15. Big blue hole part of the Belize Barrier Reef. Its diameter is 305 meters and its depth is 120 meters. Initially, this formation was a system of caves formed in ice age. When the ocean rose, the roof of the flooded cave collapsed and this sinkhole was formed. Explorer Jacques Cousteau included it in the list of the 10 best places in the world for diving. Divers may encounter several interesting species fish including giant grouper, nurse sharks and several species of reef sharks. During high tides, real whirlpools form at the site of the great blue hole, in which people often die. 14. The Udachnaya pipe is an active diamond deposit in the north of Yakutia, 20 kilometers from the Arctic Circle. Mining began in 1982. This is the largest diamond deposit in Russia in terms of raw material volumes and ore body size. The Alexander Pushkin diamond, weighing 320 carats, was mined here, and more recently a stone was discovered containing 30 thousand diamonds, which is a million times more than their usual concentration. The depth of the quarry is 640 meters, and the length on the surface is 2 km. 13. The Kola superdeep well is the most deep well in the world. Its depth is 12262 meters, and the temperature at the bottom is 220 degrees. Celsius. The well was laid in 1970 to study the deep structure of the earth. The well was the source of the urban legend about the “well to hell.” Allegedly, on approaching the 13th kilometer, the instruments recorded a strange noise coming from the bowels of the planet - the yellow newspapers unanimously assured that only the cries of sinners from the underworld could sound like that. In 2008, due to financial difficulties, the well was abandoned and the equipment was dismantled. 12. Deluxe Mystery Hole is a hole in the ground turned attraction in Oregon. According to the owner of the hole, this is the most interesting archaeological site in the state. Its depth has not yet been determined by modern scientific methods, but the fact is that it is very deep. Some say it was dug by ancient people, others say by aliens. The owner of the hole, Pastor Barron, claims that the hole is already 5000 years old and if you go down into it even a little, you will find success in finance and personal life. 11. Devil's Sinkhole is a huge underground cave 15 meters wide and 106 meters deep, located in Texas. Visitors are not allowed to go into the cave, but in the summer you can see more than 3 million bats, flying out of it at night. 10. In 2010, in Guatemala, a three-story garment factory, along with a nearby residential building, fell into the ground in broad daylight. It didn’t just fall through, but disappeared into a huge hole, the bottom of which can only be seen from a helicopter. This is not the first sinkhole in Guatemala. In 2007, a similar crater 150 meters deep formed there. Employees of the geological survey cannot explain how a black hole of such a regular shape turned out, but local residents We are confident that the cause of the failure was the city’s dilapidated sewer system. 9. Over the past three decades, more than 3,000 sinkholes have appeared in the dry parts of the ever-shrinking Dead Sea, up from just 40 in 1990. As the number of cracks increases, the Dead Sea continues to die. His coastline is decreasing by about a meter per year. Irrational irrigation in relation to Jordan River, which feeds the Dead Sea, and the over-extraction of the resources of the sea itself due to the increasing population of the countries of the Middle East. The less salt water there is in the sea, the easier it is for fresh underground springs to dissolve the salt and destroy the familiar landscape of the Dead Sea. 8. Diamond mining in the Mir deposit in Yakutia began in 1957. The quarry has a depth of 525 m and a diameter of 1.2 km. Open pit mining of diamond-bearing kimberlite ore was discontinued in June 2001. Since 2009, diamond ore mining has been carried out only at the Mir underground mine. Its capacity is 1 million tons of ore per year. In 2013, the mine produced more than 2 million carats of diamonds. 7. In Siberia, scientists are finding more and more giant craters of unknown origin. According to one version, the depressions were formed by explosions of methane accumulated underground, according to another - as a result of the melting of underground glaciers due to previously established abnormal heat in the region. So far, scientists have discovered seven craters, but in their opinion there are more than 30 craters in total. 