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

A reservoir was established to ensure a minimum water level in the river.

Additionally, the reservoir provides flood control for the Isar River between Bad Tölz and Munich.

During the 2005 European floods, the reservoir's maximum capacity was reached.

The Faller-Klamm-Brücke connects road traffic to the North (Bundesstraße 307).