and household needs, and though we would agree that a rain water tank can never be too large, you are always restricted by your rainwater harvesting capacity.

Water usage

The first thing you need to determine is how much water storage you need for your home. This will help you determine the minimum size water tank you need. If the rainwater tank is just going to be for the garden or to supplement your washing machine and toilet, then a slimline water tank or small round tank may be enough water supply. However if you are looking to be, or need to be independent from mains water, you will need enough tank water to cover all of your property’s water usage.

For a two person home, Pioneer would typically recommend a tank size of at least 90 000 litres of water storage, for three people 110 000 litres, for four people 150 000 litres and for six people 250 000 litres. Keeping in mind, if you can both afford to and capture more rainfall, it is always safer to have a larger water tank that you estimate you need.

Rainwater harvesting ability

The biggest restriction on water tank levels is often how much water you can capture from your roof. To find this number, you need to work out the roof area of where any rainfall is being captured, this could be not only the roof of your home, but also of any sheds near the water tank. Once you have this roof area in metres squared, multiply it by your mm of annual rainfall. This will give you an average litre amount that you will be able to capture annually. Any larger tank than this will be unlikely to be filled.

If you do need additional rainwater harvesting capacity, the Smart Water Saver, exclusive to Pioneer Water Tanks, turns the roof area of your rainwater tank into additional water harvesting space. Using a patented design, free from the downfalls of tank gutters, the Smart Water Savers are fittings to the roof of your tank, which allow you to harvest additional rainfall directly from the tank roof.

What type of water tank is best?

There is no definitive answer to what type of rainwater tank is best, because as mentioned above, what you are using the rain water tank for is going to impact your decision.

Improvements in poly tank and steel tank technology have rendered the concrete water tank and underground tank obsolete for most residential rain harvesting purposes, as they are harder to access and repair. The stainless steel rainwater tank is designed for commercial use.

A poly rainwater tank is lightweight and typically more affordable than a steel water tank, if your water storage isn’t as pressing of an issue. A slimline tank is perfect for those without much room, looking to provide water to a garden, or use it for washing a car. Another popular poly tank is the round water tank, which typically has a larger capacity, up to a 50 000 or 60 000 litre tank size. These round tanks are often used for gardens, and to supplement homes still connected to mains water.

Steel rainwater tanks are available in a full range of Zincalume® and Colorbond® colours, and are the popular choice for anyone looking to use their rainwater storage to supply water to their entire house, either due to no mains water or to reduce the water bill. Larger and more durable than polyethylene plastic tanks, and fitted with a food grade liner, steel rainwater tanks are often more affordable than you might think

Much like people, water tanks come in all shapes and sizes, and the space taken up by your rainwater tank is going to depend on the size of water tank you choose. Many slimline tanks are only about a metre wide, and a few metres long, and can be snug up to the side of a house, whereas larger round steel tanks or poly tanks need space around them for installation and access.

The below table outlines the sizes of Pioneer Water Tanks, and their diameters and heights to better give you an idea of how much space you might need for your tank installation. Along with the tank diameter, a 1m wide gap around the tank must also be maintained, away from walls, trees or sheds.

The Litres/Gallons stated above are gross capacities. Actual useable volume will vary depending on the size and position of inlets and outlets

Further questions

If you have any further questions around what size water tank would best suit your needs, contact Pioneer Water Tanks today.

Information on Water Tank Prices