Design for fish passage at roadway-stream crossings: Synthesis Report
design, fish passage, literature review, survey, channel, Substrate, hydraulic design, baffles, weir, fish movement, fish biology, culverts, barriers, hydrology, history, monitoring, future research
Federal Highway Administration
Cataloguing and synthesizing existing methods for the design of roadway-streamcrossings for fish passage began in January 2005 with an extensive literature review coveringthe topics of culvert design and assessment to facilitate fish passage. A survey was postedonline to gather input from design professionals across the country, and a Culvert SummitMeeting was held in Denver Colorado from February 15-16, 2006, to allow presentation anddiscussion of state-of-practice design and assessment techniques. Following the Summitmeeting, a Technical Advisory Committee was developed with individuals specificallyknowledgeable in the topics of interest. Members were crucial in shaping and reviewing thedirection of these guidelines. This document places current culvert design techniques into fourcategories based on design premise and objectives. These categories include: No Impedancetechniques, which span the entire stream channel and floodplain; Geomorphic Simulationtechniques, which create fish passage by matching natural channel conditions within the culvertcrossing; Hydraulic Simulation techniques, which attempt to closely resemble hydraulic diversityfound in the natural channels through the use of natural and oversized substrate; and HydraulicDesign techniques, which may utilize roughness elements such as baffles and weirs to meetspecies specific fish passage criteria during periods of fish movement. Preliminary chapterscovering the topics of fish biology and capabilities, culverts as barriers, fish passage hydrology,and design considerations aid in the selection of appropriate design techniques based onhydraulic, biologic, and geomorphic considerations. A further section presents examples ofdesign techniques fitting the defined design categories. Design examples and case histories fora selection of design techniques are presented next, and are followed by a discussion onconstruction, maintenance, monitoring, and future research needs.