Julio Alberto Alterach*, Maximo Aurelio Peviani*, Alberto Elli*, Milena Vergata* Giornale: European Small Hydropower Association: ESHA Publications-Ottobre 2008 * CESI RICERCA A methodology to evaluate the residual potential hydropower energy taking into account the current water resource exploitation (irrigation, drinkable water, existing hydro power, etc) was developed. The model applied to the Italian territory uses a numerical technique coupled with a GIS, the hydrological and physiographic characteristics of nearly 1500 interconnected sub-basins at a national scale and the rainfall maps information. The Italian maps of the water resources availability and the maximum potential hydropower are produced and illustrated in the web. To analyse the hydropower potential at a watercourse scale, the VAPIDRO-ASTE GIS software tool was developed: users select an Italian river of interest, then input the hydrological data and the actual water uses and the model implemented in the tool assists to configure the best hydropower exploitation system considering minimal costs and the maximum power generation. These tools and maps demonstrate to be a quite helpful support to administrations, decision makers and stakeholders in general, to make Energy Master Plans, or assess and implement small scale hydropower plants. For more information please contact julio.alterach@cesiricerca.it or visit the internet site www.cesiricerca.it, Potential Hydropower production in Italy (left) and the upper Oglio River (right) .