In the paper was presented the influence of block ramp on system and morphological river bed. One of twenty-five block ramps was chosen to test. This structure was located in the Porębianka river and was situated in the center part of cascade. The morphological variability of the river bed was observed in the years 2010–2011. These changes were caused by floods. The morphological changes were also caused by river training work. These action consisted in repairing block ramps, which were destroyed during the flood. However, the river training work was conducted in the channel bed river, which was leveled. The pools were filled a gravel and the bars were mined from the channel. Despite the anthropogenic impact on the channel river, the research has been shown that the morphology river bed returns to its natural structures, which are characteristic of the braided river. This confirms the thesis that the block ramps cause differentiation of morphology river and restoration of braided channel. The river defend itself against injurious human activities. In addition, in the paper was described the beginning of the pebbles grains movement located in the Porębianka river for the hydrodynamic conditions in during field measurement series. These conditions were based on Shields’ diagram and graph is showing the relationship of boundary shear stress to grain diameter of pebbles.