Ontonagon County, MI flood risk explained
Flood hazard in Ontonagon County sits at the 15th national percentile, among the lowest flood hazard in the country; split between inland river flooding (about once every 4 years) and coastal storm surge (about once every 90027827 years). County-wide, not parcel-specific: FEMA's real flood-zone map is queried live, never shipped as a download.
Mandatory flood insurance compliance in Ontonagon County
FEMA hasn't published a residential structure count for Ontonagon County's mapped flood zone, so a reliable mandatory-compliance percentage can't be computed here — see the data quality guide for why this gap exists for roughly a quarter of US counties. Looking beyond the mandated zone, 0.2% of all residential structures in Ontonagon County carry flood coverage voluntarily or otherwise — relevant because most NFIP claims nationally come from outside the mapped SFHA.
How Ontonagon County compares nationally
Among the 3144 US counties FEMA scores for flood hazard, Ontonagon County ranks 2703 — 1 being the highest hazard nationally — and 2746 by population among all 3144 counties covered here, where 1 is the largest. About 5,824 people live in Ontonagon County, Michigan, spread over 1,310.978 square miles.
What to do next if you own or are buying in Ontonagon County
12 of Ontonagon County's 5,118 residential structures carry flood coverage of some kind, per FEMA's latest count — useful context, not a substitute for checking one parcel.
Where Ontonagon County's figures come from
Every figure on this page traces to a named FEMA dataset, documented in the methodology guide. Ontonagon County's compliance figure is one of the ones affected by FEMA's incomplete denominator data — the data quality guide explains what that means and how many counties it touches.