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Floodplain Development Permits

Floodplain Development Permits

Floodplain Permitting Information on this page:

General Floodplain Development Permits (FDP)

The Boulder County Floodplain Management Program issues General Floodplain Development Permits (FDP) in accordance with Section 4-404.1 of the Boulder County Land Use Code:

General FDPs cover projects and uses in the FO District that have been determined by the Floodplain Management Program to meet the applicable criteria set forth in Section 4-404.1(B) of the Boulder County Land Use Code, which, among other criteria, includes those projects and uses that have been determined to have minimal or no impact on flood hazards.

General FDPs allow certain projects and uses to take place without the need for an Individual Floodplain Development Permit. Some projects permitted by the General FDP still require notification of the Floodplain Management Program as described below.

For Projects Under the General FDPs That Require Notification Be Submitted to the Floodplain Management Program

Notification can be submitted by:

  • Email:
  • Mail:
    Boulder County – Floodplain Management Program
    Attention: General FDP Notifications
    P.O. Box 471
    Boulder, CO 80306

Notification submittals, at a minimum, must include the following information:

  • Project description, including materials to be used and a narrative on the expected impact to the channel and Floodplain
  • Location description with accompanying location map
  • Site Plan

Boulder County will respond in writing no later than 14 days following submittal of notification and confirm whether or not a project is covered under the General FDPs, whether more information is required in order to make a determination, or whether the project is NOT covered by the General FDPs and submittal of an application for an Individual FDP is required.

Individual Floodplain Development Permit

An individual floodplain development permit is required for all development in the floodplain that is not covered under a General Floodplain Development Permit.

Floodplain Development Permits:

  • Must be obtained from the Boulder County Floodplain Management Program, before the start of construction.
  • Floodplain Development Permit Fees

Individual Floodplain Development Permit Application

Floodplain Management provides more information on floodplain regulations, drainage, flood preparations, maps and requirements. To check to see if your property is within a regulatory floodplain go to Boulder County e-mapping (searchable property information), or visit the official interactive web map.

Floodway Review

A Boulder County Floodway Review is required for any project in a county-administered floodway that results in 100-year surface elevation increases between 0.00 and 0.5 foot (existing vs. proposed conditions). For increases in a county-administered floodway that are greater that 0.5 foot, an approved Conditional Letter of Map Revision (CLOMR) is required prior to permitting. In FEMA-administered floodways, a CLOMR is required for projects that result in any increase (greater than 0.00) in 100-year water surface elevations prior to permitting.


For information on requirements for new buildings or improvements, review the Individual Floodplain Development Permit (FDP) Checklist for Buildings.

Agricultural Structures in the Floodplain

In May 2023, to comply with FEMA policy, the Board of County Commissioners approved updates to the Land Use Code regarding agricultural structures in the floodplain.

New or Substantially Improved agricultural structures may only be built at grade if an Administrative Variance is granted and the structure:

  • Has low damage potential and cost of recovery with respect to construction materials, location within the floodplain, flood depths and velocities, potential for debris, building contents, and function;
  • Complies with all other requirements for new floodplain construction;
  • Is “wet-floodproofed” with an appropriate number of flood vents; and
  • Does not increase risks to public safety.

View the Administrative Variance Request form. Variance applications should be submitted with an individual FDP application.

Bridge Construction

For more information about permit requirements, please visit the Bridge Construction Permit Requirements page.

Stream Restoration

Visit the Stream Restoration Permit Requirements page for more information.

Contact Us

Community Planning & Permitting - Floodplain Administration



2045 13th St.
Boulder, CO 80302

Map and Directions


8 a.m. to 3 p.m. Monday, Wednesday, Thursday
10 a.m. to 3 p.m. Tuesday

Mailing Address

Community Planning & Permitting
Floodplain Administration
P.O. Box 471
Boulder, CO 80306