The detection of watersource channel proves to be of primary importance in water control and preventing floods in mines. The present paper suggests the application of such comprehensive underground geophysical techniques as drill hole radiowave penetration decay coefficient method and drill-hole high-pre cision temperature maasurement to the search for watersource channel. The tests conducted in two pits (one is flooded and the other not flooded) are given as examples, with a description of their effectiveness and economic benefits.