6. Harwood Hole is a cave located in the southern part of New Zealand. On the surface its diameter is 50 meters, and as it dives it reaches 183 meters. The total depth of Harwood Hole is 357 meters. Since its exploration in 1959, the cave has remained the deepest in New Zealand for many years. 5. The Monticello Dam is famous for its original spillway design, in the form of a giant funnel called the “Glory Hole.” In the middle of Lake Berryessa there is a large concrete pipe with streams of water flowing into a huge hole. From the outside it may seem that the water, forming a giant funnel, merges into the very depths of the earth. It is worth admiring the funnel during the rainy season, since the drainage does not occur all the time, but only when the water level in Beryessa rises high enough. Previously, on the site of the dam there was the city of Monticello, which was flooded and the artificial Lake Berryessa was created. 4. Dean's Blue Hole is the deepest currently known blue hole on the planet. Its depth is 202 meters. The hole is located on Long Island in the Bahamas. This sinkhole is the training base for the Vertical Blue freediver team, led by world champion William Trubridge. On December 16, 2010, he reached a depth of 101 m at Dean's Blue Hole, becoming the first person to overcome a depth of 100 m without using fins. 3. Bingham Canyon is a mining site in the Western United States, one of the largest quarries in the world, where a giant copper deposit is being developed open method. Copper ore was first discovered here in 1850, and quarrying began in 1863, which continues to this day. About 1,400 people work in a quarry more than a kilometer deep and 4 kilometers wide, who extract about 450 thousand tons of rock every day. 2. Another blue hole in the Bahamas, Sawmill Sink, has more scientific significance than Dean's Blue Hole. This sinkhole was the site of an archaeological dig that helped scientists change their views about what the earth was like about 1,000 years ago. Interestingly, this hole was once dry, but gradually began to fill with water. The remains of birds have been preserved giant turtle and a crocodile that swam here. Researchers also found the remains of one of the very first inhabitants of the Bahamas, which is about 1050 years old. 1. This huge sinkhole in China is called the Heavenly Pit. Formed 128 thousand years ago, this funnel is the deepest in the world, its depth is as much as 662 meters. Thanks to your huge size, it is a favorite place for extreme skydiving. An underground river 8 and a half kilometers long flows at the bottom of the crater. During the rainy season, you can see a beautiful waterfall here.
A regime has been introduced in northern California emergency and an evacuation order was issued for 190 thousand people due to the threat of a dam failure near the city of Oroville, one of the largest dams in the United States. Now the water level in the Oroville Reservoir has risen to a critical level due to torrential rains, and the dam’s drains are damaged, which at any time can lead to flooding of the surrounding area.
In California, the evacuation of residents of the city of Oroville and neighboring areas has been announced due to the threat of a breach of one of the largest dams in the United States. A total of 190 thousand people were ordered to evacuate. California Governor Jerry Brown declared a state of emergency in the area. According to the California Fire Department, 35 thousand people were evacuated in Butte County, where Oroville is located, 65 thousand people in Yuba County, as well as 76 thousand residents of Yuba City and 12 thousand residents of Marysville.
The dam itself is intact, but the emergency spillway, designed to quickly empty if water levels rise sharply, was destroyed on Sunday. According to authorities, the spillway may not be able to withstand the load and collapse at any time, causing water to be released from the Oroville Reservoir. The main spillway was also washed out earlier last week.
If the dam breaks, water could flood nearby towns. Water levels in the Oroville Reservoir have risen due to heavy rainfall. Precipitation levels in Northern California are 228% above average for this time of year. “A dam failure like this is a disaster. We have determined that we cannot repair the damage,” said the head of the California Department during a press conference. water resources Bill Croyle.
The Oroville Dam on the Feather River is the tallest in the United States, reaching a height of 230 m. The dam was built in the 1960s. Oroville Reservoir is the largest in California.
