Water Quality Mapping Center

The Water Quality Mapping Center provides access to surface water quality information in a geographic format.  It was designed to make the Integrated Report (303(d)) assessments and Tier II information more widely available to those without specialized GIS software. It was also created to provide easier access to any applicable TMDLs or WQAs directly from the assessment information (Integrated Report data only).

Click on one of the links below to access information specific to either the Integrated Report (water quality impairments) or Tier II high quality waters.  Note: No special software is needed for the map pages.  However, maps will load faster using the latest version browsers (e.g. Internet Explorer 9). 

For guidance on using the maps, please watch the on-line video tutorial.  It has been offered in two different formats.  If your computer has difficulty with one format, please try the other. Reminder: Make sure your speakers are turned on. 

• Online video tutorial in SWF format
• Online video tutorial posted to YouTube (This link takes you away from MDE's website.)

 General Information

• Find My Watershed - This map was designed to help individuals find out what watershed they live in or what watershed their project affects.

Integrated Report - Water Quality Assessment Information

• Integrated Report Maps - This page provides links to a series of water quality maps each displaying water quality status for a unique set of pollutants.
• Information about the Integrated Report

Tier II High Quality Waters

• Tier II High Quality Waters Map - This map displays all Tier II high quality stream segments and their drainage areas/catchments.  Streams and their catchments are symbolized as to whether assimilative capacity remains.
• Information about Tier II High Quality Waters

Maryland's Shellfish Harvesting and Closure Information

• Interactive Harvesting and Closure Map