Söse Dam, Embankment dam in Lower Saxony, Germany.

Söse Dam is an embankment structure that crosses the Söse valley in the Harz mountains and holds back a large reservoir. The facility stores water for regional needs and spans a considerable distance across the landscape.

The dam was built in 1931 and became the first modern reservoir facility in the Harz region. The project arose from the need to secure water supplies for regional industry and towns.

Since 1933 a long-distance water main has run from the reservoir, its northern branch reaching Bremen; today it mainly supplies towns around Hildesheim and Hanover, and since 1980 also Göttingen. Anglers need a health certificate because the water is used for drinking, and fly-fishing only is allowed in the pre-dam.

A walking path of about 9 kilometers circles the reservoir and offers good navigation through marked routes. Visitors should bring sturdy footwear since the path crosses natural terrain.

The pre-dam is a separate barrier 350 m long and 18 m high, impounding 0.75 million m³; it lets particles settle before water reaches the main reservoir. Since March 2023 it has been under renovation, a project costing over 30 million euros, delayed by high inflows and now due for completion in 2026/27.