USING HIGH-RESOLUTION WATER TABLE DATA AS A TOOL TO EVALUATE RESTORED WETLAND HYDROLOGIC FUNCTIONING

Over the past 20 years, wetland restoration has been stimulated by high wetland loss rates and recognition of wetland values. Research has shown that understanding wetland hydrology is essential to efficient wetland restoration. However, there is a lack of high-resolution water table data from recently restored wetlands and our understanding of wetland hydrology is often inadequate to evaluate the effect of restoration on wetland hydrology. We removed or disabled nearly 300 m of agricultural drainage tile in an effort to restore a slope wetland in central Indiana, and tested several wetland water table classification methods to determine whether or not wetland hydrology had been restored. In order to determine well response to precipitation events and the relationship between wetland water table and stream stage, water levels were recorded biweekly throughout the wetland and in 15-minute intervals at selected locations in the wetland from March 2005 to present. We hypothesized that disabled drainage tiles and former drainage tile locations were creating preferential flowpaths that adversely affected attempts to restore wetland hydrology. Data indicate that apparent soil hydraulic conductivities measured in wells and piezometers were strongly influenced by the location of former drainage tiles, rather than by the actual soil hydraulic conductivity. Based on current wetland water table classifications available in the literature, many parts of the wetland would have what is considered wetland hydrology, despite the nearly instantaneous response to precipitation of several wells. Nevertheless, results indicate large variations in the portion of the wetland area considered to possess wetland hydrology depending on the water table classification scheme used.