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Watershed Index Online

Download and Use the WSIO Tool

Download the Tool

The WSIO Tool is a customized watershed analysis application that calculates indices, compares watersheds and produces results in rank-ordered tables, graphs and maps.  You can use the WSIO Tool to select and compare watersheds in your area of interest. To open the tool, click on the link in the box to start creating your custom-built WSIO tool for a specific geographic area. Once the tool is downloaded, you will be able to:
  • define the geographic extent of the project area,
  • select indicators from the database, and
  • save your custom WSIO Tool for offline use.

NOTE: The URL for the data and map service essential to this tool has changed. Please note that the URL is case-sensitive and wsio must appear in lower-case letters for the tool service to work. The following URL should be entered exactly when requesting the service:   https://gispub.epa.gov/arcgis/rest/services/r4/wsio/MapServer

Indicator Data and Metadata

We recommend that you obtain data from WSIO by creating and downloading a custom WSIO Tool, but you can also download just the indicator data for an EPA Region of your choice from the WSIO Indicator Data Library page.  The data include measurements of ecological, stressor, and social characteristics compiled for roughly 83,000 small (HUC12 scale) watersheds across the conterminous United States. 

From the WSIO Indicator Data Library page, you can also open the WSIO indicator library metadata file and review indicator types and descriptions, which can be a useful planning step before selecting indicators while creating the tool.  The page also includes water mask, hydrologically-connected zone, riparian zone, and wetness index datasets.  

Support Documents

These documents provide general and specific directions on how to open the WSIO Tool online, select a geographic area, choose indicators, do comparative watershed assessments, and save the analyses.

You may need a PDF reader to view some of the files on this page. See EPA’s About PDF page to learn more.
  • Quick Start Users Guide (PDF)(21 pp, 2 MB)
    This file contains the basic steps to get started, and is recommended for download along with your WSIO customized tool.
  • The Watershed Index Online User Manual (PDF)(40 pp, 3 MB)
    Detailed guidance on all functions of the WSIO Tool. Users should review this document before and during online WSIO Tool use.
  • About the Watershed Index Online (PDF)(11 pp, 755 K)
    This file contains a detailed account of the design and development of the Watershed Index, along with its transformation into an online support tool, the WSIO.