This paper analyzes in quantitative terms the effectiveness of information in real-time operation of multipurpose reservoirs. For this, a simple and heuristic method strongly based on the experience of the manager is proposed and tested on the case of Lake Como (northern Italy). Particular attention is devoted to the possibility of evaluating the surplus of benefit due to the information available in real-time in addition to reservoir storage (e.g., snow cover, aquifer depth, and rainfall in the catchment). Moreover, a management scheme based on the direct use of the raw data is compared with a more sophisticated scheme using inflow predictors. Surprisingly, the first scheme, although more simple, performs better, thus justifying to a certain extent the little interest that practitioners sometimes seem to have for real-time forecasting techniques
