Štěchovice Reservoir, lake in the Czech Republic

Štěchovice Reservoir is a narrow valley reservoir on the Vltava, held back by a dam 22.5 m high and 124 m long at the arch, filled in 1943. Its water runs 9.4 km from the 84.3rd river kilometre to the foot of the Slapy dam, and both banks drop as rocky slopes straight into the water, so no path follows the shoreline.

Construction began in 1937 and the power station was put into operation in 1943, as the second stage of the Vltava Cascade; the reservoir flooded St John's Rapids (Svatojánské proudy). Its main role is to balance the runoff from the peak-load station at Slapy Reservoir. The 2002 floods severely damaged the turbines of both power plants, which returned to service in 2004 and 2005.

The reservoir covers the former Svatojánské proudy rapids, named from the 18th century, which made the Vltava a one-way route for rafts. In 1919 tramps founded the settlement Ztracená naděje on the banks below the rapids; it disappeared under the water in 1943. The 5.2 km Svatojánské proudy educational trail between Třebenice and Štěchovice passes the rebuilt settlement.

Neither bank can be walked along the waterline, so the two shores are reached by separate trails. On the left bank a path cut through rock tunnels runs just above the water; the right-bank route stays high on the ridges and gives views into the canyon. The 5.2 km Svatojánské proudy educational trail between Třebenice and Štěchovice is the most visited route.

The reservoir feeds two Kaplan turbines at Štěchovice I with a combined installed power of 2 × 11.25 MW, and the lock beside the dam handles a 20.1 m difference in water levels for ships up to 1,000 tons. The upper reservoir of the pumped-storage plant Štěchovice II was built on top of Homole hill.