Everything our customers in Cohuna flush down the toilet or wash down the drain ends up at the Cohuna Water Reclamation Plant.

To ensure this important facility keeps pace with population growth, we're undertaking important work to increase storage and disposal capacity, so we can deliver sustainable and reliable wastewater services for the local community.

A new 15-hectare lagoon, in two cells, is planned for construction adjacent to the existing plant, on Coliban Water land south of Chuggs Road.

We have lodged planning and EPA approvals and expect to commence construction in 2026.

Our plans also involve:

  • Maintenance relining work in two of our four existing lagoons.
  • Construction of a new pump station and supporting pipework.
  • A new power supply to pump wastewater from the existing lagoons to the new lagoon.

This work will improve our environmental sustainability and day-to-day operations.

Inflows to the plant consist of used water from the local community, wash-water from Cohuna Water Treatment Plant (which treats the community's drinking water), stormwater, and groundwater.

By 2053, inflows to the Cohuna Water Reclamation Plant are expected to reach up to 290 megalitres per year.

Currently, an average of 240 megalitres per year is treated at the plant. We also require additional capacity for winter storage in years with higher rainfall.

The current surface area of the lagoons is not large enough to provide adequate evaporation for the expected increase to inflows.

This $15 million project is essential to improve the plant’s resilience and sustainability over the next 25 years.

We don't expect you'll notice any significant change as a result of these works.

As the construction period approaches, we'll be in touch with neighbours with an update on our plans.

Your wastewater services continue as normal.

Please call us during business hours on 1300 363 200.

There is a possibility of odour, as with all lagoons at water reclamation plants.

However, the new lagoon will store the highest quality water within the plant, meaning it has the lowest potential for odour production.

We encourage you to call us on 1300 363 200 to report any odour you experience.

The lagoon banks will be approximately 600mm to 1.1 metres above the existing ground level, similar to the existing lagoon adjacent to Chuggs Road.

A lack of space and land-use restrictions within the aerodrome precinct prevent the construction of the new lagoon in the area of the existing lagoons.

The highly saline, shallow water table in the Cohuna area infiltrates into the gravity sewer network, meaning that the wastewater transferred to the Cohuna Water Reclamation Plant has a high salt content.

This limits opportunities for wastewater reuse, including for irrigation or discharge to local waterways.

Treatment options to remove the salt and allow for reuse are cost-prohibitive, meaning a lagoon-based, wastewater treatment and evaporation disposal system is the most feasible option for Cohuna.