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

Perth's property and planning databases contain thousands of duplicate image records — scanned title documents, heritage photographs and site inspection files stored more than once, sometimes under different reference numbers — and the effort to clean them up is now a live project inside Landgate, the state's land information authority based in Midland. The scale of the problem is not unique to Western Australia, but the way Perth handles it is starting to diverge from approaches taken in comparable cities, and not always in the city's favour.

The issue has sharpened in 2026 for a straightforward reason: the WA government's Metronet expansion and the accompanying wave of transit-oriented development rezoning have forced planning officers to pull historical imagery from databases at a rate not seen in years. When a suburb like Bayswater or Midland Central gets redesignated, heritage assessors, private surveyors and Development WA all reach into the same document repositories. Duplicate records slow that process down, and in a market where rezoning approvals translate directly into construction timelines and project finance, delays carry a dollar cost.

What Other Cities Have Done

Singapore's Urban Redevelopment Authority completed a systematic deduplication of its property image archive in 2023, reducing its spatial media library by roughly 34 percent after a two-year audit, according to a public technical report the URA published on its website in March 2024. Amsterdam's Kadaster land registry began a similar program in 2021, partnering with the Delft University of Technology to automate detection of near-identical scanned documents using perceptual hashing — a method that flags images which look visually identical even when their file metadata differs. Vancouver's BC Assessment Authority, which covers Greater Vancouver, adopted cloud-based deduplication tools from a Canadian GovTech firm in late 2022 as part of a broader digital asset strategy.

Perth, by comparison, has moved more incrementally. Landgate has operated its Shared Location Information Platform, known as SLIP, since the mid-2000s, and while the platform has been updated repeatedly, a structured program specifically targeting duplicate image files within SLIP's document layers is a more recent priority. Development WA, the state's land development agency headquartered on The Esplanade in Perth's CBD, flagged the duplication issue in internal workflow reviews tied to the Metronet corridor projects, particularly around the Forrestfield–Airport Link precincts and the Thornlie–Cockburn Cross Link corridor.

The Local Lag — and What's Being Done

The core difficulty in Perth is one shared with Auckland and Calgary: a legacy archive built over decades when different agencies — the former Department of Land Administration, the Water Corporation, local councils — each maintained their own image stores before those stores were partially consolidated. Full consolidation never happened. That means the same 1987 aerial photograph of a Scarborough foreshore site, for instance, might exist in three separate folders under three different file names, all technically accessible through SLIP but indexed inconsistently.

The City of Vincent, which covers inner suburbs including Mount Hawthorn and Leederville, updated its own document management system in late 2025 to include automated duplicate flagging on all incoming planning imagery. That is a local government initiative, separate from Landgate's state-level work, but planning officers at the City of Vincent have said the change has reduced the time taken to compile heritage assessments for development applications — though specific time savings have not been released publicly.

For property developers and surveyors working across multiple Perth local government areas, the practical advice from industry groups including the Spatial Sciences Institute is straightforward for now: always request a fresh certified title search from Landgate rather than relying on cached imagery from third-party platforms, and verify document reference numbers against the current SLIP portal before lodging applications with local councils. The deduplication work is ongoing, which means the archive is in a transitional state where older duplicates may still surface in some searches.

Perth is not the worst-positioned city globally on this measure — Auckland's multiple-agency legacy problem is widely regarded within spatial data circles as more entrenched — but Singapore and Amsterdam have demonstrated that a targeted two-to-three-year program, properly resourced, can resolve most of the backlog. Whether Landgate receives dedicated budget allocation for that kind of structured effort will likely become clearer when the WA government hands down its mid-year financial update later in 2026.