Flood Hazard Protection

Flood waters between a large home and a parking lot for a business

The City of Norman is dedicated to minimizing the loss of life and property that is associated with flooding events. Education and prevention are valuable and proven tools that help communities become resistant to these natural disasters. The City of Norman recognizes that areas outside the City’s floodplains can be susceptible to flooding, not just those structures located within Special Flood Hazard Areas (SFHA’s). The SFHA is also known as the 1% chance floodplain or 100 year floodplain. The following information has been provided to help inform property owners located within the SFHA, flood prone areas, and all properties within the City of Norman. More information can be found at the links below:

City of Norman Flood Hazard Ordinance

Cleveland County Hazard Mitigation Plan

Oklahoma Water Resources Board

FEMA FloodSmart


Report Storm-Related Flooding and Property Damage

Flood Hazard

Most flooding in Norman is due to heavy runoff produced by rainstorms that cause the levels of the Canadian and Little Rivers, as well as 10 Mile Flat, Brookhaven, Merkle, Imhoff, and Bishop Creeks to rise. There are older parts of town in core Norman where local drainage problems contribute to flooding such as south of Lahoma Avenue between West Main Street and West Symmes Street.

Flood Insurance

Basic homeowner’s insurance policies do not cover damage from floods. The City of Norman participates in the National Flood Insurance Program (NFIP), which means that federally subsidized flood insurance is available to everyone in the City. The purchase of flood insurance is highly recommended. Some people have purchased flood insurance because it was required by the bank or mortgage company when they obtained a mortgage or home improvement loan. Flood insurance policies are available to cover the building's structure and its contents.  Remember, there is a 30 day waiting period before the policy becomes effective, and it must be renewed every year. 

Norman’s floodplain ordinance standards are above FEMA’s minimum requirements, which allows Norman to participate in FEMA’s Community Rating System (CRS) program. Norman is a Class 6 Community, which results in a discount of flood insurance premiums for structures in the Special Flood Hazard Area. Please visit the FEMA website, or contact the City of Norman for further information.

Mandatory Purchase Requirement: The mandatory purchase requirement applies to all forms of federal or federally related financial assistance for homes and buildings located in the SFHA. This requirement affects loans and grants for the purchase, construction, repair, or improvement of any public or privately owned buildings in the SFHA including machinery, equipment, fixtures, and furnishings contained in the homes and buildings. If a home or building is located in the SFHA, the agency or lender is required by law to require the recipient to purchase a flood insurance policy on the building. For information about flood insurance rates, please contact your local insurance agent.

Notice to Lending, Real Estate, or Insurance Agents

Additional Information

Property Protection

Rather than waiting for a flood to occur, you can act now to protect your property from flood damage. Various alternatives are available to help minimize flooding. If the floor level of your property or structure is lower than the Base Flood Elevation (BFE) as shown on the City’s Digital Flood Insurance Rate Map (DFIRM), consider ways to prevent flooding from occurring such as retrofitting your home or building. “Retrofitting” means altering your building to eliminate or reduce flood damage.

Retrofitting measures include:

Elevating the structure so that flood waters do not enter or reach any damageable portion of it.

Constructing barriers out of fill or concrete between the building and flood waters.

“Dry floodproofing” to make the building walls and floors watertight so water does not enter.

"Wet floodproofing" to modify the structure and relocate the contents so that when flood waters enter the building there is little or no damage.

There are several good references on retrofitting available from the Public Works Department or FEMA’s website. Many of these will inform you about retrofitting techniques and help you decide which is best for you. One of these is FEMA's Homeowner's Guide to Retrofitting.

Natural and Beneficial Functions

The City of Norman’s floodplains, such as those in the Little River and 10 Mile Flat Creek watersheds, provide a wide range of benefits to human and natural systems. They provide flood storage and conveyance and reduce flood velocities and flood peaks. Water quality is improved through the soil and vegetation’s ability to filter out nutrients and impurities from runoff and process organic wastes. floodplains and wetlands provide breeding and feeding grounds for fish and wildlife, create and enhance waterfowl habitat, and protect habitats for rare and endangered species. The floodplains are an important asset to the City of Norman. They provide open space, aesthetic pleasure, and areas for active uses such as parks. Norman has also enacted a Manufactured Fertilizer Ordinance as well as a Water Quality Protection Zone Ordinance to improve water quality.

Floodplain Development Permit Requirements

All development within the City of Norman’s floodplains requires a floodplain permit. Development is defined as any man made change to improved or unimproved real estate, including, but not limited to, buildings or other structures, mining, dredging, filling, grading, paving, excavation, drilling, or storage of equipment or materials. Please visit or contact the Department of Public Works-Stormwater Division by mail or in-person at 201-A West Gray, Norman, OK, 73069, by phone at (405) 329-2524, or by email for advice before you develop in the floodplain.

