Elevated, and often increasing, chloride concentrations from deicing salt use are observed in streams and groundwater across Canada and the US. Elevated chloride reduces drinking water quality and is toxic to many freshwater organisms. Previous work suggests that chloride may be transported to streams via surface runoff at fast timescales (hours to days), soil water and fast-moving shallow groundwater over intermediate timescales (weeks to months), and infiltration into deeper groundwater and base flow over slow timescales (years to decades). Slow transport is likely the main contributor to long-term increases in chloride. We will use concentration, discharge, and flux data to investigate approaches for quantitatively partitioning chloride concentrations and transport into these three categories. In urban watersheds, fast transport likely causes acute winter spikes in chloride concentrations (and fluxes), intermediate transport likely causes sustained high concentrations for several weeks, while slow transport via groundwater contributes to persistent (but more moderate) elevated baseflow chloride concentrations in non-winter months and in years with little to no salt application. In rural watersheds, intermediate and slow transport are dominant with fewer and less acute winter chloride spikes. Managing and reducing salt application to mitigate impacts on stream ecosystems will require determination of chloride transport proportions via the different transport pathways. Initial responses to reduced salt application approaches will likely be observed as lower concentrations and fluxes via fast and intermediate pathways. However, elevated baseflow concentrations, especially in non-winter months, may persist for years since slow transport pathways are the main contributor.