FEMA flood zones · Michigan

Mason County, Michigan Flood Zone Map

13 flood insurance claims·$237,710 paid·2 federal flood & hurricane disasters

3% of Mason County’s area is in FEMA’s high-risk flood zones.

Share of the whole county outline, rivers and lakes included; parts FEMA hasn’t mapped count as zero.

Coastal high risk (V, VE)FloodwayHigh risk (A, AE)Moderate (X, 500-year)Minimal (X)Undetermined (D)

Shaded areas are FEMA’s mapped flood hazard zones in and around Mason County, Michigan. Zoomed out they are simplified; at street level the map switches to FEMA’s exact layer. Tap anywhere to check that spot, or search an address above.

How deep the water got

outlet80″ door12″24″36″48″60″72″84″

In flood insurance claims here that reported a flood depth, the average was 13 inches.

Drawn to scale against an 80-inch door. Even a few inches soaks flooring, the bottom of the drywall and anything plugged in near the floor.

Average of the depths reported on claims (zero and implausible values left out); FEMA’s record doesn’t say exactly where each depth was measured. Source: OpenFEMA NFIP claims.

Flood claims, year by year

The worst year was 1986, with 4 claims and $20,878 paid, the year of Severe Storms & Flooding.

1986: 4 claims1990: 1 claims2007: 1 claims2008: 1 claims2018: 2 claims2019: 2 claims2020: 1 claims2023: 1 claims19801990200020102020

Bar height is scaled by square root so ordinary years stay visible next to the worst one. NFIP claims by year of loss. Source: OpenFEMA.

In their words

10 NOAA storm reports from Mason County describe what happened, in the words of the forecasters who covered it. Read the Michigan flood stories →

Federal disasters

9 federal disaster declarations since 1977, 2 of them floods, coastal storms or hurricanes.

DisasterBegan
Severe Storms, Tornadoes, And FloodingJun 6, 2008
Hurricane Katrina EvacuationAug 29, 2005
Severe StormsMay 29, 1998
Severe Storms & FloodingSep 10, 1986
Severe Storms And FloodingSep 5, 1985
Blizzards & SnowstormsJan 27, 1978
DroughtMar 2, 1977

Weather and water disasters only; most recent first. Source: OpenFEMA Disaster Declarations.

Recorded flood events

14 since 1996: 9 flash floods and 5 river or area floods.

EventDateDamage
FloodJul 20, 2019$500,000
FloodApr 17, 2013$3.0M
Flash FloodMay 3, 2012$75,000
Flash FloodJun 13, 2008$3.0M
FloodMay 23, 2004$1.0M
FloodJun 9, 2004$20,000
Flash FloodMay 16, 2001$25,000
Flash FloodMay 16, 2001$50,000

— = no damage estimate in the record. Source: NOAA Storm Events Database.

From the storm reports

Flood · Jul 20, 2019. A round of severe storms resulted in numerous reports of downed trees and power lines. Peak wind gusts were estimated at up to around 70 to 80 mph. In addition 6 to 10 inches of rain fell across much of Mason and Lake counties. There were several road washouts, a few culvert failures, and a couple of bridge washouts. At least 48 homes were damaged by water in Lake county.

Flood · Apr 17, 2013. Record flooding occurred during the month of April and record crests occurred on the lower portions of the Grand River at Ionia, Lowell, Ada, Comstock Park, and Grand Rapids, Michigan. Due to the severity of the flooding, Michigan���s Governor Rick Snyder declared a state of disaster for 19 counties and two cities. ||The two cities declared in the disaster were Grand Rapids and Ionia. The counties included…

Flash Flood · May 3, 2012. An upper low moving over a warm front that stretched across northern Lower Michigan set the stage for heavy rainfall on May 3rd. Training thunderstorms (storms that move over the same location) produced 5 to 7 inches of rainfall across portions of Mason and Lake counties. The heavy rainfall resulted in roads that were either flooded or washed out. As the day progressed, strong to severe storms developed in the wa…

Flash Flood · Jun 13, 2008. A round of strong to severe thunderstorms accompanied by very heavy rainfall resulted in significant flash flooding across Mason and Lake counties.

National Weather Service narratives, lightly trimmed. Source: NOAA Storm Events Database.

The zones you’ll see on the map

Every colour on the map above is a place on this drawing: where the ground sits relative to the flood FEMA plans for.

Cross-section of a river floodplainDiagram: a river valley. The floodway is the channel and the land beside it; the 1%-annual-chance flood surface (the base flood elevation) covers the valley floor as zone A or AE; a narrow band higher up is shaded X, the 0.2% floodplain; higher ground is X.0.2% CHANCE A YEAR (500-YEAR)BASE FLOOD ELEVATION · 1% A YEARXAEFloodwayAEX
  1. A / AE Inside the 1%-a-year floodplain: about a 26% chance of flooding over a 30-year mortgage. AE has a mapped base flood elevation; plain A does not.
  2. Floodway The channel and the land beside it that has to be kept clear enough to carry the flood. Building here is tightly limited.
  3. X shaded The 0.2% (500-year) floodplain, plus some levee-protected and very shallow flood areas.
  4. X Outside both lines. No federal requirement to insure, which is not the same as no risk.

Every flood zone code explained →

Flood insurance in Mason County

If a building in Mason County is in a high-risk zone (A or V) and its mortgage comes from a federally regulated or insured lender, or is federally backed, flood insurance is required.

Outside those zones it is optional, and often worth having: from 2014 to 2024 nearly one-third of NFIP claims came from outside the high-risk Special Flood Hazard Area. Since Risk Rating 2.0, NFIP premiums are set for each building, so the only reliable price is a quote: FloodSmart.gov or a local agent.