Constructed water structures and hydropower plants almost certainly create a barrier for the ichthyofauna migration. This is the reason for decrease of fish population downstream as well as upstream the river. Fish passes are designed to enable fish migration. This book proposes a methodology for design of fish passes. The design begins with obtaining and analyzing of background materials, water management inputs, situation, ichthyologist data, etc. The next step is design of longitudinal section and cross section according to maximal discharge, fish numbers and space possibilities, boulder...