Hydrogeological study of West Siberia is still incomplete. Its southern half (south to the Irtysh River mouth) is covered by hydrogeological mapping of 1:200.000 scale. Its northern part (oil and gas regions) has been studied in 1:500.000 and 1:1.000.000 scale. There are hydrogeological stages in the Mesozoic-Cenozoic cross-sections: upper (most interesting for the water supplying services) is composed of water-bearing horizons of Paleogene, Neogene and Quaternary deposits and lower stage is represented by water-bearing horizons of the Triassic, Jurassic, and Cretaceous. In 1972-1984 regional assessment of exploitational resources of the underground waters for the most studied regions of Tyumen', Tomsk, Novosibirsk, Omsk, Kemerovo, Pavlodar, Kokchetav, Semipalatinsk, and Altai (in the West Siberia Plate boundaries) at the square of 1.183.700 km(2) was carried out. Total exploitation resources of fresh and saline underground waters, suitable for drinking, are about 183.148.300 km(3)/day. Total amount of resources is about 8.565.600 km(3)/day, which is only 4.68% of the revealed exploitation resources. Because of irregular distribution of the underground waters over the area (there are maps of 1:1.000.000 scale) the water supply in some cities (Barnaul, Tyumen', Pavlodar, Aleysk) may be done by using of the surface waters. The existing water flow of the underground waters over the territory reaches 1.874.000 m(3)/day or 1.02% from the calculated exploitation resources. The natural resources of underground waters over the West Siberian Plate are estimated as 355.588.000 m(3)/day. 90% of them are generated in the zones of moderate and superfluous moistening, including saline and saline-like waters with a volume about 37.152.000 m(3)/day. Thus, the potential exploitation resources of fresh underground waters in West Siberia Plate are about 318.436 km(3)/day.
