FEMA flood zone rules in Jefferson County, CO β also called floodplain regulations or special flood hazard area (SFHA) rules β determine flood insurance requirements and elevation standards for new construction.
Jefferson County participates in the FEMA National Flood Insurance Program (NFIP) under FIS 08059CV001D and administers Section 30 (Floodplain Overlay District) of the Zoning Resolution. A Floodplain Development Permit is required before any work in a Special Flood Hazard Area mapped on the FEMA FIRM. Substantial improvements (50% of market value, cumulative over 5 years) trigger full compliance. Colorado state rules at 2 CCR 408-1 require 1 ft of freeboard above base flood elevation for residential structures.
Jefferson County is an NFIP-participating community covered by FEMA Flood Insurance Study 08059CV001D (revised December 20, 2019). Floodplain rules are codified in Section 30 (Floodplain Overlay District) of the Jefferson County Zoning Resolution, with stormwater design governed by the Storm Drainage Design and Technical Criteria manual. Any development - new construction, fill, grading, substantial improvement, or storage of materials - in a Special Flood Hazard Area (Zone A, AE, AO, AH, or floodway) requires a Floodplain Development Permit, applied for through the Jefferson County Citizen Portal before a building permit can issue. Major mapped floodplains include Clear Creek (with channelization in and near Golden), Bear Creek, North Turkey Creek, and tributaries of the South Platte. The 'substantial improvement' rule applies when the cost of repair, reconstruction, or improvement equals or exceeds 50% of the structure's market value; Jefferson County uses a 5-year cumulative window starting from the initial permit. Per Colorado state rule 2 CCR 408-1 (Colorado Water Conservation Board), residential structures in the SFHA must have the lowest floor at least 1 foot above base flood elevation (1 ft of freeboard). Federal NFIP rules at 44 CFR Parts 59-60 also apply. Contact Planning & Zoning at 303-271-8700.
Development in a Special Flood Hazard Area without a Floodplain Development Permit violates Section 30 of the Zoning Resolution and can trigger stop-work orders, after-the-fact permitting, structure removal, or corrective action. Cumulative improvements that breach the 50% substantial-improvement threshold without compliant elevation can disqualify the property from NFIP flood insurance. Federal sanctions under 44 CFR Part 60 apply if the county is found out of NFIP compliance.
Jefferson County, CO
Unincorporated Jefferson County enforces a Noise Abatement Regulation (Policy Manual Part 3, Chapter 1, Section 1; adopted by Resolution CC07-202) that mirro...
Jefferson County, CO
Unincorporated Jefferson County does not require a fence permit, but the Zoning Resolution caps fence height in Residential Districts at 6 feet (Section 30.F...
Jefferson County, CO
Jefferson County's Animal Control Regulation (Resolution CC24-042, effective March 10, 2024) requires every dog in unincorporated Jefferson County to be on a...
Jefferson County, CO
Only 'permissible fireworks' under Colorado C.R.S. 12-28-101(8) - sparklers, ground spinners, fountains, and snakes - are legal in Colorado. All aerials, fir...
Jefferson County, CO
Section 46 of the Jefferson County Zoning Resolution (adopted Dec 16, 2025) requires unincorporated STRs to provide a minimum of one off-street parking space...
Jefferson County, CO
Under Section 46 of the Jefferson County Zoning Resolution (adopted Dec 16, 2025), an unincorporated STR must be a single-family detached dwelling with no mo...
See how Jefferson County's flood zones rules stack up against other locations.
Help us keep this page accurate. If you notice an error or outdated information, let us know.