Duplicate Images, Duplicate Headaches: How Central Coast Stacks Up Against Cities Tackling a Growing Digital Planning Problem

Central Coast Council's digital planning portal contains hundreds of property files carrying duplicated images — scanned site photos, streetscape records and flood-assessment imagery uploaded more than once, sometimes under different reference numbers. The problem is not unique to Gosford. But how councils handle it is increasingly separating the efficient from the embarrassing.

The issue matters right now because New South Wales is in the middle of a state-mandated push to digitise planning records under the Environmental Planning and Assessment Act amendments that took effect in 2023. Councils that cannot demonstrate clean, non-duplicated document registers risk delays in development application processing — a pressure Central Coast, still rebuilding institutional credibility after its 2020 administration period, can ill afford.

What the Problem Looks Like on the Ground

Talk to anyone filing a DA near Mann Street, Gosford, or through the Wyong office on Margaret Street, and they will mention the same frustration: the council's ePlanning portal flags uploaded documents as duplicates mid-submission, forcing applicants to rename files or restart uploads entirely. The duplication issue is not confined to applicant-submitted material. Internal cadastral imagery — aerial and street-level photos used by assessors to verify site conditions — has accumulated redundant copies since the council merged the former Gosford City Council and Wyong Shire Council databases in 2016.

The Central Coast's Local Housing Strategy, adopted in 2022, relies on accurate spatial data to track dwelling approvals against targets across corridors including Tuggerah, Warnervale and the Gosford waterfront precinct. Duplicate image records inflate apparent documentation volume without adding analytical value, and in at least two audited cases have contributed to assessors pulling the wrong site photograph during site verification checks, according to the council's own digital records governance review circulated to councillors in late 2025.

The council has engaged the NSW Government's Spatial Services directorate — part of the Department of Customer Service — to run a deduplication pass across its geographic information system layers. That work is ongoing.

How Other Cities Are Handling It

The comparison with peer cities is instructive. Auckland Council completed a systematic deduplication of its Unitary Plan imagery archive in 2024, using automated hash-matching software to identify bit-for-bit identical files before a manual review team cleared ambiguous cases. The project reportedly reduced Auckland's planning image repository by roughly 18 per cent, freeing server capacity and cutting retrieval times for assessors. The UK's Bristol City Council embedded deduplication checks directly into its planning portal at the point of upload in 2023, rejecting duplicate submissions automatically and redirecting applicants to the existing file. Both approaches are now cited in planning-technology literature as models for mid-size councils managing legacy migration debt.

Singapore's Urban Redevelopment Authority takes a different tack — its GovTech-integrated ePlanning system hashes every uploaded image against a central repository the moment it is submitted, preventing duplicates from ever entering the database. That system serves a city-state with a single authority and far less legacy infrastructure than a council like Central Coast, which inherited two separate IT environments and has been consolidating them across nearly a decade.

Central Coast's position sits somewhere between Bristol's reactive fix and Auckland's retrospective clean-up. The council does not yet have a real-time deduplication check on its public portal, but the Spatial Services engagement suggests a longer-term structural fix is at least being planned rather than ignored.

For context on scale: Central Coast Council manages planning records for a local government area covering roughly 1,681 square kilometres and a population that passed 350,000 at the 2021 census. The volume of imagery generated by development applications, flooding events and infrastructure audits is substantial — the January 2022 floods alone generated thousands of new site photographs that were uploaded, in many cases, multiple times across different emergency-response and planning files.

Residents and developers with active applications can cross-check whether their submitted files have been correctly singularly registered by contacting the council's Development Assessment team at the Gosford office, 49 Mann Street. The council's public DA tracker, accessible through its website, displays document counts per application — a rough but usable proxy for whether duplicates have inflated a file. The Spatial Services deduplication work is expected to complete before the end of the 2026 calendar year, at which point the council has indicated it will assess whether automated upload-time checking becomes feasible within its current software contract.