Several rivers have their sources in the national park, including the Bode, the Oder and the Ilse, a tributary of the Oker. The waters of the Oder, flowing southwards, are collected in the historic Oderteich reservoir, finished in 1722 to supply the mines in Sankt Andreasberg, and feed the Oder Dam on the southeastern edge of the park. Other dams and lakes within or bordering on the national park include the Ecker Dam and the Silberteich. The highest elevations are the Brocken, the Bruchberg and the Achtermann.