PHYSICAL AND PLANT COMMUNITY CONTROLS ON NITROGEN AND PHOSPHORUS LEACHING FROM IMPOUNDED RIVERINE WETLANDS FOLLOWING DAM REMOVAL
Article first published online: 5 JUN 2011
Copyright © 2011 John Wiley & Sons, Ltd.
River Research and Applications
Volume 28, Issue 9, pages 1439–1450, November 2012
How to Cite
Riggsbee, J. A., Wetzel, R. and Doyle, M. W. (2012), PHYSICAL AND PLANT COMMUNITY CONTROLS ON NITROGEN AND PHOSPHORUS LEACHING FROM IMPOUNDED RIVERINE WETLANDS FOLLOWING DAM REMOVAL. River Res. Applic., 28: 1439–1450. doi: 10.1002/rra.1536
- Issue published online: 24 OCT 2012
- Article first published online: 5 JUN 2011
- Manuscript Accepted: 6 APR 2011
- Manuscript Revised: 25 MAR 2011
- Manuscript Received: 9 SEP 2010
- US Fish and Wildlife Service and Restoration Systems
- dam removal;
Dam removal has emerged as a critical issue in water resources engineering and management. Of particular concern in many regions of the USA is the effect of dam removal on downstream water quality and potential methods of decreasing sediment and nutrient loading to downstream reaches. Rapid revegetation of reservoir sediments has been suggested as a means of reducing the impact of dam removal, although little data exist about the role of vegetation in controlling the downstream release of sediment or nutrients.
This study investigated an impounded riverine wetland complex on the Little River, North Carolina, before and after the removal of a low-head dam. We quantified the leaching of interstitial nitrogen (N) and phosphorus (P) to the adjacent river channel during reservoir dewatering and, through experimental manipulations, isolated the difference between physical (soil) and biological (plant) controls on N and P leaching from dewatering impoundment sediments. We found that the rate and the quantity of N and P leaching from impounded dewatering sediment are predominately controlled by sediment porosity and specific yield. Although vegetation controls on N and P leaching were statistically significant during the first growing season following dam removal, vegetation is likely to be more important as a long-term control on sediment and nutrient loads. Our results suggest that the initial release of N and P from a dewatered reservoir will be difficult to control but that vegetation may play an important long-term role. Copyright © 2011 John Wiley & Sons, Ltd.