Perth's Duplicate Image Problem: The Key Decisions That Will Shape What Comes Next

Perth's land-information managers are staring down a mounting backlog of duplicate and mismatched aerial imagery embedded across at least three separate government database systems, a situation that planners, emergency responders and private surveyors say is creating real-world errors in everything from development approvals to bushfire boundary mapping. The issue has sharpened in 2026 as the Cook government's Metronet expansion pushes new cadastral surveys through corridors stretching from Yanchep to Byford, flooding Landgate's records with fresh imagery that sometimes conflicts with older layers.

Why now? The state's infrastructure pipeline is moving fast. The $9.7 billion Metronet program — which encompasses rail corridor acquisitions through suburbs including Ellenbrook, Morley and Thornlie — requires precise, current geospatial records at every step of compulsory acquisition. When a duplicate image sits unresolved in the system, it can attach the wrong property boundary or a stale easement to a parcel, triggering delays in settlement and, in some documented cases, contested valuations. With AUKUS-related works also beginning to reshape land use around HMAS Stirling on Garden Island, the accuracy of Defence estate boundaries in civilian databases has taken on new sensitivity.

Where the Pressure Points Are

Landgate, the state's land information authority based in Midland, manages the Western Australian Land Information System — the backbone database that local governments, surveyors and emergency services draw on. Sources familiar with the system's structure — though not authorised to speak publicly — have pointed to the Pilot project as the program most directly tasked with image rationalisation, though the agency has not confirmed a public timeline for resolution. The City of Wanneroo, which covers a vast development frontier from Neerabup to Two Rocks, has been among the councils with the heaviest workflow through Landgate's imaging pipeline over the past two years, given the scale of greenfield subdivisions processed there since 2024.

The Department of Fire and Emergency Services, operating from its Cockburn headquarters, relies on the same geospatial layers for bushfire hazard mapping. Duplicate images that assign old fuel-load classifications to parcels that have since been cleared — or vice versa — can mean a property sits in the wrong hazard band under the Planning and Development (Local Planning Schemes) Regulations 2015. For a homeowner in the Swan Valley or along the Helena Valley ridge, that classification feeds directly into insurance premiums and building code requirements.

The property market adds further urgency. Perth's median house price crossed $780,000 in early 2026, according to Real Estate Institute of Western Australia data, meaning the financial exposure from a misregistered boundary or a duplicate title image has grown substantially. Surveyors working the Ellenbrook and Alkimos corridors report a higher rate of requisitions — formal requests to correct title documentation — compared with 2023 levels, though comprehensive industry-wide figures have not been publicly released.

Decisions That Will Define the Fix

Three choices sit at the centre of what happens next. First, Landgate must decide whether to pursue a batch-reconciliation approach — systematically comparing every imagery layer acquired since 2022 against current survey control marks — or to triage by high-risk zones first, prioritising Metronet corridors and bushfire-prone fringe suburbs. The batch method is thorough but resource-intensive; the triage model is faster in the short run but risks leaving errors in lower-profile parcels for years.

Second, the state government must confirm whether the existing Shared Location Information Platform contract, renewed in 2023, covers the additional processing load that duplicate resolution will generate, or whether a supplementary procurement process is needed. That decision has budget implications in a year when the Treasurer has flagged a narrowing surplus.

Third, local councils — particularly the Cities of Swan and Stirling, both of which sit astride major infrastructure corridors — will need to decide whether to contribute their own aerial capture programs to a unified reconciliation effort or to maintain separate datasets. Fragmented capture schedules have historically been a root cause of duplication.

The working expectation among geospatial professionals is that any meaningful resolution framework will need to be in place before the wet season survey window closes in October 2026. After that, fresh acquisition flights become harder to schedule, and another season of accumulated mismatches becomes the baseline for 2027.