Burrawang to Avon Tunnel
Burrawang to Avon Tunnel
WaterNSW manages and protects Greater Sydney’s drinking water catchments and bulk water supply infrastructure. We supply high quality raw water to a number of local councils and to Sydney Water. The Greater Sydney Water Supply System consists of 21 storage dams which store a total of 2.5 million megalitres of water.
The Water Sharing Plan for the Greater Metropolitan Region Unregulated River Water Sources 2011 outlines challenges associated with:
- servicing population growth and the resultant increase in water demand, particularly during drought
- the environmental and hydrological constraints limiting the volume of water that can be transferred along the natural river courses in the Greater Sydney Water Supply System
- the need to improve supply system resilience to protect against any form of asset outage or failure
WaterNSW is investigating a suite of options to improve environmental outcomes, provide certainty and security of water supply to its customers and all whilst meeting the projected demand from Greater Sydney’s future population growth.
Our team are currently looking into the feasibility of the Burrawang to Avon Tunnel as one of the preferred options to meet all of these objectives, including better outcomes for the natural environment.
About the project
The Burrawang to Avon Tunnel proposal is the final piece in completing the NSW Government's decade long strategy for restoring river health and protecting environmental flows in the Shoalhaven.
The current proposal is to design and build a 20 kilometre tunnel from Fitzroy Falls Reservoir to Avon Dam with an indicative carrying capacity of 1800 megalitres per day. The tunnel would protect the Illawarra from exposure to drought or asset failure, provide a secondary source of raw water supply to Greater Sydney and alleviate future stress on the Warragamba Dam catchment.
To improve network resilience, the project will also consider additional methods of supplying the Illawarra Water Treatment Plant, particularly in drought. Alternatives include an ‘off-shoot’ tunnel to connect the proposed Burrawang to Avon Tunnel to Sydney Water’s Illawarra Water Treatment Plant, and infrastructure to access deeper water in Avon Dam that is currently unavailable for supply. These options will provide greater certainty in water quality and the security of water supplied to the Illawarra, and by effectively increasing the available storage within the dam by 65 gigalitres.
As part of WaterNSW’s commitment to support the NSW Government’s ‘NSW Pumped Hydro Roadmap’, the feasibility of a hydropower generation plant will be a key part of the development of this project.
The overall objective of the Burrawang to Avon Tunnel project is to improve environmental outcomes, provide greater certainty and security of water supply to WaterNSW customers in drought, and to help meet the demand of Greater Sydney’s future population growth. The transfer of water from Fitzroy Falls Reservoir to the Avon Dam via a tunnel will provide an alternative water supply route to that of the creeks and streams of the Southern Highlands, currently used to supply water to the Illawarra Water Treatment Plant when pumping from the Shoalhaven is triggered under the Metropolitan Water Plan.
This proposal aims to:
- provide environmental benefits by removing large bulk water transfers along natural creeks and rivers
- increase the active storage of the Avon Dam by 65 gigalitres
- protect the Illawarra from exposure to drought or the risks of unexpected asset failure
- increase the calculated yield for the Greater Sydney Supply area by up to 35 gigalitres per year, on a long-term average basis.
- investigate inclusion of a hydropower generation plant
- increase the resilience of the Greater Sydney bulk water supply system to drought and water quality incidents.
WaterNSW has a team assessing the feasibility of the Burrawang to Avon Tunnel project. Options are currently being investigated and a concept design will be developed to inform the early stages of the proposal and provide due consideration for preliminary environmental impact studies and broader assessments.
- 2018 - 2020 – Early investigation and concept design phase
- 2019 - 2020 – Environmental assessments undertaken
- 2020 - 2020 – Business case development
Project Director: Justin Cairns
Phone: 1300 662 077