The actions of erosion caused by precipitation, the alternation between frost and thaw as well as liquid runoff in the receiving basin on the slopes and riverbeds lead to the existence of a significant amount of solid material that is transported by water from the source to the discharge. The Dniester and Prut rivers are cross-border rivers and are also the largest in the territory of the Republic of Moldova. The volume of alluvium runoff and its variability are determined by several factors, which are discussed below. The maximum amount of alluvium in the Dniester transports it during the high spring waters (48–50%) and rainstorms (35–45%). In rainy springs, during the high spring waters, 70–90% of the annual volume of alluvium passes through rivers. In dry years the flow of the summer period is about 40% of the annual one. The alluvium runoff in the Dniester River is regulated by 2 hydroelectric power plants, CHE Novodnestrovsk and CHE Dubasari. They play a major role in the distribution of alluvium in the Dniester River. Thus, for the hydrological post (ph) Hrușca we can speak of 2 periods of observations 1969–1980 and 1981–2019. Until the construction of CHE Novodnestrovsk, at the entrance to the country, at pH Hrușca the average multiannual alluvial flow was equal to 236 kg/s and had a leakage of 7342 thousand tons. In the second observation period, 1981–2019, the transport of alluvium decreased considerably and amounted to 19 kg/s, and the average leakage was reduced by about 90% and is equal to 806 thousand tons. Currently, the amount of alluvium transported downstream of the dam on the Dniester River is much lower, so the risk of clogging the lakes in the basin has been significantly reduced. The alluvium that is collected from the territory of the Republic of Moldova and transported to the mouth of the Dniester, is retained by the dam of the Dubasari reservoir. Downstream of the lake, the alluvium accumulated over a distance of 275 km, is measured at pH Olănești. Thus, the average multiannual alluvium flow increases and is 19 kg s. The construction of all dams on the Dniester had a significant effect on the transport of alluvium downstream to the mouth. The maximum amount of alluvium the Prut transports during the high spring waters (48–50%) and the storm floods (35–45%). In rainy springs, during the high spring waters, 70-90% of the annual volume of alluvium passes through the river. In dry years the flow of the summer period is about 40% of the annual one. Alluvium runoff in the Prut River was assessed based on data from the monitoring network of the State Hydrometeorological Service of the Republic of Moldova at 2 hydrological stations: ġirăuți (located on the border with Ukraine) and the city of Ungheni. Very high turbidity is observed during the passage of intensive rainstorms. An example is the flood of June 1965, when the degree of saturation with alluvium in suspension in the town. Ungheni was 12000g/m3. The concentration of suspended alluvium increases from the source to the mouth of the river.