Abstract: Identification of mountain and sub-mountain streams - small rivers suitable for rapid development of small hydropower plants (SHP) in the Republic of Uzbekistan and in order to evaluate their hydroecology retrospectively and the level of study of their current state, the river ichthyofauna was studied from the hydro-ecological parameters of the Koksuv River in the Shahimardan aclave, which is one of the enclaves of our country, and where the Shahimardon small hydroelectric power station is planned to be built and put into operation in the next few years and the effects of the small hydroelectric power station on them were considered.