Using Hydrogeology to Site Wetland Compensation

In the conterminous United States, it is estimated that 53% of pre-settlement wetlands were lost between 1780 and 1980; in Illinois, as in much of the Midwest cornbelt, wetland loss climbs to 90% for the same period. While the loss of wetland acreage is less than in the past, a net loss of the wetland resource continues. Wetland compensation projects have contributed to this net loss both in subtle functional shifts of wetland types and outright project failure. In our experience, failures of compensation projects are often attributable to improper hydrologic conditions to sustain a wetland habitat. Poor site-selection, poor design, poor construction methods, and inadequate management can lead to improper hydrologic conditions. While it may be possible to overcome poor site selection with herculean efforts in engineering, construction, and management, increased costs and project failure usually ensue.