We're upgrading the Malmsbury Sewer Network

During November 2022, we commenced the review and planning phase for the upgrade of the Malmsbury sewer network, to ensure it can meet the needs of the local community for the next 25 years.

When complete, the planned works will enable the local sewer network to better handle future wet weather events by limiting the amount of excess stormwater entering the system.

The works follow a number of incidents where ongoing wet conditions and the infiltration of excess stormwater into the local sewer system have contributed to overflows to nearby land and the Coliban River.

We acknowledge that members of the community are concerned about the potential for impact to the local environment. We look forward to working with residents and other stakeholders throughout the planning and works process.

Project details will be added to this page and the timeline regularly. Or, why not click 'Follow' to receive regular updates?

Stormwater infiltration occurs when stormwater enters the sewer system directly. The stormwater can come from a number of different sources, including non-compliant downpipe connections from homes, sheds and other buildings, low or damaged gully traps, or damaged or uncovered sewer access points.

Too much stormwater in the sewer network robs the sewer pipes of space usually used to transport sewage for treatment.

During extended periods of rainfall, or even after one heavy rain event, the sewer pipes in Malmsbury are currently becoming surcharged or 'overfull'.

A small amount of stormwater entering the sewer network is unavoidable during wet conditions.

However, excess inflow places significant strain on the sewer system.

When sewer pipes are surcharged or 'overfull' they can back-up or an overflow or sewage spill may occur.

The excess water in the system also places pressure on our storage lagoons and treatment process at the Water Reclamation Plant in Kyneton, which treats Malmsbury's wastewater.

Details of the planned works

Step 1

Step 1: Community and stakeholder consultation

In September and December 2022 we wrote to all residents, businesses and property owners in Malmsbury. A Community Pop Up was conducted to answer questions and gather further community feedback and input.

Our Customer Service team continues to work collaboratively with members of the community as the project progresses. Members of the community are invited to contact us with questions or feedback.

We will also working with other stakeholders throughout the project.

Step 2

Step 2: Design and planning

Design and planning work for the Malmsbury sewer upgrade has commenced. The design phase will include a review of the sewer pump station in Ellesmere Place, Malmsbury, which has been the site of a number of recent sewer spills during wet conditions.

The sewer upgrade program will see the the pump station in Ellesmere Place upgraded during the current financial year.

Step 3

Step 3: Review of Coliban Water assets

We will review Coliban Water assets in Malmsbury for potential sources of infiltration and investigate solutions. We will then schedule any works required, prioritising those which will have the greatest impact.

Step 4

Step 4: Review of private property

Connecting stormwater to the sewer system is a widespread problem in all towns and suburbs and is not permitted under building or plumbing regulations.

Connections can often be made in error and some property owners will not be aware they are contributing to problems in the sewer network.

As part of this project, we are working with local community residents, businesses and other stakeholders to ensure everyone's pipes are correctly connected and do not place additional pressure on the sewer network.

Where possible, we ask customers in Malmsbury to check their own connections to ensure downpipes are connected to the stormwater system and not the sewer network.

A five-day program of visual inspections and smoke testing was carried out from Monday 22 May 2022 to help identify and remedy sources of stormwater infiltration.

Step 5

Step 5: Ellesmere Place Sewer Pump Station redesign

We will redesign the sewer pump station currently in Ellesmere Place, based on realistic flow rates. Data gained from smoke testing and inspections of the network, along with modelling following the announced closure of the Malmsbury Youth Justice Centre, will be used to finalise the design process.

Step 6

Step 6: Tender and delivery

Contractors will be engaged and works in Ellesmere Place will be scheduled for completion by the end of FY23/24.

How stormwater enters the sewer system

This image shows the locations where excess stormwater can enter the sewer network.

This image shows the locations where excess stormwater can enter the sewer network.

How smoke testing is used to identify stormwater infiltration

Smoke testing is a common method used to identify sections of the sewer network that have defects such as cracks, leaks or faulty connections that allow stormwater to enter and overwhelm the underground pipe network.

During smoke testing, a dense coloured smoke is blown into the sewer network and escapes through open or broken covers, damaged pipes or seals, or pipes or drains, with non-compliant connections.

If properties have stormwater connected to the sewer, smoke will rise from roof gutters. Some smoke may also enter a property if the water seals in the pipes of toilets, baths or sinks are not in place.

The smoke used during testing is a food-grade white oil. It is odourless, non-toxic and non-staining - similar to smoke used in theatrical productions.

The smoke is generally harmless to most people. However, if you suffer from asthma or a respiratory illness please inform us ahead of the scheduled smoke testing.

What happens if I have a non-compliant connection on my property?

We understand current owners or occupants may not be aware that stormwater from their property is entering the sewer network. Previous owners or residents may have improperly connected stormwater pipes.

If we discover a non-compliant connection on your property we will let you know what we find, along with any site-specific information available.

Our team will be available on the day to speak with you if you are at home (or will leave information in your letterbox), and we will follow-up with a letter outlining the nature of the issue to be addressed and any timelines.

Depending on the issue identified, you may need to engage a registered plumber or contact Macedon Ranges Shire Council.

What you can do now

  • Check your downpipes

    If you run some water into a stormwater collection point and it does not flow out through your legal stormwater discharge point, you may have a non-compliant connection.

  • Inspect your Overflow Relief Gully

    Inspect the area around your Overflow Relief Gully (usually outside your home near your kitchen, bathroom or laundry) to ensure any stormwater run-off is flowing away from it. Adjust the landscaping or remove any obstacles is required.