In complex of agrotechnical actions is included the plowing of slopes, creating of the forest strips, snow protection aimed to preserving and enhancing the moisture, creating needed water-air regime in the soil, improving the anti-erosion resilience mountainsides [2, 6]. The article provides assessment of the effect of the impact of farming on the annual runoff in the conditions of the forest-steppe and steppe zones of Moldova. Under influence of agrotechnical actions norms of natural annual runoff declining in value, equal to the increased evaporation from the surface of the river catchment [3, 5]. According to the available data, the degree of reduction norms of annual runoff of small rivers is changed from 3.9% to 6.1% and mostly depends on percentage of ploughing slopes River catchment.