Cataloging and synthesizing existing methods for the design of roadway-streamcrossings for fish passage began in January 2005 with an extensive literature review covering thetopics of culvert design and assessment to facilitate fish passage. A survey was posted online togather input from design professionals across the country, and a Culvert Summit Meeting washeld in Denver Colorado from February 15-16, 2006, to allow presentation and discussion of state-of-practice design and assessment techniques. Following the Summit meeting, a TechnicalAdvisory Committee was developed with individuals specifically knowledgeable in the topics ofinterest. Members were crucial in shaping and reviewing the direction of these guidelines.This document places current culvert design techniques into four categories based on designpremise and objectives. These categories include: No Impedance techniques, which span theentire stream channel and floodplain; Geomorphic Simulation techniques, which create fishpassage by matching natural channel conditions within the culvert crossing; Hydraulic Simulationtechniques, which attempt to closely resemble hydraulic diversity found in the natural channelsthrough the use of natural and oversized substrate; and Hydraulic Design techniques, which mayutilize roughness elements such as baffles and weirs to meet species specific fish passagecriteria during periods of fish movement.Preliminary chapters covering the topics of fish biology and capabilities, culverts as barriers, fishpassage hydrology, and design considerations aid in the selection of appropriate designtechniques based on hydraulic, biologic, and geomorphic considerations. A further sectionpresents examples of design techniques fitting the defined design categories. Design examplesand case histories for a selection of design techniques are presented next, and are followed by adiscussion on construction, maintenance, monitoring, and future research needs.