For the Wamuran Irrigation Scheme to be viable over the long term, we need to be sure that we can consistently produce enough water of the desired quality for use on edible crops.

Our preliminary investigations into the potential supply and demand for high quality recycled water for the Wamuran Irrigation Scheme show that, based on current volumes received and treated at South Caboolture STP, we could deliver up to 2.6 gigalitres of Class A water a year.

While the demand for recycled water indicated by our modelling is higher than this, the population across the catchment of the Caboolture River is forecast to grow significantly. This growth could over time increase the volumes of recycled water produced by South Caboolture STP for use in the Wamuran Irrigation Scheme.

A cohort of foundation growers will be identified to participate in establishing the feasibility of the Wamuran Irrigation Scheme. These growers will help us understand if the scheme is viable for a broader Wamuran region and if it could be extended to further participants.

Growers in Wamuran rely on their own dams or local creeks as irrigation sources for their crops.

In early 2017 Unitywater carried out preliminary surveys with a number of Wamuran growers to determine if there was an appetite for a more secure water supply.

Expected population increases in the Moreton Bay region will create increased loads through Unitywater’s sewage treatment plants (STPs) and higher effluent volumes following treatment.

Unitywater identified a potential opportunity to divert effluent from South Caboolture STP to Wamuran via a new recycled water pipeline. If proved a viable scheme, this could provide high quality, secure water supply for growers and reduce effluent and nutrient volumes being discharged into the South Caboolture River.

Phase 1: Design and feasibility

March 2020 – October 2021

Investigations undertaken in this phase include the way in which we treat the water, the design of the pipeline and associated infrastructure, and how the recycled water is used by farms for irrigation.

Early design and feasibility investigations will take place, to be reviewed and considered by Unitywater by October 2020. At this time Unitywater will determine if the scheme is considered viable and if it continues to a more detailed design and feasibility stage.

Phase 2: Construction
Mid-late 2021 – Mid 2023

If the scheme is determined to be viable, based on the successful outcome of Phase 1, the construction of infrastructure including water treatment facilities, transfer and network pipelines, storage tank, pumping stations, valves and meters will occur in Phase 2.

Phase 3: Operate and maintain
From April 2023

After the infrastructure is commissioned, Wamuran Irrigation Scheme Joint Venture will operate and maintain it. They will manage the distribution of recycled water from the treatment plant to end users, undertake monitoring for compliance, regulatory reporting and ongoing liaison with foundation growers.

Wamuran timeline

March 2020
Early design and feasibility phase commences
Mid-late 2021
Construction phase commences

Depending on the design and feasibility stage success, the construction phase commences

Mid 2023
Operation and maintenance 

Operation and maintenance of the scheme commences for foundation participants