Oregon Culvert Fish Passage Survey.
culverts, design, fish passage, instream flow, pipes, streams, survey
This report presents the findings from a fish passage survey conducted on various types of highway culverts. This survey includes 39 culverts located throughout the state of Oregon. To simplify the findings, the report places the 39 Oregon culverts into four categories: (1) pipes and pipe-arches with no special provisions for fish passage, (2) pipes and pipe-arches with special provisions for fish passage, (3) pipes and pipe-arches with natural stream beds, and (4) arches. Based upon the survey, the report concludes that culverts with natural stream bed surfaces provide the best facilities for passing fish. The report also presents procedures and criteria for designing and installing highway culverts that must pass fish. From the presented survey findings and recommended design and installation methods contained in the report, the reader should, therefore, be able to resolve most problems associated with designing and installing highway culverts to pass fish.