Regulating the Level of Lake Baikal: Research Results

This paper presents the main results of comprehensive systems research into the issues of regulating the level of Lake Baikal. The research was conducted in 2021‒2023 as part of State Task FWEW-2021-0009 On the Influence of Changes in the Lake Baikal Water Level on the Lake’s Ecosystem and Assessment of the Damage to Economic Facilities and Infrastructure of the Coastal Territory of the Republic of Buryatia and Irkutsk Oblast, in the Context of the Lake’s Level and Discharges of the Irkutsk HPP (final third stage of FWEW-2021-0009). The research involves analyzing the historical background for the emergence and evolution of the issue of regulating Lake Baikal, considering the need to take into account environmental and socioeconomic factors, and shedding the light on the reasons and relevance of this research. Critical intra-annual periods and components of the ecosystem are identified for the coastal part of the lake whose successful functioning largely depends on seasonal changes in the lake level. Environmental and fishery requirements are formulated for regulating the level of Lake Baikal. Socioeconomic damage is assessed for various lake levels and flow rates of the Irkutsk Hydroelectric Power Plant (HPP). Critical levels and flow rates are identified. Projected changes in the components of the water balance and net inflow into Baikal are presented considering the expected climate changes for the period up to 2060. A procedure (rules) for regulating the level of the lake is proposed with due regard for the environmental and socioeconomic factors for various streamflow water conditions. The permissible maximum and minimum levels, ranges for the lake level fluctuations, and flow rates of the Irkutsk HPP, which could minimize potential environmental and socioeconomic damage, are determined. Proposals are formulated to amend federal legislation related to the issues of regulating the level of Lake level.