In progress

Warrnambool Sewage Treatment Plant upgrade

We’re upgrading our Warrnambool Sewage Treatment Plant to meet the needs of housing and economic growth in the region.

We’re upgrading our Warrnambool Sewage Treatment Plant to meet the needs of housing and economic growth in the region. The $85 million project is our largest ever single infrastructure project and is designed to meet the needs of housing and economic growth in the region.

It’s an absolutely vital project designed to meet future industrial and residential growth in our region and return huge economic benefits
Andrew Jeffers
Wannon Water Managing Director
project cost
annual economic value
more jobs for the region by 2040

The issue

Our Warrnambool Sewage Treatment Plant services Warrnambool, Allansford and Koroit and is currently operating near the limit of its treatment capacity. Around half the incoming flow (influent) is domestic sewage, while the other half is trade waste from local industries, creating unique challenges in treatment and operation.

The region’s importance as a food industry hub means that demands on the plant are much higher than would normally be expected based purely on population levels. Development in the area is expected to continue as a result of population growth and industry expansion. New housing estates are being established north, east and west of Warrnambool and infill development is occurring in established residential areas.

The detail

The upgrade is based on the proven technology of the existing plant. However, new treatment technologies, latest design principles and allowances for the future are being incorporated into the new structure.

The key components of the design include:

  • A new influent pump station and screening facility,
  • A septage receival system.
  • Two new treatment tanks.
  • A chemical dosing facility.
  • An odour control facility.
  • Tertiary effluent screening.

Rehabilitating the site

One of our priorities is to ensure the surrounding area on Thunder Point is returned to a state that protects its environmental values. This was important during the initial site clearing where we removed tonnes of contaminated material from the area. This contained heavy metal from the adjoining rifle target facility which had been abandoned many years earlier.

The large mound that’s been created along the east and north of the treatment plant will help to minimise visual impacts once the area is revegetated at the end of the project.

We’ve engaged with community and environmental groups who have an interest in the Thunder Point area to consider how this particular site might look in future and agreed on a set of draft principles.


The upgrade will ensure the plant has sufficient capacity for a projected increase in sewage volumes while continuing to protect public health and the environment. It will help secure the region’s future as a popular and attractive region for investment.

The upgrade will provide additional capacity at the plant, allowing for an additional $199 million of annual economic value and 1,512 more jobs for the region by 2040.

The plant currently services nearly 15,000 houses – a figure expected to increase by more than 80 per cent to 25,000 properties in the next 50 years.

Managing effluent

In conjunction with this project, we’re preparing a new Effluent Management Strategy for the plant. This is a condition of the development licence approved by the Environment Protection Authority.

The strategy aims to identify alternatives for the disposal of wastewater from the plant which is currently discharged via an ocean outfall.

Options may include:

  • Disinfection
  • Recycling
  • Tertiary treatment
  • Optimising the existing ocean outfall design and location
  • Retaining the existing outfall with additional treatment processes.

The strategy is being guided by a reference group of community representatives and agency stakeholders.

What have we been up to?

Want to know more?
Visit our Engage & Explore website to find out more or ask a question about the project.