Fig. 5. Daily data of outflow discharge (m3s-1) plotted against lake level (m ASL) from 1946 to 1990 (light gray) and from 1991 to 2007 (dark gray, covers some light gray data points); dashed black line: rating curve for Lake Como in natural conditions (before construction of the dam in 1946); plain black line: rating curve for Lake Como in regulated conditions, all dam gates open (free regime); dotted red lines: regulation range; plain red line: lowest elevation of Piazza Cavour measured in 1997 (Comerci et al. 2007). Rating curves were elaborated by the Hydrographic Office of the Po River and reported by Moisello and Vullo (2011).