Land use effects on stream nutrients at Beaver Lake Watershed

Abstract

Elevated stream nutrient concentrations and transport downstream can accelerate the eutrophication of drinking water supply reservoirs. The objectives of this study were to compare nutrient concentrations (1) during storm events and base flow conditions, (2) across land use gradients, and (3) within the water column to those within the fluvial bed material across the streams draining the Beaver Lake Watershed in northwest Arkansas. The water samples collected during storm events had greater nutrient concentrations compared with base flow conditions. Stream nutrient concentrations during base flow conditions and storm events increased with increasing proportions of pasture and urban land use within the watershed. Dissolved nutrient concentrations were positively correlated to nutrient content within streambed sediments, representing a potential nutrient source when inundated. An understanding of nutrient sources and effects of land use is important for developing effective watershed management plans, as well as the influence of sediments on in‐stream nutrient concentrations.