The results of studies in the paleochannel of the Volga River, which was discovered earlier on the northwestern slope of the Derbent Basin, Caspian Sea, are presented. Seismoacoustic profiling in the paleochannel, combined with placement of submerged buoy stations equipped with current gauges, water temperature gauges, and sediment traps showed that the channel is not silted and cold heavy water is transported along it to the deep sea part of the sea, avoiding the general water transit along the western coast of the Central Caspian Sea. The preliminary calculations show that water discharge through the channel to the near-bottom part of the sea can be about 8–10 km³/yr.