Tirrengower Drainage Scheme

The Tirrengower Drainage Area includes approximately 10,000 ha of land in Bungador, Swan Marsh and Irrewillipe areas.

The land is flat and drainage of farmland relies on the effective functioning of drainage lines that run through private land.

Minor changes in effectiveness of the drain can have significant impacts on the performance of the system overall and contribute to widespread flooding of farmland and other assets.

There has historically been in place a designated drainage scheme to ensure that the drains are kept well maintained and function as intended.  

In 1995 a Special Rate was introduced by the Colac Otway Shire (Council), where the monies raised were spent on the re-establishment and maintenance of the Tirrengower Drainage System.

This Scheme remains in place and has been declared by Council as being subject to a Special Rate in its annual budget, with payments used to fund maintenance works to the drainage scheme.

Under the former Local Government Act 1989 Council had delegated the function of managing maintenance of the scheme to a Committee of Council comprising community members. With the introduction of a new Local Government Act in 2020, this Committee structure no longer applies. 

Completed in the last financial year:

• Helicopter weed spraying was completed in December 2025
• Carsons Lane drainage works completed by Colac Otway Shire Services & Operations crew
• These works will include reinforcing and cleaning identified sections of the drainage system within Bernards section. Identified sections include rocks in the middle diverting water and eroding the bank and reinforcing dog legs to prevent erosion.

Scheduled for the upcoming financial year:

• Helicopter spraying for broad leaf (annual)
• Removal of willows from Cirillo’s fenceline and replace any damaged fencing
• Drainage works which will include reinforcing and cleaning identified sections of the drainage system. Identified sections include rocks in the middle diverting water and eroding the bank and reinforcing dog legs to prevent erosion.

Following a review of governance options for the future maintenance of the drainage scheme, Council considered the findings at its meeting on 11 September 2024. As a result, Council resolved to establish an Advisory Committee of Council under its Committees Policy.

Under this model, landowners affected by the drainage scheme will continue to advise Council on maintenance priorities through the Committee. The key change is that Council will now be responsible for engaging contractors to undertake maintenance works.

It is important that Colac Otway Shire continues to receive advice from landowners on maintenance priorities to support the effective operation of the Tirrengower Drainage Scheme. Landowners are encouraged to contact a committee member with any issues, concerns, or observations as they arise. 

Committee members are local community representatives who have a direct interest in the Tirrengower Drainage Scheme. They may be landholders, residents, business owners or individuals with relevant knowledge or experience. Members join the committee because they want to contribute positively to the management, planning and long-term effectiveness of the drainage scheme.

Committee meetings are held quarterly.

The committee members are:

• Lucy Ackerley
• Donna Scott
• Chris Smith
• Russell Ford
• Christopher Hickman
• Bevin Smith
• Bernard Whytcross
• Michael Everett
• Hayden Veenstra
• Craig Smart 

Colac Otway Shire representatives:

• Dave Thornburg - Manager, Services and Operations
• Darren Graham - Business Coordinator, Services and Operations
• Stacey Alfred - Division Support Officer, Infrastructure and Environment

If you have any questions, please contact Council by phone on 5232 9400 or email inq@colacotway.vic.gov.au