Excess nutrients in waterways contribute to eutrophication and decrease aquatic ecosystem health, a problem affecting both rural and urban catchments. In order to address excess nutrient problems in urban waterways, authorities have been developing strategies to mitigate impacts by using in-channel and landbased stormwater treatment to remove pollutants via settling and other physical, chemical and/or biological processes. However, little is known about how pollutants are transported and transformed in urban in-channel systems under the influence of different groundwater conditions. Therefore, this research aims to understand nutrient dynamics (nitrogen and phosphorus) in waterway channels under the influence of seepage, neutral, and drainage conditions. It was hypothesized that groundwater and bed material characteristics affect the concentration and form of surface pollutants, as well as their mobility. This understanding could help guide stream management decisions.