Main issues concerning drinking water supply in the Angara River watershed. Water supply for drinking and communal-general purposes plays an important role in every economy all over the world as water is not only widely used for people’s everyday purposes, but is also essential for people’s vital functions. The principle concerning the priorities of supplying drinking and communal water, stipulated in relevant norms and regulations, presumes that in the first place people should be provided with water according to the existing scientifically grounded health standards. At the same time, drinking water is only a part of natural water resources; thus, it is closely linked to the whole hydro-economic situation of the region, and the connection is one of interrelation and interdependence. The territory under consideration stretches from the source of the Angara River downwards to the city of Bratsk and constitutes the upper and middle sections of the river. The following features are typical of this territory: high level of urban development, high level of anthropogenic pressure on water resources, wide scope of water quality and quantity conditions; all of the above result in a difference in drinking water provision between the regions and communities.