Sylvenstein Dam

Sylvenstein Dam is an earthen embankment dam in the Isar valley, in the alpine part of Upper Bavaria, Germany which impounds the Sylvenstein Reservoir.

In the 1920s, several hydropower plants were built in the tributary of the upper Isar river such as ones at the Achensee and Lake Walchen Power Plant. Therefore, the river ran nearly dry during the dry season, and the low water flow affected the town of Bad Tölz. A reservoir was established to ensure a minimum level of water in the river. During the dry season a volumetric flow of 4 cubic metres per second is released to prevent the Isar from running dry. Additionally, the reservoir provides flood control for Isar river between Bad Tölz and Munich.

Source: Wikipedia