RIVER GAUGE · BIG SIOUX RIVER
Big Sioux River at Lake Poinsett Inlet/Outlet
Hamlin County, South Dakota
Water level1650.89 ft
Flow—
Last readingSep 16, 2026, 5:00 PM UTC (last recorded)
Action1651.5 ft
Minor flood1654 ft
Moderate flood1655 ft
Major flood1657 ft
The past week
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What floods at each level
- 1658 ft
The Highway 28 bridge on the north side of the lake is overtopped.
- 1657 ft
Highway 81 on the west side of Lake Poinsett begins to flood, as does Highway 28 on the north and east side of the lake, and the Highway 28 bridge at the inlet/outlet begins to flood.
- 1655 ft
Homes along the north side of the lake begin to flood, and water will begin overflowing 459th Avenue.
- 1654 ft
Boat docks and yards along the lake begin to flood.
- 1651.5 ft
Lake Poinsett is considered full
- 1650.5 ft
Lake outlet elevation
Highest crests on record
| Date | Level | Flow |
|---|---|---|
| Apr 4, 2011 | 1657.6 ft | — |
| Apr 21, 2019 | 1657 ft | — |
| Jul 16, 2010 | 1656.44 ft | — |
More on Big Sioux River
UpstreamBig Sioux River near Castlewood
DownstreamBig Sioux River near Estelline
Big Sioux River near Brandon
Big Sioux River near Bruce
Big Sioux River near Brookings
Big Sioux River near Estelline
Big Sioux River above Flandreau
Big Sioux River near Jefferson
Big Sioux River near Richland
Big Sioux River below Watertown
Big Sioux River above Canton
Big Sioux River near Castlewood
Get an alert when Big Sioux River rises
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