We’re planning important lagoon upgrades at our Cohuna Water Reclamation Plant, to increase capacity and keep pace with future population growth.
Everything you flush down the toilet or drain ends up at our plant, and these works are essential to provide sustainable and reliable wastewater services to the community.
A new lagoon is planned for construction south of our plant, near Chuggs Road.
We have purchased a piece of land in preparation for this and hope to begin construction in spring 2025.
Our plans also involve:
- maintenance relining works in two of our four existing lagoons
- building a new pump station and supporting pipework
These works will improve our environmental sustainability and day-to-day operations.
A new power supply will be needed to pump wastewater from the existing lagoons through to the new one.
The inflows to our plant includes wastewater from those in Cohuna, as well as wash-water from Cohuna Water Treatment Plant, stormwater and groundwater.
We know that by 2040, our plant is expected to receive inflows of up to 290 ML per year. Currently, an average of 240 ML per year is treated at the plant. We need additional capacity to provide for winter storage in higher rainfall years.
We also know that the current surface area of the lagoons is not large enough to provide adequate evaporation for the future increased inflows.
That’s why these $10 million upgrades are essential to improve the plant’s resilience and long-term sustainability for the next 25 years.
We don't expect you'll notice any significant changes as a result of these works. As the construction period approaches, we'll be in touch with neighbours and those nearby to update them on our plans.
Your wastewater services continue as normal.
Please call our Customer Support Team 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. This means it will have the least 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 1.5 to 2 metres high, similar to the existing lagoons.
Unfortunately there is not enough space for a new lagoon on existing land. There are also land-use restrictions within the aerodrome precinct which we must abide by. This restricts us from building a lagoon near the current ones.
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 our options for wastewater reuse, such as irrigation or discharge to waterways. Treatment options to remove the salt and allow for reuse or disposal are cost-prohibitive, meaning that a lagoon-based, wastewater treatment and evaporation disposal system is the most feasible option for Cohuna.
