The City of Boulder's floodplain regulations are intended to reduce risk to life and property in areas along the 15 major drainageways within city limits that are prone to flooding. The City of Boulder regulates development based on FEMA Flood Insurance Rate Maps of the 1% Annual Chance Storm (a.k.a. the 100-year floodplain). There are also special regulations for senior housing, schools and emergency facilities. The regulated floodplain currently covers approximately 15 percent of Boulder including over 2,500 individual structures.
Select the Boulder Revised Code, Chapter 9-3-2: Floodplains link to view the complete regulations.
Review the Flood Fact Sheet for a summary of the three different types of regulated flood areas in the city of Boulder and their development potential.
Floodplain Development Permits
Property owners with buildings located in the 100-year floodplain are required to obtain a Floodplain Development Permit before expanding a building or constructing improvements.
Floodplain Information Requests
Use the Map of Floodplains (Interactive) to see if your property is located in a floodplain.
To have city staff look up your floodplain information, apply online through the Customer Self-Service Portal.
Use the FEMA Map Service Center to access a Public Flood Map or a Flood Insurance Rate Map.
Adding Your Property to the Regulated Floodplain
There are many areas in Boulder that are currently outside of the highest-risk floodplains, but are still at risk for flooding. In these areas, property owners may choose to meet or exceed floodplain regulations and/or obtain discounted flood insurance, depending on their tolerance for risk.
Removing Your Property from the Regulated Floodplain
If your structure is elevated or if your property was incorrectly mapped in the regulated floodplain, you may request that it be removed from the floodplain. Contact a licensed land surveyor to determine if your property qualifies for a Letter of Map Amendment to potentially remove your property from the floodplain. Although Boulder’s floodplain mitigation and regulation is aligned with a 100-year flood, that doesn’t mean flooding can’t happen outside of the floodplain at any time.
Flood Elevation Certificate Search