The lake was created in 1966 primarily to regulate the water levels of the Helpe Majeure river.
The reservoir reaches a maximum depth of approximately 16 meters near the dam wall.
It is a significant site for migratory birds, particularly waterfowl that utilize the lake during seasonal transits.
The dam structure is a gravity dam constructed using earth and stone materials.
The surrounding Avesnois Regional Natural Park is renowned for its specific 'bocage' ecosystem, which is protected under local environmental management plans.
Lac du Val-Joly is an artificial reservoir located in the Avesnois Regional Natural Park, created by damming the Helpe Majeure River. Covering 180 hectares, it is the largest lake in the Nord department of France. The site serves as a multipurpose recreational hub offering water sports, cycling, and hiking. The surrounding forest, the Forêt de Val-Joly, encompasses approximately 6,000 hectares of protected landscape. The lake is situated near the Belgian border in a region historically characterized by bocage landscapes and traditional hedgerow farming. Visitors can access a dedicated marina, a swimming area, and an indoor aquatic center.
The viewpoint atop the dam wall, providing a wide-angle perspective of the lake surface against the forested backdrop.
Bring binoculars for birdwatching, as the quiet coves offer excellent vantage points for local fauna.
Rent a mountain bike to explore the extensive trail network that encircles the entire perimeter of the lake.
Pack weather-resistant clothing, as the Avesnois region can experience sudden localized rain showers even in summer.
Attempting to swim outside of the designated, lifeguard-supervised zones during the summer months.
Water sports and supervised swimming areas operate seasonally from late spring through early autumn; the site remains accessible for hiking year-round.
Maintain silence near bird nesting areas; respect designated swimming zones and refrain from littering in protected forest trails.
