For the first time, the connection between the formation of the ultra-high pressure ice dam on the Chuya-Kurai glacier-dammed lake and the development of aufeis processes on the Chuya river was substantiated. Consideration is given to the mechanisms of self-regulation in the process of glacier-dammed lake self-freezing as a consequence of a consequence of synchronous processes of Chuya river aufeis formation and the filling of the hollow with water. It is found that aufeis formation in sections of initial damming of the water flow caused an increase in the height and area of the dam and, hence, in its weight. Due to the large weight, favorable conditions were created for the development of the processes of regelation and plastic viscous flow of the monolithic ice massif, without formation of cracks and water flow channels inside the ice body. These factors were responsible for the long-term resistance of the dam to destruction processes. A possible retrospective assessment of the lake filling duration at different flow rates in the Chuya channel is made. It is established that the suggested formation mechanism for a high-pressure ice dam is consistent the well-known cryogenic-hydrophysical patterns and can, therefore, apply for realistic events.Keywords: glacier-dammed lake, high pressure ice dam, ice reservoir, perennial aufeis, regelation, stability.