The presented monograph consists of two parts. This book is the first part of the general work of the university staff. The monograph deals with general issues related to water bodies and monitoring of their condition. The authors present the methods of econometric modeling that are used for estimation of the level of pollution of water bodies and for prediction of their further state, such as pairs and multiple regression models, the simplest models of time series. The monograph contains examples of practical application for the construction of regressions and time series models. This allowed the authors to formulate some proposals for improving the procedure of monitoring the status of water bodies. Earlier the authors published the following works on this topic: Arhitektura programmnoj podderzhki i dannyh monitoringa vodnyh resursov Voprosy radioehlektroniki /Igrunova S.V., Putivceva N.P. [et all]. Seriya EHlektronnaya vychislitel'naya tekhnika. Vyp. 1. - Moskva. 2013.- S. 46-58. Mnogokriterial'nyj vybor investicionnyh proektov / Putivceva N.P., Igrunova S.V., Nesterova E.V. [et all]. Verlag: LAP LAMBERT. OmniScriptum GmbH & Co. KG Alle Rechte vorbehalten, 2015. . 89.