A new EPA draft report titled “Connectivity of Streams and Wetlands to Downstream Waters” is drawing attention across the country. When finalized, the document will provide the scientific basis for clarifying and possibly expanding Clean Water Act jurisdiction over isolated wetlands and other marginal waters. The process is expected to be controversial.
Federal officials increasingly have been at odds with public and private property owners, developers and project proponents over the jurisdiction of such waters in the wake of recent U.S. Supreme Court decisions, including Rapanos v. United States, 547 U.S. 715 (2006). The EPA’s new report, released in September, synthesizes a large body of peer-reviewed literature on the topic. The report describes the effects that wetlands, ephemeral and intermittent streams, vernal pools, ponds, prairie potholes, and other “unidirectional” water bodies have on larger downstream waters, including lakes, rivers, oceans, and estuaries. The effects studied include not only hydrological connections to traditional downstream waters, but also biological, physical, chemical and ecological impacts.
The report will play a key role in the upcoming joint rulemaking by the U.S. Environmental Protection Agency and the Army Corps of Engineers to clarify which streams, wetlands and other waters fall under Clean Water Act jurisdiction as “waters of the United States.” The two agencies sent a draft rule to the federal Office of Management and Budget on Sept. 17 for interagency review. The draft rule has not yet been made public.
According to the EPA, the report contains three primary conclusions:
- All streams, regardless of their size and flow rate, are connected to and have important effects on downstream waters, including providing habitat for species and transporting sediment and organic matter.
- Wetlands and open-waters in the floodplains of streams and rivers and in riparian areas are integrated with streams and rivers. Such waters influence downstream waters by affecting flows, exchanging biological species, and trapping and reducing pollutants.
- There is insufficient information to generalize about wetlands and open-waters that are located outside of riparian areas and their connectivity to downstream rivers, streams and oceans.
The draft “Connectivity” report is available here:
The EPA Science Advisory Board plans to hold a three-day public hearing Dec. 16–18, 2013, in Washington, D.C. to review the report.