Discreet Urban Underground Rainwater Tanks

Thinking of installing a rainwater tank but either lack the space in your backyard or wish to keep it out of sight? Global’s urban underground rainwater tanks are designed for you!

We even have urban underground rainwater tanks that will fit under your deck – just mask with a trellis in a matching colour to your house, and you’ll never know it’s there!

Key Features

Our underground and under deck rainwater tanks come in 2000L, 3000L and 5000L. All are moulded in food grade Polyethylene and are easy to manage and install onsite. The underground tanks are FEA structurally approved, so you can rest assured that the soil it is buried in will not cause warping to the plastic walls.

The benefits of an underground or under deck tank

  • Great for anyone lacking space in their backyard or around their house
  • Discreet and does not disrupt the visual consistency of your home
  • A smart decision for those building a house – the placement of the tank can be factored into building plans for optimum spatial consideration
  • Constant access to clean water through water bans applied during droughts
  • Sustainable and environmentally friendly – make the most of our natural resources!
  • A one-off cost for a life of savings, utilising a free resource

What size tank will you need?

  • A few things to consider when judging what size tank you will need include:
  • The size of your roof
  • How many appliances in your home use water
  • The WELS rating of your appliances
  • If you want to use your tank water for indoor or outdoor use, or both
  • How many people are living in your home on a daily basis
  • The level of rainfall common in your area

Here is a quick view of typical season rainfall trends across all zones within Australia:

rainfall australia

Bureau of Meteorology

How to calculate your water usage

If you are still scratching your chin and wanting a more accurate approximation of your water usage, you can use this nifty tool. Tankulator will calculate the size of the tank you need by taking into consideration your current water meter readings as well as information about your household water usage and the rainfall within your area.

How to calculate your roof’s water runoff

Another easy way to calculate the rainwater runoff capable with your existing roof is to follow this simple logic: 1 millimetre of rain on 1 metre squared of roofing will produce 1 litre of water into your tank.

Don’t know how big your roof is in metres squared?

  • An average 3 bedroom house is approximately 150 metres squared
  • An average 4 bedroom house is approximately 200 metres squared
  • An average 5 bedroom house is approximately 300 metres squared

Thinking long term

Underground rainwater tanks can be more expensive to buy and install than above ground tanks. However, their long-term benefits are worth the investment! If you are living in a small space, an underground tank will optimise the area you have and drastically change your water bill in the process. Thinking sustainably in an urban environment is an essential mindset in the contemporary age – get one step ahead and install an underground water tank!

Can’t find the right sized tank for your needs? Contact Global Rotomoulding and chat to our friendly staff about how we can design something to fit your home.

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