Wetlands & Mitigation

Wetlands and Mitigation

Wetlands serve an important role in the ecological health of the nation by helping to control flooding, improve water quality, and provide important wildlife habitat.

Congress added Section 404 to the Water Pollution Control Act of 1972 (now the Clean Water Act) specifically to preserve wetlands adjacent to lakes, estuaries, rivers, and streams, and to maintain their water quality-enhancing benefits.

As early as the 1980s, growing pressures of development and an accelerating decline of wetlands nationwide led to a federal policy of "no net loss" of wetlands acreage. Mitigation is a way to replace wetlands that are filled in or otherwise lost through development with newly created or enhanced wetlands in another location.

According to federal law, mitigation is an option only after development in wetland areas is avoided or minimized as much as possible. Early on, agencies and developers attempted to mitigate for wetlands loss with their own smaller, on-site properties. As these early attempts proved unsatisfactory, a consensus grew in the 1990s for the concept of "mitigation banking," which focuses on preserving the important functions and natural values of wetlands on larger, contiguous properties with a greater potential for long-term success. In 2008, the U.S. Army Corps of Engineers and Environmental Protection Agency (EPA) issued a final rule that establishes a preference for mitigation banking when compensatory mitigation is required.

A wetlands mitigation bank also benefits developers by streamlining the permitting process. As compared to "permittee-responsible mitigation," a mitigation bank gives developers, utility providers, and state and local governments the opportunity to satisfy their statutory wetland mitigation requirements by paying a predictable, one-time fee for credits. The permit-holder assumes no long-term monitoring or maintenance obligations. The bank operator is responsible for monitoring and maintenance, and for ensuring the sustainability of the mitigation bank.

Why Mitigation Banking is "the preferred alternative"

  • Mitigation banking is considered a superior option when compared to project-by-project or "permittee-responsible mitigation" on smaller, often isolated tracts.
  • Mitigation banking leads to better-organized planning and consolidation of habitat, and encourages a long-term commitment to wetland protection.
  • Larger tracts provide greater floodplain storage, support a greater diversity of habitat and wetland functions, and give wildlife room to roam freely.
  • By creating the mitigation bank BEFORE development impacts occur, the mitigation bank helps prevent temporary losses of important wetland functions and values.

Types of Wetlands

Wetlands come in many types, depending on variations in soils, landscape, climate, water regime and chemistry, and vegetation. To be called a wetland, an area must be filled or soaked with water at least part of the year. Depending on the type of wetland, it may be covered with trees, grasses, shrubs or moss. Some grassy wetlands are actually dry at certain times of the year.