Agriculture and tourism are the two economic sectors with the highest water demand in the island of Sardinia. Water demands are mostly satisfied by reservoirs that store water from winter precipitations. The paper reports the impact of climate change on water availability in 2050 and draws patterns of water demand for the two sectors under different development scenarios. On average climate change has a minor impact on water availability, but a sharper decline in precipitations is expected in the years beyond 2050. Water demands for agriculture are projected to increase up to 18% depending on the development scenarios, while those for tourism could more than double under Intensive Tourism Growth scenarios. Reservoirs are found to be able to sustain the increased water demand under the different scenarios, however the cost to implement the water distribution network for both agriculture and tourism sectors are large and require accurate integrated management planning and choices.