The floodplain ordinance regulates construction in the floodplain. Without these provisions, flood insurance through the National Flood Insurance Program (NFIP) would not be available to property owners in Norman. Any development in the floodplain without a permit is illegal; such activity can be reported to the Department of Public Works at (405) 329-2524 or through the Action Center at (405) 366-5396.

Floodplain Permit Application

Substantial Improvement Requirements

What is substantial improvement? 

  • The National Flood Insurance Program (NFIP) requires that any combination of repairs, reconstruction, rehabilitation, addition, or other improvement of a structure, the cost of which equals or exceeds fifty (50) percent of the market value of the structure before “start of construction” of the improvement. This includes structures that have incurred “substantial damage”, regardless of the actual work performed. The cost used in the substantial improvement determination shall be the cumulative costs of all previous improvements for a specific building or structure during the immediate past 10-year period. The term "substantial improvement" does not, however, include either:

1. Any project for improvement of a structure to correct existing violations of State or local health, sanitary, or safety code specifications that have been identified by the local code enforcement official and which    are the minimum necessary conditions; or

2. Any alteration of an historic structure, provided that the alteration will not preclude the structure's continued designation as a historic structure.

What is substantial damage? Substantial damage means damage of any origin (including fire, wind, tornado, and flood) sustained by a building or structure when the cost of restoring the building to its pre-damaged condition would equal or exceed 50% of the market value of the structure before damage occurred. Substantial damage is determined regardless of the actual repair work performed.

The City of Norman's floodplain ordinance requires that any substantial improvement must have a floodplain permit prior to construction. Floodplain permit applications are available from the Department of Public Works.

Summary of Rules for New Construction in the Floodplain

All new construction or remodeling in the regulatory floodplain requires a floodplain permit. After a floodplain permit has been obtained, a building permit needs to be obtained from the Development Services Division.  Inspection will be performed by the City throughout the construction process.  Before final acceptance and issuance of a Certificate of Occupancy, a complete and correct Elevation Certificate must be received and accepted by the Stormwater Division.


Drainage System Maintenance

It is illegal in the City of Norman to dump any type of debris into a river, creek, channel, drainage ditch, stormwater inlet, or detention pond. The debris can become entangled in culverts and channels and impede drainage causing the flow of water to back up and possibly cause flooding. Citizens of Norman should also keep drainage ditches on their property free of debris, foliage, and vegetation that would impede the flow of water. Debris dumping should be reported to the Department of Public Works or to the Action Center.


Flood Information

Citizens of Norman can obtain flood information concerning flooding history, flood maps, floodways, flood depths, mandatory flood insurance purchase requirements, inquiries, and flood zone determinations on properties from the Department of Public Works in Building A of the City Municipal Complex on Gray Street, or by calling (405) 329-2524. (Interactive Norman Maps)

Information on whether a property is in the Water Quality Protection Zone or a dam inundation area can also be provided.

Elevation Certificates on some properties in the Special Flood Hazard Areas (SFHAs) are on file at the Department of Public Works and are available upon request. (Link to Elevation Certificates)

Real time gauge information can be obtained for the Canadian River and Lake Thunderbird through the following websites:

National Water Information System, Real-Time Data for Oklahoma

Canadian River at Norman, Oklahoma

Lake Thunderbird near Norman, Oklahoma

Little River Below Lake Thunderbird near Norman, Oklahoma

Flood Protection Assistance

Concerned citizens and the general public can obtain information on flood protection assistance from the Department of Public Works by calling (405) 329-2524. Flood protection assistance is site-specific flood-related data based on historical flooding in the neighborhood, high water marks, and local drainage problems.

List of Services Provided:

Make site visits to review flooding and drainage problems and provide one-on-one advice to property owners.

Provide advice and assistance on retrofitting techniques, such as elevating buildings above the Base Flood Elevation (BFE), dry floodproofing, and wet floodproofing.


Flood Safety

Learn the safest route from your home or business to higher, safer ground.

If Emergency Management Officials tell you to evacuate or leave your home, go immediately to a safe shelter, hotel, or relative’s house.

Before you leave, turn off all utilities, gas, and electricity at the main switch. Stay away from power and electrical lines. Be alert for gas leaks.

Do not walk through flowing water. Drowning is the number one cause of flood related deaths. Currents can be deceptive; six inches of moving water can knock you off your feet.

Do not drive through a flooded area. More people drown in their cars than in any other location. Remember "Turn Around Don't Drown".

WHAT TO DO: Before, During and After a Flood Event