Why Restore Wetlands?
Throughout this country’s history, wetlands have been overlooked as an important national resource. The Swamp Lands Acts of 1849, 1850, and 1860 encouraged the destruction of wetlands. As a result, more than 100 million acres of wetland have been drained with engineered efficiency, leaving only 50% of original wetlands intact in the 48 contiguous states (Dahl 1990). Based on mean annual wetland losses from 1974 to 1983, it is estimated that the nation is still losing approximately 290,000 acres of wetlands each year (Dahl and Johnson 1991). In Illinois, a small fraction (1 to 5%) of the state’s presettlement wetlands remain (Dahl 1990; Bell 1981).
Without the meandering channels and broad riparian wetlands of undeveloped streams, flood damage has escalated and polluted streams have increased in number and extent. Populations of wetland-dependent species of wildlife, particularly waterfowl, have declined. This is in spite of the fact that hundreds of billions of dollars from both the public and private sector have been spent in recent decades to control flooding, achieve better water quality, and protect wildlife populations. Return on this investment has been poor because dams, levees, and wastewater treatment plants have failed to address the ecological structure of our nation's surface waters.
Wetlands provide that structure; they are the keystone in healthy aquatic systems. Wetlands help prevent shoreline erosion by creating buffers between land and the destructive forces of water. They help protect aquatic systems by filtering the harmful pollutants that are washed into surface waters during and after heavy rainfall. Through photosynthesis, wetland plants contribute to atmospheric oxygen upon which mankind depends. Scientists now understand that wetlands are among the most productive ecosystems on earth.
Even in urban areas, such as Chicago, wetlands provide a variety of critical functions. Wetlands serve as natural basins that absorb and detain great quantities of water that might otherwise cause flooding. They are often instrumental in replenishing important groundwater aquifers used for drinking water and for industrial and agricultural purposes. Wetland vegetation and the associated microbiotic communities remove pollutants from water by absorbing nutrients and filtering out other contaminants from urban storm water runoff. Wetlands provide the critical conditions for the breeding and spawning of a wide variety of native wildlife.
While wetlands are not a panacea for solving all water-related problems, there are many benefits to strategically re-creating their natural functions. The nation’s need to restore its wetlands is underscored by the recent recommendations from the U.S. Fish and Wildlife Service’s Status and Trends of Wetlands in the Conterminous United States 2004 to 2009. In his letter to the Members of Congress, Ken Salazar, Secretary for the Department of the Interior, stated:
“While I am heartened to note that the Nation is making important progress in the conservation of our wetland resources, there is also reason for concern and continued diligence. Findings from this study indicate that between 2004 and 2009, wetland losses outdistanced wetland gains. The reasons for these changes are complex but they serve as a warning signal that additional work is needed to protect wetland resources.”
The extent to which this restoration and re-creation of wetlands are pursued depends on the delicate balance between economic growth and environmental need. First, however, engineers need proven methods of wetland design, construction and management. Developing these techniques was the primary purpose of the Des Plaines River Wetlands Demonstration Project. Wetlands Research Inc., remains dedicated to providing additional research opportunities to continue to expand our knowledge and understanding of wetland systems.