Surface-water nutrient and sediment mappers are now available

SPARROW (SPAtially Referenced Regression On Watershed attributes) models estimate the amount of a contaminant transported from inland watersheds to larger water bodies by linking monitoring data with information on watershed characteristics and contaminant sources.  Interactive, online SPARROW mapping tools allow for easy access to explore relations between human activities, natural processes and contaminant transport. The USGS recently published SPARROW streamflow, nutrient, and suspended-sediment models for the five major hydrologic regions of the United States, including the Pacific region (which consists of the Columbia River basin, the Puget Sound basin, the coastal drainages of Washington, Oregon, and California, and the Central Valley of California). The SPARROW mappers for the Pacific region can be accessed under the “Data and Tools” tab below, while SPARROW mappers for other regions of the United States can be accessed under the “Science” tab. A report describing the development of the Pacific region SPARROW models can be obtained from the “Publications” tab. In addition to presenting the model predictions, the report describes the geo-spatial data sets that were evaluated during model development. These data sets are publicly available and represent nutrient sources such as agricultural fertilizer, livestock manure, atmospheric nitrogen deposition, natural phosphorus in soil, permitted wastewater discharge, and septic systems.