bisse

Bisse is the term used for traditional irrigation channels in Switzerland, constructed to convey water from mountain streams to agricultural land. The word is most commonly used in the French-speaking regions, with a high concentration in Valais (Wallis) and surrounding cantons such as Vaud and Bern. Bisses form an old and distinctive component of the Alpine water-management landscape, delivering snowmelt and spring flow to meadows and fields at lower elevations.

Construction and operation: Water is diverted from a source at higher altitude and carried along a channel that typically follows the contour of a hillside or along valley sides by gravity. Channels can be open ditches with stone edging or fully enclosed in stone galleries known as bisses couvertes. Water regulation is managed at weirs or sluices to match irrigation needs. Bisses vary in length and gradient; some sections are supported by stone structures or arches and may cross over rock faces, ridges, or other obstacles. Maintenance is usually organized by local communities or irrigation associations, with responsibilities shared among landowners and users.

History and significance: Bisses date from the Middle Ages and were expanded in the early modern period as alpine agriculture developed. They enabled farming on high meadows by providing a reliable water supply, and they remain an important testament to historical hydraulic engineering and communal effort. Today, many bisses are preserved as cultural heritage and are integrated into regional hiking networks; some sections continue to support irrigation, illustrating a living link between past and present agricultural practice.