It has long been known that vicarience events such as storms can shift fish populations in the wild, but the effects of vicarience events in urban freshwater streams has been poorly studied. An observational study was conducted by measuring the population size of five different species of fish in Waller Creek at five locations that run through the University of Texas campus and the surrounding areas over a period of 16 months. It was found that all species of fish can be displaced downstream over dams with only a moderate storm, but the distance they are displaced varied with the general size of the fish species and the severity of the storm. This understanding of population dynamics in urban creeks allows for the possibility of predictive modeling of vicarience phenomena, as well as the possibility for better assessments of urban creek health.