Doctor of Technical Sciences, Head of the Simulation Laboratory surface waters Institute of Water Problems of the Russian Academy of Sciences Mikhail Bolgov: “You need to know the design of this dam and what place the emergency spillway occupies in it in order to give a full forecast. But according to preliminary data, the consequences of its breakthrough could be catastrophic; there is a very large reservoir with high pressure, so the destruction could be colossal. Typically the spillway is designed to start operating as soon as the reservoir is close to overflowing. Operational services try to never let the situation get to this point; this is an extreme measure. Why all the negative conditions accumulated there so much, why this, roughly speaking, hole began to work in emergency mode, is unclear. During construction, water conduits are specially left, which are then filled with concrete. Maybe this is one of the remaining construction water pipelines, but, as I said, they are plugging with concrete. Evacuation of people always occurs when the risks become great. This does not mean that the dam will definitely fail, but it is necessary to evacuate. It is necessary to carry out a full set of emergency measures, because it is better to resettle people than to fish out corpses later. There is only one way to reduce the level - all spillway devices are opened, all turbines, if they are in the dam, are turned on at full power, for this the thermal stations are shut down and in this beyond design mode the hydraulic structure begins to work in order to reduce the pressure on this place as much as possible where the accident occurred."
Former Director for Technical Policy of JSC RusHydro Rasim Khaziakhmetov:“Information about the condition of the Oroville Dam is contradictory, I would say too much in the media and does not allow us to accurately predict the consequences. If the media and local authorities overestimate the risks - nothing serious will happen. If the photos and video materials from the first half of the day are accurate, then the watersheds may be destroyed and, again, the consequences will not be overly catastrophic, especially since the authorities have taken serious measures to evacuate the population. It was a little annoying that in one of the helicopter shots, signs of filtration of the dam itself were visible, but this was scary. Imagine that a landslide occurs and a wave more than 200 meters high with a pressure of 20 atmospheres rushes down. Then it may turn out that it was not 180 thousand people who had to be evacuated, but much more. There was already an accident in history when in 1963 a landslide occurred in Italy and water overflowed over a dam. Given that there was almost flat desert around and the wave height was about 20 meters, several villages were washed away in 7 minutes, killing 3 thousand people. Everything seems much more dangerous here.”
Former Deputy Minister of Energy and former chairman of the Board of Directors of RAO UES of Russia Viktor Kudryavy: “Very few accurate information about the real situation with the dam, to what height it can collapse, at what speed, the characteristics of the lake itself, the volume of water accumulated in it, what the height difference is downstream, the terrain, whether there are turns that can provide overflow and smooth out the consequences. There are a lot of factors. But it is clear that the foundation of the dam is good, since they are not very afraid, and a breakthrough can only occur in the upper part. The dynamics of destruction, wave height and speed are scary. Complete destruction will lead to a catastrophe the likes of which the world has never seen. I really hope it doesn’t happen.”
Yana Rozhdestvenskaya; group "Direct Speech"
Residents of Oroville, California and surrounding areas have been ordered to leave their homes immediately as parts of the Oroville Dam itself high dam of all the US countries is experiencing severe structural collapse.
Damage to the main dam structure is expected within an hour. Once this structure is destroyed, over two cubic miles of water will be released. The flood will wipe out an entire area.
Oroville Reservoir is located 240 kilometers from San Francisco. The city of Oroville, located by the lake, is home to 16,000 people. The dam about which we're talking about, is the tallest in the United States, its height is 235 meters. The reservoir is also the main source of water supply for California. Agriculture in the Central Valley and businesses across the state.
Old video clip showing what the Oroville Spillway should look like in normal operation:
This is what it looks like now:
If earlier the water extinguished its energy, smoothly flowing from a height of 770 feet, then today, after spontaneous damage to the spillway about a week ago
Due to a series of downpours that flooded the region, the lower part of the structure looks like a seething stream of water with flying blocks of reinforced concrete, eroding the surface down to the rocks.
Evacuation zone maps:
Here's what American bloggers think about the situation:
Flyingcuttlefish: Several years ago I spoke with a volunteer lifeguard from North Carolina. He secretly, fearing that someone would hear us, told me that they were conducting special exercises in case the dam upstream from a large populated area was destroyed. He even gave me an approximate date when this could happen. The rescuer’s words were not a surprise to me and only confirmed my suspicions. The fact is that in some strange coincidence it turned out that the United States Army of Engineers built more than 50% of their dams on the sites of active underground faults and in those places where large populations were gathered down the river. What if the dams were built this way on purpose - in anticipation of future events, natural Disasters? Or even disasters launched artificially, for example using devices such as HAARP. If a flood kills a lot of people, destroys the local economy - HAARP can influence not just the weather, but politics.
