The publisher regrets that due to an error in production the length of a tunnel was printed incorrectly in the published version. We wish to apologise to the authors and to the readers for any inconvenience caused. The correct paragraph from page 6 of the paper can be found below:
In general, the bisse system consists of four major components: the head of the bisse where the water is taken in, the main channel which transports the water, the water storage areas in land depressions forming lakes and ponds, and the water distribution network including secondary and tertiary channels and distribution points (Mariétan 1948). Bisses twist the landscape often openly, dug into the ground or suspended on the rocky walls by ‘boutzets’; the channels are sometimes covered or have sections in tunnels which, in many cases, replace the suspended parts for they are difficult to access and their maintenance is dangerous, which is properly the case for this bisse (Reynard et al. 2012). Indeed, in 1936, a 4,700 m long tunnel, named tunnel du Prabé, replaced the suspended part of the main channel (Mariétan 1948). The bisse of Savièse is still active (Figure 3), and it is providing water from Nétage and Morge at about 1,400 m altitude to irrigate the grasslands and vineyards of Savièse and Grimisuat, mainly (Gisiger 1997).