Denver's Digital Archives Have a Duplicate Image Problem — and City Officials Are Starting to Talk About It

Denver's municipal and cultural institutions are sitting on millions of duplicate digital images — redundant files clogging servers, inflating storage costs, and quietly undermining the accuracy of public-facing databases. City technology staff and archivists say the problem is no longer theoretical. It is costing real money and causing real confusion, and pressure is mounting to fix it before a planned citywide digital infrastructure upgrade rolls out later this year.

The issue gained sharper attention this spring when the Denver Public Library's Western History and Genealogy department — one of the largest regional photo archives in the American West, holding more than 600,000 digitized images — flagged a systematic problem during a routine quality audit. Duplicate scans of the same historic photograph were appearing under different catalog numbers, in some cases with conflicting metadata. Staff could not always determine which version was the authoritative file. The library has not publicly released figures on how many duplicates were found, but the audit is ongoing.

What Officials and Experts Are Saying

City technology officials have been careful with their language, but the direction of their concern is clear. Denver's Office of the Chief Information Officer, which oversees technology standards across city agencies, has been in discussions with department heads about adopting a unified digital asset management policy. The conversations accelerated after the library audit surfaced broader questions about how the city's roughly two dozen departments each handle image files independently, with no shared deduplication standard.

Urban planners at Denver Community Planning and Development — the agency responsible for neighborhood rezoning documents and development review records along the East Colfax corridor and in the River North Art District — say duplicate images have caused specific headaches in project documentation. When multiple staff members upload site photographs to the same case file without a check for existing uploads, the same image can appear dozens of times. That inflates file sizes, slows document retrieval, and, in at least one recent instance, led a reviewer to flag a project for additional inspection because an image was miscounted as showing a different date than it actually did.

Digital preservation specialists outside city government have been pointing to this problem for years. The Colorado State Archives, located on Sherman Street just north of the Capitol, has publicly documented its own deduplication work as part of a records modernization project begun in 2023. That project identified storage redundancy as a primary cost driver, though the Archives has not released a specific dollar figure tied to duplicate image files alone.

The Stakes for Denver's $47 Million Tech Upgrade

Denver voters approved a $47 million technology infrastructure bond in November 2024, with implementation phased through 2028. A portion of those funds is earmarked for cloud migration of city records. Technology policy analysts who study municipal government say cloud migration is exactly the moment when duplicate image problems become expensive — cloud storage is billed by volume, meaning every redundant file carries a recurring cost rather than a one-time hardware footprint.

The Denver Public Library Foundation has separately been raising private funds for a digital collections expansion, with a goal of making 1 million items accessible online by the end of 2027. Archivists say that goal is achievable, but only if the deduplication work is completed first. Uploading duplicate images to a public-facing platform doesn't just waste storage — it creates a confusing user experience and can damage the credibility of the collection.

Practical steps are already being discussed. The city's IT office is evaluating two commercial deduplication platforms — neither of which has been selected yet — and is expected to issue a request for proposals before the end of the third quarter. The Denver Public Library's digital team has begun manually reviewing flagged files in its Western History collection, prioritizing photographs from the 1880–1940 period, which are both the most fragile and the most frequently searched. Anyone with a stake in how Denver manages its public digital records — developers, historians, neighborhood associations in places like Five Points or Globeville — has until the RFP process opens to make their preferences known to the CIO's office directly.