Keeping your Rainwater Tank Opaque

By Alison Mitchell, Friends of Willow Park

Many of us have rainwater tanks, but we don’t always use them to their best advantage.  We often let them become “transparent”.  Before I explain that concept, we should consider the advantages of having a rainwater tank for both us and the environment.

Rainwater tanksstore water for us to use and they save us money by reducing the amount of potable water we purchase.  One of the biggest environmental advantages of rainwater tanks is that they can also limit the amount of water going to the storm water system.  Before our urban areas were built rainwater entered the soil, slowly made its way to streams and was cleaned by organisms in the soil as it travelled.  As our urban areas grow, rainwater increasingly falls on solid and potentially polluted roofs, roads, car parks and footpaths.  Rainwater now rushes through the nearest drainage system and into our urban streams resulting in what are known as “flashy” flows.  Most of us have seen the results of these “flashy” flows in our local streamsrecently – the rapid rises and falls in water level, flooding, bank and bed erosion, vegetation and habitat losses and damage to infrastructure and homes.  These impacts are not only costly for our environment, but also for our economic system.

So, what is a “transparent” rainwater tank?  A rainwater tank that is full.  Rainwater entering your full tank goes directly to the storm water system and your rainwater tank is now transparent with respect to any capacity to limit flashy flows in your urban stream.

There are a number of ways to keep your rainwater tank opaque to gain the maximum benefit for you and the environment.  Both the NSW and VIC State Governments have rebates to plumb your rainwater tank to your toilet and washing machine.  You can also gain some benefit for your physical fitness if you choose to bucket your rainwater to these water-hungry household appliances.  Regardless of how you choose to keep your rainwater tank opaque you know you will be gaining economic advantages for you and potentially your community and you will be living a little more lightly on our planet too.  Relying on keeping your rainwater tank opaque by using it to only water your garden will undoubtedly fail – when don’t you water the garden?  When it’s raining!