When using modern methods of analyzing information about accidents at hydrotechnical structures, one can make forecasts of the probability accidents and calculate the possible consequences. Estimation of qualitative and quantitative characteristics of the accident at HTS barrage regulatory structure on the river Bolshoy Uzen near the village Alexandrov Gai of Alexandrov-Gai district Saratov region, the emergency situations and their consequences was carried out in accordance with the decree of the Government of the Russian Federation dated 21.05.07 N° 304 “On the classification of emergency situations of natural and technogenic character” (with amendments and additions of May 17, 2011). According to the decree of the Government dated 21.05.07 N° 304 “On the classification of emergency situations of natural and technogenic character” the accident at HTS barrage regulatory structure of Alexandrov-Gai district refers to the emergency situation of municipal character, as in the breakout barrage regulatory structure the emergency zone does not extend beyond the territory of the municipality; in the case of hydrodynamic accident the life of people, property of individuals and legal persons, the environment will not damage, and the total amount of detriment caused by damage to the health of 1 person and water supply disruption (the most difficult situation), will not exceed 5 million rubles. The object is not potentially dangerous.