Wetlands Monitoring and Assessment
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?
Levels of Monitoring and Assessment
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
National Monitoring and Assessment Efforts
The National Wetland Condition Assessment (NWCA) is a national wetland monitoring effort lead by EPA in collaboration with states, tribes, and other organizations. The goal of NWCA is to assess the status of and condition of tidal and nontidal wetlands in the lower 48 states. The NWCA is a statistical survey that would not be possible without another large federal effort by U.S. Fish and Wildlife Service which maps the extent of wetlands across the nation.
Regional Monitoring and Assessment Efforts
EPA helps to support several regional studies on the the condition and status of wetlands through out the nation.