Three Factors To Consider When Choosing Rainwater Tanks

Many Australians waste water by watering the garden or flushing the toilet. Rainwater harvesting is a smart way to make huge savings in water bills. To make the most of your rainwater harvesting efforts, you should select an appropriate water tank. Here are some of the factors you need to consider when choosing a rainwater tank.

Tank Size

It's recommended that you buy the largest tank possible for your household water requirements. This is because when it rains, water doesn't fall from the sky at a uniform rate. Sometimes the rainfall is more on one day compared to other days. To harvest as much water as you can when it rains, you need to buy the biggest tank you are able to afford.

When choosing a tank size, you also need to consider the rain capacity in your area. You need to calculate how much rainfall your catchment area receives. Refer to the Bureau of Meteorology site to determine the potential annual rainfall in your area.


There are different materials that are used for rainwater tanks. The basic materials are polyethylene, metal, fibreglass and concrete tanks. Polyethylene or poly tanks are cheap and long-lasting tanks. This material is rust-resistant and, therefore, suitable for harsh climates.

Tanks can also be made from flat-rolled or corrugated metal. This metal may be coated or galvanised. On the other hand, fibreglass tanks are expensive compared to metal and polyethylene. Fibreglass tanks are chemical- and rust-resistant. Last but not least, you can opt for concrete material for underground tanks. Concrete tanks are also suited for areas prone to wildfires. These tanks are resistant against burning, melting and rusting.


Another important consideration when choosing a water tank is where it is going to be located. A rule of thumb is to install your water tank at the highest point of your property. This will ensure that the water in the tank is under gravity and can be used when the pump is broken or when there is a power outage. This positioning is also convenient for firewater.

If you are using the tank for rainwater harvesting, the top of the tank should be below the roofline of the house. Another consideration when choosing the location is whether vehicles will need to be near the tank for filling, emptying or maintenance. This is an important factor to consider for farm vehicles such as boom sprayers.