HYDROLOGIC CONNECTIVITY AND WATER QUALITY FUNCTION OF COASTAL PLAIN GEOGRAPHICALLY ISOLATED WETLANDS

Isolated wetlands are a critically important ecosystem that provide ecological value and hydrological and water quality functions. Although the importance of the ecological and functional value of wetlands in the landscape is well documented, there are still significant gaps in our knowledge of “isolated” wetlands, especially in regards to water quality and hydrology. Additionally, isolated wetlands are particularly vulnerable to losses from development and agriculture because they are often surrounded by developable uplands, are often small in size (less then an acre), and have varying degrees of regulatory protection. This project seeks to gain a better understanding of the hydrologic connectivity to the downstream water body and water quality enhancement capacity of these systems.

Eight isolated wetlands are being studied, six in Bladen County, NC and two in Brunswick County, NC. The wetlands, surrounding uplands, and adjacent receiving streams or surface water bodies were cored extensively to determine stratigraphy. Wells were installed in a transect from the wetland to the downstream water body and water level and water quality data are being obtained for a one year period beginning in May of 2010. Aquifer pumping tests will be conducted at three of the sites. Preliminary results indicate an unimpeded groundwater connection between the isolated wetland and its receiving surface water body in all cases. There is some indication of nitrate reduction in some of the well transects. Data collection will be complete in June of 2011. The information on isolated wetlands gained from this study can be used to improve management decisions and provide better protection for these ecosystems.