Souš Reservoir, reservoir on the Černá Desná in Desná

Souš Reservoir is a large body of water in Desná surrounded by Czech mountain landscape and forested hills. Today it functions as a drinking water source for the towns of Jablonec nad Nisou and Tanvald, with the dam structure clearly visible from nearby trails.

Built between 1911 and 1915 on the Černá Desná to designs by Otto Intze and Wilhelm Plenkner, the dam cost 1,454,882 Austrian kronen; the hamlet of Hinterdarre and much of Souš were demolished for it. After the Bílá Desná dam burst on 18 September 1916, the reservoir was lowered to a third of its capacity, then fully drained in 1924–1927 for reinforcement of the dam and a drainage system. A second reconstruction in 1971–1974 converted it to drinking water supply.

The reservoir takes its Czech name, Souš, from the village of Vorderdarre that was demolished to make way for it; 14 houses of the hamlet Hinterdarre and large parts of Vorderdarre were torn down, and some owners rebuilt their homes elsewhere. Until it was converted for drinking water between 1970 and 1973, the 86-hectare lake was a popular local recreation area and angling spot.

The reservoir lies 4 km north of Desná on the road toward Smědava, at 760 m above sea level in the Jizera Mountains. A narrow road runs along the right shore past the stone building at the water's edge and the concrete spillway channel. Because the water is treated for drinking supply, access to the banks is restricted; visitors stay on the surrounding paths.

The reservoir once covered 86 hectares and was a well-known fishing and recreation spot. From 1970 to 1973 it was drained and rebuilt as a drinking water reservoir, after which all other uses of the water were forbidden. The intake tower in the water feeds a 395 m pipe to the treatment plant.