This chapter presents a compilation of techniques and research results published by the authors in journal articles concerning the use of numerical methods and univariate and multivariate statistical methods applied to evaluate, predict and control the behavior of important engineering variables that are monitored by instruments in the dam of the Itaipu hydroelectric plant. The introductory section contextualizes Itaipu and the importance of the methods used. Next, we present a brief theoretical description of univariate forecasting methods, multivariate statistical techniques, and the finite element method. After describing the set of techniques, the reader can always find specific applications in Itaipu of one or more of the preceding techniques. The results, in general, show that the combination of statistical and numerical methods helps to improve the performance of forecasts and, in general, can collaborate in the decision-making of Itaipu engineers and are an additional risk analysis tool that can be applied to any dam.