How To Select The Right Water Tank

Did you know that Australians are the biggest per capita consumers of water in the world? Yet we’re living in a dry country where the yearly rainfall is way below the global average. 

So it makes sense to collect our rainwater as much as we can. Particularly as 12.5% of Australia’s total water use is for homes and gardens – we’re literally flushing it down the toilet! 

Using rainwater tanks can potentially save millions of litres of water each year. That’s good for the environment, good for our infrastructure, and good for our hip pockets when our water bills arrive.

Let’s look at how to select the right water tank for your home.

Step 1: Find out how much rain you can expect 

Some areas get more rainfall than others. Average rainfall across Victoria can vary from 200mm to over 1000mm per year. Knowing your pattern of rainfall gives you an idea of how much rain you can reasonably expect.

Check your area’s historic average rainfall data at the Bureau of Meteorology. 

Step 2: Calculate your rainwater harvesting capacity

Each square metre of roof area collects 1 litre of water for every 1 millimetre of rainfall received. 

For example, if your roof area is 200m2, you can expect to harvest 100,000L of rain for every 500mm of rain. 

To calculate your roof surface area, multiply its length by its width. Then multiply this number by your area’s average rainfall. That’s your rainwater harvesting capacity.

Step 3: Work out how much water you’ll need

This involves thinking about what you will be using your collected water for. 

Will you just be using it for the garden? If so, how big is your garden and how many times a week do you water it?

Garden water use varies from 25% to 50% of household water in Victoria. To maintain your lush green garden during summer’s dry months, you’ll need at least a 4,000-5,000L tank.

What about the laundry and bathroom? How big is your family, and how much water do they use for the shower? How much water is used for washing clothes each week? 

A toilet can use up to 12L of water per flush, with the average person using 210L of water per week just on the loo! Washing machines are also water guzzlers, and can use 50L – 150L of water per load depending on their efficiency levels. 

Step 4: Decide on your tank size

After bringing your calculations from steps 1-3 together, you should have a good idea of how much rainwater you can expect to collect for your area and roof size, as well as how much water your household needs. 

Working out how big your tank needs to be is done by calculating the amount of water caught by the number of times your tank will fill each year. At ASC Water Tanks, we recommend choosing a size that will hold a minimum of 4 weeks’ supply. 

This process is not an exact science as rainfall can vary, but proving you choose a tank size with a buffer for drier years, you’ll be fine. 

Step 5: Choose your tank’s location

The best place to put your water tank is next to a wall or fence, as long as it doesn’t block any doors or paths. Your tank location needs to be a sturdy, level surface, as rainwater tanks can weigh several tonnes when they’re full. 

Round water tanks are a great option if you have the yard space to fit one. If you’re in an urban area with a smaller yard, a slimline water tank might be your preferred tank type.

Both round and slimline tanks are available in tall or squat options, and in a variety of colours to suit your individual space. 

Installing an underground water tank might also be something to consider, as they are the ultimate space savers. If you choose this option, you will need a water pump to get the water up and out of the tank for your household use. 

If your home is in a high density urban area, you can install a rainwater tank under your decking. It’s a great way of making use of otherwise wasted space.

Step 6: Select your tank’s materials

There are a variety of materials that tanks can be made from. Each material is suited best to a certain kind of use. Fibreglass, Colourbond steel and concrete are all popular options depending on how your tank is setup for use. 

If you’d like help choosing the right water tank for your property, we can help. At ASC Water Tanks, our rain water tanks are premium quality, reliable and durable. We deliver high-quality water tanks Melbourne and Victoria-wide, as well as to New South Wales, South Australia and Queensland.

Give us a call on 1300 229 606 to discuss your water tank needs.