The Effect of Urbanization and Development on Freshwater Emergent Wetland Biogeochemistry and Hydrology in Western Maryland

Abstract

Urbanization alters watershed hydrology and biogeochemistry, often compromising the ability of wetlands to retain nutrients and regulate flow. This study compared two riparian wetlands in Western Maryland—one in an urbanized watershed and one in an undeveloped watershed—to evaluate the effects of impervious surface cover on nutrient export and storm hydrology. Over five months, upstream and downstream water samples and continuous hydrologic monitoring were analyzed. Results showed that the urban wetland exhibited significantly flashier hydrology and higher porewater conductivity, suggesting greater stormwater and salt input. While nutrient concentrations were not statistically different between sites, emerging trends—particularly higher TOC exports in the rural site—suggest differences in productivity and legacy nutrient effects. These findings emphasize that even moderate development can alter wetland function, highlighting the importance of green infrastructure, alternative deicing practices, and restoration timelines in sustaining wetland ecosystem services in urban landscapes.