Welcome to the Water Quality and Biological Index Maps. The Susquehanna River Basin Water Quality Index (WQI) is a tool created by Commission scientists to assess and compare water quality conditions throughout the basin. The Water Quality Index Map was developed using 15,874 samples collected from 2000-2019 at 1,781 sites. Scoring is comprised of three category scores and an overall water quality score. All sites on the map have at least one category score, but may not have all three scores or an overall score. This map displays overall water quality conditions for tributaries (watersheds) and sites in the Susquehanna River Basin.

The Biological Index Map was created using the Chesapeake Bay basin-wide index of biotic integrity (Chessie BIBI). More information on the Chessie BIBI can be found at: https://www.potomacriver.org/focus-areas/aquatic-life/macroinvertebrates/chessie-bibi-index-for-streams/. The Chessie BIBI uses family level macroinvertebrate metrics on small, wadeable freshwater sytems in the Chesapeake Bay watershed. Commission scientists used the Chessie BIBI to score each macroinvertebrate sample collected in the Susquehanna River basin by Commission staff or other agencies. The Biological Index Map displays biological conditions for individual sites and HUCs within the basin.

How to use the map:

• Toggle layers in the legend to change the information displayed on the map.
• Zoom to a watershed or by selecting a subbasin and then a watershed from the drop down lists.
• Zoom to a political boundary by selecting from the drop down lists.
• Click the sample locations (circles) to view additional information.