FEMA flood zones · South Dakota

Todd County, South Dakota Flood Zone Map

4 flood insurance claims·$1,937 paid·5 federal flood & hurricane disasters

FEMA’s digital flood map shows no high- or moderate-risk zones in Todd County. That can mean the area was never studied in detail or has no digital map, not that it can’t flood; the county floodplain administrator can say which.

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 Todd County, South Dakota. 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 Todd County floods

Flash flooding from summer thunderstorms dominates the flood profile of Todd County, supported by 10 flash flood events and 6 general flood events recorded over the last 30 years. Heavy rainfall, monsoonal moisture, and training storms frequently drive these occurrences. For instance, on August 5, 2022, training thunderstorms dropped three to four inches of rain, washing gravel off rural roads and causing the Little White River to rise several feet in an hour. Additionally, prolonged precipitation and snowmelt can trigger broader flooding, as occurred with a powerful storm system on May 22, 2019, and from ice jams on March 22 and 23, 2019.

National Flood Insurance Program records show four claims in Zone A, with an average payout of $969 and an average recorded water depth of 0 inches. Property owners located near creeks, rivers, low-lying areas, and rural roads, as well as those situated in Zone A, should pay the closest attention to flood risks in the county.

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

Flood claims, year by year

The worst year was 1997, with 2 claims and $1,362 paid, the year of Severe Winter Storms and Blizzard Conditions and Severe Flooding, Sever Winter Storms,heavy Rains High Winds.

1997: 2 claims2016: 1 claims2019: 1 claims1980199020002010

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

3 NOAA storm reports from Todd County describe what happened, in the words of the forecasters who covered it. Read the South Dakota flood stories →

Federal disasters

13 federal disaster declarations since 1976, 5 of them floods, coastal storms or hurricanes.

DisasterBegan
Severe Winter Storms And SnowstormDec 12, 2022
Severe Storms And FloodingMay 21, 2019
Severe Winter Storm, Snowstorm, And FloodingMar 13, 2019
Severe Winter Storm And SnowstormDec 23, 2009
Severe Winter Storm And Record And Near Record SnowNov 5, 2008
Hurricane Katrina EvacuationSep 6, 2005
Severe Storms And FloodingMay 28, 2004
Severe Winter Storms, Flooding, And Ice JamsMar 1, 2001

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

Recorded flood events

16 since 1996: 10 flash floods and 6 river or area floods.

EventDateDamage
Flash FloodAug 5, 2022—
FloodMar 23, 2019$250,000
FloodMay 22, 2019$100,000
FloodMar 22, 2019$250,000
Flash FloodJul 26, 2016—
Flash FloodJul 30, 2013$60,000
Flash FloodJul 22, 2011—
Flash FloodJun 16, 2011$10,000

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

From the storm reports

Flash Flood · Aug 5, 2022. A line of strong to severe thunderstorms produced gusty winds across portions of Todd County. Monsoonal moisture, combined with training storms, resulted in flash flooding across southern Mellette and northern Todd Counties. Rainfall amounts of three to four inches were reported. Flash flooding quickly occurred as water ponded in fields. Heavy rain washed gravel off rural roads. The Little White River around the c…

Flood · Mar 23, 2019. Runoff from snowmelt and ice jams caused flooding along many creeks and rivers across south central South Dakota.

Flood · May 22, 2019. A powerful storm system slowly moved from the Four Corners region northeastward through the Plains, leading to a prolonged period of precipitation across western South Dakota May 20-22. This three day period was among the coldest, wettest, and snowiest on record for late May, with several temperature and precipitation records set. Runoff from the rain and melting snow led to flooding of creeks, rivers, low-lying a…

Flood · Mar 22, 2019. Runoff from snowmelt and ice jams caused flooding along many creeks and rivers across south central South Dakota.

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 Todd County

If a building in Todd 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.