St. Francis Dam, USA

The 59-meter-high St. Francis Dam collapsed, broken through by water, in California.
Water rushed along the canyon in a wall that reached a height of up to 40 meters, and demolished the power plant, located 25 kilometers downstream. The valley was flooded for 80 kilometers. Not many people who found themselves in the disaster zone survived. About 600 people died.
The reason for the scale of this accident was, on the one hand, insufficient engineering vigilance when the first cracks appeared in the concrete dam being built. But, as the court recognized, the control of government organizations over the design and construction of the facility was also insufficient. The main thing is that a paleo-fault was discovered under the eastern support of the dam only after the tragedy.

DneproGES, Ukraine

Undermining the DneproGES in Ukraine during fierce battles with the Nazi invaders. A difficult but necessary operation was undertaken by the Soviet leadership in connection with enemy attacks in order to capture the Dnieper hydroelectric power station and the dam, through which it was planned to break into the city of Zaporozhye. From the explosion, a large gap formed in the body of the dam, an active discharge of water began. As a result, a vast flood zone appeared in the lower reaches of the Dnieper.

A giant wave washed away several enemy crossings, sank many fascist units that had taken refuge in the floodplains. But the water that escaped to freedom did not divide people into “us” and “them”. An almost thirty-meter avalanche of water swept through the Dnieper floodplain, flooding everything in its path. The entire lower part of Zaporozhye with huge stocks of various goods, military materials and tens of thousands of tons of food and other property was demolished in an hour. Dozens of ships, along with ship crews, perished in that terrible flood. The death toll and property damage were catastrophic.

Eder and Maine dams, Germany

eder dam

myeon dam

May 17, 1943 was raided by the 617th Squadron of the Royal Air Force, later known as the destroyers of dams (Eng. Dambusters). As a result of the raid, the dams on Möhne and Eder were partially destroyed, causing the Ruhr Valley and villages in the Eder Valley to be flooded.

Malpasse Dam, France

On the Reyran River, the 222-meter crested concrete arch dam Malpassé, built about 7 kilometers north of the city of Fréjus in southern France, collapsed for irrigation and water supply. The reasons matured gradually: the geological survey was not carried out in full; builders "saved" the cost of high-quality concrete due to scarce funding; in the immediate vicinity of the structure, the military carried out explosions; with the use of explosives, a highway was being built nearby; torrential rains overwhelmed the reservoir…
The city of Fréjus was subjected to almost complete flooding. As a result of the flood, according to official figures, 423 people died, the total amount of damage in monetary terms amounted to about 68 million US dollars.

Vaiont Dam, Italy

Disaster at Vaiont - one of the highest dams in the world (262 meters) in the Italian Alps.
As a result of heavy rains, part of the rock descended into the reservoir. A rising wave 200 meters high surged over the crest of the dam.
The water washed away only about 1 meter of the upper layer of the dam, but even this was enough for 5 villages to be destroyed by flooding in the Piave river valley, according to various estimates, from 1900 to 2500 people died, 350 families completely died. The dam itself survived, but the reservoir has not been filled since.

Banqiao Dam, China

Destruction of the Bainqiao hydroelectric dam in China. The height of the dam is 118 meters, the volume of the reservoir is 375 million cubic meters.

As a result of the annual precipitation in one day and the overflow of the reservoir, the dam was destroyed, which led to the formation of a tidal wave 3-7 meters high and 10 kilometers wide.

7 district centers and countless villages were flooded. According to official figures, a total of 26,000 people died as a result of the floods, and another 145,000 people died immediately and after due to famine and epidemics. 5960 thousand houses were destroyed, 11 million people were affected in one way or another.

Teton Dam, USA

44 miles northeast of Idaho Falls in southeastern Idaho, a terrible tragedy occurred when the Teton Dam suddenly burst. As a result, 300,000 acres of farmland and cities downstream were flooded with water. 14 people died. The total damage was estimated at $1 billion!!!

The Teton earth dam (USA), 93 m high, collapsed in 1976, again after the reservoir was first filled. The reason is increased filtration through the rocks of the dam base, which led to its erosion. The process developed gradually, as a result, timely evacuation made it possible to avoid large casualties.

