Nitrification and denitrification in freshwater ecosystems alter and remove a substantial amount of nitrogen draining from landscapes. Despite the global prevalence of nonperennial streams, the influence of the drying and rewetting on nitrogen (N) cycling is not well understood. We hypothesize that drying and rewetting could have lasting impacts on downstream water quality. To test this hypothesis, we performed a streamflow diversion experiment at Shane’s Creek (434 ha, 3rd order) at the Konza Prairie Biological Station, Kansas. We diverted flow in a 150m reach for five weeks, resulting in reduced surface flow and a cessation of flow in riffles leading to a series of disconnected pools in the experimental reach. Water and sediment samples were collected prior to and during flow diversion, upon resumption encompassing a Before-After-Control-Impact design. This experiment was followed by a natural drydown across both the control and impact reaches, during which additional opportunistic samples were obtained. Denitrification enzyme assays and nitrification incubations were performed weekly. We hypothesized that (1) denitrification rates would decrease over a period of drying while (2) nitrification rates would increase due to increased oxygen availability and (3) rates of both would increase upon flow resumption due to increased water and nutrient availability. We found that nitrification rates were halved in the impact reach during the experimental dry down and in both reaches during the natural dry down. Denitrification rates in the impact reach increased and surpassed rates in the control reach during the experimental dry down. Denitrification rates further increased during the natural dry down in both reaches. Denitrification and nitrification are controlled by N and DOC availability, redox conditions, and microbial communities. Further work is being performed to explore how these variables are impacted by drying and rewetting, and the resulting impacts on N processing rates. With the ubiquity of nonperennial streams, their ability to process N is relevant worldwide.