At present time, during the period of intensive climatic changes, it's important to thoroughly take into account hydrological regimes of water bodies. Оnе of the major conditions of ensuring hydrological safety of territories is а reliable forecast of stream-channel deformations and channel-related processes in case of water bodies and their separate sections. This paper reviews different methods of calculating bed load discharge. Based on this a proposed new technique оf calculation оf bed load discharge was developed with consideration оn the probabilistic estimate оf the beginning оf bed load motion, the method shows satisfactory results compared to previous techniques in use.