EAST VERMILLION - SD00031-3411
Dam Name: EAST VERMILLION
State: SD
Downstream Hazard Potential: L
Incident Type: Non-Failure
Incident Date: 09/11/2019
Incident Driver: Hydrologic/Flooding
Incident Mechanism 1: Spillway Erosion/Head Cutting
Incident Mechanism 2
Incident Mechanism 3
Incident IDSD00031-3411
Incident DescriptionEarthcut secondary spillway experienced significant heading cutting when it operated during as a result of runoff from heavy rainfalls on Sept. 11-12, 2019.
Named Hydrologic Event
EAP Enacted (Y/N) due to IncidentNo
Fatalities (Number)0
Number of People Evacuatedunknown
Number of Habitable Structures Evacuatedunknown
Number of Habitable Structures Floodedunknown
Other Infrastructure ImpactsRoads
Economic Damages (in $)
ResponseOwner increased monitoring of the dam and secondary spillway until water levels dropped. East campground and boat ramp was temporarily closed and assistance was provided to get groceries to any stranded campers.
Volume released at failure (ac-ft)
Additional Remarks or UpdatesDownstream road was washed out. Access road to east campground and boat ramp access the secondary spillway was washed out. Several campers were stranded in the east campground until the access road was repair. Secondary spillway damage was repaired Winter 2019.
Owner TypeS
Dam TypeRE
Primary Purpose(s)CR
EAPNR
Dam Height41 ft
Max Storage (ac-ft)17400.00
Surface Area (acres)294.00
Year Completed1958
NID NumberSD00031
River NameE FORK VERMILLION RIVER
Latitude43.59
Longitude-97.1717
Year Modified
1994
Regulatory Agency(ies)DENR
Incident Time
Incident Duration
Incident Report Produced
Information SourcesSD Dam Safety
