Lewis, E., S. Inamdar, A.J. Gold, K. Addy, T.L.E. Trammell, D. Merritts, M. Peipoch, P.M. Groffman, J. Hripto, M. Sherman, J. Kan, R. Walter, and E. Peck. 2021. Journal of Geophysical Research Biogeosciences 126(8), e2021JG006444.
Dams are being removed to allow fish passage and improve safety for water users. Dam removal results in a drop of stream water level and a drying-out of the streamside (riparian) zones. We investigated if these changes would undermine the N-filtering service of riparian zones and increase N concentrations in groundwater and stream waters. We monitored soil and water N concentrations for two years following the removal of a 1.5 m milldam on Chiques Creek in Pennsylvania. Our data showed that while denitrification in soils did decrease, the N concentrations in riparian groundwaters and stream waters did not increase over the study period.