Wetlands Monitoring and Assessment

Basic Information

Consistent, thorough and timely wetland monitoring and assessment programs are a critical tool for states and tribes to better manage and protect their wetland resources. These programs allow states and tribes to:

• establish a baseline in wetlands extent, condition and function;
• detect change; and
• characterize trends over time.

Wetlands monitoring and assessment data can be used to help make decisions in:

• the Clean Water Act Section 404 regulatory program
• wetland restoration and watershed planning 
• integrated reporting -- the ambient condition of wetland resources
• the development of meaningful water quality standards for wetlands

For more information on how to develop a state or tribal monitoring and assessment program, go to How Do I Develop a Monitoring Program?

EPA´s National Wetlands Monitoring Workgroup supports the concept of a Level 1, 2 and 3 approach to wetland monitoring.

Level 1, "landscape assessment" relies on coarse, landscape scale inventory information, typically gathered through remote sensing and preferably stored in, or convertible to, a geographic information system (GIS) format. Classification of wetlands is also done at this level.

Level 2 is "rapid assessment" (PDF)(82 pp, 278 K, About PDF) at the specific wetland site scale, using relatively simple, rapid protocols. Level 2 assessment protocols are to be validated by and calibrated to Level 3 assessments.

Because of the location-specific nature of rapid assessments, there are many rapid assessment methods currently in use and under development. Some examples of different rapid assessment methods are listed in the Regional Monitoring and Assessment Efforts section below.   

Level 3 is "intensive site assessment" and uses intensive research-derived, multi-metric indices such as the Hydrogeomorphic Approach or Biological Assessments. They are meant to give detailed information regarding how well a wetland is functioning.

For additional information on the Hydrogeomorphic Approach (HGM), see:

• Hydrogeomorphic Approach for Assessing Wetlands Functions (U.S. Army Corp of Engineers)
• Hydrogeomorphic Wetland Profiling: An Approach to Landscape and Cumulative Impacts Analysis (PDF)(106 pp, 2 MB, About PDF)
• National Action Plan: Hydrogeomorphic Approach (PDF)(14 pp, 218 K, About PDF)

Bioassessments vs. Functional Assessments

Biological Assessments and functional assessments both evaluate the condition of individual wetlands by comparing them to the conditions found in an established set of reference wetlands. The goal of both approaches is to maintain wetlands in their minimally disturbed conditions, and wetlands are only compared to other wetlands of the same type.  

The following documents and links provide additional information on Biological Assessments:

• Benefits and Applications of Wetland Bioassessments
• Bioassessment Fact Sheets
• Wetland Bioassessment Resources
• Indices of Biologic Integrity

• Mid-Atlantic Monitoring and Assessment
• Pacific Southwest (EPA Region 9) Monitoring and Assessment efforts