Dam at Kiselyovskoye reservoir, Russia

June 1993

Breakthrough of a dam 2 kilometers long and 17 meters high at the Kiselyovskoye reservoir on the Kakva River, 17 kilometers from the city of Serov in the Sverdlovsk region of the Russian Federation.
When filling the reservoir, a breakthrough of the dam body occurred.
The flood affected 6.5 thousand people, killing 12 people. 1772 houses fell into the flood zone, of which 1250 became uninhabitable. The railway and 5 road bridges were destroyed, 500 meters of the main railway track were washed out.

Dam of the Sayano-Shushenskaya HPP, Russia

August 2009

The accident in the Russian Federation at the Sayano-Shushenskaya HPP between the Krasnoyarsk Territory and Khakassia is an industrial man-made disaster.
As a result of the accident, 75 people died, and serious damage was caused to the equipment and premises of the station. The work of the station for the production of electricity was suspended. The consequences of the accident affected the ecological situation in the water area adjacent to the HPP, the social and economic spheres of the region. The amount of damage amounted to more than 40 billion rubles.

Dam on the Fuhe River, Jiangxi Province, China

June 2010

A dam breaks on the Fuhe River in eastern China's Jiangxi province due to heavy rains.
About 100 thousand people were evacuated from the breakthrough zone. A total of 199 people were killed in ten territorial units of South and East China due to heavy rains that caused floods and landslides, and 123 people are considered missing. Nearly 2.4 million people were evacuated from dangerous areas. One way or another, 29 million people were affected by the disaster. Economic damage from the bad weather amounted to about 42 billion yuan (6.2 billion US dollars).

Dam on the Indus River, Pakistan

Break of the dam on the Indus River in southern Pakistan. Destroyed up to 895 thousand houses, flooded more than 2 million hectares of agricultural land. More than 1700 people died. The flooding, according to the UN, affected up to 20 million people in the country.

Dam on the Qiantang River, Zhejiang Province, China

A dam burst on the Qiantang River near the city of Hangzhou in Zhejiang province in eastern China.
Usually tourists tend to admire a unique natural phenomenon - the highest tidal wave in the world, up to 9 meters. But sometimes the wave overflows through protective dams, from which 59 people died in 1993, and 11 people died in 2007. This time the wave broke the dam and washed away many.

March 12, 1928. The 59-meter-high St. Francis Dam collapsed, broken through by water, in California.

Water rushed along the canyon in a wall that reached a height of up to 40 meters, and demolished the power plant, located 25 kilometers downstream. The valley was flooded for 80 kilometers. Not many people who found themselves in the disaster zone survived. About 600 people died.

The reason for the scale of this accident was, on the one hand, insufficient engineering vigilance when the first cracks appeared in the concrete dam being built. But, as the court recognized, the control of government organizations over the design and construction of the facility was also insufficient. The main thing is that a paleo-fault was discovered under the eastern support of the dam only after the tragedy.

August 18, 1941. Undermining the DneproGES in Ukraine during fierce battles with the Nazi invaders.

A difficult but necessary operation was undertaken by the Soviet leadership in connection with enemy attacks in order to capture the Dnieper hydroelectric power station and the dam, through which it was planned to break into the city of Zaporozhye. From the explosion, a large gap formed in the body of the dam, an active discharge of water began. As a result, a vast flood zone appeared in the lower reaches of the Dnieper. A giant wave washed away several enemy crossings, sank many fascist units that had taken refuge in the floodplains. But the water that escaped to freedom did not divide people into “us” and “them”. An almost thirty-meter avalanche of water swept through the Dnieper floodplain, flooding everything in its path. The entire lower part of Zaporozhye with huge stocks of various goods, military materials and tens of thousands of tons of food and other property was demolished in an hour. Dozens of ships, along with ship crews, perished in that terrible stream. The death toll and property damage were catastrophic.

December 2, 1959. On the Reyran River, the 222-meter crested concrete arch dam Malpassé, built about 7 kilometers north of the city of Fréjus in southern France, collapsed for irrigation and water supply.

