New Flood Map: Ann Arbor Gives Final OK

At its March 5, 2012 meeting, the Ann Arbor city council gave final approval to an ordinance change that will adopt a new Flood Insurance Rate Map (FIRM) for the city.

By way of background on those maps, the National Flood Insurance Program (NFIP) makes flood insurance available for properties in participating communities – Ann Arbor is a participant. If a building has a federally-backed mortgage and it’s located within the “1% annual change floodplain” (previously called the “100-year floodplain) then flood insurance is required.

Ann Arbor’s most recent FIRM dates from Jan. 2, 1992. In 2004, the Federal Emergency Management Agency (FEMA) began a map revision process for Washtenaw County. Various drains in the city were re-analyzed, using updated data, and on July 27, 2007, FEMA issued preliminary maps. After required public review, appeal and revisions, on Oct. 3, 2011, FEMA issued a letter with a final determination, indicating that the new maps would become effective on April 3, 2012. [.pdf of Oct. 3, 2011 letter] [.pdf of Dec. 20, 2011 reminder letter]

Compared to the previous 1992 maps, 321 parcels are no longer analyzed as lying within a floodplain. However, 116 parcels that were previously not analyzed as in a floodplain are now in a floodplain, according to the new maps. Building-wise, 452 structures are no longer analyzed as lying within a floodplain, while 88 buildings are now in a floodplain, according to the new maps. [See also Chronicle coverage: "Column: Digital Information Flood."]

This brief was filed from the city council’s chambers on the second floor of city hall, located at 301 E. Huron. A more detailed report will follow: [link]