FONTENELLE - WY01389-3506
Dam Name: FONTENELLE
State: WY
Downstream Hazard Potential: H
Incident Type: Non-Failure
Incident Date: 09/04/1965
Incident Driver: Seepage/Internal Erosion
Incident Mechanism 1: Piping
Incident Mechanism 2
Incident Mechanism 3
Incident IDWY01389-3506
Incident DescriptionFontenelle Dam nearly failed on first filling in 1965. The embankment materials were placed directly over open joints in the right abutment. After a large spring runoff event, seepage from the reservoir worked its way through these joints and into the right abutment of the embankment dam. Massive sloughing occurred and within 12 hours 10,000 cubic yards of material were eroded away.
Named Hydrologic Event
EAP Enacted (Y/N) due to Incident
Fatalities (Number)
Number of People Evacuated
Number of Habitable Structures EvacuatedUnknown
Number of Habitable Structures Flooded0
Other Infrastructure ImpactsOther
Economic Damages (in $)
ResponseThe engineers opened the large outlet works full open lowering the reservoir 4 feet per day. This was the only thing that saved the dam from failing
Volume released at failure (ac-ft)
Additional Remarks or UpdatesFlooding downstream with outlet works at full capacity.
Owner TypeF
Dam TypeRE
Primary Purpose(s)FHRS
EAPY
Dam Height139 ft
Max Storage (ac-ft)405160.00
Surface Area (acres)8058.00
Year Completed1963
NID NumberWY01389
River NameGREEN RIVER
Latitude42.0286
Longitude-107.867
Year Modified
1989
Regulatory Agency(ies)SEO
Incident Time7:00 PM
Incident Duration12 Days
Incident Report ProducedYes
Information SourcesASDSO Decade Dam Series
