Dam Failure Floods

The Huang He: “China’s Sorrow” 1887: 2,000,000 dead 1931: 3,700,000 dead 1938: The Chinese dynamite levees to slow the Japanese; 800,000 Chinese died.

Relief of Eastern China

Loess in China

Huang He and Mississippi

Johnstown, Pennsylvania May 31, 1889 Heavy Rain, Dam Failure killed March 17, 1936 Heavy rain + snow melt. 25 fatalities July 19-20, inches rain, multiple dam failures. 85 killed

The Johnstown Flood

Flood Aftermath

St. Francis Dam, California March 12, 1928, 11:57 PM Reservoir drained in one hour Water 140 feet deep 500 killed 50 mile flood

St. Francis Dam, California

Built to supply water and power to Los Angeles Hydraulic lifting Solution of gypsum in bedrock Presence of fault and leakage through fault gouge Reactivation of paleo-landslide

Teton Dam, Idaho June 5, killed Generally sound engineering practices Cause of failure –Dam fill inadequately compacted, too dry –Fractured bedrock abutments –Excessive reliance on grout barrier –Piping: erosion of tunnels by leaking water

Teton Dam, Idaho (University of Notre Dame, Department of Engineering and Geological Sciences)

Teton Dam, Idaho: The Moment of Failure (University of Notre Dame, Department of Engineering and Geological Sciences)

Teton Dam, Idaho (University of Notre Dame, Department of Engineering and Geological Sciences)

Teton Dam, Idaho (Bureau of Reclamation)

Teton Dam, Idaho (University of Notre Dame, Department of Engineering and Geological Sciences)

Teton Dam, Idaho in 2001 (A. G. Sylvester)

Dam Site From Air, 2009

Flood Area From Air, 2009

Piping, Guatemala, 2010

Tangiwai Rail Disaster, 1953 North Island, New Zealand, Dec. 24, 1953 Crater of Mount Ruapehu collapsed, releasing flood Mudflow takes out support of rail bridge at Tangiwai Bridge collapses as train crosses it 151 killed, 134 survivors

Jokulhlaups Glacial Floods Subglacial volcanism (Iceland) Subglacial outbursts –Mont Blanc, July 12, 1898, 200 killed Ice dam failure –Missoula floods (Pleistocene) –Altai floods (Pleistocene) –Russell Fiord, Alaska, 1986

Russell Fiord, Alaska, 2002 (National Park Service)

Patagonia, 2004 (ESA)

Predicting Flood Fatalities Wayne J. Graham, 1999 A Procedure for Estimating Loss of Life Caused by Dam Failure DSO U.S. Department of Interior, Bureau of Reclamation, Dam Safety Office

Fatal Dam Failures Events –Piping: 6 –Overtopping: 9 –Slope Failure: 2 –Spillway Failure: 2 –Other: 4

Fatality Factors Flood Severity Warning Time Understanding of risk based on events upstream

Flood Severity High: Area swept clean Medium: Homes destroyed but trees and wreckage provide refuge, flooding depth greater than 10 feet Low: Buildings survive, flooding depth less than 10 feet

High Severity % fatality rate 75% used in risk planning If there is warning, percents apply to people who remain in risk zone

Medium Severity No warning –Fatality rate 3 – 35% –15% used in risk planning 15 – 60 minutes warning –Fatality rate 1 – 8% –4% used in risk planning More than 60 minutes warning –Fatality rate 0.5 – 6% –1% used in risk planning

Low Severity No warning –Fatality rate 0 – 2% –1% used in risk planning 15 – 60 minutes warning –Fatality rate 0 – 1.5% –0.7% used in risk planning More than 60 minutes warning –Fatality rate 0 –.06% –.03% used in risk planning