EPA releases draft report on condition of the nation’s wetlands

Recently, the U.S. Environmental Protection Agency (EPA) announced availability of a draft report titled The National Wetland Condition Assessment (NWCA) 2011: A Collaborative Survey of the Nation’s Wetlands (80 Federal Register 68536). Comments on the draft report will be accepted through December 7, 2015. 

The report documents results of the agency’s first evaluation of the ecological condition of the nation’s wetlands. The NWCA is part of a broader effort by EPA and state, tribal, and federal partners to characterize the ecological condition of the nation’s waters. Under the National Aquatic Resource Survey (NARS) program, studies have been completed for wadeable streams (2004), lakes (2007), rivers and streams (2008-2009), and coastal waters (2010). The issuance of the NWCA 2011 report marks completion of the first full cycle of assessments under the NARS program. 

For the 2011 study, field work was conducted by 50 crews at a series of points across the nation in tidal and non-tidal wetlands with rooted vegetation and, when present, shallow open water less than one meter deep, that are not currently being used in the production of crops. At each point, the crews collected data on vegetation, soils, hydrology, algae, and water chemistry. Within a 100-m buffer surrounding each sample point, crews also collected data on habitat and the presence of stressors.

Major conclusions from the draft report include:

  • Nationally, 48% of wetland area is in good condition, 20% is in fair condition and the remaining 32% is in poor condition.
  • Of the four major ecoregion-based units, the West has the lowest percentage of wetland area in good condition (21%).
  • Wetland area in good condition for the Coastal Plains, Eastern Mountains and Upper Midwest, and Interior Plains regions ranges from 44% to 52%.
  • Nationally, vegetation removal, surface hardening (e.g., pavement, soil compaction), and ditching are the most widespread indicators of stress. Vegetation removal and surface hardening indicators are high for 27% of wetland area, while the ditching stressor is high for 23% of wetland area.

The draft report is available at http://www2.epa.gov/national-aquatic-resource-surveys/national-wetland-condition-assessment-2011-results.