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Maryland State Government Maryland Department of the Environment

Water Quality Mapping Center

image of mapThe Water Quality Mapping Center provides access to surface water quality information in a geographic format. The first set of headings and links provided (from General Information to Maryland's Shellfish Harvesting and Closure Information) were designed to make water quality GIS information more widely available to those without specialized software. The last link, under the heading "For Advanced Users", is provided for those users who have and are proficient with ArcGIS software.  Users who follow this last link will have the option to download GIS data by several different methods. 

Click on one of the links below to access information specific to the Designated Use Classes, Integrated Report (water quality impairments), Tier II high quality waters, or Shellfish Harvesting Area Closure information.  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, Google Chrome). 

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. 

 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.

Designated Uses and Use Class Information

Water Quality Assessment Information - Integrated Report

Tier II High Quality Waters

Maryland's Shellfish Harvesting and Closure Information


For Advanced Users

Users who have ArcGIS software installed on their computer and wish to download water quality information should click here.