Grand River (SD) near Thunder Hawk, SD
River level and flood forecast · Corson County
Normal5.2 ftas of Mon 2 PM
Flow: 38 cubic feet per second (USGS).
The last 7 days and the forecast
NWS forecast issued Sun, Dec 31, 5 PM. Forecasts change as rain falls and as upstream water arrives.
Highest crests on record
- 10.76 ft — August 17, 2025
- 8.6 ft — April 11, 2023
Recent crests: 10.76 ft (August 17, 2025) · 8.6 ft (April 11, 2023)
Up and down the river, and nearby
Not an official source. River levels, forecasts, flood stages and impacts are from the National Weather Service (GTHS2); flow from the U.S. Geological Survey. Readings are provisional. In a flood, follow your local officials and the NWS at weather.gov.