Underground stormwater detention vaults (UDVs) are structures that store stormwater runoff but do not provide water quality treatment. UDVs provide a place for runoff to flow and help prevent flooding and erosion. In Denver, these are required with certain urban properties and are often found below parking lots or garages.
Because these facilities are located below ground, they are prone to being overlooked and may not receive the regular maintenance needed to function as designed. Sediment accumulation, debris, clogged inlets or outlets can all compromise a vault’s performance over time, allowing pollutants to reach local waterways.
Property owners are responsible for ensuring their UDV is properly inspected and maintained. Inspections are required twice a year, and the reporting form is required to be submitted once per year. Email the completed UDV annual reporting form to wqinvestigations@denvergov.org
Failure to maintain these facilities may result in enforcement action by the City and County of Denver.
Maintenance Contractors for Underground Stormwater Quality Systems(PDF, 206KB)
UDV Annual Inspection and Maintenance Reporting Form(PDF, 159KB)
Source: Aqualis
Source: Exact Stormwater Management