|Aiwe di Lesse|
The Lesse in Han-sur-Lesse.
|Municipalities||Daverdisse, Libin, Libramont-Chevigny, Paliseul, Tellin, Wellin, Dinant, Houyet, Rochefort|
|- left||Our, Almache, Wimbe, Biran, Hileau|
|- right||Lomme, Vachaux, Iwoigne|
|- location||Libin, Ardennes, Belgium|
|- elevation||480 m (1,575 ft)|
|- location||Dinant, Namur, Belgium|
|Length||89 km (55 mi)|
|Basin||1,343 km² (519 sq mi)|
|- average||19 m³/s (671 cu ft/s) |
The Lesse is 89 km (55 mi) long. It flows roughly in a northwestern direction. Its source is near Libramont-Chevigny, in the Belgian province of Luxembourg. The mean discharge for Anseremme between 1995 and 2004 was 19.0 m3.
The watershed of the Lesse Basin, with an area of 1,343.4 km2 (518.7 sq mi), has about 1,920 km (1,193 mi). With only 62,500 people living there, it is the least densely populated of all small watersheds of Walloon region.
Part of the watershed of the Lesse is on limestone where there are some karstic phenomena. Near Han-sur-Lesse (commune of Rochefort), by the Gouffre de Belvaux, the entire river goes underground, flowing through limestone caves.
From its source to its mouth, the main tributaries of the Lesse are:
- Our, left tributary; it joins the Lesse near Redu.
- Almache, left tributary; it joins the Lesse in Daverdisse.
- Lomme, right tributary; it joins the Lesse in Éprave.
- Wimbe, left tributary; it joins the Lesse in Villers-sur-Lesse.
- Vachaux, right tributary; it joins the Lesse in Ciergnon.
- Biran, left tributary; it joins the Lesse in Wanlin.
- Hileau, left tributary; it joins the Lesse in Houyet.
- Iwoigne, left tributary; it joins the Lesse near Houyet.
The valley of the Lesse and this part of the Ardennes are covered with forests. The area surrounding the caves is the National Park Lesse et Lomme. On the mountains along the lower part of the river there are several castles. The route of the former railway line from Houyet to Rochefort is used as a hiking and cycling trail.
Many of the caves along the banks of the Lesse are important archaeological sites - these include the Trou de Chaleux (by the Cirque de Chaleux), and the Trou des Nutons and Trou du Frontal at Furfooz.
- Région Wallonne de Belgique: État des lieux du sous-bassin hydrographique de la Lesse (PDF; 5,9 MB), 2005, S. 8