a history of dam failures - engineering | siu

A History of Dam Failures

Bruce A. DeVantier

Department of Civil & Environmental EngineeringSouthern Illinois University Carbondale

Presentation to Egyptian Chapter ISPEApril 24, 2017

Recent Focus

• Oroville Dam 3/17LA Times photo

• Spillway begin to break apart at 55,000 cfsDesign capacity was 300,000

• Nearly 200,000 evacuated – no direct deaths• Main design flaw was too thin concrete spillway

floor – also too little anchoring• Emergency spillway was ineffective with erosion

soon after its implementation – maintenance schedules slipped with many low flow years

US Agencies Concerned with Dam Safety

• FEMA and various state emergency management organizations

• US Army Corps of Engineersincludes dams and levees

• Association of Dam Safety Officials

• ASCE – March 2013 Infrastructure Report Card Nation’s dams given overall D grade with no state receiving A or F grade

Johnstown Flood 1889

• Over 2,000 deaths in western Pennsylvania• South Fork Hunting and Fishing Club

reclaimed an abandoned earthen dam impoundment for members – including magnates Carnagie, Frick and Mellon

• After continued heavy rains, the dam failed on the morning of May 31 (now National Dam Safety Awareness Day)

• Only effective outlet (emergency spillway) had been screened to hold in fish

• Dam failed catastrophically

Saint Francis 1928

St. Francis Dam was built in San

Francisquito Canyon about 7

miles upstream of its mouth

between 1924-26 by the City of Los Angeles Bureau of Waterworks and Supply• Official death toll: 432 people• Dam unknowingly built on landslides due to

fault line near dam is primary cause• Only operated two years

Vajont Italy 1963

•

• Landslide into impoundment caused giant wave of water without dam failure

• 1917 deaths• Actually considered as a manmade mega-

tsunami

Teton Dam 1976

•

Leaks of earthen Bureau of Reclamation Damcaused catastrophic failure

• 14 killed, more than 200 families homeless• Seepage through dam well below water

level eventually lead to whirlpool which

swallowed 2 of 4 bulldozers filling it

Teton Dam continued

•

• Water pore pressure during seepage can lead to actual separation of grains and actually lead to fluidization

Lawn Lake (near Estes Park) 1982

• Built in 1903 as a 3xexpansion of natural lake

• Lax inspection (remote)• Piping leaks lead to

erosion and eventual earthen dam failure

• 3 people killed• $30 million un-

compensated loss

Lawn Lake Photo

Hurricane Katrina levee failures 2005

• Six major levee breaks – numerous smaller• Storm surge overtopping weakened levees

More Katrina breaks

• Quality of levee materials & placement cited as deficient • Over 100,000 homes flood, no direct death estimates

Ka Loko Dam Failure, Kauai 2006

• Reservoir created by earthen dam on north side of island 1890

• Complicated ownership• Irrigation ditch responsibility

disconnected from reservoir

• Primary causes were filling of spillway by new owner and lack of maintenance of reservoir and irrication ditch

Kaloko Dam Failure Results

• 7 people killed including pregnant woman• Uneven dam crest also a contributing factor

The Great Flood (Younger Dryas Impact Hypothesis J. Geology, 2014)

• At greatest glacial extent (12,000 – 14,000 years ago) there was a mass extinction by geological records

• Hypothesis is that large objects in a comet tail struck earth with great energy to create mass flooding

The Great Flood (Younger Dryas Impact Hypothesis)

• Many cultures in the proposed impact field have flood stories

• Anthropological digs show evidence ofhuman survivor centers of knowledge

• A return of comet remnants several thousand years later also hypothosized

Northwest US Geologic Evidence

• For same geological period (12,000 – 14,000 years ago) geologist Randall Carlson sees mud and water wallas the impetus for dramatic erosion