Floodplain Mapping

As part of the National Flood Insurance Program (NFIP), the federal government provides Flood Insurance Rate Maps (FIRM) to municipalities that agree to regulate development in high risk flood areas. The maps identify flood prone areas that form the basis for the federally backed flood insurance rates.

A FIRM is an official map on which FEMA has delineated both the special flood hazard areas (SFHA) and the lower risk premium zones applicable to the community. SFHAs depict areas subject to the 1% annual chance flood (or base flood). The A and V zones are designated as SFHAs on the maps. Lower risk areas, 0.2% annual chance flood, are displayed to demonstrate extent of potential flooding.

The FEMA Map Service Center (MSC) serves as the official public source for flood hazard information produced in support of the NFIP. To support user accessibility, FEMA has developed a tutorial on how to locate a FIRM and create a smaller map printout (FIRMette) through the MSC website.

Flood Insurance Rate Maps

FIRMs are typically used to determine:

  • If a structure is in a floodplain
  • The flood insurance zone that applies to the structure
  • The approximate base flood elevation for the site

Flood Zone Descriptions

Zone

Risk Type

Description

X (Unshaded)

Low to Moderate

 Area of minimal flood hazard.

X (Shaded)

Low to Moderate

 Areas subject to inundation by the 0.2% annual-chance flood event.

A

High

 Areas subject to inundation by the 1% annual-chance flood event generally determined using approximate methodologies.

AE

High

 Areas subject to inundation by the 1% annual-chance flood event determined by detailed methods.

AH

High

 Areas subject to inundation by the 1% annual-chance shallow flooding (usually areas of ponding) where average depths are between 1-3 ft.

AO

High

 Areas subject to inundation by the 1% annual-chance shallow flooding (usually sheet flow) where average depths are between 1-3 ft.

VE

High - Coastal

 Coastal areas subject to inundation by the 1% annual-chance flood event with additional hazards due to storm-induced velocity wave action.

Rhode Island Floodplain Mapping Tool

The Rhode Island Floodplain Mapping Tool is an online mapping resource. The Tool provides users with flood risk information relative to residences, businesses, or other structures statewide.

While the tool is not intended for legal, engineering, or surveying purposes, it does provide users with an approximate flood zone determination relative to the flood hazard areas delineated on FEMA’s FIRMs. Multiple links are embedded in the program to guide users towards relevant information pertaining to the National Flood Insurance Program.

 

Click here to access the Rhode Island Floodplain Mapping Tool*

Letter of Map Change

A Letter of Map Change (LOMC) reflects an official amendment or revision of the FIRM. If the LOMC request is granted, property owners may be eligible for lower flood insurance premiums or the option to not purchase flood insurance. Professional Land Surveyors may complete this form and submit to FEMA for consideration either electronically or hard copy.

The Rhode Island Department of Business Regulations maintains a list of licensed design professionals capable of completing a FEMA Elevation Certificate.

Additional Resources