Neustadt Dam, Heritage dam in Harztor, Germany.

Neustadt Dam is a curved gravity dam of rubble stone built on the Intze Principle, impounding the Krebsbach in the southern Harz. Its crest is about 134 m long and 4.25 m wide, the wall rises 32 m above the valley floor, and the reservoir covers roughly 14 ha. The masonry air side is faced with natural stone, and the spillway has 11 openings of 5 m each.

Built between 1904 and 1905 as a curved rubble-stone gravity dam following the Intze Principle, it is the oldest dam in Thuringia. The Nordhausen city council approved construction on 17 March 1902; Italian specialists carried out much of the work, and the dam was raised by 6.26 metres in 1922–1923. It was refurbished between 1997 and 2001.

The Krebsbach stream feeds the reservoir, and the water is delivered to the Wasserversorgungsverband Nordhausen. The electricity from the dam's Pelton turbine, about 300,000 to 400,000 kWh a year, powered Nordhausen's trams by day and the town's street lighting at night. A checkpoint (no. 218) of the Harzer Wandernadel hiking system stands on the western side of the valley.

Swimming and water sports are prohibited in the reservoir, and the dam crest itself may not be walked on. A public path instead circles the roughly 14-hectare lake, which stretches about 1.5 km north-northeast to south-southwest. On the western side of the valley, hikers pass checkpoint no. 218 of the Harzer Wandernadel stamp system.

The water drives a Pelton turbine by Siemens: about 180 m of head between dam and Nordhausen, fed through an 11 km cast-iron pipe of 400 mm diameter to a turbine house at the Osterstraße high reservoir. It yields roughly 300,000–400,000 kWh a year, powering Nordhausen's trams by day and the street lighting at night.