Floodplain Management Ordinances
Every community in the NFIP must adopt local regulations that meet or exceed federal flood standards. Your community's ordinance determines what you can build in a flood zone and how.
Last updated: August 2026
What Is a Floodplain Management Ordinance?
A floodplain management ordinance is a local law that regulates development in flood-prone areas. To participate in the National Flood Insurance Program (NFIP), communities must adopt and enforce an ordinance that meets or exceeds the minimum standards set by FEMA in 44 CFR Part 60.
The purpose of these regulations is to ensure that communities account for flood hazards in all official actions related to land management and use. This includes zoning decisions, building permits, subdivision approvals, and any development within identified flood hazard areas.
Without a compliant ordinance, a community cannot participate in the NFIP, meaning its residents lose access to federal flood insurance and federally-backed mortgages for properties in the Special Flood Hazard Area (SFHA).
NFIP Regulatory Requirements (Section 60.3)
The specific requirements a community must enforce depend on the flood data FEMA has provided. As FEMA provides more detailed data, the regulatory requirements increase. These tiers are defined in Section 60.3 of the NFIP regulations and are cumulative: each level includes all requirements from the levels before it.
60.3(a) - No Maps or Data Provided
FEMA has not yet provided flood maps or data. The community must still require permits for all development in known flood-prone areas, review proposed development to minimize flood damage, and ensure new construction uses materials and methods that minimize future flood damage.
60.3(b) - Approximate A Zones Mapped
FEMA has provided a map showing approximate flood boundaries (Zone A) but no base flood elevations. The community must require that new construction and substantial improvements have the lowest floor elevated to or above the base flood level, using the best available data to determine that elevation.
60.3(c) - FIRM with Base Flood Elevations
FEMA has provided a Flood Insurance Rate Map (FIRM) with base flood elevations (BFEs). The community must require elevation to or above the BFE, obtain elevation certificates for new and substantially improved structures, and ensure that new subdivisions and development proposals include BFE data.
60.3(d) - FIRM with BFEs and Floodway
FEMA has provided a FIRM that delineates both BFEs and a regulatory floodway. In addition to all prior requirements, the community must prohibit any encroachment in the floodway that would cause any increase in the base flood elevation. This is the "no-rise" standard.
60.3(e) - FIRM with Coastal High Hazard Areas
FEMA has provided a FIRM showing coastal high hazard areas (V Zones). The community must require that new construction in V Zones be elevated on pilings or columns, that the space below the lowest floor is free of obstructions, and that structures are designed to withstand wave action and storm surge. No fill is allowed for structural support in V Zones.
Can My City Have Stricter Flood Rules Than FEMA?
The Section 60.3 requirements are federal minimums. Many states and communities adopt regulations that go well beyond these standards. The requirements are also cumulative: a community subject to 60.3(d), for example, must also meet all requirements from 60.3(a) through 60.3(c).
Always check your specific community's ordinance. The rules that apply to your property may be stricter than the federal minimums described on this page.
Common Ways Communities Exceed NFIP Minimums
- Requiring buildings to be elevated 1 to 3 feet above the BFE rather than just to the BFE. Many states mandate at least 1 foot of freeboard.
- Tracking all improvements over a multi-year period (often 5 or 10 years) toward the 50% substantial improvement threshold, rather than evaluating each project individually.
- Limiting or prohibiting the use of fill material in the floodplain to prevent displacing floodwater onto neighboring properties.
- Requiring that any fill placed in the floodplain be offset by an equal volume of excavation nearby to maintain flood storage capacity.
- Some communities prohibit all new development in the floodway regardless of whether a no-rise certification can be obtained.
- Regulating areas beyond the FEMA-mapped SFHA based on local flood history or future-conditions modeling.
Communities that adopt higher standards may qualify for premium discounts for their residents through the Community Rating System (CRS).
The Regulatory Floodway
The floodway is the most restricted zone under 60.3(d): the channel of a river or stream plus adjacent floodplain areas that must remain open to carry floodwater. Communities must ensure the base flood can pass through without increasing the water surface elevation by more than a designated height, typically 1 foot. Any remaining floodplain area outside the floodway is called the flood fringe, where development is allowed with elevation requirements.
Floodways are only designated in riverine areas with detailed engineering studies (typically Zone AE). Zone A areas studied by approximate methods do not have a designated floodway, and coastal zones (V, VE) never do since coastal flooding is driven by storm surge, not channelized flow.
Floodway
Development is effectively prohibited: no encroachment (fill, new construction, substantial improvement) is permitted if it would cause any increase in the base flood elevation. Even small additions require a "no-rise certification" from a licensed engineer, a high bar most projects cannot meet.
Flood Fringe
Development is allowed with restrictions: the lowest floor must be at or above the BFE, using flood-resistant materials. Still within the SFHA, so flood insurance is required for federally-backed mortgages.
