Perth's Duplicate Image Problem: How the City Stacks Up Against Singapore, Dublin and Denver

Perth's rapid population surge has exposed a quiet but costly problem buried inside the state's land and planning records: thousands of duplicate property images clogging cadastral databases, slowing development approvals, and frustrating the Metronet corridor planning work underway from Yanchep to Byford. The Western Australian Land Information Authority — known as Landgate, headquartered in Midland — confirmed earlier this year that duplicate image management had become a formal operational priority as the agency works through a broader data-quality overhaul.

The timing matters. WA's state budget, handed down in May, earmarked further funding to accelerate digitisation of land records, and the Cook government's housing agenda is entirely dependent on planners, developers and local governments accessing clean, reliable property data. When duplicate aerial and cadastral images sit unresolved in a shared system, approval workflows at councils from the City of Perth to the City of Wanneroo can stall. A single duplicated polygon on a Joondalup residential lot sounds trivial. Across a database of more than two million parcels, the compounding effect is not.

What Other Cities Are Doing

Singapore's Singapore Land Authority rolled out an automated duplicate-detection layer across its OneMap platform in 2023, using hash-comparison algorithms to flag redundant imagery before it enters the live database. The result, according to the agency's published technical documentation, was a reduction in manual image-review workload for cadastral officers. Dublin's Tailte Éireann — the Irish national mapping and property registration body — took a different approach, running a retrospective cleanse of legacy scanned title records dating to before 2005, completing the first phase in late 2024. Denver, Colorado, embedded duplicate-image rules directly into its GIS submission portal, requiring third-party surveyors to run a de-duplication check as a condition of file upload from January 2025.

Perth sits somewhere between the proactive and reactive ends of that spectrum. Landgate has adopted automated flagging for new submissions since mid-2024, but the retrospective backlog — records accumulated through decades of paper-to-digital migration, plus imagery ingested from local government systems that applied inconsistent file-naming conventions — remains a work in progress. The Stirling Highway and Scarborough Beach Road corridors, both subject to intense rezoning activity under the State Government's housing densification push, have been flagged internally as priority zones for data cleansing, given the volume of development applications flowing through those precincts.

Local Pressure Points

The City of Vincent, which covers Leederville, Mount Hawthorn and North Perth, processes some of Perth's densest infill development. Planning officers there cross-reference Landgate records constantly. When duplicates appear — typically older aerial captures overlapping with newer high-resolution drone surveys commissioned by private developers — the resolution process has historically required manual intervention, adding days to already stretched assessment timelines.

The Western Australian Planning Commission has been working with Landgate under a memorandum of understanding to synchronise data standards across both agencies' systems. That alignment work, which began formally in late 2024, is expected to reduce the category of duplicates caused by format incompatibility by the middle of 2026. Whether the retrospective backlog across older suburban records — particularly in growth corridors like Ellenbrook and the Alkimos-Eglinton precinct — is resolved on the same timeline is less certain.

Globally, the cities that have moved fastest on this problem share one characteristic: they tied de-duplication directly to a revenue or approval process, making clean data a gate rather than a goal. Singapore and Denver both did this. Perth's approach has been more consultative, involving local government peak bodies and the development industry through working groups convened by the Department of Planning, Lands and Heritage. That process has buy-in, but it moves slower.

For property owners in suburbs like Balga or Mirrabooka, where older cadastral records are patchiest, the practical advice is straightforward: if a development application is lodged and a planning officer raises a data discrepancy, request in writing that the officer log a Landgate data-quality report at the same time the application is being assessed. That parallel process, available under Landgate's public data-correction framework, can prevent the same image error from affecting future transactions on the same parcel. The fix, when it comes, should be permanent — not something the next buyer has to navigate all over again.