Winter Works / Weed Treatment

Investing in water for northern Victoria

Each year, GMW undertakes essential maintenance and upgrades during the irrigation off-season to ensure our network is ready for the season ahead. The 2025 Winter Works Program will run from 16 May to 14 August 2025, and focuses on improving the performance, safety, and longevity of our irrigation infrastructure.

Program overview

With an investment of approximately $14.7 million, this year’s program continues our significant investment in resilience, reliability, efficiency and value for money water services for our customers and the communities we work in. 

More than 60 GMW staff, supported by specialist contractors, will be working across the region to deliver critical upgrades and maintenance.

Our teams will be undertaking a wide range of activities, including:

• The most comprehensive GMW channel dewatering campaign in more than a decade
• Treatment of aquatic weeds along close to 300km of channels
• Bridge and culvert replacements to maintain safe crossings and efficient water delivery
• Replacing the Waranga Western channel regulator
• The structural renewal of nine aging bridges along the Stuart Murray Canal to improve safety, and maintain access for local communities and agricultural operations, and
• An innovative channel bank remodelling program to restore profile, integrity and improve performance.

Targeted weed treatment

Our winter weed treatment program will focus on controlling submerged aquatic weeds such as Hornwort, Saggitaria, Ribbon Weed, and Egeria across the East, West, and Central regions.

We will combine natural exposure to frost and the targeted application of low environmental impact herbicides directly to aquatic weeds to:

• Improve water flow
• Reduce sediment build-up
• Prevent issues with automated regulators

GMW will be treating affected channels from 16 May to 14 August 2025. During this time, customers will not have access to channel water until the season starts on 15 August.

While some water will remain in parts of the channel network while we undertake the treatment, this static water will then be injected with herbicides proven to effectively treat aquatic weeds.

While the chemicals have low toxicity to humans and animals, we advise you should not use the channel water for your livestock or spray horticulture and broad-acre crops with channel water during this period.

Customers on channels that are being treated will be informed by a letter at the start of the irrigation shutdown period, and a text message reminder will be sent prior to treatment beginning.

More information on how we treat weeds in our channels can be found in the fact sheet below:

Fact sheet - Treatment of submersed aquatic weeds

If you have any questions about weed treatment in your channel, please phone us on 1800 013 357 to speak to your local Customer Service team.

Timeline

We aim to complete all works by early August, allowing time for channels to recharge before irrigation resumes on 15 August 2025.

Safety first

The safety of our staff, customers, and the community is our top priority. We ask all road users to take extra care near work sites, as increased traffic and machinery may be present during this period.

Stay informed

GMW has developed an interactive map that customers can view to see where works are taking place across the region.

	Use the plus and minus buttons to zoom in and out, or scroll with your mouse wheel.
	To search by meter number, click the magnifying glass and key in your details.
	To display the legend, click this button on the right hand side of the screen.
	Scheduled works
	Weed treatment
	Dewatering
	Asset works

For questions, contact our Customer Experience team on 1800 013 357.