Flood — Codington, South Dakota

2025-08-22 to 2025-08-23 · near Appleby, Codington, South Dakota

Event narrative

The Big Sioux River below Watertown river gauge would exceed flood stage starting in the morning of August 22nd, peaking at 11.68 or 0.68 feet above flood stage. The river crested in the evening and was back below flood stage by the late morning of August 23rd.

Wider weather episode

Storms moved over portions of northeast South Dakota that had really no extra room for moisture from the preceding months of nearly constant rainfall. Thus, this moisture went straight into the Big Sioux and tributaries from the Watertown area down south to Castlewood. The COOP observer in Rauville would record 1.51 inches of rainfall pushing their monthly total up to 5.73 and a 3 month total of 23.32. The Watertown COOP would likewise come up with 1.86 inches, putting the monthly total at 5.85 and 20.1 for the preceding 3 months. Even Castlewood, while only topping out at 0.31 inches, would see their monthly total top out at 4.99 inches with a 3 month total of 22 inches.

View location on OpenStreetMap → (44.8700, -97.0300)

Source: NOAA Storm Events Database, event_id 1291981. Narrative written by the NWS forecast office that issued the report.