Aurora, CO Environmental Rules: Flood Zones (2026)

Aurora City Code Chapter 70 establishes floodplain management regulations administered by the city's floodplain administrator. The city participates in FEMA's National Flood Insurance Program (NFIP). Development in FEMA-designated zones A, AE, and AH requires a floodplain development permit. The floodplain administrator maintains records of the lowest floor elevation of all new or substantially improved structures and any flood-proofing certificates. If an improvement equals or exceeds 50% of the structure's pre-improvement value, the entire structure must comply with the floodplain damage prevention ordinance. The city may approve certain development that increases the base flood water surface elevation by more than 6 inches, but must first obtain a conditional FIRM revision (CLOMR) from FEMA. Prior to any watercourse alteration or relocation, the city must notify adjacent communities and the Colorado Water Conservation Board and submit evidence to FEMA. Aurora's floodplain areas primarily follow Cherry Creek, Toll Gate Creek, Sand Creek, and their tributaries.