Abstract
The article presents the results of a study of the hydrological regime of the Ural river in the territory of the West Kazakhstan region, the average annual flow of the river, as well as the average decadal water levels during the spring flood. According to the presented results, there is a noticeable decrease in annual runoff, which directly has a negative impact on the local ichthyofauna of the reservoir. The decrease in the water level in the Ural river affects the efficiency of natural reproduction of phytophilic fish. In 2019, due to a decrease in the water content of the Ural river, carp fish, namely common carp, did not have the opportunity to spawn in floodplains and flood meadows of the river. When catching producers for the purpose of artificial reproduction, the spawning herd of common carp was represented by individuals aged from 5 to 12 years.