North Wanneroo Blueprint, 2020
The Government’s commitment to expand horticulture within North Wanneroo was a strategic development priority that lead to the development of a Business Case predicated upon:
- Utilise 500ha of State Forrest land;
- Irrigate using treated wastewater;
- Use a Managed Aquifer Recharge (MAR) scheme; and
- Required significant ongoing contributions from Government
Recycled wastewater to North Wanneroo for intensive horticultural expansion
Arris was commissioned by DPIRD to review the Business Case and provide a blueprint with an innovative solution that would enable horticultural development in North Wanneroo without the need for significant ongoing financial support from Government.
In developing the blueprint, we:
- Reviewed existing studies;
- Outlined recycled water schemes in other jurisdictions;
- Characterised the State Forest area; and
- Outlined a water supply solution addressing the water reduction pressures of North Wanneroo.
Highlights included:
- Process for direct application of recycled wastewater without an expensive, complex MAR scheme;
- Provided for a range of horticulture uses of water including both traditional field crops and high-tech greenhouses;
- Provision of a scheme that reduces impacts to the environmental and groundwater aquifers;
- Total scheme cost of $40-$60 million; and
- Estimated annual water charge of $400-$500 per megalitre.
In this project, we provided an innovative, secure water supply by assessing the viability of using treated wastewater to establish a new intensive horticultural development in North Wanneroo.
We developed a high-level economic model for the irrigators in the North Wanneroo area including capacity to pay. This model outlined the viability of a new recycled wastewater scheme to irrigate up to 500 ha of new irrigated agriculture including high-tech greenhouses.
Low cost, high quality multibarrier water treatment processes
Arris outlined a multiple barrier approach with appropriate treatment (e.g. filtration, disinfection) and responsible management which demonstrated that Alkimos treated wastewater can be recycled to provide a new and valuable water source for irrigated agriculture that meets the water quality standards identified in the WA Guidelines.
Outcomes
- Arris outlined a financially viable irrigation development opportunity for North Wanneroo;
- DPIRD can develop a new Business Case; and
- DPIRD can apply to the Commonwealth for water supply infrastructure funding.