Monitoring Water Use Regimes and Density in a Tourist Mountain Territory

Abstract

Lack of water use data at the user scale is frequently noted in integrated water management and water demand modelling studies. This situation affects particularly mountain tourist areas, where high seasonal water demand related to the variation of temporary population are rarely documented. Irrigation is also a major water use in moutain territories but is not commonly measured. This paper proposes a framework for local-scale monitoring of seasonal water use behaviours and their territorial inprint. A monitoring strategy was developed to collect water demand data at thin spatio-temporal scales which were analysed using two concepts: (i) the water use regime, describing the dynamics of water uses throughout the year using normalised values, and (ii) the water use density, expressing the territorial footprint of a water use, in terms of unit area. This strategy was applied in the alpine tourist municipality of Montana (Switzerland). A two-year monitoring campaign of irrigation and drinking water uses was carried out combining in-field measurement (water metres) with interviews of water users. The temporal resolution of the collected water use dataset (bi-weekly, daily) was sufficient to assess the specific water demand patterns and the short-term water use peaks responsible for water stress in Alpine tourist regions. It provided the first irrigation monitoring in the area and a classification of drinking water data according to their spatial distribution, the type of building and the permanency of residents. The water use density method gives a new prespective on the spatial intensity of water uses, highlighting the importance of garden irrigation in Montana. Also, the water use regime method identified July as the period of water demand peaking. The monitoring of water uses at such thin temporal scale constitutes the necessary dataset for the creation of water balance models that accurately reproduce the effective water use behaviours.