It is correct that the origins of the first bisses remain unknown, but the main phase of development (15th century) can be historically explained.

Due to climate warming at the beginning of the 12th century and, above all, to significant population growth, there was an initial extension of the bisses, especially between 1250 and 1350. The great period of bisses construction occurred in the beginning of the 15th century. Pierre Dubuis, Professor of History at the University of Geneva, has clearly pointed out the cause of this extension. We must remember that a traditional society, based on cereal cultivation and sheep breeding, lived in this area without an irrigation system. In the middle of the 14th century, the Valais was struck by the Plague. The decrease of population meant less demand for crops. Rather than letting land revert to a wild state, local communities turned cultivated land into pasture. The development of bisses was the result of economic reorientation. The bisses played a major role in the design of a specific agro-pastoral mountain production system. Local populations raised cows not only for subsistence but also because the economy focused on export, notably of cheese. The bisses were needed to irrigate meadows and to increase yield. Grass was produced to feed the cattle during the winter. The construction of bisses stabilized after 1500, probably due to more humid and colder climatic conditions (Little Ice Age). In 1860, the railway reached Sion, the capital of the Valais, heralding the arrival of cheap cereals. There was an increase of cattle rearing in response and consequently an extension of the irrigation system.

What is interesting about the bisses is their long history. They have not been a static element. They have been used for purposes other than meadow irrigation, including vineyard and fruit tree irrigation, for example. These choices were made depending on market conditions.

With the decline of mountain agriculture in the second part of the 20th century, the importance of bisses has also declined. In the regional context of the Valais, it is hard to agree with the philosophical perspective expressed by the author: “A bisse will survive economically only where it provides real livelihood opportunities at the household level” (p 52). In fact, 75% of the farming concerns in the Valais are a secondary activity (Institut d'économie rurale, ETHZ, 2000). Agriculture itself does not play a major economic role. The bisses appear to have continued to evolve through time. Even if they are still a part of the agricultural infrastructure, they play a role in tourism nowadays and also in social identity, the link between the two being patrimony.