This article collects toponymic data concerning historical names of large lake systems and rivers of Kazakhstan. Toponymic data are important in determining the geographical representation of natural objects in the historical period. The use of valuable geographical names data as a source of information and research is an essential component of toponymy.In the article, we considered this using the example of hydronyms of the southeastern part of the country. That is, the historical names of the Balkhash and Alakol lakes, the main artery of the Zhetysu Land, the Ili River, which are of great importance in the socio-economic development of the country, explained from different sides based on scientific sources.Landscape changes of natural objects over time were determined based on historical and cartographic data and scientific writings. The information burden of toponyms, language and explanatory reasoning may be a source for the fields of applied science related to history, geography and the environment