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  • Floodplain Map
  • Creeks of Boulder
  • Floodplain Development
  • Be Prepared
  • Community Resilience

Prepare for Floods

 « Return to Flood Info

BE AWARE | BE VIGILENT | BE SAFE - you may only have minutes to react.

The City of Boulder is the No. 1 Flash Flood Risk community in the state of Colorado. Floods can happen at any time with little or no warning. Are you prepared? 

  • Sign up for FREE emergency alerts at You can get alerts via home, work, and cell phones, text messages, and email. When a flood watch or warning is issued for your area, seek response information by tuning to local news and visiting
  • Prepare an emergency kit pdf
  • PURCHASE flood insurance to protect your property.
  • Be Flood Smart
  • Protect Natural Floodplain Functions. The city has adopted regulations for development within streams, wetlands, and water bodies to help preserve and protect these natural resources.

Flood Watches and Warnings

Flash Flood Watch  - Weather conditions may cause flash flooding in the specified area. Be ready to move to higher ground during heavy rainfall.

Flash Flood Warning  - Flash flooding is occurring or is imminent in the specified area. Move to higher ground immediately. In some locations and situations, it may be safest to shelter in place on the upper floor of the building.

The Office of Emergency Management tests the city's emergency warning system on the first Monday of each month during Flood Season (Apr - Sept). Sirens are tested at 10 a.m. and 7 p.m.

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  • Disconnect electricity and gas;
  • Do NOT walk or drive through flood waters;
  • Get to higher ground; and
  • Follow emergency response orders.

Floods of any size can be devastating. Before you plan any post-flood repair, make sure to check if you need any permits prior to starting your repairs. 


A City of Boulder permit and inspection is required for projects that affect the structure of a building or its electrical, mechanical, or plumbing systems.

Before beginning any flood-related projects for your property, contact P&DS to determine if a City of Boulder permit is required. Email [email protected], visit Planning and Development Services Center.

Any modifications or improvements to protect private property must not adversely impact adjacent properties and must comply with all adopted building codes, design and construction standards, and land use regulations.

Floodplain Development

Specific Floodplain Development requirements may be applicable for properties located in the floodplain. Property owners with buildings located in the 100-year floodplain are required to obtain a Floodplain Development Permit pdf before expanding a building or constructing improvements.


Qualified maintenance staff or professional contractors licensed with the City of Boulder must complete many of the projects that require a city permit. Visit the Hiring a Contractor page for lists of city-licensed professionals.


Flood Insurance Information

Review your existing insurance policies to determine if your current coverage is comprehensive enough to cover potential losses. In addition to buying flood insurance, property owners should also consider purchasing additional insurance coverage for sewer backups.

Insurance can be purchased from a licensed private insurance company or an independent property and casualty insurance agent. This is usually the homeowner's insurance agent. Any local insurance agent can sell an insurance policy and must legally charge the same rate.

The City of Boulder participates in the National Flood Insurance Program (NFIP) by adopting and enforcing floodplain management ordinances to reduce future flood damage. In exchange, the NFIP makes federal government-backed flood insurance available to homeowners, renters and business owners, whether or not their properties are in a floodplain. 

The city also participates in the Community Rating System The NFIP’s Community Rating System (CRS) is a voluntary incentive program that recognizes and encourages community floodplain management activities that exceed the minimum NFIP requirements. Flood insurance premium rates are discounted to reflect the reduced flood risk resulting from community actions that meet the three goals of the CRS:

  1. Reduce flood losses;
  2. Facilitate accurate insurance rating; and
  3. Promote the awareness of flood insurance.

Participating communities must implement specific measures to reduce the impacts of floods, including:

  • Adoption of federal Flood Insurance Rate Maps (FIRMs);
  • Local floodplain regulations;
  • Floodplain development permits;
  • Inspection for compliance;
  • Maintaining records of floodplain development;
  • Helping community members obtain flood information;
  • Floodplain master planning; and
  • Stormwater maintenance activities.

For CRS participating communities, flood insurance premium rates are discounted in increments of 5%: i.e., a Class 9 community would receive a 5% premium discount, while a Class 8 community would receive a 10% discount. The city joined the CRS in 1992 as a Class 8 community, improved to a Class 7 in 2008 and then to a Class 6 in 2012. The city was awarded a Class 5 rating in early 2013. As a result, standard policyholders now receive a 25% discount on flood insurance with anticipated citywide annual savings of more than half a million dollars.  

To find a qualified NFIP agent, call toll-free at 1-888-379-9531 or visit

To see if your property is located in a floodplain, select the Map of Floodplains (Interactive).

For information about updates to the Flood Insurance Rate Maps (FIRM) and Letter Of Map Amendment process (LOMA), see the  Maps of Floodplains page.

You can also get a Public Flood Map or a Flood Insurance Rate Map from the FEMA Map Service Center.

Do not wait to buy insurance! 
With most policies, there is a 30-day waiting period before flood insurance will take effect.

Elevation & Flood Proofing Certificates

When purchasing flood insurance, the insurance agent may ask for an Elevation Certificate or Floodproofing Certificate. These certificates identify protection measures that may have been incorporated into the building's construction and are used to determine the annual premium costs for an insurance policy.

Only Elevation Certificates apply to residential structures, since FEMA does not recognize floodproofing measures for residential construction. If the lowest floor of a dwelling and its associated structures are located above the 100-year flood elevation, insurance premium costs are reduced. For new residential construction in Boulder, the lowest floor and associated structures must be constructed a minimum of two feet above the 100-year flood elevation.

Elevation Certificates must be prepared and certified by a Colorado-registered professional land surveyor. Floodproofing Certificates must be prepared and certified by a Colorado-registered professional engineer or architect.

Use the Flood Elevation Certificate Search feature to see if a property has an elevation certificate on file with the city's building department.

Additional Resources

View these helpful resources to learn more about flood safety and personal preparedness:

View these helpful resources to learn more about flood emergency plans:

Take protective measures now to help reduce property damage during future floods.

Flood Insurance

Most standard homeowner's insurance policies do not cover flood damage. Property owners may purchase flood insurance coverage for building structures, contents insurance for personal possessions, and additional insurance coverage for sewer backups. Boulder residents and businesses are eligible for up to a 25 percent discount on standard flood insurance rates.

Sewer Backup Prevention

Learn more about how to prevent sewer backups in your building.

The sanitary sewer service line is the responsibility of the property owner, up to and including the connection to the city-owned sewer line. Property owners should consult with a professional plumber to investigate and resolve problems determined to be in the sewer service line.