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Abstract Dam removal is widely used as an approach for river restoration in the United States. The increase in dam removals--particularly large dams--and associated dam-removal studies over the last few decades motivated a working group at the USGS John Wesley Powell Center for Analysis and Synthesis to review and synthesize available studies of dam removals and their findings. Based on dam removals thus far, some general conclusions have emerged: (1) physical responses are typically fast, with the rate of sediment erosion largely dependent on sediment characteristics and dam-removal strategy; (2) ecological responses to dam removal differ among the affected upstream, downstream, and reservoir reaches; (3) dam removal...
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The U.S. Geological Survey, in collaboration with American Rivers and other partners, conducted a monitoring program beginning in 2010 to track river response to a series of dam removals on the Patapsco River intended to restore anadromous fish habitat in the watershed. Dam removals included the November 2010 removal of the Simkins dam, a 3.3 m tall and 66 m wide dam, with a reservoir sediment volume of ~67,000 cubic meters. As part of the dam removal monitoring program, three USGS streamgaging stations were established in late 2010 along the mainstem of the Patapsco River to estimate flow and suspended sediment-transport for constraining sediment budgets. USGS 01589000 Patapsco River at Hollofield, MD was reestablished...
Categories: Data;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Geomorphology,
Hydrology,
Patapsco River,
Simkins Dam,
USGS Science Data Catalog (SDC), All tags...
biota,
channel evolution,
dam removal,
deposition,
dispersion,
geomorphology,
sediment,
sediment pulse,
sediment transport,
sedimentation,
specific stage,
stream-gage measurement,
streamflow,
suspended material (water),
translation, Fewer tags
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Dam removals with unmanaged sediment releases are good opportunities to learn about channel response to abruptly increased bed material supply. Understanding these events is important because they affect aquatic habitats and human uses of floodplains. A longstanding paradigm in geomorphology holds that response rates to landscape disturbance exponentially decay through time. However, a previous study of the Merrimack Village Dam (MVD) removal on the Souhegan River in New Hampshire, USA, showed that an exponential function poorly described the early geomorphic response. Erosion of impounded sediments there was two-phased. We had an opportunity to quantitatively test the two-phase response model proposed for MVD by...
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Recent decades have seen a marked increase in the number of dams removed in the United States. Investigations following a number of removals are beginning to inform how, and how fast, rivers and their ecosystems respond to released sediment. Though only a few tens of studies detail physical responses to removals, common findings have begun to emerge. They include: (1) Rivers are resilient and respond quickly to dam removals, especially when removals are sudden rather than prolonged. Rivers can swiftly evacuate large fractions of reservoir sediment (≥50% within one year), especially when sediment is coarse grained (sand and gravel). The channel downstream typically takes months to years--not decades--to achieve a...
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Aging infrastructure coupled with growing interest in river restoration has driven a dramatic increase in the practice of dam removal. With this increase, there has been a proliferation of studies that assess the physical and ecological responses of rivers to these removals. As more dams are considered for removal, scientific information from these dam‐removal studies will increasingly be called upon to inform decisions about whether, and how best, to bring down dams. This raises a critical question: what is the current state of dam‐removal science in the United States? To explore the status, trends, and characteristics of dam‐removal research in the U.S., we searched the scientific literature and extracted basic...
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