Quincy presentation: new FEMA maps remove hundreds from floodplain; council moves floodplain-overlay amendment to ordinance committee

Joseph Daniel Shea, a principal with Granite City Partners, told the Quincy City Council Monday that new preliminary FEMA flood maps — if adopted by this body — will take effect on July 8, 2025, and will remove about 300 properties from the federally designated floodplain.

The update matters because floodplain designation can trigger mortgage‑holder requirements for flood insurance and because city engineering work included in the new modeling — notably the Deep Rock Tunnel and the Quincy Center Street flood relief system — reduced the area FEMA now marks as at risk, Shea and city staff said.

Why it matters: the maps directly affect whether homeowners with mortgages are required to maintain federal flood insurance and how much those policies cost. Quincy officials said the city’s longstanding flood‑mitigation investments and a proactive mapping effort have already reduced insurance costs for ratepayers and that the updated maps preserve prior map corrections.

Shea and Al Grazioso, commissioner of the Department of Public Works, told the council the National Flood Insurance Program (NFIP) map methodology changed in 2014, which initially expanded the mapped floodplain for Quincy; the city then pursued repeated amendments and reached a corrected map in 2017. The consultants said the 2025 preliminary maps reflect engineering work the city performed since then and show “no backsliding” on prior corrections.

City staff and the…