EPA’s Index of Watershed Indicators upgraded

The new version adds atmospheric deposition estimates for Total Nitrogen as a data layer and updates six of the 15 original indicators.

The IWI is a compilation of information on the ‘health’ of aquatic resources in the United States. The Index looks at a variety of indicators that point to whether rivers, lakes, streams, wetlands and coastal areas are ‘well’ or ‘ailing’ and whether activities on the surrounding lands that affect US waters are placing them at risk.