All works related to the maintenance of mountain rivers engineering structures especially to river banks protection works are very important in river engineering and flood protection works. The selection of appropriate hydraulic structures depends on many factors. When designing, one should take into account, among others, the type of soil, hydrodynamic conditions, atmospheric phenomena and chemical state of water. Examples of hydraulic structures are: weirs, gabions, rip-rap, boulder ramps etc. This paper discusses the methods of river bank protection, which is rip-rap. We test the quality of the filter material used for rip-rap. If not appropriate material for rip-rap is used very often rip-rap suffers failture. For this paper we have chosen three rip-raps on the Czarny Dunajec river in Nowy Targ. A number of granulometry measurements were carried out at each station. Two stability conditions and a permeability condition were tested.