THE LEVEL OF INCOMING WATER WILL NOT BE CHANGED, BUT REDISTRIBUTED.Vyacheslav Nikitin
This article focuses on the danger of construction and its impact to the ecosystem of the lake.
On the southern shore of Lake Baikal Mongolian power engineers calculate the financial benefits and risks from the construction of a hydropower plant on the inflows and main channel of the Selenga River. Meanwhile, on the northern shore of the great lake scientists are already talking about the great danger this project poses for the main source of drinking water on the planet.
Mongolia intends to solve the internal energy problems of the republic by building several hydropower plants in the Selenga basin. This river supplies Lake Baikal with its great body of water. The proposed hydropower plants are Shuren HPP in the channel of the Selenga, Aeguin Gol, Orkhon and Chargait, which are planned to be located at the inflows of this river.
The benefits of these constructions for the republic of Mongolia are obvious but how bad is this for Lake Baikal?
“Harmful” sounds too judgmental, but it is obvious that it will have an impact,” Vyacheslav Nikitin, head of the laboratory of hydropower and water management systems at the Institute of Energy Systems of the SB RAS, gives a balanced opinion on the project of building the Mongolian hydropower plant. “This is the subject of our study now”.
Shurenskaya hydropower plant, which is planned to be built on the main channel of the Selenga, is located 150 kilometers from the border with Russia and there are almost no other rivers inflows from the Selenga to Naushki. It means that all the changes in the runoffs as a result of hydropower plant activity will be permanent both approximately in the downstream area of the Shuren and a hundred and fifty kilometers downstream where the Russian territory begins.
“Ordinary people usually see it in the following way: they will build HPP, water everywhere will be blocked and the Baikal will become shallow. But this project will make insignificant impact on the water level in Lake Baikal, because what will be changed is not the amount of water coming from Selenga, but the regime of river flow,” explains Vyacheslav Mikhailovich.
THE LEVEL OF INCOMING WATER WILL NOT BE CHANGED, BUT REDISTRIBUTED.Vyacheslav Nikitin
This means that naturally only 7-9% of the annual flow of water from Selenga to Baikal occurs for the winter period, and up to 90% comes with the beginning of the water management year in the spring with the melting of ice.
The entire ecosystem has adapted to this regime: high water in the spring until summer and a period of low water coming closer to the cold weather throughout the winter.
When the hydropower plant will operate, the natural runoff regime will be changed abruptly. “High water” will be saved in the summer and drawn down measuredly in winter.
“According to our calculations, the amount of water coming from Selenga will decrease in 2-5 times in the summer, and it will increase in 3-5 times in winter,” says Vyacheslav Nikitin. “It is difficult to predict how the bio system of the lake will react. At the first stage last year we assessed the change in the flow, we know how it will be regulated by the Mongolian side. Simulation of the effect on the biosystem is currently underway.”
The whole food reserve complies to the high water period. Fish herds, water animals gather and vegetation develops in May to June period. How the sharp decrease in runoff will affect all this biological activity? It is difficult to predict, and we can only hope for, as experts call it, "the stability of the biosystem". According to scientists, it is obvious that the flood zone will be changed, and then the temperature of the water and its turbidity will be changed and this must have an impact on the animal world of Lake Baikal.
“With that, there is no need to overestimate the impact on the entire Baikal of water, altered by the presence of hydropower plants in Mongolia. Indeed, two-thirds of Selenga's length are located in Mongolia, and one third is in Russia. However, it should be taken into account that out of 30 cubic kilometers of water, which come into Lake Baikal from the Selenga during the year, only ten cubic kilometers come from the Mongolian side. Two-thirds of the water body from the river are formed in the tributaries when it flows three hundred kilometers through the territory of Russia, and this part is not the subject to the influence of the Mongolian hydropower plants," clarifies Vyacheslav Mikhailovich.
