Fish-spawning channels are a means of improving the conditions of natural reproduction of populations of anadromous fish on regulated rivers

Abstract

The relevance of the development is predetermined by the need to solve the problem of creating conditions for the natural reproduction of commercial stocks and the restoration of populations of passable, semi-passable and aquatic fish in the conditions of river flow regulation carried out by the construction of cascades of waterworks on them. One of the ways to solve this problem on the Lower Don is the creation of near-hydro-node fish-spawning channels that provide conditions for the passage and spawning of anadromous-migrating fish. When designing such structures, specialists feel a lack of information and recommendations on the technical justification of their layout and design solutions. This circumstance predetermined the purpose of the study, which consists in summarizing information and evaluating the layout and design solutions of the Nikolaev, Konstantinovsky, Bagaevsky and Kochetovsky fish-spawning channels (FSCs) and developing proposals for their improvement. The factual basis of the development was made up of the materials of the survey of existing and analysis of projects of fishspawning channels on the Lower Don low-pressure waterworks. Based on the materials of the survey and analysis, the schemes of their layout and design solutions, flow-rate parameters and geometric dimensions were established, the advantages of fish-spawning channels over other types of fish-passing structures were determined. Based on the materials of the survey of existing structures, the disadvantages of their layout and design solutions were found, consisting in the remoteness of the entrances to the channels from the dams, excessive flow rates in their tracts, the absence of recreation areas for fish, the inability to regulate the values of speeds attracting fish with changing water levels in the river, the lack of equipment of the entrance heads, the failure of the technical execution of the channel coating and elements of enhanced roughness. The directions of improving the layout and design solutions of the channels in terms of eliminating their shortcomings in the projects of the Bagaevsky and Kochetovsky waterworks are determined. The evaluation of design solutions is given and generalizations are made to determine the parameters of channels and their layout and design solutions, which are recommended to be taken into account and used in their design.