Significance Statement
This field study evaluated fish passage through a series of vortex rock weirs that were built to address channel migration and erosion alongside a road. The fish that use this channel are relatively small minnows and need the water moving over and through the rock weirs to be slow enough that they can swim through or situated such that they can leap over the rock weirs. The significant findings from this study show that key design stage elements (e.g., material size, material placement) ensured fish passage was possible under low, intermediate and higher water levels throughout the study period.