Pitkin County, CO Environmental Rules: Flood Zones (2026)

Floodplain regulation in unincorporated Pitkin County is governed by the Pitkin County Land Use Code (Title 8 of the County Code), with the controlling development standards set out in Section 7-20-40 (Floodplain) and the related river-corridor protections in Section 7-20-80 (River and Stream Corridors and Wetlands). Section 7-20-40 applies to ALL development within the 100-year floodplain, expressly including BOTH FEMA-identified jurisdictional floodplains shown on effective Flood Insurance Rate Maps AND non-jurisdictional floodplains that have not been mapped by FEMA but are determined by a Colorado-Registered engineer or by the Pitkin County Floodplain Administrator. The Pitkin County Community Development Department serves as the local NFIP Floodplain Administrator for unincorporated Pitkin County under FEMA Community Identification Number 080287; the City of Aspen (CID 080143), Town of Snowmass Village (CID 080312), and Town of Basalt (CID 080052) participate independently for areas inside their corporate limits. The current effective countywide Flood Insurance Rate Maps were adopted on August 14, 2019, the product of a multi-year FEMA Risk MAP restudy of the Roaring Fork watershed that updated mapping last revised in the 1980s. A Floodplain Development Permit is required before any new construction, substantial improvement, fill, grading, retaining wall, driveway, road, bank stabilization, bridge, dredging, irrigation infrastructure, or revegetation work within the regulatory 100-year floodplain. Under the NFIP framework adopted into Section 7-20-40 and 44 CFR 60.3, new construction and substantial improvements must have the lowest floor (including basement) elevated to or above the regulatory flood protection elevation, be anchored to resist flotation, collapse, and lateral movement, and use flood-resistant materials below that elevation. Colorado's statewide floodplain rules at 2 CCR 408-1 require a minimum of one foot of freeboard above the Base Flood Elevation for residential structures, with critical facilities required to be protected to a higher standard. Substantial improvement or substantial damage equal to or exceeding 50 percent of pre-improvement market value triggers full compliance with current flood standards. Section 7-20-80 imposes additional river-corridor protection requirements along the Roaring Fork, Crystal, Fryingpan, and other regulated waterways, including limits on disturbance, vegetation, and structures within the river corridor. FIRM panels and the National Flood Hazard Layer for Pitkin County can be viewed at the FEMA Map Service Center (msc.fema.gov), through Pitkin County's Maps and More ComDev viewer at maps.pitkincounty.com, or through Colorado's coloradohazardmapping.com portal operated by the Colorado Water Conservation Board. Property owners who believe a structure is mistakenly mapped in a Special Flood Hazard Area may apply to FEMA for a Letter of Map Amendment (LOMA) or Letter of Map Revision (LOMR).