Conservation and Restoration Priorities for Water Purification

Clean water is important for a variety of uses, including drinking, recreation, and as habitat for aquatic species. Nonpoint-source pollution, such as nutrients, sediment, and pesticides from agricultural runoff, is a major cause of impaired water quality in the United States . Vegetation and soil in natural land cover help to remove pollutants from runoff water before it reaches streams and other waterways by slowing water flow and physically trapping sediment. To assess the spatial distribution of water purification potential in the southeastern United States, we mapped the demand for purification as the total area of agricultural land and the supply of natural land cover in the flowpath over which water moves from agricultural land to waterways. We used this information to identify priority areas for restoration of natural land cover in the flowpath (areas with high demand for water purification and low supply of purifying land cover) and priority areas for conservation of purifying land cover (areas with high demand for water purification with moderate supply of purifying land cover).