Fish Passage Behavior for Severe Hydraulic Conditions in Baffled Culverts

摘要

Laboratory tests were conducted with brown trout to evaluate their ability to pass through a small, baffled prototype-scale culvert under a variety of culvert slopes and discharge conditions. The culvert was 18.3m long and 0.60 m in diameter with 0.15D baffle height and 0.9D spacing, where D is the culvert inside diameter. An inverse relationship was observed between fish passage success and flow rate and/or culvert slope. The influence of the sample fish population and the length of the individual fish on passage rates were investigated; the data showed that the brown trout fish passage sample size evaluated in this study (25 per test) was sufficiently large to minimize sample size dependency. The elapsed time required for fish to traverse the culvert decreased with increasing hydraulic difficulty primarily owing to diminishing resting zones. The behavior of fish traversing the culvert was observed and reported, including resting/staging zone locations.