Hydraulic Modeling of an Upstream Passage Barrier for Adult Spring-Run Chinook Salmon on Butte Creek

River2D was used to develop a hydraulic model of an upstream passage barrier for adult spring-run Chinook salmon on Butte Creek. Topographic data were collected using total station, survey-grade RTK GPS and terrestrial LIDAR. Stage-discharge relationships were developed at the upstream and downstream ends of the site to use as boundary conditions and to calibrate the 2D model. A pressure transducer was installed at the downstream boundary of the model to provide a time series of flow and water temperatures. Parameters of the hydraulic model that will be examined to assess upstream passage include minimum thalweg depth, depths, velocities and water surface elevations above and below a jump, and the flow split between the two main flow paths through the site. These hydraulic parameters for the time series of flows, together with recorded water temperatures, will be compared to passage data from a VAKI unit located just upstream of the site to evaluate how hydraulic conditions affect upstream passage of adult spring-run Chinook salmon, for the purpose of assessing what flows are needed for upstream passage. The topographic dataset can also be used to develop potential structural solutions for upstream fish passage.