Got a rainwater tank? Thinking of getting one? Well, you'll want to keep mozzies, sludge and fecal matter out of them - and here are the 5 tips for how.
The humble rainwater tank sits silently, dutifully doing its part for the environment - and your wallet. Image: Michael Coghlan
The humble rainwater tank sits silently, dutifully doing its part for the environment - and your wallet. Image: Michael Coghlan

The humble rainwater tank sits silently, dutifully doing its part for the environment – and your wallet. Image: Michael Coghlan

Australia is the driest populated continent in the world, and yet our water consumption per person is among the highest on the planet. For Australians, water is scarce and how we manage this resource is a concern for us all.

It’s no surprise that people are looking to install some form of water catchment for their property. Recent data shows that 26 per cent of Australian homes have already installed a rainwater tank and an overwhelming majority reported that they are positive about the tanks.

From saving money on your water bills to the conservation of a valuable natural resource, there is a lot to like about the humble rainwater tank.

They can even have other positive flow-on effects for the community. For example, the use of rainwater tanks in urban areas can relieve pressure on public infrastructure because of reduced stormwater runoff. We’ve also seen the popularity of rainwater tanks increase year on year, with the ABS reporting that the total storage capacity in Australia has gone up by 30 per cent between 2006 and 2011.

This is all very encouraging news for the environment – but, it’s not all drinking water and skittles. Just like buying a puppy dog or a Tamagotchi, owning a rainwater tank comes with its own responsibilities.

A recent study we conducted with the Smart Water Fund has shown that households may not be aware of some of the maintenance requirements that come with rainwater tank ownership.

In the report, Survey of savings and conditions of rainwater tanks, we conducted extensive research into rainwater systems across Melbourne, looking at the efficiency of the tanks and the water savings that can be generated at an individual household level.

One of the most interesting findings was lack of awareness around maintenance. Only 58 per cent of Melbournians indicated that they have conducted some form of maintenance on their system.

It’s important to know that the installation of a rainwater tank isn’t a set-and-forget scenario. There are some maintenance tasks that are unavoidable if you want to keep the tank healthy and efficient.

So here are our top tips for rainwater tank owners, or those considering a purchase in the near future.

Top 5 tips for maintaining your rainwater tank

  1. Get your mind (and the leaves) out of the gutter – every 3 months 
  • Cleaning out the gutters is a simple way to improve the water quality and the efficiency of the tank.
  • 4 per cent of tested households were found to have faecal matter in the gutters. In addition, 31 per cent of sites inspected were found to have half or completely full gutters.
  • Look into installing gutter meshing.

  1. Mozzie mesh – every 3 months
  • A rainwater tank is a great place for mosquitoes and pests to set up shop and thrive.
  • Of the tanks reviewed in the study 91.1 per cent had mosquito meshing, but more than 10 per cent were in a condition that would allow pests or vermin into the tank.
  • Poorly maintained mesh can pose a risk to the health of the community, particularly if populations of disease carrying insects are free to multiply in the rainwater tank hotel in your backyard.

  1. Spend some quality time getting to know your water quality – every 6 months
  • A majority of households use rainwater for the toilet or the washing machine so cleanliness of the water is less important. However, for those properties that use the water for showers, drinking or cooking, checking the water is crucial.
  • We found 57 per cent of tanks had discoloured water and 19 per cent had odorous water, while 25 per cent of tanks had medium or high concentrations of sediment.

  1. Pump it real good – every 6 months
  • The condition of the pumps and outlets will affect the quality of the water and the efficiency of how the household can access and use the water. A well-maintained system can also protect against long-term damage.
  • Our report found that in homes with pumps installed, 5 per cent were not functioning and 18 per cent of properties inspected were reported to have leaky pipes.

  1. It’s time to desludge
  • Standards Australia recommends that households organise the removal of sediment with a qualified contractor once every two to three years.
  • You probably don’t want to be dealing with this water.

The report also advises should check to make sure tank foundations are even, and that the tank has a reliable water switch.

If you would like to review the report in full you can find it here.



