These data represent the National Nutrient Inventory's quantification of major inputs (farm fertilizer, urban fertilizer, livestock manure, human waste, deposition, biological crop nitrogen (N) fixation, and point source loads) and outputs (crop removal by harvest) of N and phosphorus (P) within individual local NHDPlusV2 catchments and contributing watersheds. The dataset also includes the following metrics derived from these inputs and outputs: legacy agricultural surplus, annual agricultural surplus, and total inputs. All metrics are available as an annual time series from 1987-2017, except for N deposition (1990-2017), P deposition (1997-2013), and point source loads (1978, 1980, 1982, 1984, 1986, 1988, 1990, 1992, 1996, 2000, 2004, 2008, 2012). StreamCatNNI metrics are in kilograms. For more information on National Nutrient Inventory metrics, see: https://www.epa.gov/water-research/national-nutrient-inventory-portfolio.