How the Central Coast is tackling duplicate image sprawl in its planning records — and how it compares to cities worldwide

Central Coast Council has begun a systematic audit of duplicate imagery embedded in its development application and asset management systems, a housekeeping project that sounds mundane until you consider the cost: councils in New South Wales have collectively spent millions in recent years storing redundant digital files that slow planning approvals and create version-control errors in infrastructure projects. The Central Coast's effort, running through the council's Gosford-based planning directorate, puts it ahead of most regional NSW peers — though it still trails leading international benchmarks set in cities like Helsinki and Christchurch.

The timing matters. The council only emerged from state-imposed administration in 2022 after a financial crisis that left it more than $500 million in debt, according to figures published during the administration period. Rebuilding trust with residents and with the NSW Department of Planning means demonstrating clean, reliable data governance — especially as major rezoning proposals for the Mann Street and Kibble Park precincts in Gosford CBD move through the approval pipeline. Duplicate or mismatched images attached to planning submissions have previously caused delays in development consent processing across regional councils, according to audit findings published by the NSW Audit Office.

What the local picture looks like

The council's records improvement program sits within its broader Digital Transformation Strategy, which targets the Gosford Civic Centre on Mann Street as a test site for upgraded document management workflows. Officers are using deduplication software to compare image metadata across the council's property information system, flagging files where the same photograph — of a site inspection, a stormwater drain, or a heritage facade — has been uploaded under different file names or by different staff at different dates. The problem is more common than it sounds: a single development application for a multi-storey residential block on Donnison Street, for example, can attract dozens of image attachments from consultants, council officers, and referral agencies, with no automated check for redundancy.

Central Coast's Waterwise program, which manages stormwater and flood resilience infrastructure from Tuggerah to Woy Woy, has also been identified as an area where duplicate aerial survey imagery created confusion during the 2022 flooding events on the Tuggerah Lakes system. Streamlining that archive is now part of the broader push.

The global comparison

Helsinki's city planning authority completed a full deduplication of its zoning image database in 2023, reducing storage load by roughly 34 percent and cutting average document retrieval times, according to a case study published by the Open Government Partnership. Christchurch City Council, still managing a vast post-earthquake rebuild dataset, introduced automated image hashing across its asset register in 2021. Both cities operate with significantly larger budgets than a regional NSW council, but the technical approach — metadata comparison, hash-based matching, and staff training on upload protocols — is scalable.

Closer to home, Newcastle City Council began a similar project in late 2024 as part of its Smart City program. Wollongong has integrated deduplication checks into its Objective ECM system. The Central Coast's approach draws on both models but is being rolled out in stages, partly because the council's IT team, operating from the Wyong Council Chambers site, is simultaneously managing a migration to a cloud-based records platform. The phased approach means full deduplication across all asset classes is not expected until mid-2027.

For residents and developers lodging applications through the NSW Planning Portal, the practical effect should eventually be faster turnaround times on image-heavy submissions — particularly for dual occupancy and secondary dwelling applications in growth corridors around Warnervale and Hamlyn Terrace, where development activity has picked up sharply since 2024. The council's customer service team at Gosford has already noted a reduction in resubmission requests linked to mismatched imagery since the audit began in March 2026. It is a small but measurable sign that the cleanup is working.