Friday, May 02, 2008

Of mythical water grids, pipelines and logging in catchments

After a period of denial and inaction about our looming water crisis, the Brumby Labor government is now hell bent on pushing their so called "water grid" as a solution for our ongoing reduced rainfall. I am not sure where they got this concept from. It seems to have entered "government speak" around the world from the Thames in the UK to Queensland.

Unfortunately the concept as described in Victoria has a number of serious flaws and seems to be mainly a public relations exercise.

My understanding of the concept in Victoria is that large scale engineering works - such as the North South pipeline, and perhaps the planned $3b desalination plant at Wonthaggi - will create a system where water can be transferred long distances to places where it will be used.

The major problems with this approach are:
  • Any pipelines that are not gravity fed will require a lot of energy (mostly derived from coal-fired power) to pump the water. This will result in major greenhouse gas emissions.
  • The proposed North South pipeline is taking water from the Murray Darling catchment - where it is desperately needed - to Melbourne, where it is not. This has major impacts for people living both along the Goulburn, and all the way down the Murray River to Adelaide, whose residents rely on the river for most of their drinking water
  • The costs of pipelines is high. The 70km North South pipeline is estimated to cost $750m.
  • The environmental impacts of pipelines is high. The North South pipeline route has the potential to affect 75 threatened animal and plant species.
  • The planned desalination plant will produce a lot greenhouse gas emissions too, and the water from it will have to be pumped all the way to Melbourne.
  • Logging in Melbourne's water catchments continues - which is resulting in less water and a reduction in its quality.
The Brumby Government's rationale for all this is not clear. We are quite obviously running low on water, but we are not yet on Stage 4 restrictions, and Melbourne's daily household water usage is still quite high.

People still have their swimming pools full too - topped up with water trucked in, resulting in yet more greenhouse gas emissions.

There is a cruel irony in climate change causing reduced rainfall, then most of the governments measures to address water shortages resulting in more greenhouse gas emissions, which will further exacerbate climate change.

Brumby has also stated that:

"the only way you can find new water is by reducing savings, evaporation and seepage and those things".

Fixing leaky irrigation channels and pipes does save water loss and is worth doing, but it doesn't "find new water" (or create it).

Here is my proposal for addressing the water shortage:
  • Mandate water tanks for every new household - 5000 litres storage per bedroom - to catch and use rainwater.
  • Subsidise a retrofit scheme for water tanks to existing households, or provide a rebate on water bills for those who have tanks installed.
  • Aim to recycle 80% of the water we use, rather than just flushing it down sewers and out to the ocean. Cease putting water out at the Gunnamatta and other ocean outfalls.
  • Aim to reduce domestic usage to 120 litres per person per day
  • Stop logging in Melbourne's water catchments immediately - this should save 30 gigalitres of water per year.
  • Use recycled water for the cooling towers of Latrobe Valley power stations, rather than drinking water.
  • Design gardens that capture water. A lot of new housing developments have more paved area than garden, which results in more water runoff and less entering the soil and water table.
  • Shift agricultural usage to the most efficient methods. Eliminate sprinkler application and flood irrigation where they are still in use, in favour of drip irrigation.

1 comment:

Anonymous said...

Some good plans here Peter. It seems ironic that we have more water than political willpower. Which drought is worst?