Before buying property near a floodway, check the FIRM to see whether any portion of the lot or structure falls within the boundary. If any part of a building is in the floodway, the entire building is regulated under the more restrictive rules. Many communities adopt floodway regulations stricter than the federal minimum, including some that prohibit all development regardless of engineering analysis, so confirm the specifics with your local floodplain administrator.
What Is the FEMA 50% Rule (Substantial Improvement)?
Any renovation, addition, or repair to a building in the SFHA must comply with current floodplain management standards, typically elevation to or above the BFE, if the cost equals or exceeds 50% of the building's pre-improvement market value (building only, not land). The same threshold applies to substantial damage: if repair costs after a flood, fire, or other disaster reach 50% of the pre-damage value, the building must be brought into compliance during reconstruction, regardless of the damage cause. Some communities track cumulative improvement costs over 5 to 10 years, so several smaller projects can trigger the rule even if no single one does.
The 50% Test
Cost of Improvement or Repair / Market Value of Building = 50% or more?
Two federal exclusions apply regardless of local rules (44 CFR § 59.1): the minimum work needed to correct existing health, sanitary, or safety code violations, and alterations to structures on the National Register of Historic Places or a State Inventory of Historic Places.
If your building is determined substantially damaged or substantially improved and you carry an NFIP policy, you may be eligible for Increased Cost of Compliance (ICC) coverage, up to $30,000 toward elevating, relocating, demolishing, or floodproofing the building, at no additional premium cost.
How to Find Your Community's Ordinance
Local Building or Planning Department
Your city or county building department administers floodplain development permits. They can provide the full ordinance text and explain how it applies to your property and project.
Local Floodplain Administrator
Every NFIP community has a designated floodplain administrator responsible for enforcing the ordinance. This person can answer questions about specific requirements, variances, and the permit process.
State NFIP Coordinator
Each state has an NFIP coordinator who can direct you to your community's floodplain management program. FEMA publishes a directory of state coordinators on its website.
Municipal Code Online
Many communities publish their ordinances through services like Municode or American Legal Publishing. Search for your city or county name along with "floodplain management ordinance" to find the full text.
NFIP Regulatory Reference (44 CFR Part 60)
The full NFIP floodplain management requirements are codified in 44 CFR Part 60. The key sections are:
- § 60.1Purpose and applicability of floodplain management criteria
- § 60.2Minimum compliance with floodplain management criteria
- § 60.3Floodplain management criteria for flood-prone areas (the five-tier system described above)
- § 60.6Variances and exceptions to floodplain management requirements
Frequently Asked Questions
What happens if a community does not adopt a floodplain management ordinance?
Communities that fail to adopt and enforce adequate floodplain management regulations can be suspended from the NFIP. Suspension means residents and businesses in that community cannot purchase or renew federal flood insurance policies, and federally-backed mortgages in the SFHA become unavailable.
Can local floodplain regulations be stricter than FEMA requirements?
Yes. The NFIP requirements in Section 60.3 are minimums. States and communities frequently adopt higher standards such as additional freeboard above the base flood elevation, cumulative substantial improvement tracking, prohibitions on fill in the floodplain, and stricter floodway encroachment rules. Communities that exceed NFIP minimums may earn discounts through the Community Rating System.
How do floodplain management ordinances affect building projects?
Any construction, substantial improvement, or development in a mapped flood hazard area must comply with the community's floodplain management ordinance. This typically means obtaining a floodplain development permit, elevating structures to or above the base flood elevation, using flood-resistant materials, and meeting specific requirements based on the flood zone designation.
What is the difference between Section 60.3(c) and 60.3(d)?
Section 60.3(c) applies when FEMA has provided a FIRM with base flood elevations. It requires communities to regulate new construction and substantial improvements to be elevated at or above the BFE. Section 60.3(d) adds floodway requirements: once FEMA provides a FIRM that delineates a regulatory floodway, the community must prohibit any encroachment in the floodway that would cause any increase in the base flood elevation.
What is the substantial improvement rule?
The substantial improvement rule (the 50% rule) requires any renovation, repair, or addition to a building in the SFHA to comply with current floodplain management standards if the cost equals or exceeds 50% of the building's pre-improvement market value. This typically means elevating the building to or above the Base Flood Elevation. The same 50% threshold applies to substantial damage from any cause.
Can I build in a floodway?
Building in a regulatory floodway is extremely restricted. Under NFIP regulations (44 CFR 60.3(d)), no development is permitted in the floodway if it would cause any increase in the base flood elevation. Most new construction is effectively prohibited unless a licensed engineer can certify no rise in flood levels.
Related Resources
Sources
- FEMA Flood Insurance (opens in new tab)General Reference
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Disclaimer: This guide is for general informational purposes only and is not a substitute for professional advice. Floodplain management ordinances are adopted and enforced locally, and requirements exceed the federal minimum in many communities. Consult your local floodplain administrator or building department for the rules that apply to your property. FludZone results are informational and are not a substitute for an official flood zone determination from a certified provider.