Z-23-0001 Zoning Map Amendments to the Floodplain Overlay District

This amendment is a proposed change to Boulder County’s Land Use Code that updates the county’s floodplain boundaries based on new flood‑risk information. Learn more on the Building, Safety and Inspection homepage.

Docket Z‑23‑0001 updates the Floodplain Overlay District to incorporate FEMA’s revised Preliminary Flood Insurance Rate Maps and changes from the CHAMP study, ensuring county regulations reflect the best available flood hazard data.

Docket Z-23-0001 – Approved March 26, 2024

The Board of County Commissioners approved zoning map amendments in Docket Z-23-0001 at a public hearing on March 26, 2024. View Resolution 2024-032.

The Proposed Map Amendments were approved for incorporation into the Floodplain Overlay District, effective March 26, 2024 for the portion of Lefthand Creek affected by the Scientific Resolution Panel re-study (between Geer Canyon and 49th Street) and an effective date coincident with the FEMA effective date, on or after Sept. 26, 2024, for the rest of the Proposed Amendments.

Visit the Floodplain Remapping Project  webpage to learn more about the project, sign up to receive texts and/or email alerts, and to view the current and proposed floodplain maps.

Background

The 2013 Flood event caused widespread damage along waterways throughout Boulder County and other areas of the state. In response, the State of Colorado took steps to bolster long-term planning and resiliency efforts by funding Colorado Hazard Mapping Program (CHAMP), managed by the Colorado Water Conservation Board (CWCB). CHAMP is updating local hazard information, including producing new regulatory floodplain maps for the most affected waterways.

The county’s Floodplain Overlay District is comprised of both the FEMA Floodplain and Floodway and the Boulder County Floodplain and Floodway. The county has already incorporated draft CHAMP data into the Boulder County Floodplain and Floodway via Resolutions 2017-68, 2018-78, and 2020-11.

In July 2023, FEMA released revised Preliminary Flood Insurance Rate Maps (Preliminary FIRMs) based on the CHAMP remapping efforts. The revised Preliminary FIRMs differed from the already adopted draft CHAMP maps in eight areas where FEMA approved changes submitted during FEMA’s 2020 and 2021 appeal periods. The appeals included a Scientific Resolution Panel for portions of Lefthand Creek. We expect the revised Preliminary FIRMs will become the future effective FIRMs in the autumn of 2024.

In accordance with Section 4-403 of the Land Use Code, it is necessary to amend the Boulder County Floodplain to incorporate the changes FEMA made during their appeal resolution process. Aligning the Boulder County Floodplain and Floodway with the revised Preliminary FIRMs will reflect the best available flood hazard data. Specifically, staff propose removing Boulder County Floodplain and Floodway for stream reaches included in the CHAMP study, such that the FEMA FIRM will be the only effective regulatory floodplain for CHAMP reaches after the FEMA map update.

Past Public Meetings

Board of County Commissioners (BOCC) Public Hearing: Docket Z-23-0001: Zoning Map Amendments to the Floodplain Overlay District – March 26, 2024

Documents:

• Board of County Commissioners Staff Report for March 26, 2024

Planning Commission Hearing: Amendments to the Boulder County Floodplain and Floodway based on FEMA’s Physical Map Revision reflecting the Colorado Hazard Mapping Program (CHAMP) study – Jan. 17, 2024

Documents:

• Planning Commission Video Recording and Staff Report, Jan. 17, 2024

Dec. 13, 2023 – Virtual General Countywide Floodplain Remapping Informational Meeting

Documents:

• Floodplain Information Meeting Recording, Dec. 13, 2023
• Floodplain Community Meeting Presentation, Dec. 13, 2023

Nov. 30, 2023 – Floodplain Remapping Meeting for Residents on Lefthand Creek Between Geer Canyon and 49th St.

This meeting was held by Boulder County Parks and Open Space, Longmont. Property owners in this area were sent a letter with a meeting invitation, although the meeting was to the public.

Documents:

• Floodplain Community Meeting Presentation, Nov. 30, 2023

Public Comment Period Nov. 15 – Dec. 31, 2023

The public was invited to provide written comments on the proposed changes to the Boulder County Floodplain and Floodway through Dec. 31, 2023. All comments become part of the public record and will be provided to the Planning Commission and Board of County Commissioners for their consideration.