Since their origin the Alps have been a great reserve of water for the European continent. Nevertheless there are entire valleys, as for example Rodano valley that suffer drought in summer. To exploit these rich and sunny lands, the inhabitants of the Swiss Canton of Valais have built an elaborate irrigation system called “les bisses”, (non poisonous snakes) that takes the water straight from the glaciers to the farmlands. The film portrays the “les bisses” countryside in summertime and, with past and present images, shows the work connected with the operation and maintenance of the system.