FISHWAY TO PASS FISH FROM LOWER POOL OF HYDRAULIC WORKS INTO UPPER POOL

摘要

FIELD: hydraulic engineering. SUBSTANCE: fishway is designed for continuously attracting the fish into fish conservation works providing controlled fish attracting water flow at fishway swim-in hole and transferring fish from lower pool of hydraulic works into upper pool and back. Fishway is located in dam site depending on type and layout of hydraulic works and is made in form of flume (fish passage duct) with crosswise vertical walls 3 dividing total head of hydraulic works into parts, 3 to 10 m each. Rectangular fishway (swim-in) holes are made in lower part of walls. Water from feed pump is delivered along pipeline to jet forming nozzles located over perimeter of fishway (swim-in) hole at an angle to hole axis. Water jets, thus formed, create partial counterpressure to main flow providing limited velocities of accompanying (fish attracting) flow through fishway (swim-in) hole. This provides continuous attraction of fish and practically nonlimited pool level differential rise reduced length of fishway duct and time taken for fish to pass along fishway. EFFECT: reduced water discharge, provision of safety of fish, no adverse effect on environment. 2 dwg