The dam is a double-curvature arch dam, a design choice necessitated by the narrow Oker valley topography.
During extreme droughts, the ruins of the village of Schulenberg, which was flooded to create the reservoir, can occasionally be partially seen.
The reservoir's hydroelectric plant has an installed capacity of approximately 8 megawatts.
It is the largest reservoir in the Harz region in terms of dam height.
The reservoir area encompasses the 'Romkerhalle' waterfall, which is a man-made waterfall created by a local hotelier in the 19th century.
The water level fluctuates significantly depending on seasonal rainfall and water management requirements for the regional grid.
The dam sits directly on the border between the Lower Saxony districts of Goslar and Clausthal-Zellerfeld.
The Okertalsperre is a large reservoir located in the Harz mountains of Germany, known for its 75-meter-high concrete arch dam. Completed in 1956, the structure serves as a key facility for flood control, drinking water supply, and hydroelectric power generation. The reservoir basin spans approximately 225 hectares and features a prominent pre-dam called the Vorsperre Oker. Surrounding the water are numerous marked hiking trails, including the Harzer Hexenstieg, which passes through the dense surrounding forests. Boat tours are available during the summer months, allowing access to parts of the reservoir otherwise unreachable by land. The area is also popular for anglers, provided they possess a valid permit for specific fishing zones. The dam wall itself offers a vantage point overlooking the Oker valley. Geological formations, such as the Treppenstein granite cliffs, are situated within immediate proximity to the shoreline.
The crest of the dam wall looking towards the main reservoir basin.
Bring binoculars to spot climbing activity on the nearby granite crags.
Follow the circular 'Wald- und Wasserpfad' trail for a well-marked interpretative route around the reservoir.
Ensure you check local water management websites before planning water-based activities, as levels can shift.
Attempting to swim in non-designated zones, which is strictly prohibited for safety and water quality reasons.
Boat tours operate strictly during the summer season and are subject to weather conditions.
Stick to marked trails to protect the surrounding Harz National Park ecosystem.
