Rivers are important components of many urban systems, and research into urban rivers are considerable research. The object of the research is technogenically transformed aquatic ecosystem of small rivers passing through urban areas of Kyiv city. These small rivers are tributaries of the Irpin River. The study used an ecosystem-basin approach, statistical processing of data. The complex research on patterns of their development for the long-term period were made, the quality class of water and indexes characteristic were ostended.