Around 1200 BC, the Mediterranean (Aegean) migration led to the invasion of the «sea peoples» into Palestine, Syria and Egypt. And, as a consequence, the natives were displaced (but not to the south – there are deserts there, but to the northeast). The migration of the Dorian tribes, the death of the Mycenaean culture and the destruction of Troy were also associated with this migration. When we visited the remote areas of Kazakhstan, we asked the indigenous people why the rivers were called Aksu and Karasu, and were surprised by their deep knowledge of toponymy and local natural conditions. It turns out that when naming a particular stove or lake, the ancient nomads took into account whether they would be able to water their cattle in a given place, say, in the middle of summer or not. After all, in the dry season, temporary flowing rivers, designated in Kazakh by the word «aksu», dry up, and, on the contrary, the reaches of rivers with groundwater feeding – «karasu» «hold» water. Thus, the names Aksu, Akbulak, Aksay, Akkol, as well as Karasu, Karabutak, Karakol, etc., so widespread in the Ural basin, characterize not the color of the water, but the features of the water regime. These are either «flowing» or «ground» reservoirs. Among the Kazakh names of rivers, you can most often find those beginning with the words «ak» and «kara». There is a widespread opinion that the geographical network of Kazakhstan and adjacent regions of Russia consists almost half of «white» («ak») and «black» («kara») rivers, streams, gullies, lakes. However, it is absolutely clear that such a name does not explain the local features of geographical objects. Therefore, it is necessary not only to translate the name, but also to explain its origin.