the Italian Alps Paola Faggian*, Stefano Maran*, Stefano Barontini**, Giovanna Grossi**, Roberto Ranzi**, Nick Kouwen*** 33rd International Association of Hydraulic Engineering & Research (IAHR) Biennial Congress Vancouver, British Columbia, 9-14 Agosto 2009 * ERSE SpA ** UNIVERSITA’ DI BRESCIA *** UNIVERSITA’ WATERLOO We simulated runoff in the current and future climate scenarios in two Alpine basins (1840 and 236 km²) in Northern Italy relevant for irrigation water supply and water power generation. Simulated rainy days and daily precipitation from NCARPCM scenarios for the 2000-2099 period were downscaled with the multiplicative cascade ß-model to force the WATFLOOD hydrological model and assess changes of runoff regimes in the two watersheds. In spite of a slight increase of precipitation, a decrease of about 5% of runoff volume, for the 2050 scenario, and of 13% for the 2090 scenario was estimated at the outlet of the two basins, on average. Same changes in energy generation are expected for the hydropower plants with significant storage capacity and the outlet of the Lys basin, with a run-of-river type of hydropower plant, changes in the runoff regime would result in a decrease of energy generation of 2.5% and 6.9%.