Scholarly Work - Civil Engineering
Permanent URI for this collectionhttps://scholarworks.montana.edu/handle/1/3460
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Item Flow-Control Plates to Manage Denil Fishways in Irrigation Diversions for Upstream Passage of Arctic Grayling(U.S. Fish and Wildlife Service, 2023-06) Plymesser, Kathryn; Blue, Tyler; Kappenman, Kevin M.; Blank, Matthew; Cahoon, Joel; Dockery, DavidSmall-stream irrigation diversions are key elements of many on-farm irrigation systems but can act as barriers to aquatic species. Denil fishways have been installed at irrigation diversion structures throughout the Big Hole River watershed in Montana to provide upstream passage for a population of Arctic Grayling Thymallus arcticus. When stream flows are low and irrigation demand is high, irrigators look for ways to maintain adequate diversion, but doing so may reduce the effectiveness of the fishways. In response, agencies and irrigators have proposed flow-control plates placed at the upstream end of fishways. We conducted laboratory-based fishway efficiency experiments with Arctic Grayling placed in an open-channel flume fitted with a Denil fishway and three flow plates. Of the total 200 fish that we used, the fishway entrance attracted 154 fish and we counted these fish as participants. We operated the fishway under varying flow conditions using three flow-control plate treatments and a control to investigate 1) the extent to which each treatment reduced flow compared to the control, and 2) the extent to which each treatment impacted passage success of Arctic Grayling relative to the control. We measured passage success as the ratio of the number of fish that fully ascended the fishway treatment to the number of participant fish attracted to the fishway treatment. One of the three plates, the Denil slot treatment, showed no evidence of reducing either flow or passage success. Another plate, the standard treatment, showed no evidence of reducing flow but moderate evidence of reducing passage success (P = 0.03). The only treatment to significantly reduce water flow rate was the narrowed Denil slot treatment and there was no evidence this treatment reduced passage in comparison to the control. Over all trials, water flow rate through the Denil fishway had a strong positive influence on fish passage success.Item Swimming Performance of Rainbow Trout and Westslope Cutthroat Trout in an Open-Channel Flume(2020-06) Blank, Matt D.; Kappenman, Kevin M.; Plymesser, Kathryn; Banner, Katharine M.; Cahoon, JoelWe used an open-channel flume to characterize the swimming performance of Rainbow Trout Oncorhynchus mykiss and Westslope Cutthroat Trout Oncorhynchus clarki lewisi ranging nominally in fork length from 15 to 30 cm. With an open-channel flume, we observed volitional swim performance of wild-caught Rainbow Trout and Westslope Cutthroat Trout; the fish were not coerced, prodded, or spooked into action. We also observed the maximum short-duration swim speed of the fish, providing important effective leap or velocity challenge information for the design of intentional barriers. We conducted the experiment with a consistently low water velocity challenge and characterized swim speeds by using weighted least-squares regression, revealing no evidence of a difference in swim speeds between the two species. We estimated the overall average swim speed for Rainbow Trout to be 0.84 m/s (SE = 0.02), with a 95% confidence interval of 0.79–0.89 m/s, and that for Westslope Cutthroat Trout to be 0.84 m/s (SE = 0.03), with a 95% confidence interval of 0.78–0.90 m/s. The maximum swim speeds observed were 2.72 m/s for Rainbow Trout and 3.55 m/s for Westslope Cutthroat Trout. The project results provide new information on the swimming ability of wild Rainbow Trout and Westslope Cutthroat Trout that can be used to improve fish passage or barrier design.Item Pressure gradients in a steeppass fishway using a computational fluid dynamics model(2017-11) Plymesser, Kathryn; Cahoon, JoelThe Alaska steeppass is a fishway used commonly in the eastern United States and in remote locations, and is an example of the many configurations of fishways, ladders, bypass channels and other structures intended to facilitate fish mobility in river systems fractured by in-stream structures. Passage success for this fishway is varied and depends on many factors including species of interest. The cause of this variation is relatively unknown and typically ascribed to “other hydraulic factors†, meaning a hydraulic variable other than the mean (spatial and temporal) velocity. Attempts have been made to move from velocity-based to energy-based fish passage models to pinpoint these “other factors†, however energy-based passage models rely on assumptions that may be inappropriate when applied to hydraulically complicated fishways. An assumption that has facilitated wide ranging discussions of the performance of fish ladders without the develop of very specific and detailed computational models is that pressure forces that a fish might experience can be adequately estimated using uniform flow pressure distributions. In uniform flow, the vertical pressure distribution is as if hydrostatic, and there is no pressure gradient in the horizontal plane. To test this assumption, very detailed three-dimensional hydraulics information was generated from a computational fluid dynamics (CFD) model of the steeppass to calculate the pressure. The results demonstrate the significance of considering dynamic pressure distributions when modeling the interaction between hydraulics and fish mobility.Item Sedimentological Analyses of Eggshell Transport & Deposition: Implication and Application to Eggshell Taphonomy(2015-06) Imai, Takuya; Varricchio, David J.; Cahoon, Joel; Plymesser, KathrynThe interpretation of fossil eggshells can be problematic because eggshells may be transported by hydraulic flow in floodplains, making it difficult to interpret the reproductive behavior and ecology of parent animals. A series of flume studies was conducted to establish analytical techniques for assessing eggshell hydraulic transport in the fossil record. We investigated preferred eggshell orientation after transport, the relationship of flow competence with eggshell height and volume, and the size of clastic sediment expected to be associated with transported eggshells. Goose, emu, and ostrich eggshell fragments were released in a flume with decelerating flow. The transport of each eggshell was observed five times on each of four substrates (coarse sand, sparse gravel, dense gravel, and polyvinyl chloride). At eggshell deposition, eggshell orientation and flow depths were recorded. Critical bed shear stress for eggshell deposition was estimated based on the flow depth at the point of eggshell deposition, tested relative to eggshell height and volume, and used to estimate the size of hydraulically equivalent particles. The probability of concave-down orientation after transport was > 85% regardless of eggshell type or substrate. The bed shear stress at eggshell deposition reflected the eggshell height and volume. The estimated size of hydraulically equivalent particles was coarse sand or larger. A high proportion of concave-down eggshells in a fossil assemblage may indicate transport. In addition, eggshells may be sorted according to their height and volume. Coarse sand or larger particles observed in a matrix of fossil eggshells may suggest eggshell transport.