Abstract <p>A distinctive feature of the tectonic structure of the eastern coast of Lake Baikal is the alternation of coastal horsts with rear depressions. The depressions accumulate products of physical and chemical weathering of rocks. Surface and underground waters flowing down from the surrounding area are located at a shallow depth. Horsts composed of bedrock prevent free flow of groundwater into the lake. As a result, vast areas of the coast are underflooded. It has been shown that flooding can be caused by the hydraulic connection of groundwater in the coastal area with the water level in Lake Baikal. Lake water can penetrate hundreds of meters from the shore through highly permeable rocks. The near-surface location of permeable zones contributes to the formation of domes in the groundwater table. Ground-penetrating radar sounding and well drilling were used to study the conditions for the development of flooding in populated areas located on the eastern coast of Lake Baikal.</p>