Scientific paper ID 2761 : 2025/3

A large part of earth-fill dam walls and their facilities in Bulgaria were designed and built in the middle of the last century, more than 60-70 years ago. Over 3500 dams have been built. A large part of these dams are still in operation.

An important element of hydrotechnical facilities are the relief facilities. Their role is to divert high waves and protect both the dam wall and the infrastructure located in the area below it. When the dam wall is destroyed, the accumulated water masses in the dam lake form the so-called flood zones and cause landslides and huge damage to the infrastructure.

One of the most popular climate classifications in the world - that of Köppen from 1936 (Da Cunha, A.R., E.R. Schöffel, 2011), places Bulgaria in the zone of moderately humid climate with tendencies towards semi-arid. This zone is characterized by unevenly distributed precipitation, and climate scenarios predict changes in temperature, precipitation, cloudiness, air humidity, warming and drying of the climate in Bulgaria. Global climate models show a tendency towards an increase in maximum daily precipitation in the region of the Balkan Peninsula. Intense and extreme precipitation can very quickly raise water levels in small agricultural dams.

The article examines the behavior of an earthen dam and its facilities during intense rain. For this purpose, a hydrological analysis of climate change in the area of the selected hydrotechnical facilities was carried out.