Barcelona's Digital Archive Push Hits a Snag: Thousands of Duplicate Images Clog City Records

Barcelona's municipal archive system is sitting on tens of thousands of duplicate digital images — identical or near-identical files stored across multiple servers — and the city's information management teams are now racing to clean up the mess before a planned database migration scheduled for the fourth quarter of 2026. The problem, which came into sharper focus this week after an internal review by the Arxiu Municipal de Barcelona, touches everything from planning permit photographs stored at the Eixample district office to construction site records held by the Institut Municipal d'Urbanisme.

The timing matters. Mayor Jaume Collboni's administration has been pushing hard to digitise public services and expand open-data access to residents, particularly around housing and urban planning decisions — areas of acute political sensitivity given the ongoing rental crisis and short-term rental crackdown. A bloated, redundant image archive undermines that transparency goal directly. When the same photograph appears under three different file names in three different folders, search results become unreliable and staff waste time verifying which version is authoritative.

Where the Problem Shows Up

The duplication issue is most visible in two operational areas. First, the permit and inspection records tied to the city's short-term rental enforcement programme, which has generated a high volume of photographic evidence since the council began cracking down on unlicensed tourist apartments in neighbourhoods like Gràcia and Sant Pere, Santa Caterina i la Ribera. Inspectors upload images from mobile devices that sometimes sync automatically to shared drives already holding copies sent by email — producing doubles, and occasionally triples, of the same file. Second, the archive of Barcelona's public spaces and heritage sites, managed in part through the Centre de Documentació del Museu d'Història de Barcelona (MUHBA) at Plaça del Rei, has accumulated duplicate scans from successive digitisation campaigns run between 2019 and 2024.

Staff at the Arxiu Municipal — headquartered on Carrer de Santa Llúcia, just behind the Cathedral in the Barri Gòtic — have been using a combination of manual checks and automated deduplication software to identify redundant files. The process is labour-intensive. Digital asset management specialists in similar European municipal contexts have estimated that duplicate image problems can inflate storage requirements by 20 to 40 percent, and that clearing backlogs in mid-sized city archives typically takes between six and eighteen months depending on the volume of legacy data involved.

What Happens to the Files

The practical approach being applied this week involves a triage system. Files flagged as exact duplicates — identical checksums — are queued for deletion after a 30-day review window. Near-duplicates, meaning images that are visually similar but may differ in resolution, metadata, or cropping, are being reviewed manually before any action is taken. This second category is proving the most time-consuming, particularly for heritage photographs where minor variations between scans can carry documentary significance.

The migration deadline is pressing. The city's contract for its current primary storage infrastructure expires in November 2026, and moving a database inflated with redundant files would increase both migration time and licensing costs on the new platform. Archive managers have reportedly been asked to reduce the total image file count by at least 15 percent before the migration begins. Whether that target is achievable in the available window depends on how quickly the near-duplicate review can be completed with current staffing levels.

For residents and researchers who use the municipal archive — including journalists, urban planners, and lawyers working on property disputes in areas like Poblenou and the 22@ innovation district — the practical advice this week is to expect some search inconsistencies in the online catalogue through at least September. The Arxiu Municipal's public consultation desk on Carrer de Santa Llúcia is open Monday through Friday and staff can assist with locating specific documents if the digital search returns conflicting results. The city has indicated it will publish an updated catalogue index once the deduplication phase is complete, though no specific date for that publication has been confirmed.