Istanbul Confronts a Digital Archive Problem Plaguing Cities from Athens to Amsterdam

Istanbul's municipal digital infrastructure directorate confirmed this spring that the city's public works image database — used to document everything from cracked pavements in Kadıköy to scaffolding permits along İstiklal Caddesi — contains an estimated 40 percent rate of duplicate or misidentified photographic records, a figure that has complicated urban maintenance planning across all 39 districts. The backlog stretches back to at least 2019, when the İBB, the Istanbul Metropolitan Municipality, began its first systematic push to digitize inspection records.

The timing matters. With the city still processing hundreds of thousands of post-2023 earthquake damage assessments from the Kahramanmaraş disaster zone, and Istanbul itself overdue for the so-called Big One on the North Anatolian Fault, reliable visual documentation of structural conditions is not a bureaucratic nicety — it is a public safety obligation. Duplicate image records can trigger redundant repair orders, inflate cost estimates, or worse, mask genuine structural deterioration because a file appears to have been reviewed when it has not.

What Istanbul Is Doing — and Where It Lags

The İBB's Smart City unit, headquartered in the Sütlüce campus on the Golden Horn, launched a deduplication pilot program in the first quarter of 2026 covering the Fatih and Beyoğlu districts. The pilot uses perceptual hashing algorithms — the same broad approach adopted by Rotterdam's municipal data office in 2023 — to flag visually identical or near-identical images before they are logged into the master database. Early results from the Fatih pilot reportedly reduced new duplicate entries by roughly 60 percent during the trial window, though that figure applies only to incoming records, not the existing backlog.

Clearing the backlog is where Istanbul diverges sharply from comparable cities. Amsterdam completed a full retrospective deduplication of its public space monitoring archive in 2024 after a two-year project that cost the municipality approximately €2.1 million. Athens, which faced a similar problem after rapid digitization of heritage-site inspection records ahead of European Capital of Culture preparations, contracted the work to a consortium of Greek universities. Istanbul has no equivalent retrospective contract publicly tendered as of July 2026, according to procurement records on the İhale platform, Turkey's public e-procurement system.

The scale difference is significant. Istanbul's database reportedly holds upward of 11 million individual image records accumulated since 2015. Amsterdam's comparable archive at the time of its clean-up covered roughly 3.4 million records. The cost of a retrospective project in Istanbul, were it modeled on Amsterdam's per-record pricing, would likely exceed 40 million Turkish lira at current exchange rates — a sum that sits awkwardly against the İBB's ongoing budget pressures amid sustained lira depreciation.

Political Friction Compounds the Technical Problem

The deduplication issue has also acquired a political dimension that purely technical cities do not face. The İBB, controlled by CHP mayor Ekrem İmamoğlu's administration, has repeatedly clashed with the central government over access to national address and cadastral databases maintained by the Ministry of Environment and Urbanisation. Without matching those databases to the image archive, deduplication is only partial — a photograph of a building facade in Üsküdar is only definitively matched when its cadastral record can be cross-referenced. That data-sharing agreement has been pending since at least early 2025, according to agenda documents from the İBB's March 2026 council session.

City technology officers in both Lisbon and Warsaw have cited similar inter-agency data-sharing disputes as the primary cause of stalled deduplication projects, suggesting Istanbul's friction is not unique, even if the political stakes here are unusually high.

For residents and contractors, the practical consequences are visible at street level. Construction permit applicants in Beşiktaş have reported receiving duplicate inspection requests for the same site photographs, adding days to approval timelines. The İBB's online permit portal, e-Belediye, currently carries no public indicator of whether a submitted image has been flagged as a potential duplicate before it enters the review queue.

The Smart City unit's pilot is scheduled for expansion into Beşiktaş and Şişli districts by September 2026, according to the İBB's published 2026 digital transformation roadmap. Whether the retrospective backlog receives dedicated funding in the supplementary budget expected in the autumn remains the open question that will determine whether Istanbul closes the gap with Amsterdam and Rotterdam — or watches it widen.