In most of the Swiss Alpine regions, the availability of water resources for irrigation is usually adequate, even in period of drought, as evidenced by the summers of 2003 and 2018. Indeed, important natural stocks are for the moment available in the form of snow and ice, but the situation is likely to change in the future considering global and regional climate change. The municipality of Val de Bagnes located in the canton of Valais, Switzerland, is a region where water is a very important economic factor used for hydropower, winter and summer tourism and agriculture. The study will make it possible to apprehend the needs and future availabilities for irrigation water, by 2050 and 2085, and to plan as soon as possible the modifications required to the water supply or distribution networks. This article focuses on the modeling and simulation of future scenarios of the water network. The results are based on the principle of deficit on the water demand compared to the available water in the adduction network. To illustrate the influence of the climate change on these deficits, simulations based on RCP scenarios have been run for years 2050 and 2085. The current network configuration seems to be suitable for the demand and the variability of the input until 2050. Nevertheless, for the 2085 forecasts, the existing network would not be able to match the demand. This study shows that a regional interdisciplinary approach between the technical, agricultural and social fields is necessary to manage water resources in the future even in Alpine regions where no extreme water stress is observed today.