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The Anaconda and Union City Dams oil the Naugatuck River in Connecticut were removed in February and October 1999. A detailed Study of the sites prior to removal was undertaken including sediment testing and predictions Of upstream channel formation post-darn removal. The 3.35-m-high timber crib/rock fill spillway of the Anaconda Dam partially breached during a storm prior to the dam's scheduled removal allowing a portion of the impounded sediment to move down through the river system. This event changed the removal plans and the remainder of the spillway was removed under an emergency order in the course of 4 days. The Union City Dam, a 2.44-m-high timber crib/rock fill dam capped with concrete and stone, was removed...
Previous studies of vegetation establishment in dam removal sites have shown that natural vegetation community establishment is highly variable and frequently includes species often considered undesirable in restorations. In this article, we examined two case studies where dam removal sites were planted with native species following dam removal in an effort to promote native species establishment and exclude invasive species. Some planted species established soon after the dam removals, but surveys four years later showed a decline in planted species and an increase in non-native species. In both cases, reed canarygrass (Phalaris arundinacea) became well established in the interval between surveys. A seedbank analysis...
In this paper, we synthesize a series of small dam removal studies to examine how changes in channel form can affect riparian vegetation, fish, macroinvertebrates, mussels, and nutrient dynamics. Each of the ecosystem attributes responded to the disturbance of dam removal in different ways and recovered at very different rates, ranging from months to decades. Riparian vegetation appeared to require the greatest time for recovery, while macroinvertebrates had the least. Mussel communities were the most adversely affected group of species and showed no signs of recovery during the time period of the study. Based on these and other studies, we suggest that ecosystems may follow two trajectories of recovery following...
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This data release includes a file geodatabase with high-resolution geospatial products that illustrate the geomorphology and various land-surface parameters along a 313-kilometer segment of the mainstem Klamath River corridor downstream of Iron Gate Dam, CA. The geospatial products were derived from topobathymetric elevation data collected to document baseline topography and bathymetry before the removal of four hydro-electric dams. The elevation survey included aerial lidar, using an integrated topobathymetric sensor (with near-infrared and green wavelengths), and boat-based sonar measurements of water depths. Acquisition dates for the aerial topobathymetric lidar spanned 06/01/2018 to 06/14/2018. For the bathymetric...
In 1998, the Quaker Neck Dam was removed from the Neuse River near Goldsboro, North Carolina, restoring access to more than 120 km of potential main-stem spawning habitat and 1,488 km of potential tributary spawning habitat to anadromous fishes. We used plankton sampling and standardized electrofishing to examine the extent to which anadromous fishes utilized this restored spawning habitat in 2003 and 2004. Evidence of spawning activity was detected upstream of the former dam site for three anadromous species: American shad Alosa sapidissima, hickory shad A. mediocris, and striped bass Morone saxatilis. The percentages of eggs and larvae collected in the restored upstream habitat were greater in 2003, when spring...
The 14-m-tall Marmot Dam was removed during the summer of 2007, and the cofferdam protecting the working area was breached during a storm on October 19, 2007, allowing approximately 750,000 m3 of reservoir deposit to be eroded freely and released downstream to the Sandy River. Prior to the Marmot Dam removal, sediment transport models were developed to predict the transport dynamics of both gravel and sand, providing key pieces of information for stakeholders and regulatory agencies to select the most appropriate dam removal alternative. A monitoring program was implemented following dam removal that was designed to examine model predictions and assess when potential fish passage issues related to dam removal were...
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The dataset includes daily counts of the number of independent photo detections from camera traps for 15 mammal species. The camera traps were placed in three study reaches of the Elwha River, Washington between July 2021 and July 2023. The dataset also includes information about the camera station locations, and the calendar date and season when the photos were captured.
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Dam decommissioning is rapidly emerging as an important river restoration strategy in the U.S., with several major removals recently completed or in progress. But few studies have evaluated the far-reaching consequences of these significant environmental perturbations, especially those resulting from removals of large (>10-15 m tall) structures during the last decade. In particular, interactions between physical and ecological aspects of dam removal are poorly known. From recent work, however, observations are now available from several diverse settings nationwide to allow synthesis of key physical and ecological processes associated with dam removals, including fish and benthic community response, reservoir erosion,...
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Incorporating climate change into conservation and restoration decisions is increasingly important for natural resource managers and restoration practitioners. Dam removal is an example of a restoration tool that may offer multiple socio-economic and ecological benefits in urban streams and promote climate resilience. With the pace of dam removals increasing, practitioners and researchers are well-poised to incorporate climate change into future dam removal decisions. Therefore, we surveyed dam removal practitioners across 14 states in the eastern United States to understand current practices of dam removals, factors driving restoration decisions, and how climate change knowledge is incorporated into these decisions....
As dam removal is increasingly used as a tool to restore rivers, developing a conceptual and field-based understanding of the upstream fluvial response is critical. Using empirical data and modeling, I investigated the spatial and temporal pattern of reservoir sediment erosion and upstream channel evolution of the Blackfoot River, MT, following the 8 m base level reduction caused by the removal of Milltown Dam. Field data collected include surveys of channel bed topography and water surface elevation profiles which were integrated into a flow modeling approach. Headward erosion extended 4.5 km upstream of the dam site during the first five months following the dam removal. In the lower 1.8 km of the reservoir, up...
