Wednesday, May 18, 2005

Drip-fed figures

Late last month Queensland Premier Peter Beattie announced $2.3 billion worth of new water projects -- the water component of the 20-year southeast Queensland infrastructure plan and program worth $55 billion.

Interestingly, while environment groups generally campaign vigorously against new dams, they have been surprisingly silent on the dams and weirs proposed for the southeast.  In fact there appears to have been little critical assessment of the water proposal at all.

The plan focuses on increasing water supply to accommodate the growing population, estimated to increase by a million people over the next 20 years.  The program's budget includes $149 million for Wyaralong Dam, $2 million to investigate desalination options and $23 million for "urban conservation initiatives".

Curiously, the list of 23 projects comes to a total of only $861 million.  It is unclear how the remaining $1.4 billion, to make up the $2.3 billion announced by the Premier, will be spent.

Furthermore, it is unclear how much water the different components of this plan will deliver.  I am curious to know how much water the Wyaralong Dam might deliver relative to a desalination plant.

Perth and Sydney are now seriously considering desalination as an option.  Certainly the water supply is assured whether or not it rains.  The cost of desalination as a source of water is reducing dramatically with improved thermal and membrane technologies.

Globally, desalination capacity has increased at about 12 per cent per year over the past 30 years.  There are now more than 12,000 desalination plants world wide, with about 20 per cent of these in the US.  Australia is an island with most major cities situated next to the ocean, making desalination a real option for urban water supplies.

It is interesting to compare the southeast proposal with the water plan for Sydney, a city with an estimated population growth of about a million people over the next 20 years.  The NSW Government recently detailed how $2.6 billion would be spent to meet their growing water requirements.

The NSW Government has committed to a water recycling scheme, improving efficiencies within Sydney's water distribution network, tough restrictions on when and how gardens are watered, and is likely to fast track a desalination plant.

In addition, new homes may need to be 40 per cent more water efficient.  The Victorian Government is ensuring new home buyers install low pressure water valves, and either a 2000-litre rainwater tank or a solar hot water system.

Interestingly, surveys in Melbourne and Sydney have found high levels of public support for water restrictions.  What is less clear, however, is how much water these programs actually save.

Brisbane Lord Mayor Campbell Newman announced water restrictions for Brisbane on Friday, including as reasons "the drought" and "Wivenhoe, Somerset and North Pine dams down to 41 per cent capacity".

The ambitious state and local government plan is to cut consumption by 15 per cent over the next six months.  This involves reducing usage from 300 litres per person per day to 280 litres, with an ultimate aim of getting this down to 230 litres by 2020.

My back-of-the-envelope calculations indicate these dams supplying the greater Brisbane metropolitan area currently hold about 421,000 litres of water for each resident.  My same calculations indicate this is about double the amount of water available for residents in the Sydney area.

Sydney dams hold more water, are also at 40 per cent capacity, but with the larger population there seems only about 231,000 litres of water available for each Sydney-sider.  The average house dweller uses about 280 litres each day.

Certainly it would be good if there were less hype surrounding water issues generally -- and more useful information provided.

We are frequently told we live on the driest inhabited continent on Earth.  Yet according to the World Resource Institute, in Australia we have 51,000 litres of available water per capita per day.  This is one of the highest levels in the world, after Russia and Iceland, and well ahead of countries such as the US (24,000) and the United Kingdom (only 3000 litres per capita per day).

Of the water that does fall on Australia, we divert only 5 per cent of average annual run-off.  About 70 per cent of this water is used for irrigated agriculture which is concentrated in the Murray Darling Basin where relatively little water falls.

Indeed most water falls in northern Australia, especially north Queensland including across the Gulf of Carpentaria and on Cape York Peninsula.  This is where we are water rich.  This doesn't mean, for example, that we should pipe the water south, but it does mean we potentially have choices.

The water component of the $55 billion infrastructure plan suggests the Beattie Government is aware of the diversity of options available to secure a good water supply.  It will be interesting, however, to see whether the various proposals are given "a fair go".

The Wilderness Society and Queensland Conservation Council are cheering the new Wild Rivers Act (pdf file 322KB) through State Parliament, legislation which will stop any dams being built in north Queensland.

Once this is achieved, will these environment groups then start campaigning against the proposed Wyaralong Dam?


ADVERTISEMENT

No comments: