Flooding

Stay Safe During Flood Season

• Sign up for emergency notifications at nocoalert.org. 
• Follow the National Weather Service, online or via an NOAA Weather Radio.
• Tune in to local TV and radio stations.

Know the difference between a 'Watch' and a 'Warning':

• Flood Watch: Flooding is possible. Be alert and prepared.
• Flood Warning: Flooding is happening or will happen soon. Take immediate action.

View Real-Time Rainfall and Streamflow Data

• Curious about how much rain is falling near your house or the current flow of the Poudre River? Check out real-time data from the City's early flood warning system, which includes the same streamflow and precipitation gauges monitored by our staff.
  • Rainfall Data
  • Streamflow Data

     

The City of Fort Collins (the City) makes no representations or warranties as to the accuracy, timeliness, or completeness of the ALERT data provided by this web site.

 THE CITY MAKES NO WARRANTY OF MERCHANTABILITY OR WARRANTY FOR FITNESS OF USE FOR A PARTICULAR PURPOSE, EXPRESSED OR IMPLIED, WITH RESPECT TO THE ALERT DATA PROVIDED BY THIS WEB SITE.

 Any user of this alert data web site accepts the same AS IS, WITH FAULTS, and assumes all the responsibility for the use thereof, and further covenants and agrees to hold the City harmless from and against all damage, loss, or liability arising from any use of this ALERT data web site, in consideration of the City having made this information on this web site available. In addition, the ALERT database contains a certain amount of erroneous data. Therefore, the user of this data should not consider any of this data as valid without further verification.

All ALERT gaging stations communicate data using 300-baud FM radio transmissions which are rebroadcast by one or more radio repeaters. Radio interference is one common source of bad data. ALERT rain measurements are affected by wind, hail, snow, birds, insects, and lawn irrigation systems. Human tampering is a problem at certain sites. Routine maintenance activities involve manual testing of rain gages, water level sensors and other measuring devices. Electronic switches on tipping-buckets occasionally malfunction causing falsely high rainfall reports. Lightning, which occurs frequently in this region, can cause false reports that may not be apparent. Even if all ALERT gauging stations could work perfectly, base stations are another possible error source. Currently there are 5 known ALERT base stations operating in the Fort Collins/Loveland area which collect data independently. Consequently, some data inconsistencies between the base stations should be expected. Each base station computer uses its internal clock to attach date/time values (using GMT or Coordinated Universal Time) to data reports received from the gages. This record is then stored in a database file and the computer displays information using the current local time setting (i.e., MDT or MST). Computer clocks very in accuracy and must be reset occasionally. Internal clock batteries eventually die and must be replaced. When sensors in the field are electronically adjusted or replaced, the ALERT database must also be re-calibrated. An improperly maintained database is sometimes difficult to detect with misinterpreted data being the likely outcome. Field maintenance reports, calibration notes, rating tables and alarm settings are available for inspection at the City's Utilities office at 700 Wood Street, Fort Collins, Colorado. Due to the large number of ALERT stations reporting data, it is not practicable to manually correct all erroneous reports received by the base stations. Attempting to do so would require considerable effort and present yet another possible source for error.

The City maintains electronic records of data collected by the City of Fort Collins Utilities ALERT Base Station located at the City's Utilities office. The data on this Base Station is reviewed for accuracy. All erroneous reports are corrected manually. Therefore, the ALERT data obtained from the City's Base Station is presumed to be the most accurate. Individuals requesting information from the City are provided with data from this Base Station unless a known problem requires using an alternate site. The evaluation, interpretation and verification of ALERT data from this system is the responsibility of the user. All ALERT data obtained via the Internet is considered provisional. Data on the web server will not be corrected.

If you experience any problems using the ALERT Web page or have any questions concerning this disclaimer, contact Utilities.

Before a Flood - Prepare Now

• Stay informed: Sign up for emergency alerts.
  
  
• Consider flood insurance: Contact your insurance broker or visit floodsmart.gov to learn more.
  
  
• Document your belongings: Make insurance claims easier after a disaster.
  
  
• Make an emergency plan and kit: Visit ready.gov for more information.
  
  
• Protect important documents and valuables: Store identification records, financial and legal documents, medical information, and sentimental items in higher areas of your home. For important documents, keep paper copies in a fireproof and waterproof container or electronic copies on an external hard drive.
  
  
• Protect your property: Extend downspouts away from your foundation, keep gutters and downspouts clear of debris, ensure the ground slopes away from your home’s foundation, and elevate window well edges to prevent water entry. Fort Collins Utilities offers free home visits to provide flood protection advice regarding these and other measures.

During a Flood - Stay Safe

• Listen for emergency updates and evacuation orders: Follow all instructions from authorities.
  
  
• Shut off utilities: If rising water threatens to reach electrical outlets or appliances, or if you are evacuating your home, turn off electricity at the main power switch and shut off water and gas.
  
  
• Climb to safety: If trapped in a building, go to its highest level. Avoid attics without escape routes.
  
  
• Turn around, don’t drown: Don’t drive or walk through floodwater. Just six inches of fast-moving water can knock you down, and one foot of moving water can sweep your vehicle away.
  
  
• Stay back: Keep away from electrical wires and downed power lines.

After a Flood - Recover

• Wait for clearance: Do not return home until officials say it’s safe.
  
  
• Watch for wildlife: Snakes or other animals could be in your house.
  
  
• Avoid wading in floodwater: It may contain dangerous debris, be contaminated or be electrically charged. Do not touch electrical equipment if it’s wet or you’re standing in water.
  
  
• Inspect for damage: When it’s safe to return home, check for structural damage, gas leaks and electrical hazards.
  
  
• Document everything: Take photos for insurance claims.
  
  
• Prevent mold: Dry out your home as quickly as possible.
  
  
• Obtain necessary permits: Get a floodplain use permit and building permit before making any repairs.
  
  
• File a claim: Contact your insurance agent and start the flood insurance claims process.

Always look at the maps for both the FEMA floodplain and City floodplains to determine if a property is in a floodplain.

Although City maps show areas outside city limits, do not use the maps to make floodplain determinations in Larimer County. Contact Larimer County Engineering at 970-498-5700 for County floodplain map information.

Please refer to the CSU Floodplain Management website for floodplain mapping and requirements on CSU’s Main Campus.

You can also obtain a copy of the FEMA maps on the FEMA website. Check out FEMA's tutorial to learn how to create a specific map.

Please call Floodplain Administration staff at 970-416-2632 to further discuss the flood risk of specific properties and floodplain regulations that apply. Additional map information such as erosion buffer zones, flood elevations and historic flood data is available.

Accessibility Assistance
We are committed to ensuring that all our documents are accessible to everyone. The City of Fort Collins is dedicated to providing equal access to information and services for all residents. We strive to create and distribute documents that meet the highest accessibility standards. The City of Fort Collins encourages individuals with disabilities to request accommodation or modifications to help ensure their effective participation in our programs and services. Examples include sign language interpretation, assistive listening devices, alternative document formats and modifications such as large print and audio playback of written content.

If you encounter any difficulties accessing, viewing or reading the attached document, we are here to help.

How to Get Assistance
For immediate assistance, please reach out to the City’s ADA Coordinator:
• Email: adacoordinator@fortcollins.gov
• Phone: 970-416-4254
• Office: 300 Laporte Ave. Fort Collins, CO 80522 -- Monday-Friday, 8:00 a.m. - 5:00 p.m.

Vol. 1(PDF, 3MB)
Vol. 2(PDF, 2MB)
Vol. 3(PDF, 18MB)
Vol. 4(PDF, 18MB)
Vol. 5(PDF, 25MB)
Vol. 6(PDF, 83MB) 

It may be hard to believe, but urban areas that are not directly adjacent to a river, such as Downtown Fort Collins, are still at risk for flooding. In fact, parts of the downtown area are more at risk for flooding than areas developed after the 1980s when design standards for storm drainage were put in place.

Street flooding is the biggest problem in this area because of the huge risk to public safety. Think about the potential for water filling up a basement resulting in costly damages and the potential for loss of life. While not as dramatic as some of the floods along the river, just six inches of flowing water can knock a person over, and one to two feet of water is enough to carry away your car.

Addressing the issue head-on, the City of Fort Collins is developing a plan to reduce and control street flooding. The Downtown Stormwater Improvement Plan (DSIP) will address flood risk and improve stormwater quality through a system of large pipe projects and green infrastructure enhancements. This long-term investment in the community will ultimately decrease the life-safety risk and property damage in the downtown area during large rainstorms.

These maps do not reflect FEMA Letters of Map Revision based on Fill (LOMR-F) or Letters of Map Amendment (LOMA).

View a list of properties(PDF, 73KB) for which these LOMA and LOMR changes have been issued. 

• Floodplain Use Permit(PDF, 343KB): Required for any work done in a floodplain
• FEMA Elevation Certificate(PDF, 3MB): See also: Elevation Certificate Guidance Document
• FEMA Floodproofing Certificate(PDF, 851KB): May not render in your browser. Download the certificate to your device and open in Adobe Reader or Acrobat to view.
• No Rise Certification Form(PDF, 21KB): Required for work in a floodway when documenting "no-rise" in flood elevations
• Floodplain Variance Application(PDF, 165KB): For variances to be heard before the Water Board
• Erosion Buffer Zone Regulation Waiver Form(PDF, 106KB)
• Substantial Damage Review Requirements(PDF, 49KB): Establishes procedures for documenting damage to structures located in a floodplain
• Owner's Affidavit(PDF, 10KB)
• Contractor's Affidavit(PDF, 12KB)
• Damage Evaluation Form(PDF, 86KB)
• Emergency Response and Preparedness Plan(PDF, 528KB): Required for non-residential development in the Poudre River floodplain
• Annual Update Form(PDF, 87KB)

Guidelines and Handouts

• Elevation Certificate Guidelines(PDF, 245KB)
• Elevation Certificate Training Videos-please watch!
• Poudre River Quick Guide(PDF, 2MB): City of Fort Collins Floodplain Regulations for the Poudre
• Quick Guide(PDF, 2MB): City of Fort Collins Floodplain Regulations for all Basins Other than the Poudre River
• Floodproofing Guidelines(PDF, 21KB)
• Floodplain Modeling Guidelines(PDF, 724KB)
• BFE and Map-Model Agreement Tables(XLS, 456KB)
• Mobile Home Submittal Requirements(PDF, 516KB)
• Substantial Improvement/Substantial Damage List(PDF, 71KB): Items to be included and excluded in determining substantial improvement
• Is Your Sign in the Floodplain?(PDF, 2MB)

Development Review Checklists

Documentation requirements for submission of plans and reports for the City's Development Review process.

• Submittal Checklist(PDF, 77KB)

Floodplain Regulations

• Chapter 10 of City Code

FEMA Technical Bulletins

• 1-20- Openings in Foundation Walls(PDF, 4MB): Provides guidance on the NFIP regulations concerning the requirement for openings in Below-Base Flood Elevation foundation walls (enclosures) for buildings located in Zones A, AE, A1-A30, AR,AO, and AH
• 2-08-Flood-Resistant Materials Requirements(PDF, 2MB): Provides guidance on the NFIP regulations concerning the required use of flood-damage resistant construction materials for building components located below the Base Flood Elevation in Special Flood Hazard Areas (both A and V zones)
• 3-21-Non-Residential Floodproofing -- Requirements and Certification(PDF, 3MB): Provides guidance on the NFIP regulations concerning watertight construction and the required certification for flood-proofed non-residential buildings in Zones A, AE, A1-A30, AR, AO, and AH whose lowest floors are below the Base Flood Elevation
• FEMA P-936-Floodproofing Non-Residential Buildings(PDF, 41MB): Provides updated (2013) guidance on floodproofing retrofits for non-residential buildings
• FEMA P-2037-Flood Mitigation for Multi-Family Buildings(PDF, 4MB): Provides guidance on the NFIP regulations concerning the protection of multi-family buildings, including mixed-use buildings (October 2019)
• 4-93-Elevator Installation(PDF, 981KB): Provides guidance on the NFIP regulations concerning the installation of elevators below the Base Flood Elevation in Special Flood Hazard Areas (both A and V zones)
• 6-21-Below-Grade Parking Requirements(PDF, 1MB): Provides guidance on the NFIP regulations concerning the design of below-grade parking garages beneath buildings located in Zones A, AE, A1-A30, AR, AO, and AH
• 7-22-Wet Floodproofing Requirements(PDF, 2MB): Provides guidance on the NFIP regulations concerning wet floodproofing of certain types of structures (garages and accessory structures) located in Zones A, AE, A1-A30, AR, AO, and AH
• 11-01-Crawlspace Construction for Buildings Located in Special Flood Hazard Areas(PDF, 608KB): Provides interim guidance on minimum NFIP requirements as well as best practices for crawlspace construction in the Special Flood Hazard Area
• P-348, Edition 2- Protecting Building Utility Systems From Flood Damage(PDF, 37MB): Illustrates the design and construction of utility systems that comply with the National Flood Insurance Program requirements for new or substantially improved residential and non-residential structures in flood-prone areas.
• P-2140-Requirements for Agricultural Structures and Accessory Structures(PDF, 4MB): Provides additional guidance related to protecting various agricultural and accessory structures from flood damage and meeting minimum NFIP standards. (August 2021)

Federal Emergency Management Agency (FEMA) Letter of Map Revision Forms

• MT-1: Application forms for Conditional and Final Letters of Map Amendment and Letters of Map Revision Based on Fill
• MT-2: Application forms for Conditional Letters of Map Revision and Letters of Map Revision
• MT-EZ: Application form for Single Residential Lot or Structure Amendments to National Flood Insurance Program Maps

It’s important to respect the power of water. The Cache la Poudre River is a force of nature, and since the water is melted snow from the Rocky Mountains, it’s always cold. “Play It Safe.” Make sure to wear a life vest and other safety equipment. Know the flow and weather conditions. Plan your route, especially where your take-out location will be.

The river typically runs fastest from spring until mid-July. If you don’t have the necessary skills and equipment, wait to recreate. Learn more and view the interactive Poudre River safety map.

Floodplains provide natural protection against flooding, helping to safeguard homes and businesses by allowing water to spread out over a large area. This reduces the speed of floodwater as it’s soaked up in wetlands like a sponge, lowering peak flows downstream. But floodplains do more than just reduce flood risk – they’re also essential to the health of our rivers and ecosystems, which rely on frequent inundations to survive and thrive.

Human activities can threaten the health of our waterways. Our storm drains run directly into lakes and streams and eventually to the Cache la Poudre River. To help keep them clean, properly dispose of motor oil, pick up grass clippings and pet waste, and use car washes instead of washing your car at home. Obstruction and pollution of our waterways and ditches are violations of Fort Collins City Code. Report any debris or dumping in ditches or streams to Fort Collins Utilities at 970-221-6700.

Before you begin any construction (new development, addition, remodel, filling, grading, etc.) on your building or property, contact Fort Collins Utilities for specific floodplain regulation requirements. Some important considerations are listed below.

Floodplain Use Permits

Work in the floodplain requires a floodplain use permit. These permits ensure that structures are protected from flood damage and that construction projects do not cause flooding problems for existing properties. According to Fort Collins City Code, all new residential structures and additions built in the 100-year floodplain must be elevated above the 100-year water surface elevation. New non-residential buildings and additions also must be elevated or floodproofed above the 100-year flood elevation.

Floodway Requirements

The floodway is the most dangerous section of the floodplain. New residential development is not allowed and commercial development is very restricted. For all other permitted development, an engineering analysis that shows no-rise in the 100-year flood elevation is required.

Substantial Improvement Requirement

If the cost of reconstruction, rehabilitation or other improvements to a building equals or exceeds 50% of the existing market value, the structure must meet some of the same requirements as those of a new building. Substantially damaged buildings must meet the same standards upon reconstruction. Improvement requirements are addressed during the floodplain development permitting process.

For more information, call 970-416-2632 or email floodplains@fortcollins.gov.

The Stormwater Master Planning program maintains flood risk data, identifies stormwater management issues, and develops solutions that reduce flood risk, improve stormwater quality, and promote stream rehabilitation. The program has developed engineering plans for each of the 12 stormwater basins across the city. Each plan looks at the unique characteristics of the basin, identifies potential problems and recommends improvements. Utilities evaluates the prioritization of all stormwater improvement and stream rehabilitation projects on an annual basis. The main categories used to assess each project include protection of structures from flooding, road overtopping, cost-benefit ratio, health and safety, equity, water quality and habitat improvement.

Oak Street Stormwater Project

As part of the overall Downtown Stormwater Improvements Program, the Oak Street project is a major priority for the City because it will help resolve urban flooding and stormwater quality issues in downtown Fort Collins. Large diameter storm pipes ranging in size from 48-78 inches will extend from the previously constructed Oak Street Outfall, starting at Mason Street and extending to Jackson Street near City Park. “Rain gardens” in three locations along the Oak Street corridor will filter street runoff and help with water quality. Construction on the project began in July 2024, with completion expected by July 2026. So far, about 35% of the work is complete, including 772 feet of tunneling and 1,555 feet of mainline storm sewer. The new storm pipe is active and already moving stormwater downstream to the river.

Larimer County's Hazard Mitigation Planning

The county is currently updating the 2021 Hazard Mitigation Plan. This five-year update supports our community's eligibility for FEMA funding and our participation in FEMA’s Community Rating System (CRS).

Did you know that your regular homeowner’s insurance policy does not cover floods? Or that 30% of flood insurance claims come from outside the mapped floodplain?

Fort Collins residents and businesses receive some of the lowest flood insurance premiums in the country due to the City’s rating in FEMA’s Community Rating System. You may qualify for a 40% discount on flood insurance premiums.

Here are a few useful tips regarding flood insurance from FEMA’s National Flood Insurance Program:

• There is usually a 30-day waiting period before coverage takes effect.
• Flood insurance is required by lenders for properties in Federal Emergency Management-designated floodplains (Poudre River, Spring Creek, Dry Creek, Boxelder Creek, and Cooper Slough)
• Flood insurance is available to everyone in Fort Collins!
• Renters can purchase flood insurance.

There are also private flood insurance options.

Learn more about flood insurance

• Floods often happen very fast in Fort Collins, so we need to be prepared in advance and know what to do when a flood occurs. Talk with family members about the situations they might encounter during a flood and what they can do to stay safe. Create a family emergency plan and Be Flood Ready!
• Don’t drive, walk or bike through floodwaters. Twelve inches of flowing water can float a small car. Streets can quickly become stream channels, especially if inlets get clogged with debris or hail. It is better to be late and safe than floating in your car and needing to be rescued.
• In Fort Collins, floods happen fast leaving little to no time to evacuate. It is often safer to stay where you are rather than try to leave.
  1. Move to upper floors of your home. Basements can quickly fill with water and become unsafe. 
  2. Turn off electricity at the main power switch and shut off water and gas before flood waters start to rise.
  3. Be careful where you walk. The ground could be eroded away or there could be sharp objects or other hazardous debris that floated onto your property.