Lake Sarez is terrifying the population of four countries at once

2024 Author: Seth Attwood | [email protected]. Last modified: 2023-12-16 15:55

When you contemplate the surface of Lake Sarez (Pamir), it seems that it is thousands of years old and has always been here. But this is a misleading impression. In fact, this huge lake with a length of 70 kilometers is very young, just over 100 years old. It arose as a result of a large-scale natural disaster, but it is itself a source of colossal danger for the population of this region of Central Asia.

Sarez Lake is the pearl of the Pamirs, located on the territory of Tajikistan. This large reservoir belongs to dammed lakes, that is, the reason for its appearance was the collapse of rocks, which blocked the narrow valley of the Bartang (Murgab) River, forming a natural dam. This event, which took place in 1911, was named the Usoy Dam. Scientists suggest that a powerful earthquake was the cause of this phenomenon.

The scale of the Usoy Dam is simply amazing. The natural rock debris dam is 567 meters high and more than 3 kilometers wide. This is the largest rock fall on the planet of all recorded during the existence of mankind. The resulting blockage blocked the river's path, and the resulting bowl of the future lake began to slowly fill with water. For 3 years after the formation of the dam, the researchers did not notice leaks in the dam, but in 1914 it was discovered that springs were leaking through the Usoi dam. The depth of the new reservoir by that time exceeded 270 meters. 7 years after the formation of the natural dam, the depth of Lake Sarez was already 477 meters, and it filled the river valley with its waters for 75 kilometers from the place of the Usoy dam.

Today Lake Sarez has a maximum depth of 505 meters. The length of the lake, depending on the amount of precipitation and occupancy, varies from 65 to 75 kilometers. Such a grandiose size of the reservoir is fraught with threats no less in scale.

The fact is that, according to studies carried out in the Bartang Valley, the Usoi Dam is far from the first. On this river before, there were landslides and dams, which led to the formation of dammed lakes. Geologists have discovered traces of at least 9 similar bodies of water in the Bartang Valley that existed here in the Quaternary period. But what happened to them? The reason for their disappearance, most likely, was either earthquakes, which occur quite often in the Pamir mountains, or heavy precipitation that eroded the dams.

Researchers fear that Lake Sarez may suffer the same fate. Despite the fact that over the past years the natural dam has shrunk 60 meters and significantly compacted, it is difficult to imagine how it will behave in a strong earthquake and whether it will withstand the pressure of the increased volume of water in the event of an abnormally large amount of precipitation. With an area of 80 sq. km the lake contains about 17 cubic meters. km. waters that, as a result of a breakthrough, rush to the lower part of the valley, washing away everything in their path. In addition, there is another danger: a collapse in the water area of the lake itself. Back in the 60s of the last century, an area with an increased risk of landslide was recorded on the coast of Lake Sarez. Even a minor earthquake can provoke a landslide, and then a significant volume of water will be displaced from the lake, which, overflowing over a natural dam, will also rush downstream of the river. Such a mudflow is less dangerous than the breakthrough of the dam itself, but also does not promise anything good to the inhabitants of the settlements in the Bartang Valley. In the event of a possible descent of the lake, not only the territory of Tajikistan, but also neighboring Kyrgyzstan, Uzbekistan and Kazakhstan will be affected. The fact is that the Bartang flows into the Pyanj River, which in turn is a tributary of the Amu Darya. In the event of a catastrophe, its scale will be such that the wave will reach the Amu Darya and the Aral Sea.

Taking into account the seriousness of the situation, back in the 70s of the last century, a project was developed for the construction of a hydroelectric power station in the location of the Usoi dam. As a result of the construction of the hydroelectric power station, the level in the lake should have dropped by 100 meters, which would have minimized the threat of a breakthrough. But due to technical and material difficulties, the project was never implemented, and the question of the safety of the population downstream of the Bartang River remains open. In 2006, with funds from international investors, an emergency warning system was installed in the region, which, in the event of a disaster, will warn the population about the threat, but the issue of the safety of Lake Sarez is still unresolved.