How much flood risk does Essex County actually carry?
Essex County lands at the 97.8th percentile of FEMA's National Risk Index for flooding, "Very High" territory — among the highest flood hazard in the country — with the hazard split between inland river flooding (about 2.7 times a year) and coastal storm surge (about 8.1 times a year). County-wide, not parcel-specific: FEMA's real flood-zone map is queried live, never shipped as a download.
Essex County's flood-insurance compliance gap
Homes with a federally backed mortgage inside Essex County's mapped high-risk flood zone (the Special Flood Hazard Area, or SFHA) are legally required to carry an NFIP flood policy. In practice, 58.1% of them do — 4,378 active policies against 7,538 structures FEMA counts in that zone, leaving a real compliance gap. Across all residential structures in Essex County, not just the ones FEMA mandates, 2.8% carry an NFIP policy — most flood damage nationally happens outside the mapped high-risk zone, so that broader number matters too.
How Essex County compares nationally
Essex County sits at rank 77 of 3144 counties on FEMA's flood hazard scale (1 is worst) and rank 79 of 3144 by population (1 is biggest). Essex County, Massachusetts is home to about 823,938 people across 492.514 square miles of land.
Checking a specific address in Essex County
Across all of Essex County's 196,259 residential structures, 5,537 carry an NFIP policy today — a county-wide count that still can't tell you one address's own mapped zone.
More on how this number was built
The methodology guide shows exactly which FEMA and Census tables feed Essex County's numbers. Because storm surge plays a real role here, the guide to coastal vs. inland flood hazard is worth reading alongside this page.