A new audit of Denver’s 16th Street Improvement Project found the renovation came in more than $27 million over budget, largely due to the discovery of a historic brick sewer system buried beneath the street — and that a key $18 million change order was approved without city council review.
The audit, released Thursday by Denver Auditor Timothy M. O’Brien, examined how the Department of Transportation & Infrastructure (DOTI) managed the project from planning through completion.
The renovation of 16th Street — which dropped the word “mall” from its name in 2025 — was years in the making. Denver City Council approved a $149 million construction contract with PCL Construction Services Inc. in March 2021, according to the audit…