Until recently, this amazing natural reservoir was of considerable interest. It was popular with tourists and was considered one of the most beautiful lakes in the Altai Republic until this terrible natural disaster happened: the lake ceased to exist.
More detailed information on the death of Lake Maashei in Altai is presented in this short article.
Lake History
A lake appeared about 100 years ago, after a huge landslide blocked the riverbed. Mazha flowing on the site of the North Chuysky ridge (height - 1984 meters). Administratively, this area belongs to the Kosh-Agach region. The lake was 1, 500 meters long and 400 meters wide.
Since then, there has been no heavy and long-term rainfall in these places. Earlier, bypassing the pond along the western bank and moving further along the riverbed of the Maasha River, it was possible to get to the glacier called Big Maashai. From under it flows a river.
According to various sources, in the upper river valley there is a modern glacier, and six kilometers from it there are moraine ridges, which are witnesses to the lower ancient position of the glacier. Of the niches that are located on the sides of the main valley, one can see huge ridges-tongues, one of which (30-40 meters high, 700 meters wide) almost blocks the entire valley. It is a powerful language of glacial-colluvial material and does not reach the steep right rocky slope of the valley (about 50 meters). It was from him that a collapse occurred, which formed a barrier to the flow of water from glaciers, which contributed to the formation of Lake Maashey. From the flooded forest and the towering dry larch trunks above the water, we can judge that the reservoir was formed relatively recently. On some larches, branches remained above the water.
Description of the lake
At one time, this lake was described by the famous glaciologist M.V. Throne. According to him, this pond is amazingly beautiful. Its turquoise water reflects the panorama of the source of the lake. Along the perimeter, it is framed by trunks of extinct trees sticking out of the water.
It was located on the river Maasha (or Mazha). The depth of Lake Maashey is 3.5 meters. It should be noted that it gradually chalked up, filling with various material that the river brought from the glacier and from the high steep slopes of the valley. It happened that in winter and early spring, the basin of the lake was completely drained, exposing the bottom.
The water level in the summer period depended on the volume of melting glaciers. With strong melting, it increased, and with a decrease in runoff, it became smaller. Excess water was filtered through the dam.
Most of the water discharge was observed from the opposite side of the dam. From them begins the river. Maash, which is one of the largest tributaries of Chui. Only one not very powerful exit was observed in the lower part of the “valley” lowering along the right slope of the valley. The majestic snow-capped peaks of the North Chuysky Range were clearly visible from the shores of the lake: Karagem (3750 meters) and Maashey (4173 meters). It was from this place that tourists made a trip to the glacier of the same name.
Lake Maashey was located about 7 kilometers from the glacier, high in the mountains (1984 meters). It should be noted that it was simply impossible to get to this wonderful reservoir: they went to him on horseback or on foot in multi-day expeditions. Nevertheless, it was popular with travelers.
The death of Lake Maashey
In 2012, on June 17, due to heavy torrential rains in the mountains (starting from July 5) and with the flow of mudflows, the transverse moraine wall (natural dam) of Lake Maashei eroded. The result of this natural disaster was the "leakage" of the lake from the bed. It went away in just a few hours through the resulting ravine. The pond has ceased to exist.
In addition, due to heavy rainfall, which led to an increase in water levels in Chuya and Ak-Tru, the bridge on Chuy was demolished by huge streams of water and trees were torn out, and a powerful stream of water came off the Akt-Tru glacier. Maasha Lake is no more.
Present
Today, a river of the same name flows through the territory of the former Maashei Lake, heavily polluted by various sedimentary rocks. Its waters run along a drying valley.
Gradually, nature took its toll, and perhaps the landscapes will soon become the same as before the formation of the lake. It turns out that this beauty (by natural standards) did not exist for long - only about 100 years. Only preserved photographs can recall the past - the existence of such a beautiful lake.
Research Results and Conclusions
How did Lake Maashey flow out? How could it disappear?
The research results confirm that the breakthrough of the natural dam occurred due to rising water levels due to heavy rainfall. Such prolonged downpours occur once every several decades. The lake was formed as a result of the debris flow, so it could be assumed in advance that it would be destroyed in the same way.
Similar phenomena, when lakes are formed on the rivers as dams, occur relatively frequently in the mountains. And this can be a threat to some settlements located downstream of the river.
For such rivers it is necessary to establish special monitoring.