The reasons matured gradually: the geological survey was not carried out in full; builders "saved" the cost of high-quality concrete due to scarce funding; in the immediate vicinity of the structure, the military carried out explosions; with the use of explosives, a highway was being built nearby; torrential rains overwhelmed the reservoir...

The city of Fréjus was subjected to almost complete flooding. As a result of the flood, according to official figures, 423 people died, the total amount of damage in monetary terms amounted to about 68 million US dollars.

October 9, 1963. Disaster on Vaiont - one of the highest dams in the world (262 meters) in the Italian Alps.

As a result of heavy rains, part of the rock descended into the reservoir. A rising wave 200 meters high surged over the crest of the dam.

The water washed away only about 1 meter of the upper layer of the dam, but even this was enough for 5 villages to be destroyed by flooding in the Piave river valley, according to various estimates, from 1900 to 2500 people died, 350 families completely died.

The dam itself survived, but the reservoir has not been filled since.

August 7, 1975 Destruction of the Bainqiao hydroelectric dam in China. The height of the dam is 118 meters, the volume of the reservoir is 375 million cubic meters.

As a result of the annual precipitation in one day and the overflow of the reservoir, the dam was destroyed, which led to the formation of a tidal wave 3-7 meters high and 10 kilometers wide.

7 district centers and countless villages were flooded. According to official figures, a total of 26,000 people died as a result of the floods, and another 145,000 people died immediately and after due to famine and epidemics. 5960 thousand houses were destroyed, 11 million people were affected in one way or another.

June 1993. Breakthrough of a dam 2 kilometers long and 17 meters high at the Kiselyovskoye reservoir on the Kakva River, 17 kilometers from the city of Serov in the Sverdlovsk region of the Russian Federation.

When filling the reservoir, a breakthrough of the dam body occurred.

The flood affected 6.5 thousand people, killing 12 people. 1772 houses fell into the flood zone, of which 1250 became uninhabitable. The railway and 5 road bridges were destroyed, 500 meters of the main railway track were washed out.

August 2009. The accident in the Russian Federation at the Sayano-Shushenskaya HPP between the Krasnoyarsk Territory and Khakassia is an industrial man-made disaster.

As a result of the accident, 75 people died, and serious damage was caused to the equipment and premises of the station. The work of the station for the production of electricity was suspended. The consequences of the accident affected the ecological situation in the water area adjacent to the HPP, the social and economic spheres of the region. The amount of damage amounted to more than 40 billion rubles.

June 2010. A dam breaks on the Fuhe River in eastern China's Jiangxi province due to heavy rains.

About 100 thousand people were evacuated from the breakthrough zone. A total of 199 people were killed in ten territorial units of South and East China due to heavy rains that caused floods and landslides, and 123 people are considered missing. Nearly 2.4 million people were evacuated from dangerous areas. One way or another, 29 million people were affected by the disaster. Economic damage from the bad weather amounted to about 42 billion yuan (6.2 billion US dollars).

August 5, 2010. Dam failure on the Indus River in southern Pakistan.

Up to 895 thousand houses were destroyed, more than 2 million hectares of agricultural land were flooded. More than 1700 people died. The flooding, according to the UN, affected up to 20 million people in the country.

September 1, 2011. A dam burst on the Qiantang River near the city of Hangzhou in Zhejiang province in eastern China.

Usually tourists tend to admire a unique natural phenomenon - the highest tidal wave in the world, up to 9 meters. But sometimes the wave overflows through protective dams, from which 59 people died in 1993, and 11 people died in 2007. This time the wave broke the dam and washed away many.

Accidents at hydraulic structures (dam breaks)

Accidents at hydraulic structures pose a serious danger to the population, the technosphere and the natural environment. In accordance with the Federal Law "On the Safety of Hydraulic Structures", such structures are: dams, buildings of hydroelectric power plants, spillways, water outlets and water outlets, tunnels, canals, pumping stations, shipping locks, ship lifts; structures designed to protect against flooding and destruction of the banks of reservoirs, banks and bottoms of river beds; structures (dams) fencing storage facilities for liquid waste from industrial and agricultural organizations; erosion control devices on canals, as well as other structures designed to use water resources and prevent the harmful effects of water and liquid waste.

