Climate Resilient Land Use: Floodplain Overlay Districts

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Climate Resilient Land Use: Floodplain Overlay Districts

Floodplain Overlay Districts

All communities that participate in the National Flood Insurance Program (NFIP) are required to enforce minimum NFIP regulations through the adoption of a Floodplain Overlay District. The Floodplain Overlay District must encompass the FEMA Special Flood Hazard Area (SFHA), also known as the 1% chance or the 100-year flood zone. The Massachusetts Flood Hazard Management Program has developed a model Floodplain Bylaw/Ordinance that identifies required and recommended language. The model includes minimum state requirements (building code, wetlands and others) that apply in the SFHA.

Limitations and restrictions associated with FEMA flood maps and the state building code can make it difficult to craft regulations that will reduce flooding and flood damage. Despite the challenges, many communities have gone beyond minimum federal and state requirements to reduce their vulnerability to flooding. Strategies include expanding overlay districts beyond the SFHA, prohibiting construction in the SFHA, requiring special permits for construction, protecting flood storage, and more. As seas rise and precipitation increases, these are important tools for protecting communities and overcoming the current limitations in FEMA flood maps and building code regulations.

This page provides short summaries of key features of regulations based on desktop review. Links to the regulations are provided below. Conduct careful review when considering adopting new language. The resources included do not constitute legal advice. Municipalities should consult legal counsel when adopting new bylaws, ordinances, and policies.

Did we miss something? Do you have regulations or policies that should be added to this website? Do you need assistance? For additions, corrections, or questions please contact Senior Environmental Planner Anne Herbst at aherbst@mapc.org.

Strategies to Strengthen Floodplain Overlay District Requirements

Establish a Strong Purpose for Your Bylaw/Ordinance

Floodplain Overlay Bylaws include an initial “Purpose” section. A broad and inclusive description of the purposes for your Bylaw/Ordinance can provide support for enacting higher standards and help defend implementation in the event of legal appeals.

The Millis Special Flood Hazard District's purpose section is an example of comprehensive language: (Millis, Section 11 Special Flood Hazard District)

“The purpose of this district is to promote the public health, safety and general welfare, and to minimize public and private losses due to flood conditions in specific areas by provisions designed:

      1. To protect human life and health;
      2. To minimize expenditure of public money for costly flood control projects;
      3. To minimize the need for rescue and relief efforts associated with flooding and generally undertaken at the expense of the general public;
      4. To minimize prolonged business interruptions;
      5. To minimize damage to public facilities and utilities such as water and gas mains, electric, telephone and sewer lines, streets and bridges located in areas of special flood hazard;
      6. To help maintain a stable tax base by providing for the second use and development of areas of special flood hazard so as to minimize future flood blight areas;
      7. To insure that potential buyers are notified that property is in an area of special flood hazard; and
      8. To ensure that those who occupy the areas of special flood hazard assume responsibility for their actions;
      9. To promote the preservation of the natural flood control characteristics and the water storage capacity of the areas of special flood hazard.
      10. To promote the safety and purity of water;
      11. To promote the control and containment of sewage.”

Oak Bluffs includes consideration of sea level rise in their purpose: (Oak Bluffs, Section 8.1 Floodplain Overlay District)

“Limit development in areas subject to flooding, particularly high hazard V zones and AO zones in order to minimize potential loss of life, destruction of property, and environmental damage inevitably resulting from storms, flooding, erosion and relative sea level rise.”

Restrict Development
Incorporate Sea Level Rise
Expand the Floodplain District
Require Special Permits
Limit Expansion of Existing Structures
Protect Flood Storage Volume
Require Vehicular and Pedestrian Access
Lot Area