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City of Boston appeals preliminary FEMA flood maps

August 27, 2014

Mayor's Office

Published by:

Mayor's Office

The City of Boston yesterday filed an appeal with the Department of Homeland Security’s Federal Emergency Management Agency (FEMA) of the 2013 Preliminary Flood Insurance Rate Maps (FIRMs) for Boston. This appeal comes after a study, completed by an independent consultant hired by the City, indicated inconsistencies and potential errors in the mapping and flood study approach used by FEMA. The City’s technical and scientific appeal will request that FEMA publish new Preliminary FIRMs based on the study’s findings, and hold a new 90-day appeal and public comment period.

“These maps have significant implications for Bostonians,” said Mayor Martin J. Walsh. “We are doing our due diligence to make sure they are established with the best available data and appropriate modeling methodology.”

FEMA released Suffolk County’s new maps on November 15, 2013, for public review. The new maps added 1,585 acres of land to the 100-year floodplain, which includes 13,709 housing units and 4,202 businesses. All properties with federally-backed mortgages or loans in the 100-year floodplain are required to carry flood insurance and comply with flood protection standards in local zoning and state building codes.

“The City is ensuring that the new FEMA maps best reflect the current flood risk of Boston,” said Brian Swett, Chief of Environment, Energy and Open Space. “However, these maps do not address the future impacts of climate change and sea level rise. We know that coastal flooding will get worse in the decades to come, and the City has a number of initiatives underway to better prepare for this challenge.”

Because of the significant impacts of these maps, the City of Boston hired Woods Hole Group (WHG) through a competitive bid process to evaluate FEMA's flood mapping methodology, data sources and modeling. WHG’s final report found inconsistencies in FEMA’s mapping and flood study approach, resulting in approximately 507 acres of land that should be removed from the 100-year floodplain, as well as 33 acres that should be included. These findings serve as the grounds for a technical appeal with FEMA. In addition, WHG is currently conducting more detailed and accurate hydrodynamic flood modeling of Boston Harbor, which will be completed and submitted as supplemental information as a basis for a scientific appeal.

After the appeal period closes, FEMA will respond to all comments and appeals.

FEMA has been updating FIRMs to more accurately delineate the areas subject to coastal flood hazards, known as the 100-year floodplain. Suffolk County’s maps were the last to be released in Massachusetts last November. The official Comment and Appeal Period began on May 29, 2014 and ended on August 27, 2014 and the City ensured that the public was informed of the appeal period via the hand-distribution of flyers to affected neighborhoods, as well as an email to relevant business umbrella groups such as A Better City, Greater Boston Real Estate Board, NAIOP and The Boston Harbor Association. The City solicited comments and appeals from the community to be submitted with its appeal. One comment was submitted. 
Supplemental Document: Mayor Walsh's appeal letter to FEMA