How the Central Coast Is Tackling Its Duplicate Image Problem — and How It Stacks Up Against Cities Worldwide

Central Coast Council is mid-way through a data remediation program aimed at eliminating thousands of duplicate and outdated property images embedded in its geographic information system — a problem that has quietly complicated development assessments, flood mapping updates and infrastructure planning across the region for years.

The issue matters now because the council, which exited NSW Government-appointed administration in 2021 after a financial crisis, is still rebuilding its digital infrastructure. At the same time, the NSW Government is pushing harder on housing approvals and climate resilience planning, both of which depend on accurate, up-to-date spatial data. Duplicated imagery — multiple conflicting aerial or cadastral photographs attached to the same land parcel — can delay development applications, generate errors in flood modelling and slow the kind of Gosford CBD renewal work that local planners have been promising ratepayers for the better part of a decade.

The council's current digital overhaul, sitting under its broader Corporate Asset Management framework, targets land parcel records across the Wyong and Gosford local government areas. Two specific zones are the focus of early rectification work: the Gosford city centre precinct around Mann Street and Donnison Street, where redevelopment pressure is highest, and the Tuggerah Business Park corridor, where infrastructure upgrades have exposed inconsistencies in legacy cadastral records dating back to the pre-amalgamation era before 2016.

What Is Happening Elsewhere

The Central Coast's challenge is not unique, but the comparison with similarly sized regions elsewhere is instructive. Greater Geelong City Council in Victoria completed a full GIS image deduplication audit in 2024 as part of a $2.1 million spatial data upgrade, according to publicly available council budget documents. The UK's Nottingham City Council, facing comparable post-amalgamation data messiness, partnered with Ordnance Survey in 2023 to purge roughly 40,000 duplicate land records from its planning database — a process that took 18 months and required dedicated data analyst resourcing the council had not previously budgeted for. In Canada, the Regional Municipality of Waterloo in Ontario tackled a similar overhaul after a 2022 audit found that 12 per cent of its property image records contained some form of duplication or version conflict, creating liability exposure in subdivision approvals.

Against those benchmarks, the Central Coast is behind on speed but comparable in scope. The council has not publicly released a completion date or a standalone budget line for this specific remediation work. What is confirmed in council planning documents is that the broader digital transformation program — of which image deduplication is one stream — is funded through a combination of general operational budgets and a NSW Government Financial Assistance Grant allocation. The council returned to elected representation under Administrator Rik Hart before transitioning back to an elected council, and the new administration has identified data integrity as a foundation requirement for any serious progress on Gosford CBD development approvals.

Why This Affects Residents Directly

For homeowners or developers lodging applications through the NSW Planning Portal for properties in suburbs like Erina, Woy Woy or Gosford itself, a duplicate image record attached to a land parcel can trigger manual review flags, adding days or weeks to processing times. The NSW Department of Planning's e-Planning system cross-references council spatial data at several points in the assessment workflow, meaning a council-level data error propagates upward into the state system.

Flood resilience planning adds another layer of urgency. With Sydney recording its hottest June in more than 160 years and climate scientists flagging the acceleration of extreme weather patterns, the Central Coast's flood mapping — critical for insurance assessments and subdivision approvals near Tuggerah Lake and the Wyong River corridor — needs clean spatial foundations to be reliable.

The practical advice for anyone with a development application currently lodged with Central Coast Council is straightforward: confirm with the council's planning team that the land parcel reference number in your application matches current cadastral records, particularly for older properties that were mapped before the 2016 amalgamation of Gosford City and Wyong Shire councils. Discrepancies between pre- and post-amalgamation records remain the single biggest source of duplicate image conflicts the council is working to resolve.