ughts. At the same time the UK is experiencing a population shift to the driest parts of the country, and households are smaller but with higher consumption.”

In the past two years southern England has had the worst droughts and the worst floods for a century, both of which resulted in water shortages.

“This is not just a southern England problem – there was a drought in Dundee in north-east Scotland a couple of years ago.

"The Government is responding to these issues by developing new legislation to promote water-efficient housing and bathroom fittings, with the aim of reducing per capita consumption from 150L (40 gallons) to 120L (32 gallons) per day.”

Tomkins also says low-flow studies have been inconclusive.

“There is some concern that reduced flow will result in sewer blockages.

However, it generally seems that the problem stems from poor sewer design and maintenance, and the flushing of non-sewerage items.”

The UK Environment Agency is due to release a report titled Less Water to Waste: The Effects of Water Efficiency on Wastewater Flows. It is hoped it will shed light on water conservation methods and their effect on infrastructure.

Yet it is clear that the UK is still lagging behind Australia. The NPRF findings should provide a telling prognosis and allow the Australian plumbing industry to more effectively combat water shortages (and global warming in the longer term) and curb any initiatives that are being taken too far.

It may be possible to take a leaf out of Veritec Consulting principal Bill Gauley’s book. Since 2003, Gauley has been conducting tests in North America on flush performance, known as MaP testing (maximum performance of toilet fixtures).

In the US and Canada it seems that the 6L systems are more than sufficient. In 2006 WPR spoke to Gauley, who uses soybean paste (with similar properties to human waste) to test the efficiency of certain toilet models and their capacity to flush.

“Based on the results of extensive performance testing, manufacturers stepped up to the plate and began making far better toilets,” he says.

“While the minimum threshold for providing customer performance satisfaction is set at 250g (0.6lbs), some models today can flush over 1,000g (2.2lbs) and be classified as truly exceptional.”

Tests by Gauley are ongoing – and required – as North America moves towards blanket manufacture of ‘ (actually HETs have “effective’” flush volumes of 4.8L (or 1.28G). As drought hits harder and initiatives to curtail water use become more prevalent, MaP testing takes on greater importance.

Gauley has also completed a series of tests to determine just how far low flush volume toilets can transport waste through the drain pipe. His research has found that while toilet flush rate is an important factor, flush volume is by far the most important aspect concerning drainline carry distance.

Gauley says, “If we intend to use toilets flushing with less than about three litres of water in our homes we may have to redesign our drainage systems, e.g., steeper slopes, smaller diameter piping, and perhaps less intrusive couplings”.

He strongly agrees that more research must be done to assess the effects of lower flow rates in our drain systems.

“One outcome may be,” he says, “that we allow lower flush volumes for residential installations where supplemental flows from showers, baths, and clothes washers help transport waste to the sewer and higher flush volumes for commercial installations where drain pipes have larger diameters, flatter slopes, and little or no supplemental flows.”

Australia is well ahead of North America in its plans to conserve water: WELS Standards are compulsory, whereas Uniform North American Requirements (UNAR) is a voluntary program.