Andrey Fedotov, director of the Limnological Institute of the SB RAS, sounds much more pessimistic. When asked how he, the employees of his institute and scientists associated with the study of Lake Baikal, generally refer to the plans of the Mongolian side to build a cascade of hydropower plants on Selenga, he answers unequivocally:
“We do not approve of this. Selenga is the main tributary of Lake Baikal. 50% of the water budget is brought in by this river. After the dam has been built, the Selenga will become less full-flowing. Less water will come to Russian territory. And recently as we all know the Baikal water level is near to or below critical, this happens due to a low amount of precipitation in recent years. These were years of low water. In Mongolia, as you know, there is even less precipitation, it is a steppe and arid country. To make the dam work, when the river is blocked, you need to take the volume of water that will be wasted later. That's similar to how you usually fill your bath at home.
“According to our calculations, it will take four years to fill the working dam at the not very deep tributary of the Selenga upon the project "Egine-gol". It is proposed that firstly large tributaries of the Selenga will be blocked by dams, and then the river will be blocked, very little will come down to us. But this is only one problem.”
“Are there another one problem?”
“Yes and not the last one. So, we are very concerned about the quality of water that will come to us. Imagine what will happen if what was previously land, will now be flooded. As at the construction of the Bratsk HPP there are forests under water. There will be a steppe under the water. And this water of a different chemical and physical quality will come to the Selenga.
WE DO NOT KNOW IF OMUL AND OTHER BAIKAL FISH WILL BE ABLE TO CLIMB FOR SPAWNING UP TO THE SELENGA IN THIS KIND OF WATER. WE CAN TALK ABOUT DAMAGE TO OUR BIORESURES OF THE BAIKAL.Andrew Fedotov
“So you are saying that this water will not be just of another quality, but it will be lower in quality and it will cause damage?”
“Absolutely! Those wastes of the cattle industry, what have the herds left walking freely along the former banks of the Selenga, will be flooded, and the level of biogenic components in the water will increase exponentially! Moreover, if you look at the satellite images, most of the farmland territory is in the areas of flooding. It will also be flooded after the launch of the hydropower plant. After the local water level will increase, the so-called basis of soil erosion will go up, and then groundwater will inevitably go up on the surface.”
“But why is it dangerous?”
“There is high solar radiation in Mongolia, simply speaking, there is a very bright sun. If groundwater rises, the level of evaporation increase; as a result salts boiling off begins, the soil becomes salinised. It’s like the boiling kettle in your home. The distillate leaves into the atmosphere in the form of steam, and the scum remains on the bottom. This salt will remain lying on the banks around the dam. But it happens sometimes that rains occur even in sunny Mongolia. And that increased concentration of salts, located in the catchment areas of reservoirs, will again come to us with the waters of the Selenga. This is another reason of the change in the chemical composition of the water due to the construction of the Selenga hydropower plant.”
According to the director of the Limnological Institute, there is no point to expect that everything will be in perfect order when the dams are built, filled and switched on, and can regulate the level of Selenga entry water without sudden natural drops, and the hydrological level will finally be straighten out. The chemical composition of water will be completely different, and this is the main problem. He did not undertake to evaluate on-the-knee the time, degree and quality of such a change, but he assured that such influence would be quite definitely negative.
The expert in the field of sustainable development of hydropower Artur Alibekov also adheres to the same point of view. According to him, the change in the hydrological regime of the Selenga river can lead to significant risks of reducing the biological diversity in the freshwater floodplain of Selenga and Lake Baikal, which are unique objects that are included in UNESCO World Heritage sites.
“These unique ecosystems have been formed for centuries, and they are adapted to the natural conditions of the ecosystem. A change in the hydrological regime of the river will lead to a change in ecosystem conditions, disruption of food chains, will change balance of forces in ecosystems and will create conditions for the development of invasive species and the possible reduction of native plant and animals that we can see in many similar floodplains and deltas of regulated rivers.
“Also, the goal-setting for hydropower projects are of great concern, because we understand that the Orkhon-Gobi drainage project does not solve the problem of developing the water management complex in Mongolia. Accordingly, other projects can be considered in the medium term as water management projects aimed at the water supply. Planned reservoirs are a convenient facility for water supply and water withdrawal. This is also an additional risk of reducing the flow entry into the Baikal in the future.”
The expert believes that the Mongolian specialists and their Russian colleagues need to join in their efforts to find and develop solutions acceptable for both sides to solve the water and energy problems of Mongolia, without harming Lake Baikal.
“The efforts should be aimed at the search for compromise and alternative options, but not create a new precedent for a trans-border water conflict.”
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