Project record

Subiaco water-resource recovery compact-plant upgrade

Participation
Planned procurement
Participation checked

Initial AUD 105 million committed to design, engineering and site preparation

Participation source

Subiaco's proposed 90 ML/day compact plant has an initial AUD 105 million design and preparation allocation. Its assessed economic case depends heavily on deferring other regional wastewater and ocean-outlet investment.

Subiaco water-resource recovery compact-plant upgrade project diagram: 67 to 90 ML/day proposed capacity; AUD 105 m design/preparation; BCR 1.2 in assessed case. Definition and retained-asset plan to ECI then design and construct to Commissioning and regional deferral.

IMWO original project diagram; sources: Water Corporation and Infrastructure WA

Location

Australia / Asia Pacific

Segment

Wastewater treatment and ocean-outlet capacity

Phase

Planning / Confirmed

Last checked

3 November 2026

Coverage

Related sectors

Wastewater treatment and ocean-outlet capacity is the primary work classification. Related sectors connect this record to adjacent marine delivery and market coverage.

Subject index

Related subjects

These subject pages bring together related projects, technical articles, reports, and evidence methods.

Project anatomy

Contract scope and delivery roles

Client / authority
Water Corporation, Western Australia
Delivery parties
ECI followed by design and construct is the business-case delivery route; construction appointment remains to follow.
Contract route
Infrastructure WA's assessed business case proposes early contractor involvement transitioning to design and construct. Final project definition, investment and procurement remain to follow.
Execution window
The assessed business case places planning in 2026/27 and final commissioning in the early 2030 s. The October allocation advances design and preparation.
Works package
Preferred 90 ML/day compact plant against a 67 ML/day base case, advanced primary and secondary treatment, odour control, energy recovery and connections to retained infrastructure.
Marine interfaces
The economic case includes deferral of Woodman Point and Sepia Depression Ocean Outlet Landline investment. Commissioning timing therefore affects capacity and capital planning beyond the Subiaco site.
Commercial evidence boundary
IWA's roughly AUD 1.3 billion whole-project estimate includes escalation and contingency on Class 4 design. The 1.2 benefit-cost ratio relies materially on the feasibility and timing of deferred regional upgrades.

Evidence gap

What remains unverified

Outstanding evidence

  • Project-definition estimate and retained-asset decisions
  • Woodman Point and ocean-outlet deferral dates
  • ECI scope, live-plant tie-ins and final investment decision

Related records 2

Reporting status

Project phase
Planning
Evidence confidence
Confirmed
Last checked
3 November 2026
Cited sources
4

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Source collections

Project sources 4