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. 2200 killed
March 17, 1936
• Heavy rain + snow melt. 25 fatalities
July 19-20, 1977
• 11.8 inches rain, multiple dam failures. 85
killed
The Johnstown Flood
Flood Aftermath
Flood
Aftermath
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
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, 1976
14 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
(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:
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
(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)
Teton Dam, Idaho in 2001
(A. G. Sylvester)
Dam Site From Air, 2009
Flood Area From Air, 2009
Piping, Guatemala, 2010
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-99-06
• U.S. Department of Interior, Bureau of
Reclamation, Dam Safety Office
Fatal Dam Failures 1960-1998
• 23 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
• 30-100% 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