limestone mountain area in the Umbria-Marche Apennines of Central Italy. The dam,
completed in 1962, was built for purposes of flood control and irrigation-water storage. The
hydrogeological budget shows that part of the water reaches a regional karstic system: some
of the water of the catchment supplies a very large high-salinity karstic spring about 30 km
away from the dam. The climatic data indicate that rainfall is decreasing, consistently with …