Lake Robertville, lake in Waimes, Wallonia, Belgium

Lake Robertville is a reservoir in Waimes created by a dam on the Warche river and surrounded by dense forests. The lake covers about 63 hectares and features a sandy beach with a designated swimming area, diving platforms and trampolines, as well as boat rentals for rowboats, electric boats, and pedal boats.

The reservoir was completed in 1928 and has supplied drinking water to nearby Malmedy ever since. The dam, roughly 54 meters high and 180 meters long, also generates electricity through hydropower and helps manage flooding in the region.

The lake lies in the Hautes-Fagnes-Eifel nature park, on the edge of the High Fens plateau, and its name comes from the village of Robertville in Waimes. Sailing, windsurfing, kayaking, pedal boats, swimming, walking, cycling, running and sport fishing are practised on and around the water; motorboats are not allowed. A 2021 book by Guy Lejoly, La construction des barrages sur la Warche, published by Malmedy Folklore, recounts the building of the dams.

The site is easy to reach by car with ample parking at main areas, while buses also stop nearby with the nearest stop about eight minutes walk from the main site, offering an alternative for those without a car.

The dam is a gravity-arch structure holding back 8,000,000 m³ of water; its wall is 54.50 m high, 182 m long along the crest and thickens from 4 m at the top to 58 m at the base, using 57,000 m³ of concrete and masonry. A 5.4 km pipe carries water to the Bévercé power station. In February 2010 the lake was drained for work on the valves and a protective membrane, refilling from September that year.