Description of the emergency in question

Accidents at hydraulic structures are diverse. The most dangerous of them are hydrodynamic accidents. A hydrodynamic accident is an accident at a hydraulic structure associated with the spread of water at high speed and posing a threat of a man-made emergency (GOST R22.05-94). The main hydraulic structures, the destruction (breakthrough) of which leads to hydrodynamic accidents, include dams and locks.

Dams are hydraulic structures (artificial dams) or natural formations (natural dams) that create a level difference along the riverbed. Artificial dams are hydraulic structures created by man for his own needs and include dams of hydroelectric power stations, water intakes in irrigation systems, dams, dams, dams, etc. Natural dams arise as a result of the action of forces of nature, for example, as a result of landslides, mudflows , avalanches, landslides, earthquakes. In front of the dam, up the watercourse, water accumulates and an artificial or natural reservoir is formed.

The section of a river between two adjacent dams on a river, or the section of a canal between two locks, is called a pool. The upstream of the dam is the part of the river above the retaining structure (dam, lock), and the part of the river below the retaining structure is called the downstream.

Reservoirs can be long-term or short-term. A long-term artificial reservoir is, for example, a reservoir upstream of a hydroelectric dam, an irrigation system. A long-term natural reservoir can be formed as a result of the closure of the river after the collapse of hard rocks. Short-term artificial dams are created to temporarily change the direction of the river during the construction of hydroelectric power plants (HPP) or other hydraulic structures. Short-term natural dams arise as a result of blocking the river with loose soil, snow or ice.

A dam break is the initial phase of a hydrodynamic accident and is a process of formation of a breach and an uncontrolled flow of reservoir water from the upstream through the breach into the downstream. A proran is a narrow channel in the body (embankment) of a dam, spit, shoal or a straightened section of a river, formed as a result of erosion of a bend in a flood.

As a result of a dam breakthrough, a breakthrough wave occurs, which is formed in the front of a stream of water rushing into the hole, which, as a rule, has a significant height of the crest and speed of movement and has great destructive power. The height of the breakthrough wave and the speed of its propagation depend on the size of the breach, the difference in water levels in the upstream and downstream, the hydrological and topographic conditions of the riverbed and its floodplain. The speed of advance of the breakthrough wave ranges from 3 to 25 km/h (for mountainous and foothill areas - about 100 km/h). The height of the breakthrough wave is in the range from 2 to 12 m, and sometimes more.

The main consequence of a dam break during hydrodynamic accidents is catastrophic flooding of the area.

Catastrophic flooding is a hydrodynamic disaster, which is the result of the destruction of an artificial or natural dam and consists in the rapid flooding of the downstream area by a breakthrough wave and the occurrence of a flood. Potential catastrophic flooding is characterized by the following parameters:

The maximum possible height and speed of the breakthrough wave;

Estimated time of arrival of the crest and the front of the breakthrough wave at the corresponding target;

The boundaries of the zone of possible flooding;

The maximum depth of flooding of a particular area;

duration of flooding.

The flooding caused by a dam break initially spreads at the speed of a breakthrough wave and leads, some time after it, to the flooding of vast areas with a layer of water from 0.5 to 10 m or more. Flood zones are formed. The zone of possible flooding during the destruction of hydraulic structures is the part of the area adjacent to the river (lake, reservoir), flooded in this case with water. Depending on the consequences of the impact of a hydroflow formed during the destruction of hydraulic structures, a zone of probable catastrophic flooding should be identified in the territory of possible flooding. This zone is a zone of probable flooding, where death of people, farm animals or plants is expected or possible, damage or destruction of property, as well as damage to the environment (GOST R22.0.03-95). The zones of probable catastrophic flooding are determined in advance at the stage of designing a hydraulic structure. The parameters of the zone depend on the size of the reservoir, water pressure and other characteristics of a particular hydroelectric complex, as well as on the hydrological and topographic features of the area. The zones of probable, including catastrophic, floods and the characteristics of the breakthrough wave are reflected on maps or in special atlases compiled for hydroelectric facilities and large dams.

