Efficiency of water intake facilities in populated areas of the Baikal region

Abstract
The population of the Baikal region (unofficial name of the Irkutsk region) amounts to 2.36 million peo-ple, mainly residing in the Angara River area. Therefore, 91% of all water intake facilities belong the surface shore, river or reservoir types. With the construction of a chain of hydroelectric power plants at the Angara River in 1961, Lake Baikal and the Irkutsk reservoir have become the only artificial reser-voir, whose water level depends on the natural inflow into the lake, as well as energy and water transport activities. As a result, the perennial water level in Lake Baikal and the Bratsk reservoir varies across a wide range, about 2 and 10 m, respectively. In this study, the effect of variations in the water level in Lake Baikal on the efficiency of all water intake facilities of the Angara River is addressed. The conducted calculations and field studies showed that an increase in the water level in water bodies leads to a decreased water quality, requiring its further purification. When the water level decreases, the performance of water intake facilities decreases, requiring replacement of the pumping equipment. An analysis of the surface water intake facilities in the populated areas of the Baikal region showed that the efficient operation of the existing structures is unachievable under significant variations in the wa-ter level in Lake Baikal and the Angara River. It is recommended to use underground water sources. Floating water intake or shore structures operating over the entire range of varying water levels in the water body may be also used.