FEMA flood zones · Iowa

Lucas County, Iowa Flood Zone Map

5 flood insurance claims·$19,113 paid·6 federal flood & hurricane disasters

10% of Lucas County’s area is in FEMA’s high-risk flood zones, and another 1% in shaded X (mostly the 0.2% floodplain and areas behind levees).

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 Lucas County, Iowa. 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 Lucas County floods

Standard river flooding events dominate Lucas County, supported by 90 recorded flood events and 17 flash flood events over the last 30 years according to the NOAA Storm Events Database. Heavy rainfall repeatedly triggered river flooding across multiple basins, including the Chariton River basin, as documented during the October 2018 flood event. Persistent weather patterns, such as a stationary boundary combined with high precipitable water values, also produced severe rainfall and flooding in late May 2019.

National Flood Insurance Program records indicate flood claims have occurred in unshaded Zone X and areas with unknown zones. Specifically, Zone X_UNSHADED recorded 4 claims with an average payout of $4,660 and an average recorded water depth of 0 inches, while Zone UNKNOWN recorded 1 claim with an average payout of $473 and an average recorded water depth of 0 inches.

Homeowners, real estate agents, and journalists should pay the most attention to properties located near river basins and within unshaded Zone X or unknown zones where past claims have been filed.

Summary written from NOAA storm reports and NFIP claims for this county. Not a prediction.

Flood claims, year by year

The worst year was 1993, with 2 claims and $11,776 paid, the year of Severe Storms & Flooding.

1979: 1 claims1993: 2 claims2007: 2 claims198019902000

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

86 NOAA storm reports from Lucas County describe what happened, in the words of the forecasters who covered it. Read the Iowa flood stories →

Federal disasters

15 federal disaster declarations since 1973, 6 of them floods, coastal storms or hurricanes.

DisasterBegan
Severe Storms And FloodingMar 12, 2019
Severe Storms, Tornadoes, Straight-line Winds, And FloodingJun 20, 2015
Severe Storms, Straight-line Winds, And FloodingApr 17, 2013
Severe Storms, Flooding, And TornadoesJun 1, 2010
Severe Storms, Tornadoes, And FloodingMay 25, 2008
Severe Winter StormDec 10, 2007
Hurricane Katrina EvacuationAug 29, 2005
Severe Storms, Tornadoes, And FloodingMay 19, 2004

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

Recorded flood events

107 since 1996: 17 flash floods and 90 river or area floods.

EventDateDamage
Flash FloodJun 24, 2021—
FloodMay 28, 2019$80,000
FloodOct 9, 2018$50,000
FloodOct 9, 2018—
Flash FloodJul 19, 2016$20,000
FloodJun 25, 2015$100,000
FloodJun 25, 2015$75,000
Flash FloodAug 23, 2014$25,000

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

From the storm reports

Flash Flood · Jun 24, 2021. Deep Gulf moisture fed into the state with the LLJ pushing a warm front north into southern Iowa through the late evening. Storms motion was generally parallel to the boundary, resulting in training of storms across southern Iowa and heavy rain. Many locations in southern Iowa received 3 to 6 inches of rain in a few hours with one location reporting over 7 inches of rain.

Flood · May 28, 2019. The hits just kept on rolling, with yet another pair of rounds of strong to severe storms, heavy rainfall, and flooding. Through much of the end of May, the synoptic setup across the region remained relatively unchanged, including this event. Upper level flow continued to be out of the SW, precipitable water values remained in excess of 1.5 inches, and a relatively stationary boundary remained over the area. In ad…

Flood · Oct 9, 2018. Heavy rain continued into mid October with many rivers going into flood again across much of the forecast area. Flooding was observed in the Des Moines, Iowa, Cedar, Chariton, Thompson and Raccoon River basins.

Flood · Oct 9, 2018. Tornadoes made an October appearance along with other strong storms and heavy rainfall as a number of conditions came together. A frontal boundary stalled out across Iowa, situated from southwest to northeast, roughly cutting the state in half. Dew points were on the high side given the time of the year, in the upper 60s to low 70s, yielding low lifted condensation levels. In addition, low level turning resulted i…

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 Lucas County

If a building in Lucas 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.