Hydrographic and Impairment Statistics Database: NPS-wide Impairment GIS Coverage
The National Park Service (NPS) Water Resources Division (WRD) compiles the Hydrographic and Impairment Statistics (HIS) Database for all park units. One of the goals of HIS is to track surface water impairments as defined by the Clean Water Act (CWA). Waters within or adjacent to park units that were identified by …