In this paper the examples of the conditions of embankments small dams in Poland which caused catastrophes were presented. The similar example damage was analyses on small water reservoir to the water take off to snowing of ski lift slope in Lower Silesia. On this danger of stability object the field and laboratory test was carried. The results of investigation demonstrated that the geotechnical parameters of soils aren’t appropriately. Above 50 % values of the compatibility results were lower than 0,92, and under of the base of dam was small layer of organics soil. Also index of plasticity of cohesions ground corps dams were higher than 0,70. This condition caused that too shear down slopes of is very deformed, and settlements of corps of embankment are above 24 cm. Coefficient of stability in ran of reservoir, analyzed of Swedish method is lower than 1,0. The stone – concrete screen on up stream is absolutely no tight. The tested dams of reservoir in Potoczek is in very dangers condition and probably by the piping phenomena and sliding there will be damaged. ...
