The result of construction of a hydrochemical system in the section line of the Dniester River at Novodniestrovsk was the achievement of practically total control of the river flow in the Moldovan part. At the same time, this system controls not only the seasonal variation of the level of the river but also forms a new hydrological and hydrochemical regime of the river as a result of the controlled discharge of water through the Novosdniestrovsk barrage. The level of impact of this process on the quality of waters was the main objective of current research. With this purpose during the years 2005-2006 there were performed investigations in the segment of the River starting with buffer reservoir (200 m below the barrage) at Naslavcea and ending with c. Dubasari (100 m below the Dubasari barrage). Water samples were collected in 6 different section lines. The parameters measured included: water temperature, pH, Eh, rH, hydrogen peroxide content, OH radicals content, dissolved oxygen, total amounts of iron, copper, soluble forms of nitrogen compounds, COD, BOD5 and others. A special attention was drawn to the analysis of the redox state of waters, the content of OH radicals and other parameters that were affected by man-made systems or activities. In the frames of the project 8 expeditions were carried out.