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BASIX Water Tank Requirements for Swimming Pools and Spas (FAQs)

If you are planning on adding a swimming pool or outdoor spa in New South Wales, you may need to comply with requirements of the Building Sustainability Index (BASIX). These requirements aim to deliver equitable and effective reductions in water usage across NSW. This article provides an overview of when and what you need to do to comply with BASIX for pools and spas.

When Does BASIX Apply?

When submitting plans for a new home or addition of a swimming pool or spa with a volume exceeding 40,000 litres to an existing home, then it will need to meet BASIX requirements. These requirements vary depending on water target zone, the size of the pool and type of pool heating used, swimming pool shades and covers.

Why Meet BASIX Requirements?

The capacity of your swimming pool or spa is the volume of water (kilolitres) that the pool will hold when completely filled to the appropriate level, as indicated by the pool manufacturer. In NSW, the average home swimming pool holds 45,000 litres (45 kilolitres) and so would need to comply with BASIX since it exceeds the 40,000 litre threshold.

With swimming pools, water regularly needs to be added to replace water lost as a result of splashing, backwashing the filter and evaporation. It is estimated that swimming pools lose approximately half their volume each year, meaning a 40,000 litre pool will require as much as 20,000 litres of water each year to keep topped up.

This water can push your domestic water consumption up by as much as 10%, not to mention additional electricity costs for running your filter and chlorinator. Hundreds of thousands of swimming pools can evidently have an impact upon water sustainability, and owning one also increases your household running costs.

What Do Pool Owners Need?

If you need to comply with BASIX for your swimming pool or spa, then to receive certification there are three main areas of focus:

Dedicated Rainwater Tank with Tap

You will need to install a separate rainwater tank for storing water used for swimming pool and spa top up. Even if you have an existing rainwater tank, you need to ensure water storage is dedicated to topping up your swimming pool in line with BASIX swimming pool requirements.

The proximity of your pool-nominated rainwater tank needs to have a tap installed and be located within 10 metres from the edge of your swimming pool or spa. Many hoses can be found that meet this length, enabling you to easily top up a pool. You can also find auto-filling valves to attach to a hose, which will automatically top up your swimming pool once water falls below a certain level.

Sheltering Your Swimming Pool

Swimming pools and spas that aren’t shaded will suffer higher water evaporation levels in the sun.

This means if your swimming pool is located outdoors rather than indoors, then setting up shades over your swimming pool can improve your pool water use. Solid fencing and dense vegetation around your pool can also help shield water evaporation caused by wind.

To be classified as shaded for BASIX certification, at least 80% of the pool or spa must be covered by a shading device which is either opaque, has a shade ratio of 80% or higher, or has a shading co-efficient of less than 0.35.

Swimming Pool Cover

A great way to reduce the amount of water lost through evaporation is to invest in a swimming pool cover. Pool covers provide several benefits and can:

  • save up to 10,000 litres of water every month
  • reduce the chemicals required to balance water in your pool or spa
  • keep your pool cleaner by preventing leaves and debris blowing in
  • double up as safety covers to keep pets or animals falling into your pool.

If you like warmer pool water, you can purchase solar pool blankets. These covers retain heat and can increase the water temperature by as much as 10 degrees, extending your swimming time throughout the year by around three months.


Download – BASIX Water Tank Requirements for Swimming Pools and Spas (FAQs)