Jim Stone: All posts by maintenance The dams show that until recently the spillway was in excellent condition. I've analyzed hours of CCTV footage of the dam, and in some of the frames you can see chunks of the deck's concrete appear to be jumping high in the air. So I think the spillway was blown. Or is this some kind of deliberate sabotage. Obviously, I have no evidence of deliberate digging under the drain or traces of explosives, but you must agree that this is a completely rational explanation. Even engineers are terribly surprised how this happened. And that means a lot. Therefore, I have doubts that everything will end well. If the dam fails, it will be a double Niagara Falls. Or even Niagara times four.
Based on materials
Oroville Dam is the highest in the United States. The height of its ground part reaches 235 meters. The dam is located on the Feather River (a tributary of the Sacramento River). A rock dam with a clay core forms the Oroville Reservoir, with a surface area of 10,200 square kilometers and a water volume of 4.3 cubic kilometers.
The reservoir itself is part of a complex that includes a hydroelectric power station with a capacity of 819 MW with six generators, power point Hyatt, Thermalito pump and generator station, as well as a fish factory. The main objectives of the complex are water supply to the region, flood control and electricity generation. The facility was built in 1961–1968.
The complex buildings are located with right side along the river. The object closest to the dam is an operational spillway (a tray made of reinforced concrete) for operation in normal conditions. water mode. Even further to the right is an emergency discharge in case of catastrophic floods. Until the February incident, it was not used because there were no such floods. According to statistics, large-scale floods in this region can occur no more than once every ten thousand years.
The fault looks like a hundred-meter wall with a height of 10–20 meters. The incoming water must overflow without regulation, and its layer will be tens of centimeters. Further, at the junction with the right bank of the valley, there is a blind section of the dam with a height of up to 30 meters.
Chronology of the incident
Since the beginning of 2017, water levels in the Oroville Reservoir have been rising at an exponential rate. However, the record belongs to the summer of 1983, but no emergency situations were observed then. In January 2017, the amount of precipitation in the region exceeded the norm three times. Since the beginning of February it has been extremely warm weather, even at night it did not fall below 10 degrees Celsius.
Already on February 7, a large washout was discovered in the middle part of the spillway. The karst failure, as experts from the CIS believe, occurred due to leaching of the rock base. While repairmen were inspecting the damage, water in the reservoir was rapidly accumulating. When it reached a critical point, which already threatened the safety of the dam itself, emergency crews left the failure area and directed the water through the discharge.
The consequences were not long in coming. The concrete fastening at the bottom of the structure was destroyed, after which the water began to wash away the rock underneath the drain. The destructive process began at the moment of water consumption at the level of 1.4 thousand cubic meters per second. For comparison, in 1997 the dam passed a flow of 4 thousand cubic meters per second without problems. The gap reached a size of 150 by 90 meters and a depth of 14 meters.
The engineers who identified the problem expected that the structure would collapse at any moment, so they reduced the water flow by 15%, using an emergency discharge that had not been used previously, and by February 10 it turned out that the soil foundation of the backup drain was also damaged, and the reason was the loss of integrity It was not possible to find out the object.
The flow of water carried away the debris rock into the river bed, therefore it was necessary to stop the operation of the hydroelectric power station, otherwise due to backwater it could be flooded. Meanwhile, the rupture pit on the main fault expanded, destroying its walls and eroding the adjacent slope. The situation at the emergency drainage has become critical. The decision was made to resume increased flow through the main spillway, despite the threat of loss of control of the dam due to possible failure of the flow.
Accident response and preventive measures
Since the threat of destruction of the dam infrastructure, California Governor Jerry Brown has asked President Donald Trump to send forces and resources federal level to eliminate an emergency. In his address, the official noted that assistance should also be provided to the districts where residents evacuated from possible flood zones are located.
