Redistribution effects of wetland mitigation over space and time

Concern over the threat to wetlands from urban development has increased with rising levels of suburbanization. Under current federal and local wetland protection regulations, damage to wetlands from development must be mitigated, often by creating or restoring wetlands. This dissertation analyzes the spatial and temporal patterns that have governed wetland mitigation programs in order to address several separate issues.; The first part of this work provides an extensive overview of the literature on the history and structure of U.S. wetland conservation policy. The second section examines patterns in the use of different mitigation methods over time. During the last decade, regulators have increased their support for third party mitigation methods while lowering the minimum impact size triggering requirements for compensatory mitigation. Few studies have compared the choice of mitigation method by regulatory agency or development size. I analyze 1058 locally and federally permitted wetland mitigation transactions in the Chicago region between 1993 and 2004. This analysis shows that decreasing mitigation thresholds have had striking effects on the methods and spatial distribution of wetland mitigation. In particular, the observed increase in mitigation bank usage is driven largely by the needs of the smallest impacts. I compare the rates at which compensation required by both county and federal regulators is performed across major watershed boundaries. I show that local regulations prohibiting cross-county mitigation can lead to higher levels of cross-watershed mitigation than federal regulations without cross-county prohibitions. These data suggest that local control over wetland mitigation may prioritize administrative boundaries over hydrologic function in the matter of selecting compensation sites.; Finally, the third section uses the same Chicago dataset to analyze whether mitigation programs actually relocate wetlands through off-site mitigation from urban to rural areas and whether that relocation causes socioeconomic disparities. I demonstrate that the extent of wetland relocation and redistribution differs significantly with choice of mitigation method, while the largest differences are observed for in-lieu fee mitigation. These findings suggest that planners must take relocation and redistributive effects into account in setting up and administering mitigation programs, particularly as responsibility for wetland protection shifts from federal to local regulators.