Answering the most common question: why fluctuations in the water level influence the lake ecology and could it be harmful to Baikal.
According to the data of the Limnological Institute of the SB RAS, the level of Lake Baikal fell to the level of 455.75 m (above the level of the Pacific Ocean) on April 5, 2018. A decrease to the level of 455.68 m was recorded during the month from March 5 to April 5, which is 3 centimeters lower than the previous record of 455.71 meters in 2016. At the same time, the average level for the past month was 455.8 m, and the maximum level even reached 455.9 m. Although the lake’s ice cover has not yet begun to break, the regional Department of the Ministry of Emergency Situations of Irkutsk Oblast has recorded a change in the ice structure and not only closed all ice crossings, but also banned all mass events on the ice.
In accordance with the letter of the Federal Water Resources Agency as of April 4, 2018, the Yenisei Basin Water Administration established new operating modes for the hydropower units of the Angara cascade for the period from April 6 to May 6, 2018: Irkutsk HPP - average daily discharge of 1300 m3/s; Bratsk HPP - the mode of ensuring the established operating mode of the Ust-Ilimsk hydropower unit; Ust-Ilimsk - safety average daily discharge of 2000-2100 m3/s; Boguchany HPP - average daily discharge of 2050-2300 m3/s with the maintenance of the water level in the Boguchany water reservoir not lower than 207.0 m above the level of the Baltic Sea. The web site of the agency noted that “the operation modes of the hydroelectric power plants of the Angara-Yenisei cascade are subject to prompt adjustment by the Yenisei Basin Water Administration, depending on the current hydrological situation”.
The inflow of water to the reservoirs of the Angara cascade gradually increased at the end of March, however, the air temperature in the southern part of Irkutsk Oblast significantly decreased during the first 10 days of April. According to the forecast of the regional department of Russian meteorological service, the average temperature in April will be 1-2 degrees (Celsius) higher than the climatic standard, so, the flood will resume until the end of the month.
A month has passed since the moment of signing of the decree on the transfer of two regions from the Siberian Federal District to the Far Eastern Federal District. We talked with the experts and found out how this fact would affect the fate of Baikal and whether anything would change for the lake in the future.
During the two days, October 30 and October 31, the level of Lake Baikal rose to 456.99-457.01 meters above the level of the Pacific Ocean. The lake that had experienced a period of severe low water for four years surprised everyone once more.
It was easier to close the Baikalsk Pulp and Paper Mill than to remove the damage done by it to Lake Baikal.