Watershed suspended sediment supply and potential impacts of dam removals for an estuary
MetadataShow full item record
KeywordDam removal; Suspended sediment; Watershed sediment yield; Sediment supply; Sediment trapping
Observations and modeling are used to assess potential impacts of sediment releases due to dam removals on the Hudson River estuary. Watershed sediment loads are calculated based on sediment-discharge rating curves for gauges covering 80% of the watershed area. The annual average sediment load to the estuary is 1.2 Mt, of which about 0.6 Mt comes from side tributaries. Sediment yield varies inversely with watershed area, with regional trends that are consistent with substrate erodibility. Geophysical and sedimentological surveys in seven subwatersheds of the Lower Hudson were conducted to estimate the mass and composition of sediment trapped behind dams. Impoundments were classified as (1) active sediment traps, (2) run-of-river sites not actively trapping sediment, and (3) dammed natural lakes and spring-fed ponds. Based on this categorization and impoundment attributes from a dam inventory database, the total mass of impounded sediment in the Lower Hudson watershed is estimated as 4.9 ± 1.9 Mt. This represents about 4 years of annual watershed supply, which is small compared with some individual dam removals and is not practically available given current dam removal rates. More than half of dams impound drainage areas less than 1 km2, and play little role in downstream sediment supply. In modeling of a simulated dam removal, suspended sediment in the estuary increases modestly near the source during discharge events, but otherwise effects on suspended sediment are minimal. Fine-grained sediment deposits broadly along the estuary and coarser sediment deposits near the source, with transport distance inversely related to settling velocity.
© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Ralston, D. K., Yellen, B., & Woodruff, J. D. Watershed suspended sediment supply and potential impacts of dam removals for an estuary. Estuaries and Coasts, (2021), https://doi.org/10.1007/s12237-020-00873-3.
Suggested CitationRalston, D. K., Yellen, B., & Woodruff, J. D. (2021). Watershed suspended sediment supply and potential impacts of dam removals for an estuary. Estuaries and Coasts.
The following license files are associated with this item:
Showing items related by title, author, creator and subject.
Modern sedimentation in the Northern Barents Sea : input, dipersal and deposition of suspended sediments from glacial meltwater Pfirman, Stephanie L. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1984-08)The modern depositional environment of the northern epicontinental Barents Sea varies from proximal to distal glaciomarine. The regional surface sediment distribution is controlled by erosion of shallow banks of the ...
Bulk organic geochemistry of sediments from Puyehue Lake and its watershed (Chile, 40°S) : implications for paleoenvironmental reconstructions Bertrand, Sebastien; Sterken, Mieke; Vargas-Ramirez, Lourdes; De Batist, Marc; Vyverman, Wim; Lepoint, Gilles; Fagel, Nathalie (2009-03-04)Since the last deglaciation, the mid-latitudes of the southern Hemisphere have undergone considerable environmental changes. In order to better understand the response of continental ecosystems to paleoclimate changes in ...
Enhancement of nitrate removal at the sediment-water interface by carbon addition plus vertical mixing Chen, Xuechu; He, Shengbing; Zhang, Yueping; Huang, Xiaobo; Huang, Yingying; Chen, Danyue; Huang, Xiaochen; Tang, Jianwu (2014-12)Wetlands and ponds are frequently used to remove nitrate from effluents or runoffs. However, the efficiency of this approach is limited. Based on the assumption that introducing vertical mixing to water column plus carbon ...