  1. Good housekeeping common sense to look after the tank and its water path. But did anybody consider putting an RO water filter between the tank and the point of use?? Best regards Frank

  2. Please do NOT empty your dirty sludgy tank water into the WATERWAYS or STORMWATER like it looks is being done in the video!! One of the things a rainwater tank does is keep that sediment OUT OF our stormwater system and so helps to keep our rivers and waterways clean. When you desludge your tank, please put all the gunk on your garden – or into the sewer where it can be treated.

    1. This is a terrific point Claire, thank you for raising it. The video was included to show how the water looks left untreated, however proper disposal is an absolute must. As we indicated this job is best handled by a professional, but if you’re keen to desludge the tank on your own, please be mindful of disposing of the water in an appropriate manner.

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    2. Claire
      I am simply stunned at how naive humans are becoming in understanding the environment they live in. I have to assume that this concern about the discharge of stormwater tanks sediment into water courses was written by a person who is totally disconnected from the natural environment.

      I live in an area where literally tens of thousands of tonnes of sediment are discharged into the aquatic environment by large floods every year. This material is not toxic to the environment in fact it is actually necessary as part of the biological and horticultural processes of this planet.

      This process has been happening for thousands of millions of years in quantities far greater than you could ever imagine. It forms the underlying nutrient base for microorganisms which are the foundation of the food chain.

      Further we have an 80,000 liter rainwater storage facility which supplies 70% of our household use. I deslude (and it really is stretching the definition of ‘sludge’ to use this term to describe the product that is discharged) the tank every two years. This process usually removes about 1000 liters of water with lower sediment loads than the floods I have described and 1.2X10(13zeros)th of the impact of just the last small flood above – and here’s the crunch, our house is about 100m from a permanent running Creek and I am lucky if the sediment and water travels more than 20m in the most saturated conditions, before it is consumed by absorption into the ground.

      Every waterway has a water quality profile consistent with its catchment this profile is so unique to every waterway that if you wished waterways could be categorized by their individual water profiles just like finger prints. Some catchments even contained high amounts of arsenic when rain runoff (surface waters) travels over such expose minerals.

      Please stop living as Alice in Wonderland and start to understand the dynamics that shape this planet and is responsible for the evolution of life on its surface so you can get perspective back into your world.

      1. I think Claire is right to state this. Sedimentation is a natural process but those floods you speak of are becoming more frequent and destructive.

        The sediment these events take into the waterways and subsequently the ocean is coming from environments that have been modified over the last few hundreds of years from their natural state and into agricultural land. Sediments associated with these events have increased substantially due to this change in land use to the point where the Great Barrier Reef is a real chance of being declared endangered by UNESCO.

        The overall water quality of this natural icon is still in decline from these processes and others (runoff also contains elevated levels of nutrient from fertilizers – higher levels of nitrogen have led to an explosion in the coral crunching Crown of Thorns etc) you describe as natural.

        Whilst it is not possible/feasible to do away with food production it is possible to manage the loss of precious soils as sediment and improve water quality outcomes through appropriate land use and best practice management.

        In the end the state of our “natural” environment is the responsibility of everyone all the time and anything that reminds us of this should be supported.

      2. They have a saying drought on land is drought in the ocean , flooding of land based sediment to the ocean enviroment restarts stalled equatic life

  3. I’m glad you recommend gutter cleaning every 3 months. There I was thinking I was obsessive compulsive. But what you forgot to mention was the range of first-flush devices to minimise the amount of gutter debris going into your tank. Also, the need to flush your U-tube if you have one (i.e. if your roof water goes down to ground level, then up the side of the tank). My U-tube gets really brown (especially while gutter cleaning) so I flush it regularly. I also frequently put my tank into by-pass because I collect more rain than I can use. So rather than it (and the dirt) going into the tank, causing clean water to exit the overflow, I send the dirty roof water straight to waste if the tank is full. Needless to say, I really value the clean taste of my water once I implemented all these measures.

  4. It’s worth knowing that on an average size tank (about 800 gallons or 4,000 litres) a once a month dose with about 10mL of kerosene will control wrigglers. A fine layer of the hydrocarbon forms on the surface of the water presenting wrigglers from breathing at the surface.

    1. dont do it to a tank you drink from. I did once and the kero taste permeated the tank. My family was not happy

  5. If your guttering is mounted 100mm below the edge of the roof clading it greatly reduces the collection of contamination and facilitates easy cleaning. (blowers work well)

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