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The data release presents observations of riparian vegetation, topography, soil characteristics, and ground cover in three river segments located above, below, and between the former Glines Canyon and Elwha Dams on the Elwha River, near Port Angeles, WA (river kilometers 2.5 to 31) to assess effects of dam removal on riparian vegetation. Vegetation data were collected before dam removal in 2005 and 2010, and after dam removal in 2013, 2014, 2016, and 2017. Vegetation data were collected from 100 square meter plots located on 15 cross-river transects spanning all riparian landforms. Soil samples collected in 2017 were analyzed for soil nutrients and texture. Topographic surveys were conducted to measure the elevation...
We compared streamflow in basins under the combined impacts of an upland dam and groundwater pumping withdrawals, by examining streamflow in the presence and absence of each impact. As a qualitative analysis, inter-watershed streamflow comparisons were performed for several rivers flowing into the east side of the Central Valley, CA. Results suggest that, in the absence of upland dams supporting large reservoirs, some reaches of these rivers might develop ephemeral streamflow in late summer. As a quantitative analysis, we conducted a series of streamflow/groundwater simulations (using MODFLOW-2000 plus the streamflow routing package, SFR1) for a representative hypothetical watershed, with an upland dam and groundwater...
Dam Removal Database v2.0 data registered into the spatial feature registry. Source data are documented at https://www.sciencebase.gov/catalog/item/5ace95e3e4b0e2c2dd1a688f.
With increasing concern over degradation of aquatic resources, issues of liability, and maintenance costs, removal of small dams has become increasing popular. Although the benefits of removal seem to outweigh the drawbacks, there is a relative paucity of studies documenting the extent and magnitude of biological and chemical changes associated with dam removal, especially those evaluating potential changes in contaminant inventories. In August and November of 2000, a run-of-the-river dam on Manatawny Creek (southeast Pennsylvania) was removed in a two-stage process. To assess the effects of dam removal on the contaminant redistribution within the creek, sedimentary concentrations of polychlorinated biphenyls (PCBs),...
Categories: Publication; Types: Citation; Tags: PAHs, PCBs, dam removal, metals, sediment
Research on vegetation response post dam removal is an emerging science. Dam removal is becoming increasingly common as dams begin to become structurally unsound and reach their life capacity. This study is part of a larger plant monitoring project examining revegetation efforts following the removal of two large dams on the Elwha River in Olympic National Park. It is intended to provide project managers with data on species-specific performance in a unique environment. The data will be used to improve future restoration techniques in the newly exposed substrates. Revegetation of native woody vegetation is a key component to ecosystem restoration in the Elwha River watershed. This project will investigate plant...
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Small, surface-release dams can impair natural stream connectivity by disrupting the flow of water, sediment, nutrients, and biota. Many dams built during the 19th and 20th centuries have exceeded their functional lifespan, and as a result, dam removal has become an increasingly prevalent stream restoration method. However, many streams have not been consistently monitored before and after dam removal, and there is a paucity of information regarding how dam removals affect stream ecosystems across different dam, stream, and landscape characteristics. Therefore, this study aimed to quantify the effects of dams and dam removals on a critical water quality parameter (dissolved oxygen) across 16 Massachusetts streams...
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Estuary geomorphic units delineated at a scale of 1:1500 using a combination of (a) 03 September 2011* 0.3 meter resolution Microsoft/Digital Globe aerial imagery; and (b) elevation-colored and hillshaded digital elevation models from USGS backpack/jetski topobathy surveys (25 August 2011) for areas < MHHW and aerial lidar surveys (13-15 April 2012) for elevations > MHHW. *Image date of 3-Sep-11 corrected in metadata. During product generation the imagery date was believed to be 8-25-2011, as reported by DigitalGlobe reseller.
map background search result map search result map Geomorphic habitat units derived from 2011 aerial imagery and elevation data for the Elwha River estuary, Washington Vascular plant diversity and associated environmental variables along the Elwha River, Washington, 2005-2017 Baseline geomorphic map and land-surface parameters, derived from integrated topobathymetric elevation data, for the mainstem Klamath River corridor downstream of Iron Gate Dam, CA, 2018 Effects of Small Dams and Dam Removals on Stream Dissolved Oxygen in Massachusetts, USA Dam removal practitioner perspectives on incorporating climate change into dam removal decisions in the eastern United States Camera trap photo detections of mammals along three reaches of the Elwha River, Washington Geomorphic habitat units derived from 2011 aerial imagery and elevation data for the Elwha River estuary, Washington Vascular plant diversity and associated environmental variables along the Elwha River, Washington, 2005-2017 Camera trap photo detections of mammals along three reaches of the Elwha River, Washington Effects of Small Dams and Dam Removals on Stream Dissolved Oxygen in Massachusetts, USA Baseline geomorphic map and land-surface parameters, derived from integrated topobathymetric elevation data, for the mainstem Klamath River corridor downstream of Iron Gate Dam, CA, 2018 Dam removal practitioner perspectives on incorporating climate change into dam removal decisions in the eastern United States