Permitting in the Flood Hazard District
Flood Hazard Review is one of many compliance reviews that may be required to receive a building permit.
Please note that the Coastal Flood Resilience Overlay District (CFROD) is a SEPARATE zoning district under the purview of the Planning Department.
For more general information on floodplain management in Massachusetts, visit the State Flood Hazard Management Program website.
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Still have questions? Contact:
Inspectional Services
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1010 Massachusetts Avenue
5th FloorBoston, MA 02118
The Basics
Boston Zoning Article 25 establishes the Flood Hazard plan review for construction projects in the Flood Hazard District. The District’s geographic area is defined by the Federal Emergency Management Agency’s (FEMA’s) Special Flood Hazard Area. Flood Hazard plan review is required for long-form permits, similar to other reviews completed at Counter 2. The Flood District regulations (A.K.A. flood code or flood standards) meet FEMA’s minimum requirements for development that is “reasonably safe from flooding”. Enforcing these requirements is necessary for Boston to remain in the National Flood Insurance Program(NFIP).
The flood code is complex, but we are here to help. Below you will find essential information for two types of projects: New buildings and alterations to existing ones. If you still have questions, please email ISDFlood@Boston.gov and we will assist you as soon as possible.
Project Types
Project TypesThe key flood regulation for existing buildings in the Flood Hazard District is the Substantial Improvement / Substantial Damage rule. That is, if the cost of improvements or the cost to repair damage exceeds 50 percent of the market value of the building, it must be brought up to the current flood standards.
The Substantial Improvement / Substantial Damage (SI/SD) rule is critically important in Boston, as many of our buildings were constructed before modern flood science and building codes. SI/SD makes older, flood-prone areas of the City safer over time.
If your project is SI/SD, you will need to meet the same flood standards as a new building; refer to the next section. For additions to existing buildings (I.e., an extension or increase in floor area or height) refer to this quick guide.
ISD will conduct inspections during the life of your construction project. Reports from those inspections are required to close out the permit and issue a Certificate of Occupancy or Use. In the Flood District, this includes a requirement to document flood code compliance:
- Proponents must provide ISD with a complete and correct as-built flood certificate for any new building or substantial improvement in the Flood District. Current, standard FEMA templates must be used when available. The specific certificate that is required depends on the project and will be explicitly written on the permit by ISD. Certificates may be sent to ISDFlood@Boston.gov.
- Elevation Certificates are the most common flood certificates. These are completed by a licensed surveyor and include photographs of the finished construction to demonstrate that the building was constructed / elevated according to the approved plans and in compliance with the flood code. Elevation Certificates are required for all residential structures. Dry Floodproofing Certificates are used for non-residential structures that are dry floodproof. Other documentation requirements will be coordinated on a case-by-case basis.
The current Elevation Certificate and Dry Floodproofing Certificate templates may be downloaded from FEMA’s website. A marked-up Elevation Certificate with helpful notes is available here (for reference only).
Tip: Providing a preliminary Elevation Certificate with your project application can help expedite the review and save you time later.
This section is most relevant to licensed professionals such as architects, engineers, contractors, construction supervisors, and surveyors.
New buildings and substantial improvements / repairs in the Flood Hazard District must be designed and constructed to meet the current flood standards. Most of these standards are found in the American Society of Civil Engineers Standard 24 (ASCE24), Flood Resistant Design and Construction. A non-exhaustive list of key requirements is provided below, as well as links to other helpful resources.
- The primary purpose of the flood code is to protect public health, safety, and welfare by regulating what is constructed below the Design Flood Elevation (DFE) at a particular site. The DFE is determined by adding freeboard to the Base Flood Elevation (BFE) found on FEMA flood maps. Refer to Section 1612.4 of the Massachusetts Building Code for freeboard requirements.
- Residential buildings in the Flood District may not have basements with floors that are below grade on all sides. Also, any enclosure that is below the DFE (crawlspace, garage, etc.) must be “wet floodproof”. This often involves installation of flood vents that allow water in / out, thus reducing hydrostatic, hydrodynamic, and buoyant forces that could compromise the building’s structural integrity in the event of a flood.
- Non-residential buildings may be “dry floodproof” to the DFE, provided there is adequate egress above. Any active floodproofing measures (e.g., a deployable flood barrier) must have an emergency response plan detailing how they are deployed and by whom.
For permit applications in the Flood District, please include:
- A clearly defined datum on the building plans. The North American Vertical Datum of 1988 is the standard used for FEMA BFE’s; however, Boston City Base is also acceptable.
- Detailed plans, including elevations, for all utilities on floors below the DFE. Primary utility components should be elevated in wet floodproof designs.
- An Initial Construction Control Document signed and stamped by a registered design professional, with “Flood” written next to Other in the selection space. Additional guidance documents:
- NFIP Technical Bulletins
- FEMA Publication 348 Protecting Building Utility Systems from Flood Damage
- FEMA Publication 2037 Flood Mitigation Measures for Multi-Family Buildings
- FEMA Publication 758 Substantial Improvement / Substantial Damage Desk Reference
After a Permit is Issued
ISD will conduct inspections during the life of your construction project. Reports from those inspections are required to close out the permit and issue a Certificate of Occupancy or Use. In the Flood District, this includes a requirement to document flood code compliance:
- Proponents must provide ISD with a complete and correct as-built flood certificate for any new building or substantial improvement in the Flood District. Current, standard FEMA templates must be used when available. The specific certificate that is required depends on the project and will be explicitly written on the permit by ISD. Certificates may be sent to ISDFlood@Boston.gov.
Elevation Certificates are the most common flood certificates. These are completed by a licensed surveyor and include photographs of the finished construction to demonstrate that the building was constructed / elevated according to the approved plans and in compliance with the flood code. Elevation Certificates are required for all residential structures. Dry Floodproofing Certificates are used for non-residential structures that are dry floodproof. Other documentation requirements will be coordinated on a case-by-case basis.
The current Elevation Certificate and Dry Floodproofing Certificate templates may be downloaded from FEMA’s website. A marked-up Elevation Certificate with helpful notes is available here (for reference only).
Tip: Providing a preliminary Elevation Certificate with your project application can help expedite the review and save you time later.
-
Still have questions? Contact:
Inspectional Services
-
1010 Massachusetts Avenue
5th FloorBoston, MA 02118
