Evaluation of the Minimum Discharge from the Dam on Menta Stream (Reggio Calabria, Italy)

Abstract

Many anthropic factors may contribute to the alteration of the natural evolution of the river environment. Among them, probably the most severe is the regulation of the stream flow by a dam. To minimize this impact normally a minimum flow release is guaranteed downstream from the dam. The minimum discharge constitutes an important parameter for the evaluation of the real impact of the reservoir on the catchments downstream. The assessment of this parameter is not easy because two conflicting objectives have to be taken into account: the maximum use of water and environmental protection. The objective of this study is to optimize, apply, and discuss different methods for evaluation of the minimum discharge found in the technical literature to the reservoir on the Menta stream in the province of Reggio Calabria, Italy. In this process particular emphasis is placed on the preservation not only of acceptable levels of discharge during dry months (summer) but also of the seasonal variability of the discharge that largely contributes to the safeguard of the biological potentialities of the stream. Among the methods tested, the one adopted by the Autorità di Bacino del Fiume Serchio (Serchio River Basin Authority, Italy), although modified, provides a good indication of the minimum discharge to be adopted.