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.