Tide of water savings from new building code

New office blocks could become some of the South East Queensland’s biggest water-savers, thanks to building code changes that will take effect from January 1.

Deputy Premier and Minister for Infrastructure and Planning, Paul Lucas, said big buildings could reduce water use by up to half following State Government changes that allow them to use rainwater in toilets, and treat and reuse water that was previously sent down the drain.

“These changes are about planning for a smart future that puts water conservation at the heart of how we design and build our homes and offices,” Mr Lucas said.

“Residents have already demonstrated they can make massive water savings.

“Since mid 2004 residential users have cut average daily water use per person by more than 50% - from 300 litres to less than 140 litres. And while some businesses have made great efforts it’s estimated the non-residential sector has only made savings of around 10% over the same time.

“New homes constructed since January this year in South East Queensland, and July in the rest of the state, have been required to meet specific water savings targets through the installation of rainwater tanks or other measures.

“From January the focus will be on business, with new commercial buildings in South East Queensland required to meet efficiency targets through the smart use of rainwater, greywater treatment or other measures. Measures will come into effect in the remainder of Queensland from July 1.

“Changes to the Plumbing and Drainage Act and the Queensland Development Code, mean commercial buildings will be able to use rainwater to fill toilets and install special treatment tanks to re-use greywater generated by hand basins and showers.

“It has the potential to save South East Queensland a lot of water.

“An existing 25 floor office block with around 1,500 people would use around 28 million litres of water each year in single-flush toilets, hand basins and sinks. The water savings from installing dual-flush toilets alone, is around 6.4 million litres each year.

“If the same office block was built after 1 January 2008 and had a greywater treatment tank installed, it could treat and re-use around 11.4 million litres of water per year – a 50% saving on top of what it would be achieving by using dual-flush toilets alone.

“That’s enough water from one office building alone for around 220 people.

“Untreated greywater includes everything from bath and shower water to leftover water from the washing machine.

“Residents and businesses will be able to re-use their greywater as an alternative to installing a rainwater tank, to help meet water-saving targets.

“If using greywater, they will need to install a treatment tank to ensure the standard of the water meets strict health and safety standards before it could be used for things like vehicle washing or flushing toilets.

“And even with on-site treatment, it won’t be used for drinking water.”

Mr Lucas said once water was flushed through the toilets it wouldn’t be re-used on site but would be sent for recycling in the Western Corridor Recycled Water Project.

Mr Lucas said residents would be able to continue to re-use untreated greywater to irrigate gardens and lawns.

Other measures to be introduced on 1 January 2008, include:

• the need to install individual water meters for most new buildings;

• retro-fitting of water-efficient toilets and shower heads for houses undergoing major renovations (thoserequiring council building and plumbing approvals);

“Taken together, these changes should help contribute to substantial water savings across the state, particularly in the south east corner, which is currently experiencing the lowest rainfalls ever recorded,” Mr Lucas said.

More information on the plumbing changes, including downloadable fact sheets and a calculator to help industry determine options, is available at: www.infrastructure.qld.gov.au/bcq

Media inquiries: Robert Hoge 0419 757 868