Happurger See, Reservoir in Happurg, Germany

Happurger See is a reservoir of the Happurg pumped-storage plant, held back in the Hersbrucker Alb between the Houbirg (618 m), the Deckersberg (586 m) and Reicheneck. It lies at 366 m above sea level, measures about 1.2 km by 0.45 km and covers roughly 55 hectares on average. Steep, wooded slopes drop straight to the dark water, with green fields and a few small buildings along the lower shore.

The Happurger See was created in 1955 as the lower basin of the Happurg pumped-storage plant, built by Nuremberg architect Franz Reichel; the plant began operating in 1958. Its upper basin sits on the Deckersberg. Water seeping through underground cavities emptied that basin as early as 1962, and the plant has been out of service since January 2011. Operator Uniper announced in June 2024 that it should return to the grid by 2028.

The lake takes its name from the neighbouring village of Happurg. A marked trail around the shore carries stations of the Happurger Geschichtsweg, and the sailing club Hersbruck has its grounds and clubhouse on the northern shore. Anglers have places at the southern end.

The water level has stayed constant since the pumped-storage plant went offline in 2011; before that it swung by up to 4.5 metres with electricity demand. The southern shore road runs directly past the lake, and the S1 S-Bahn stop at Happurg is about 1.5 km on foot through the village. A restaurant with an outdoor area, a bathing beach and a car park sit on the western shore.

Since the plant shut down in January 2011, the lake's level has stayed constant; before that, pumped-storage operation shifted it by up to 4.5 metres with electricity demand. Uniper plans to reconnect the plant to the grid by 2028, investing around 250 million euros, with work begun in spring 2025.