When Dams Fail
Dams fail for a variety of reasons but when they fail they destroy everything in the path the water and the debris flows take.
AENN
In a series of videos you can see the destruction from dams that fail. Some of the examples are at small scale but do demonstrate the fundamentals of earthen dams that get into failure mode.
Brazil January 2019 Earthen Dam
On Jan. 25, a mining dam that sat above Brumadinho, a large town in southeastern Brazil, collapsed and unleashed a tidal wave of waste and mud that engulfed homes, businesses and residents in its path. It killed at least 157 people; 182 are still missing. NY Times
It was one of the deadliest mining accidents in Brazilian history — a tragedy, but not a surprise, experts told The Times in an investigation into the dam’s collapse. All the elements of a potential catastrophe had been present, and warning signs overlooked, for years.
The Auburn, CA Earthen Coffer Dam
In early 1986 a huge flood began pouring down from the Sierra Nevada mountains. In what would later be considered one of the largest regional floods in recorded history, Placer County was quickly designated a Federal Disaster Area. Rampaging streams and rivers incurred some $7.5 million in damages within the county. Ten inches (254 mm) of rain fell on the Sacramento region in 11 days. Flooding was so catastrophic, that the rating for the city’s systems, supposedly designed to prevent a 125-year flood, was dropped to a 78-year flood. The floods tore out long stretches of levees along the American, Sacramento and Feather Rivers through the Sacramento Valley, and the city of Sacramento was spared by a close margin. Folsom Lake again filled to capacity, and began spilling 134,000 cubic feet per second (3,800 m3/s) by late February.
Teton Dam Disaster 1976, Earthen Dam Built by Kiewit Co. who Rebuild Oroville Spillway 2017-2019
Teton Dam was an earthen dam on the Teton River in Idaho, United States. It was built by the Bureau of Reclamation, one of eight federal agencies authorized to construct dams.[3] Located in the eastern part of the state, between Fremont and Madison counties, it suffered a catastrophic failure on June 5, 1976, as it was filling for the first time. The contract was awarded to Morrison-Knudsen Co. of Boise, assisted by Peter Kiewit Sons Co. of Omaha, Nebraska.
The collapse of the dam resulted in the deaths of 11 people[4] and 13,000 cattle. The dam cost about $100 million to build and the federal government paid over $300 million in claims related to its failure. Total damage estimates have ranged up to $2 billion.[5] The dam has not been rebuilt.
Taiwan Small Scale Earthen Dam
Cotter Dam Concrete Dam Over Topping March 2012
The Baldwin Hills, CA Reservoir Breach and Collapse
Loa Dam Disaster 2018, Earthen and Concrete
The dam collapse occurred around 8 p.m.on Monday 23 July, and caused immediate flash flooding through the villages of Yai Thae, Hinlad, Ban Mai, Thasengchan, Tha Hin, and Samong, all in Sanamxay district. Homes, roads and bridges were swept away.The portion of the dam that collapsed was reported to be a saddle dam—its official name was “Saddle ‘D'”—or, “an auxiliary structure used to hold water beyond what is held by the main dam”. The CEO of one of the companies involved stated that “[it] was fractured and the water had leaked to the downstream area and down to the Xe-Pian River which is about five kilometers from the dam”
Earlier in the day on 23 July, Lee Kang Yeol, Head of Resettlement Office of the Xe-Pian Xe-Namnoy Power Company Resettlement Office sent a warning letter to the provincial resettlement offices in Champasak and Attapeu Provinces indicating that water levels in the dam were high and that dam failure was imminent.The letter further urged that all residents in the Xe Pian river valley be evacuated to higher ground immediately. Lao News Agency reported that “several human lives” had been lost, and that around 6,000 people may have been made homeless as a result.[9]
There were no precise figures regarding casualties within the first 24 hours, although The Guardian reported “hundreds missing” and “several” confirmed dead early the following morning.At least six villages were severely affected around 1,300 households with many survivors stranded on their rooftops and in trees. By 25 July, nearly 3,000 people had been rescued.
The village of Ban Mai alone had 50 inhabitants known to be missing.Rescue efforts were complicated by the fact that the area is densely forested with no mobile-phone coverage, which may also have contributed to the uncertainty as to casualty rates. What roads previously existed were washed away in the floods, and the affected villages were only approachable by either helicopter or flat-bottomed boats.
As of 7 August, 34 people were confirmed dead,at least 1,100 more were missing and 6,600 others were displaced.
AFTERMATH: Within days of the disaster, survivors were questioning why they had received so little warning before it happened, “with some of the displaced saying they were warned to evacuate homes only hours before disaster struck”. It was unclear how the damage affect the overall plan for Laos’ hydroelectric ambitions. Meanwhile, shares in the various companies connected to the project, particularly SK E&C plunged immediately following the disaster.
The Lawn Lake Earthen Failure July 15, 1982
Summary of National Park Service Dam Safety Program and lessons learned from the failure of Lawn Lake Dam in Rocky Mountain National Park on July 15, 1982. Courtesy of Mark Baker and the National Park Service.