Breaks of natural dams, for example, breaks of lakes dammed by a glacier, breaks of moraine lakes, can also lead to catastrophic flooding of the area.

The main damaging factors of catastrophic flooding are the dynamic impact of the breakthrough wave and water flow, as well as the impact of calm waters that flooded the territory and objects. The impact of a breakthrough wave is in many respects similar to the action of an air shock wave formed during an explosion. Significant differences between these damaging factors are the much lower speed and higher density of matter in the breakthrough wave.

As a result of major hydrodynamic accidents, the supply of electricity can be interrupted, the operation of irrigation or other water management systems, as well as pond fisheries, may collapse or be under water, settlements and industrial enterprises, disable communications and other infrastructure elements. , crops and livestock perish, agricultural lands are withdrawn from economic circulation, the life of the population and the production and economic activities of enterprises are disrupted, material, cultural and historical values ​​are lost, damage is caused to the natural environment, including as a result of landscape changes, people die .

Secondary consequences of hydrodynamic accidents are pollution of water and terrain by substances from destroyed (flooded) storage facilities of industrial and agricultural enterprises, mass diseases of people, non-agricultural animals, accidents on highways, landslides, landslides.

The long-term consequences of hydrodynamic accidents are associated with residual flooding factors - sediment, pollution, changes in the elements of the natural environment.

According to the international classification, five types of accidents at dams are distinguished by their consequences.

Note:

1. In case of destructions of the R-1 and R-2 types, a breakthrough wave is formed and the territory characterized by lowlands is flooded.

2. In case of accidents of the P-1, P-2 and P-3 types, as a rule, flooding does not occur.

In this regard, there are three states of a hydraulic structure: no damage, damage and destruction. It should be noted that catastrophic flooding can only occur with the destruction of a hydraulic structure.

The tallest dam in the US is in Oroville. Erosion of an emergency spillway can lead to an uncontrolled discharge of water from Lake Oroville, then several settlements will be under water at once.

The California National Guard is on full alert. To prevent the collapse of the dam, the authorities have stepped up the discharge of water. , but the threat of collapse of the dam remains. If the dam still fails, the scale of the disaster could be comparable to the most destructive hurricane "Katrina" in New Orleans.

The website "Vesti.Ekonomika" made a selection of the largest disasters on dams in the world.

1. The destruction of the St. Francis Dam in the United States in 1928. Water rushed along the canyon in a wall that reached a height of up to 40 meters. As a result, the valley was flooded for 80 kilometers, the power plant was demolished, and 600 people died.
2. Undermining the DneproGES in the USSR in 1941. The Soviet leadership made this decision because of enemy attempts to capture the dam. The 30-meter wave washed away not only the fascist units, the entire lower part of Zaporozhye was demolished, the death toll and material damage were catastrophic.
3. Malpassé dam disaster in France in 1959. When it collapsed, the city of Frejus was almost completely flooded, killing 423 people.
4. Disaster at the Vaiont Dam in Italy in 1963. Due to heavy rains, part of the rock descended into the reservoir. A rising wave 200 meters high surged over the crest of the dam. In the valley of the Piave River, 5 villages were destroyed by flooding, and, according to various estimates, from 1900 to 2500 people died.
5. Destruction of the Bainqiao hydroelectric dam in China in 1975. The dam could not resist Typhoon Nina. The official death toll is 26,000. However, these calculations do not take into account the deaths from epidemics and famine that spread as a result of the disaster.
6. Flooding in Russian Serov in 1993. Due to the breakthrough of the dam of the Kiselevskoye reservoir on the Kakva River, 69 square kilometers of the river floodplain, Serov districts and several villages were flooded. 15 people died.
7. State of emergency at the Sayano-Shushenskaya HPP in 2009. As a result of a man-made accident, 75 people died, and serious damage was caused to the equipment and premises of the station.
8. A dam burst on the Fuhe River in China in 2010. The disaster was triggered by heavy rains.
9. Dam failure on the Indus River in Pakistan in 2010. Water flooded over 2 million hectares. More than 1700 people died.
10. A dam burst on the Qiantang River in China in 2011. Thousands of tourists come to the river to see the beautiful tide. However, at that time the wave was so big that it broke through the dam and washed away the spectators.
11. Disaster in New Orleans, USA in 2005. The city dam could not withstand the onslaught of Hurricane Katrina, 80% of the city was under water.