On Monday, February 13, the Governor of California declared a state of emergency in the region, covering three counties - Yuba, Sutter and Butte. State National Guard units were put on alert. The White House reported that the president has entrusted the coordination of emergency response efforts to the Federal Emergency Management Agency of the Department of Homeland Security. In addition, the country's Ministry of Defense also joined the work. Pronedra wrote earlier that Trump also declared a state of emergency in the disaster zone.
The Russian side immediately offered its help. The Center for Development of the Water Economy Complex of the Ministry of Natural Resources of the Russian Federation stated that domestic specialists can work on solving the problem of the emergency condition of the dam, including by providing appropriate scientific advice. Such tasks are not new to Russians; Moscow has already provided assistance in similar emergencies to countries in Africa and Southeast Asia.
Large forces were put on alert in the United States - a total of about 20 thousand military personnel. 125 construction crews and four dozen heavy vehicles were sent directly to the work area. Aviation was involved, including helicopters of the National Guard, with the help of which they began to drop bags of sand and rock at the sites where the drain was washed out. Barriers made of sandbags are also being erected around the dam. Every hour, about 1.2 thousand tons of rock fragments are placed in the gullies.
The state authorities informed that the work carried out by February 15 made it possible to stop the development of the catastrophic situation, and the expected storm with precipitation was not as significant as expected. In general, the cost of priority measures was estimated at $200 million. It is still unknown how the condition of the spillways will affect further exploitation dams. Work continues. Thanks to measures taken The dam is already able to accommodate additional water inflow. Currently, the volume of discharge is 2.8 thousand cubic meters per second, while the rains do not stop and will continue for several more days.
According to RusHydro, measures are being taken to reduce the reservoir level by 2.5 meters per day in order to safely receive the upcoming precipitation. Debris is being removed in the riverbed to prevent possible flooding of hydroelectric power station structures. The launch of the station's capacity will make it possible to relieve some of the operational discharge. If the latter is subject to restoration, it will be repaired. If repair work is impossible, a new spillway will be built. It is possible that it is necessary to strengthen the emergency discharge slope with concrete and generally evaluate the possibility of its use in the future.
Evacuation, panic and looting
After information from the California Department of Water Resources appeared about the threat of an imminent dam failure (it later turned out that the forecasts were unjustifiably exaggerated), state authorities decided to evacuate the local population. By February 13, a total of 188 thousand people were removed or left on their own from the cities of Yuba City, Gridley, Olivehurst, Plumas Lake, Wheatland, Marysville and Live Oak. But along the route of the evacuees there were colossal traffic jams. Temporarily resettled citizens were placed in different areas at a distance of 32–120 kilometers from the possible flood zone.
Conflicting statements by officials, in particular the emergence of information about the possible destruction of the dam in a matter of hours, played a significant role in the emergence of panic. Already on February 15, the evacuated residents were told that they could return to their homes, although it was noted that the threat of flooding still remained and citizens might have to leave dangerous area again. Citizens who returned to their homes faced the consequences of looting in their cities. Such reports also came from Oroville, where, in the absence of residents, mass thefts occurred in abandoned stores.
Forecast for the development of the situation in the near future
The state authorities initially took a pessimistic position in terms of forecasting developments. The California Department of Water Resources admitted that if the dam structure is damaged, the forecast could be unfavorable. According to local police, who interviewed experts in the field of hydraulic engineering, a hole in the spillway could threaten the integrity of the entire dam. However, experts emphasize that dams using concrete components are usually less susceptible to erosion processes.
However, if the structure is damaged, this can also lead to its collapse. IN Russian Institute hydraulic engineering and energy engineering believe that the dam can survive if excess water flow is released through open gates. A disaster is potentially possible if the spillway is not functioning.
