Flood Information
Are You in a Floodplain?
FEMA (Federal Emergency Management Agency) has released its preliminary Flood Insurance Rate Maps (FIRMs) for St. Vrain and Left Hand Creeks. Visit Understanding the Floodplain Maps on Engage Longmont to learn more about these maps and how they may affect your property’s flood insurance rates.
Work has already begun to update the new floodplain maps (Preliminary FIRMs) with the projects that have been completed along the St. Vrain Creek. The first Letter of Map Revision (LOMR #1) was submitted by the City of Longmont in summer 2020. Learn more about LOMR #1.
Check your property’s flood zones on Floodplain Inquiry Map. (This link will take you to a page that explains how to use the map and what the various map zone colors mean. From there, you can click to open the map.)
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Flood Insurance
Flood insurance is available for any property, regardless of whether it's within a floodplain. Learn what to ask your agent.
Flood Preparedness & Safety
There's no way to predict how or when a flood will occur. Learn how to be alert and prepared.
Flood Awareness Brochure
If your Land is in the 100-Year Floodplain, you and your property are at risk. Find more information here about determining your flood risk, protecting your property and changing requirements for flood insurance.
Protect Your Property from Flooding
The best time to protect your home from future flooding is now. Review these resources to find ways to improve your property's resilience to flooding.
Creek Status & Monitoring
View live creek cameras, and find links to stream gage levels and weather forecasts.
FAQs - Flood
Read the answers to some frequently asked questions about floods and floodplain management.
2013 Flood
From Sept. 11-15, 2013, Longmont experienced the most devastating flash flood event in its history. Learn about the catastrophic damages to city infrastructure, the resilience of the community and the innovative efforts to rebuild and revitalize.
Ten Years After the Flood
A Story of Recovery and Resilience
Longmont is working on many ways to improve our community’s resilience to future flooding (as well as other emergency events), from building infrastructure to putting place emergency communication plans to meeting our neighbors.
Infrastructure and floodplain improvements will take several years to fully implement and will have lasting positive effects on our community. Other efforts, such as improving communication within and between neighborhood groups and enhancing cultural awareness and competency, have more immediate impacts on community resilience. Learn more >
Frequently Asked Flood Questions
A permit is required before any construction or development can begin within any special flood hazard area (SFHA). The city requires a Floodplain Development Permit for all proposed construction or other development in the city including the placement of manufactured homes proposed within flood-prone areas. Permits are required to ensure that proposed development projects meet the requirements of the NFIP and the City of Longmont floodplain regulations. Visit the Floodplain Development Permit webpage for more details.
Flood insurance is available for any property, regardless of whether it is located within a floodplain. Learn more on the Flood Information – Flood Insurance webpage.
Find out whether your property is at risk for flooding by entering your address in Longmont’s Floodplain Inquiry Map, available through the Flood Information – Are You in a Floodplain? webpage.
Collaborative efforts are under way by both Boulder County and the City of Longmont to make the St. Vrain Creek capable of safely carrying up to 100-year flood flows. Learn more about Longmont’s efforts on our Resilient St. Vrain webpages and find Boulder County’s information on the St. Vrain Creek Master Plan.
Visit the Flood Preparedness and Safety webpage to learn what actions Longmont’s Office of Emergency Management takes and how to stay connected in case of flooding in our community. And review ways to improve your property’s resilience to flooding on the Protect Your Property from Flooding webpage.
Visit our Flood Information – Status and Monitoring webpage.
Be sure you sign up for the Longmont Reverse Emergency Notification System to receive real-time, emergency notification on devices beyond a traditional landline telephone. The system is used to notify our community if evacuation is needed. You will only receive notifications during an emergency. You can register cell phones, VoIP accounts and email accounts. The system is “geo-based,” which allows you to link your devices to your home address. If an evacuation is needed and your home address is included, you will be notified regardless of where you are (at work in Denver, out shopping, etc.).




