ALVIN - SD00029-3414
Dam Name: ALVIN
State: SD
Downstream Hazard Potential: L
Incident Type: Non-Failure
Incident Date: 01/01/2019
Incident Driver: Hydrologic/Flooding
Incident Mechanism 1: Spillway Chute Failure
Incident Mechanism 2Slope Stability
Incident Mechanism 3
Incident IDSD00029-3414
Incident DescriptionMultiple high flow events in 2019 damaged primary spillway with portion of spillway wall collapsing and caused embankment sloughing adjacent to primary spillway and stilling basin.
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 did some stabilization work on sloughing and hired an engineering consultant to do additional analysis
Volume released at failure (ac-ft)
Additional Remarks or UpdatesCounty road downstream of dam was closed for several days in May 2019. Downstream highway culverts have limited capacity so during high flow event water backs up in the stilling basin, primary spillway, and against embankment area adjacent to primary spillway and stilling basin.
Owner TypeS
Dam TypeRE
Primary Purpose(s)CR
EAPNR
Dam Height36 ft
Max Storage (ac-ft)2150.00
Surface Area (acres)46.00
Year Completed1954
NID NumberSD00029
River NameNINE MILE CREEK
Latitude43.44
Longitude-96.6083
Year Modified
1994
Regulatory Agency(ies)DENR
Incident Time
Incident Duration
Incident Report Produced
Information SourcesSD Dam Safety