The most dire forecasts appeared on February 11, when state authorities announced that the water level in the river would rise to critical levels due to a possible dam failure. Although it was announced the next day that the threat had passed, on February 13, reports of the threat of the dam collapsing again appeared. The negative scenario provides for the speed of wave propagation in flat terrain within 25 kilometers per hour, in mountainous terrain - up to 100 kilometers per hour. It is stated that the height of the breakthrough wave for small reservoirs with a water volume of up to 50 million cubic meters will be up to one meter, but in the case of Oroville, whose capacity is eight and a half times greater, the wave will reach a height of up to nine meters.
Let us remind you that in this case, six settlements with a total population of up to 200 thousand people will be in the flood zone. In turn, RusHydro noted that as of February 12, when signs of active rock erosion were noticed on the slope below the emergency discharge, a certain threat arose for residents of the region. If the overflow wall collapsed due to intense erosion, it could cause an uncontrolled discharge of a layer of about 12 meters of the reservoir in height.
There are also alternative points of view. Forecasting for the coming days is a difficult matter, according to hydraulic engineers from the CIS, interviewed by journalists. It is more likely that the dam will remain unharmed, while the spillways - both the main and the emergency ones - will be washed out to the point of complete destruction, but no noticeable damage will be caused to the population and infrastructure. The overflow through the dam will stop after some time, or the process of erosion of the spillway will take place over a long period - within one month, which will not cause sudden changes in the situation and the problem will not become more complicated.
RusHydro believes that current data gives grounds to assert that there is no threat of destruction of the dam, but the spillway structures are in disrepair. The crest of the dam is located six meters above the emergency discharge mark, therefore an emergency overflow of water is also excluded. If the drainage erosion moves to the spillways themselves, then the latter will probably be destroyed. The pit immediately near the spillway stopped actively expanding, reaching the rocky base after the weak rocks were washed away.
Meanwhile, after the accident at one dam, other “hot spots” in California were simply forgotten. Reservoir overflow due to heavy rainfall is a problem not only at the Oroville Dam, but also at most hydraulic structures in the California Valley. The situation on the Sacramento River near the city of the same name is causing concern. The river dam is showing signs of deformation after prolonged exposure to flowing water. Some water has already leaked through the dam and entered the city park, which is located near the river. In addition, a threatening situation is observed in the area of the dam on the San Joaquin River.
In addition, the water level at the Don Pedro Reservoir dam has almost reached the upper edge of the structure. If a snow storm hits the Sierra Nevada Mountains in eastern California, flooding may be inevitable. To prevent the destruction of these structures, the state authorities decided to deliberately destroy the dam on the Moklamne River, which led to the flooding of nearby agricultural land, but reduced the threat of large-scale accidents.
Possible versions of the causes of the accident
ABOUT possible problems the problem with the dam became known long before the February accident in 2006. Even then, experts discovered minor violations of the integrity of the main spillway, but the facility was declared suitable for operation. Major repair work on the dam has not been carried out for half a century - from the day it was put into operation. Last decade the dam operated under a temporary license. Probably, the reason for the uncertain status of the dam is associated with the attempt to obtain a permit for a period of 50 years by the Californian authorities and the subsequent reaction of social activists.
In 2005, a group of activists representing environmental organizations - the South Yuba Citizens League, Sierra Club and Friends of the River - demanded that officials reinforce the emergency discharge with concrete instead of an earthen foundation. The joint letter from the organizations argued that during winter rains, water will begin to overflow the main spillway, which will ultimately lead to erosion, further destruction of structures and flooding. Proposals were submitted to the Presidential Administration and the Federal Energy Regulatory Commission, but they, based on the findings of the California Department of Water Resources that such work was inappropriate, rejected the initiative. According to the authors of the letter, the authorities simply decided to save money, since strengthening the emergency spillway with concrete would have cost millions of dollars. Now the department says the cause of erosion on the drainage drains is unknown.
Like any serious threat, the situation with the risk of dam collapse has already become overgrown with rumors and exotic theories. In particular, it is assumed that a possible disaster was deliberately provoked in order to smooth out the discontent of the population of California, most of whom are in presidential elections voted for Hillary Clinton. A great misfortune can unite a nation and eliminate political differences. In addition, it should be taken into account that California social activists are actively calling for the separation of the region from the United States.
