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Only a well maintained tank is water efficient

Rainwater tanks are a great way of collecting water for use on your garden, in your laundry or for toilet flushing. But its important to keep the system in good condition for both safety and operational efficiency. Many rainwater tanks will require attention within a year or two so if you've got a tank in your garden or you've just purchased a property with a tank here are some simple tasks you can do to look after it and check your water quality. If you follow these maintenance guidelines, your rainwater storage basin should provide you with suitable water for years to come.

Some quick tank maintenance tips:

  • Have your roof checked to see what it is made of and painted with, to ensure that it is safe and not toxic.
  • Cover all openings with mosquito proof mesh.
  • Fit gutters and downpipes with traps to catch litter and twigs.
  • Every few years clean out the inside of the tank.
  • Ensure there are air vents to prevent the water from becoming stagnant.

If you have connections to laundry or bathrooms:

  • Regularly check that the pump and automatic switch to mains water are both working properly.
  • Check that the pump turns on when you flush the toilet.
  • Install a level indicator on the tank so you know how much water you have.
  • The mains switch should only switch to mains water if the tank is empty or the pump fails. It may be possible to check this if the tank empties during summer.
  • If your system uses a float switch in the tank to top up the tank from mains water instead of a mains switch, then check that the tank water level is correct. Frequently check that the float switch has not failed and water is not overflowing to the stormwater drain (unless rainfall is causing the overflow).
  • If you are not confident cleaning the tank or checking that the system is operating properly then call a plumber to inspect and repair it.

Detailed maintenance guide

Once a month

  • You should first begin by installing mosquito proof mesh over gutters as well as any above ground tanks. This will prevent bugs and animals from contaminating the water and will slow the accumulation of debris. To further decrease the build-up of rubbish, consider installing gutter guards or downpipe screens to prevent blockage and contamination.
  • Check and maintain mosquito proof mesh when needed
. Mesh can often accumulate rubbish and can undergo damage in the form of holes or tears. Be sure to clear these as often as possible and repair any damage to the mesh.

  • A clean roof and gutter will prevent heavy debris in your water source and will increase water flow to your tank.

  • Make sure your water level is not running low, because you don’t want to run out of water.

  • Dead animals can contaminate your water and pose a health risk.

  • Check for signs of algae and mosquitoes
. Algae can grow in waterways that are exposed to sunlight and can be harmful to your health. Mosquitos can also inhabit any areas where water has become stagnant.

  • If you have a filter, make sure it is not blocked by debris
. Although a filter is only necessary for those who plan to cook and shower with their collected rainwater, be sure to check the filter often so that debris cannot contaminate your water supply.

  • Clean your flow restrictor
. If your flow restrictor builds up too much rubbish, water flow can be slowed and your water could experience contamination. 

Every 2 - 3 months

Every 2 to 3 months, there are a few checks you should do to ensure your water tank system is working properly.

  • Be sure to check for leaks in gutters, pipes, pumps, and the storage tank and repair any damages that are found.
  • Make sure that the water switch, which allows you to access the drinking water supply once your water tank supply has diminished is working correctly.
  • If you have an above ground tank, check that the screen cover does not have any damages. If it is in need of work, you may either repair it or replace it.

Every 6 months

Within a 6 month period, you should do the following.

  • Check the water quality of your rainwater, especially if you use your rainwater for showering and cooking purposes.
  • To test your water quality you can simply buy an at home testing kit and look for water discolouration and sediment deposits within the tank.
  • Be sure to check the tank foundations to make sure they are stable and even.
  • Also be on the lookout for ground leaks.
  • Make sure your pumps are properly functioning as they can affect water quality and the efficiency of the delivery of water.

Other precautions

There are also certain precautions you should take every so often to ensure clean, healthy water.

  • Try to thoroughly flush downpipes and drainage pathways every 12 months in order to decrease the build up of debris.
  • You may also want to hire a contractor to remove sediment within the storage basin every 2 to 3 years.

Factsheet - Maintaining Rainwater Tanks (pdf 662.2 KB)