FloodZoneMap.org

Home› Stories› South Dakota› Flood 2020

Flood — Hamlin, SD

Mar 9, 2020

Flood Cause
Heavy Rain / Snow Melt

Snowmelt water caused the Big Sioux River at Castlewood to go above and below flood stage several times in March from the 9th to the 22nd. The river went above the flood stage of 9 feet on March 9th rising to 10.5 feet on March 11th and then falling back below flood stage on March 16th. The Big Sioux river then went above and below flood stage a couple more times from March 20th to the 22nd.

Source: NOAA National Weather Service Storm Events Database (event 882829). Narrative written by NWS staff at the time of the event.

Flood Risk Context for Hamlin, SD

This event is one of many recorded floods in Hamlin County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.

View Hamlin County flood data →

More Flood Stories

Flood$202K damage

Hamlin, SD · Apr 1, 2019

The continuation of snowmelt from a much above normal snowfall winter combined with a historic heavy snow/blizzard in mid-April resulted in widespread flooding across central and northeast South Dakota.

Read the full account →
Flood$800K damage

Hamlin, SD · Apr 1, 2011

Snowmelt flooding in March continued across much of central and northeast South Dakota as the rest of the snowpack melted into early April. Many roads along with countless acres of crop and pastureland remained flooded.

Read the full account →
Flood$191K damage

Hamlin, SD · Apr 7, 2001

Heavy rain of 1 to 3 inches combined with snowmelt runoff brought flooding to parts of northeast South Dakota. Many roads across Clark, Grant, Hamlin, Deuel, and Roberts counties were flooded and damaged.

Read the full account →
Flood

Hamlin, SD · Jul 27, 2025

An afternoon thunderstorm developed near the town of Henry and very quickly spun up a violent tornado. This tornado would cause significant damage to a farmstead before dissipating.

Read the full account →