Effects Of Agricultural Land Cover On Water Quality At The Watershed Scale In The Lower Kaskaskia River Watershed

Agriculture is currently the leading cause of stream impairment in the United States. As the population continues to grow, as well as the demand for biofuels, more pressure is being exerted on land to produce greater quantities of food. To satisfy the need for increased production, marginal forest and grasslands have been converted to agriculture, fertilizers and equipment have rapidly evolved, and land has been taken out of conservation programs. Unfortunately, water quality impairment often accompanies these efforts to increase crop production. To reduce the impacts of agriculture on water quality, best management practices (BMPs) have been developed and tested at the field scale, with fewer studies focusing on the effects of agricultural land cover and BMPs (e.g., riparian buffers) on water quality at the watershed scale. Thus, this study was designed to assess the effects of riparian buffers and agricultural land cover on water quality at the watershed scale. Within Richland and Silver Creek watersheds (tributaries of the Lower Kaskaskia River watershed in Illinois), forty-three catchments were selected across an agricultural to urban land cover gradient. Having an understanding of the impacts that riparian buffers and headwater streams have on water quality is key for watershed managers to focus restoration efforts in the most critical areas for maintaining stream quality.