Proponents of the conspiracy theory believe that the failure of the main spillway was controlled and was the result of sabotage - the leak arose by interfering with the work of the already worn-out infrastructure. In addition, there were statements that rescue services carried out exercises several years ago, during which they practiced actions in the event of a dam collapse. At the same time, practically exact date possible event was already specified in the maneuver scenario.
If we talk about real facts, then RusHydro, which analyzed the development of the emergency situation and possible preconditions, came to a number of conclusions. It is noted that the destruction of the operational spillway occurred suddenly, and the water flow levels were not at all maximum. Thus, we should talk about an insufficient degree of control over the condition hydraulic structure, which did not allow timely detection of damage, the company noted.
It is difficult to call the design solution itself correct, associated with the discharge of water masses onto an ordinary unequipped slope. Spillways must undergo mandatory testing. However, it must also be noted that the safety margin of the dam turned out to be sufficient, despite the fact that accidents occurred at both spillways. Thus, large hydraulic structures can generally be considered reliable structures, the company noted.
Regardless of what the results of the accident investigation turn out to be, it is obvious even to non-specialists that, if we do not take into account dubious theories of sabotage or sabotage, the unsatisfactory condition of both spillways was most likely the result of ordinary negligence of the services, which did not timely track the process of structural damage due to natural processes wear. The lack of preventive measures almost caused a large-scale tragedy, and for the happy outcome of the situation we can only thank the reliability of the dam itself, which acted as insurance against the negligence of industry services.
In California, about 200 thousand residents are being evacuated due to the risk of the Oroville Dam breaking. This dam is the largest in the United States. California police say they are currently opening additional shelters and places to house people throughout the state.
In the United States, almost 200 thousand residents of California are being evacuated due to the threat of a breach of the Oroville Dam. This dam is considered the largest in America, its height is more than two hundred meters. The reservoir overflowed after record rainfall for the region, and the spillway system could not withstand the load. The concrete structures were partially destroyed by the powerful flow. Residents of several major cities They are hastily leaving their homes, reports.
At the Oroville Dam in California, a real disaster could occur at any moment. The volume of water that can escape from the storage facility threatens to instantly flood vast areas. Immediately after discovering a gap in the drainage system, local authorities decided to urgent evacuation residents of all settlements located below the dam. First of all, this is the city of the same name Oroville with a population of 16 thousand people, as well as whole line settlements located along the Feter River. The evacuation began on Monday night. In total, about 190 thousand people are displaced.
"We are now opening additional shelters in several cities. In the city of Chico, St. John's Church is also open to receive evacuees. We are organizing additional places for accommodation. We are acting as prescribed in the event of a flood," said Chico Police Chief Michael O'Bryan.
To accommodate people, all available premises in schools, colleges and other areas are being used where temporary accommodation centers can be set up. The roads are filled with cars. People quickly leave the dangerous area in their personal vehicles. Taking advantage of the fact that settlements They are quickly emptying out, and looters have begun to operate in some places. At least three stores were reported robbed.
After many years of drought, several last months There was heavy rainfall in northern California. The water level in Lake Oroville was rising rapidly. The first reports from engineers who discovered damage to the spillway at the dam were ominous. The structure was expected to collapse at any moment. It was decided to use a reserve spillway that had never been used before. But experts found a gap in it 90 meters wide and 150 meters long. The water pressure is constantly increasing and the hole in the spillway is increasing. Erosion of the main structure already occurred in 2009 and 2013, but then engineers were able to quickly repair the damage. Authorities have now deployed helicopters to drop rocks into the open part of the drainage system to fill the gap. But the effectiveness of these actions may be low.
"On this moment the main spillway contains about one hundred thousand tons of water. We are now working closely with experts to ensure that we have the ability to eliminate the soil erosion that led to the damage to the dam. We were able to increase the amount of water released through the backup spillway," said California Civil Defense Chief Kevin Lawson.
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