"The Banqiao Dam, 24.54 meters high and 118 meters long, was built in 1952 to protect against a flood that occurs once every thousand years. It was built to last for centuries, but no one expected that it would be destroyed by a water disaster after only 23 years.

Desire to save

The flood began on August 8, 1975 at about one in the morning local time. Civilians were sleeping when the waters in the Zhu River began to rise due to the huge amount of rainfall that had fallen during a week-long super typhoon Nina. The dam could not withstand the annual norm that had fallen during the day and fell apart under the pressure of water. On that nightmarish day, the water claimed the lives of more than 26 thousand people and washed away the crops. After that, due to the destroyed food stocks and fields, about 230 thousand people died from epidemics and famine.

The death of so many people could have been avoided by taking into account several factors in the construction of the dam. Firstly, during construction, it was worth using not soil (the Banqiao dam was completely earth - ed.), but strong materials. Even before the flood, the dam, under the influence of a humid climate, began to collapse and “float”, cracks appeared on the walls. Soviet engineers were called in to help the Chinese builders, who reinforced the flimsy structure with metal structures, after which the dam became almost the most reliable dam in all of China.

Secondly, it was necessary to take into account the opinion of one of the leading Chinese hydrologists, Chen Xin, who demanded not to save people's money and build 12 spillways. In this case, the catastrophe would have brought less casualties and damage. But then the persistence of the specialist was perceived negatively by the authorities, he was criticized by the party for calling for the waste of people's funds. The scientist was suspended from work and, having saved money, only five spillways were built.

The third reason for the disaster was that in the Zhu River basin, by analogy with the Banqiao dam, they began to build other dams.

Starting point

The fact that the disaster would happen could have been predicted more than a week before the tragedy. On July 30, 1975, the super typhoon Nina hit the Celestial Empire, which raged until August 6. After that, heavy rains began. Record rainfall, which exceeded the annual rate of 200 mm, led to flooding of land downstream of the dam.

On August 6, the Banqiao leadership decided to start draining water from the spillways, which required permission from the highest authority. On the morning of the next day, a message was sent to the management of the dam, which did not reach the addressee due to a breakdown in the communication line. In the evening of the same day, cracks began to form in one of the most “reliable” dams in China. The dam employees decided, despite the “silence” of the highest authority, to start draining water from the drains, but it was too late: because of the silt, they became clogged and stopped working.

There was a military unit next to the dam, its commander decided to help the dam management and offered to launch an airstrike and let the water flow out. Perhaps this would have helped, but at that moment the Shimantan Dam, upstream, collapsed. All the water accumulated in it with a huge seven-meter wave, the speed of which reached 50-55 kilometers per hour, hit the barely alive Banqiao. And she couldn't resist. In about an hour, water spilled over the plain at a width of up to 10-15 kilometers, it destroyed all roads, communications, villages, and crops. 26,000 people and 300,000 livestock died in its waters. In the morning, instead of green meadows, the survivors saw muddy lakes and devastated land, and all 62 dams that went downstream of the river were also destroyed.

During the calculation of the damage, it turned out that the number of destroyed houses approached 5.9 million. Human victims numbered from 90 thousand to 230 thousand people. Over time, it became clear that a wave of many carried away several kilometers from their homes, but they remained alive and after some time were able to return to their native land.

Unfortunately, the tragedy did not end there. After the flood, famine and epidemics began in the region, the victims of which were about 230 thousand people. In total, 11 million inhabitants of the affected region were affected in one way or another by the disaster.

It should be noted that the destroyed dams for many years reminded of themselves only in ruins, they were not restored until 1993. In the same year, the newly erected Banqiao dam began to work again.