Sydney's Duplicate Image Problem: How the City Stacks Up Against London, Singapore and Toronto

Sydney's land registry and urban planning databases contain tens of thousands of duplicate aerial and street-level images, a problem that has quietly ballooned alongside the city's rapid infrastructure expansion and the digitisation of records that began in earnest after 2018. The NSW Spatial Services division, which sits within the Department of Customer Service, is now running a remediation program to identify and remove redundant imagery from its public-facing platforms — a task that affects everything from property valuations in Parramatta to heritage assessments along George Street in the CBD.

The timing matters. With Metro West tunnelling already under the inner west and Western Sydney's housing precincts generating fresh cadastral surveys almost monthly, duplicated imagery is no longer a bureaucratic nuisance — it creates real risk. A duplicated drone survey of the Blacktown housing corridor, for instance, can produce conflicting elevation data, which flows into flood modelling and development approvals. Planning officers in the Greater Sydney Commission's Western City District have flagged the issue internally, though the Commission has not made a public statement on the scale of the problem.

What Sydney Is Actually Doing

NSW Spatial Services launched a deduplication audit across its ELVIS (Elevation and Depth — Foundation Spatial Data) platform in late 2024. ELVIS holds LiDAR datasets, aerial photography and bathymetric surveys, and by early 2026 the platform had catalogued more than 2.4 petabytes of spatial data for New South Wales. The audit uses automated hash-matching to flag files where imagery is identical or near-identical, then routes flagged records to human reviewers. The Land Registry Services office on Castlereagh Street in the CBD serves as the administrative anchor for disputed or ambiguous cases.

The City of Sydney Council, separately, completed a review of its own asset imagery library in March 2026, covering everything from footpath condition photos in Surry Hills to drainage infrastructure shots beneath Anzac Parade in Moore Park. Council records show the library had grown to roughly 1.1 million images by December 2025, with an estimated 18 percent flagged as probable duplicates during the review cycle. The figure is significant because duplicate images slow down the asset management software council engineers use to schedule maintenance.

How Sydney Compares With Peers Abroad

London's Ordnance Survey completed a comparable deduplication sweep of its National Geographic Database in 2023, drawing on machine-learning tools developed with the Alan Turing Institute in Kings Cross. Singapore's Singapore Land Authority has taken an even more aggressive approach: its OneMap platform, which is the official national map for Singapore, runs continuous deduplication in real time as new survey data is ingested, a system it has operated since rolling out a major platform overhaul in 2022. Toronto, by contrast, only began a formal deduplication policy for its open data portal in January 2025, prompted partly by errors that emerged in the city's flood risk mapping for the Don River watershed.

Sydney sits somewhere between Singapore's real-time model and Toronto's catch-up position. The ELVIS audit is systematic but not continuous, and the state government has not yet committed to real-time deduplication as a standard. NSW Spatial Services has not publicly stated a completion date for the current audit round. A briefing paper circulated within the Department of Customer Service in February 2026, obtained under a Government Information (Public Access) request and reviewed by The Daily Sydney, describes the agency's goal as achieving a duplication rate below five percent across core datasets by the end of the 2026–27 financial year — a more conservative target than Singapore's near-zero tolerance standard.

For residents and property owners, the immediate practical implication is in the conveyancing process. Duplicate imagery attached to a title can delay a settlement if a solicitor or buyer's agent queries the provenance of survey photographs. Law firms operating out of Macquarie Street have reported isolated cases where duplicated site photos created ambiguity about property boundaries near newly rezoned land in the Westmead precinct.

NSW Spatial Services says anyone who identifies a suspected duplicate in a publicly available dataset can lodge a data quality report through the ELVIS portal directly. The Greater Sydney Commission's next Western City District Plan review, scheduled for the second half of 2026, is expected to address spatial data standards more explicitly — which may finally give the deduplication effort the policy weight it has lacked.