Project goal:

Secure long term water supplies for the region.


In construction

Delivery Date:


What's happening?

 The Warren Blackwood Regional Water Supply Scheme supplies the towns of Manjimup, Bridgetown, Nannup, Greenbushes, Boyup Brook, Balingup and Hester. In 2021 it will be expanded to also supply Mullalyup and Kirup.

The Warren Blackwood scheme currently uses both surface and groundwater sources - nine local surface water sources contribute 25% to the scheme, as well as one groundwater bore, which is licenced to take up to 1.5 billion litres per year, from the Yarragadee Aquifer.

As climate change continues to impact the yield and quality of surface water, it is necessary for us to plan diligently to ensure local communities can continue to have access to secure drinking water supplies.

A number of upgrades to the scheme are rolling out as a staged approach. Infrastructure will be extended and upgraded in accordance with future demand growth in the area.

Why is this happening?

The South West’s water supply has traditionally relied on local surface water sources- a single dam supplying a single town. However, south west of Western Australia has been significantly affected by climate change through declining rainfall and the dam sources are now becoming unreliable due to decreased streamflow and human activity within the catchment, which in turn is creating water quality issues.

Water Corporation is responding to this new reality in a number ways including developing more robust, integrated drinking water schemes.

When is this happening?

Current projects under construction or in the planning phase:

  • Greenbushes to Kirup Link – a 16 kilometre pipeline between Greenbushes and Kirup is due to start construction in late 2020. Securing the supply to Balingup, Kirup and Mullalyup and removing the need of water carting from Donnybrook. More information can be found on the project page located here.
  • Regional Water Treatment Plant – a new water treatment plant may also be required to service the expanding scheme and we are investigating suitable locations.
  • Groundwater exploration - Investigative bores will be installed to build a comprehensive understanding of groundwater sources in the area, so that we can determine if they have the potential to play a role in securing future supply for local towns. Between October and January 2021, Water Corporation plans to drill a total of 10 investigation bores within the Warren Blackwood region.
  • Infrastructure upgrades - we will be undertaking a number of smaller projects aimed at improving water treatment and storage at our existing assets in the region.

Various projects have already been completed in the scheme upgrade, including:

  • Millstream-to-Greenbushes pipeline – a new 16.2 kilometre pipeline between Millstream Dam and the town of Greenbushes commenced in November 2013. Construction on this project was completed at the end of January 2017. Commissioning of this new pipeline, with water being supplied into Greenbushes was completed on 1 March 2017. Two new pump stations and two one million litre storage tanks were also constructed as part of this work.
  • Hester Dam remedial works – an upgrade to Hester Dam was completed in April 2011, ensuring the reservoir can continue to operate at full capacity. This project involved modifications to the dam embankment and new outlet works.
  • Hester-to-Boyup Brook pipeline upgrade – works to duplicate the existing 9 kilometre pipeline between the Hallett tanks and Boyup Brook were completed in October 2015.
  • Doubling the capacity of Millstream Dam – works to upgrade the Millstream Dam from 0.45 billion litres to 1 billion litres capacity were completed in January 2013. The upgrade to the Scheme’s central storage component enables capture of more water during wet years, ensuring adequate surface water storage capacity.
  • Manjimup supply from Nannup Bore – in June 2013, Manjimup joined the Scheme following the construction of a pipeline to link the Nannup bore to Manjimup Dam. Whilst the town’s two dams will remain the principal supply source for Manjimup, the new pipeline is now supplementing Manjimup Dam with groundwater as required, securing water supply for the town even in the driest of years.
  • Yarragadee Bore – a new bore near Nannup was completed in 2009 and has since been used to boost supply to Bridgetown, Boyup Brook and Hester via Millstream Dam when needed.

Water conservation

While this infrastructure will guarantee a safe, reliable and sustainable drinking water supply in an increasingly dry climate, demand management remains a vital aspect of our strategy to deliver long-term climate resilience to the 8 scheme communities.

To support achievement of this objective, water efficiency and other compliance measures will continue to be complemented by educational initiatives and partnerships as required.Information on the current Waterwise Towns program can be found here.

Communities in the Warren–Blackwood are commended for embracing water conservation efforts to date.