Why bringing a pipeline down from the north won’t solve Perth’s water supply issue

If you’ve ever seen the glistening abundance of water in Lake Argyle and the Ord River and you thought to yourself, “why don’t we bring that down to Perth”, you wouldn’t be alone. Members of the community have suggested a pipeline would fix our water supply issues, and wouldn’t require us to build any more desalination plants or groundwater replenishment facilities.

To see if it was a viable solution, in 2006, the State Government’s Department of Premier and Cabinet commissioned an independent study into options for bringing water to Perth from the Kimberley. The findings were that bringing water down from the North wasn’t viable. This article will help you understand why.

Financially, it doesn’t quite add up

The cost of building and maintaining the pipe would make the cost of delivering water to Perth customers significantly more expensive. This is a cost that would either need to be passed on to customers, or worn by the State Government. Either way, it has the potential be a burden our state’s economy, which is a risk we can avoid by using our current water supply options.

Water availability is limited

We also need to consider the amount of water available for use from the Kimberley. While there is a perception that large amounts of excess water are available in the north-west region, its wet and dry cycle of water abundance and scarcity means that it remains a water-limited environment. Rainfall in the north is generally prolonged and widespread during the wet season and river flows are significant during this time. During the dry season, however, some rivers cease to flow and the hot climatic conditions lead to very high evaporation rates that far exceed mean annual rainfall. Annual inflows to Lake Argyle are also highly variable.

In addition, the Department of Water and Environmental Regulation who manages water resources across the State has informed us that much of the water in Lake Argyle is already allocated for use within the region. The demand for hydro-electric power in the Kimberley region to supply industry and towns is growing, the Ord River Irrigation Area is currently expanding, and water is released from the dam into the lower Ord River to maintain the environment. Lake Argyle’s large storage capacity provides a buffer against dry years thereby maintaining the security of the supply for allocated uses.

It wouldn’t be great for the environment

To deliver 200 billion litres of water to Perth, the pipeline would release about 0.6 million tonnes of carbon dioxide a year. It would take between 70,000 and 250,000 hectares of actively growing forest to make up for that amount of carbon dioxide!

On top of this, it’s almost impossible to find a route from the north to the south of WA that wouldn’t impact any of our endangered or protected flora and fauna. The pipeline could also be a barrier to the seasonal movement of our native animals when they are seeking water in dry seasons.

Technically, we can do better

In WA, we’re at the forefront of technology. We lead the way in groundwater replenishment, we’re the home of spray on skin and WA is where the orbital engine you find in many boats, motorcycles and small cars first came to life. This expertise makes us confident that the pipeline coming down from the north presents some serious technical issues. From the land required both above and below ground, to the multiple pump stations needed along the way that would need to be operated and maintained in sometimes very remote areas, the sheer length of the pipeline makes it far different to what lies underground in Perth.

We have better options for securing our water supply than building the pipeline

Innovative solutions such as increasing recycling, replenishing groundwater stores with highly recycled water, desalination and protecting our precious groundwater are the way forward.

You can learn more about the study in the Options for bringing water to Perth from the Kimberley report. To find out where your water comes from now, check out our water supply tool.