Water Quality and Exurbanization in Southern Appalachian Streams

Many rural areas of the United States are undergoing increasing development pressure from surrounding metropolitan areas, a phenomenon described as 'exurbanization'. This study examines how stream chemistry in a traditionally rural area of the southern Appalachian Mountains is being influenced by changes in both land cover and land use. Results illustrate the importance of distinguishing between these two measures. Nitrate and specific conductance were well related to catchment-scale land cover. Variables associated with particle transport, such as turbidity, were not well predicted by either catchment land cover or land use, but relationships with land use were somewhat clearer because development and agricultural land-use occur primarily in the valleys where land disturbance can more directly affect sediment inputs to streams. However, recent residential development is now occurring largely on mountainsides rather than in valleys. This mountainside development is associated with higher stream nitrate concentrations and degraded water quality to downstream communities. The paradox of exurbanization is that by moving from the city to enjoy forested and rural landscapes, people threaten the quality of life in their new communities and also in their old ones downstream.