North America | “The Abiquiu TTX hopes to increase mutual
Ryan Brooks, Dam Safety Program Manager for the Albuquerque District of the US Army Corps of Engineers, provides an in-depth briefing to participants during the Abiquiu Dam Safety Tabletop Exercise in May 2026
investigations to understand if dam safety risks were present. Based on this analysis, Reclamation initiated a Corrective Action Study in March 2025 to develop alternatives for addressing the seepage issue in the spillway. The project aims to address concerns with the foundation material under the spillway and increase operability of the three spillway radial gates. Data collected during drilling will be used to inform the next phase of design, where repair alternatives will be evaluated. “The exploratory drilling at Vallecito Dam represents a critical step in ensuring the long-term safety and reliability of this important infrastructure,” said Western Colorado Area Office Manager Bart Deming. “By gathering detailed data, we’re laying the groundwork for informed decisions on future repairs and rehabilitation. This effort is not only about addressing current concerns, but also about safeguarding the dam for the communities and resources it serves.”
Dam safety The Albuquerque District of the USACE recently held
a Dam Safety Tabletop Exercise (TTX) for Abiquiu Dam in New Mexico during May 2026. The purpose of the exercise was to improve mutual awareness among Abiquiu Dam stakeholders of the roles and duties, communication needs, and coordination efforts necessary in the event of a dam emergency.
References
2026 World Hydropower Outlook Pathways to sustainable and secure energy systems. International Hydropower Association.
www.hydro.org
Large Power Transformer Supply Chain Gap Analysis and Domestic Content Strategies for Hydropower Rehabilitation: Supplemental Report. Ramasamy, Vignesh, Aubryn Cooperman, Rakesh Jayswal, and Margaux Seward. 2026. Golden, CO: National Laboratory of the Rockies. NLR/TP-5700-96742.
https://www.nlr.gov/docs/fy26osti/96742.pdf.
Floating Solar in Hydropower Reservoirs in the United States Techno-economics, Environmental Considerations, Regulatory Pathways, and Technical Potential. Juan Gallego-Calderon, Tyler B. Phillips, Mucun Sun, and Tanveer Hussain from Idaho National Laboratory. Aaron Levine, Evan Rosenlib, and Marie Rivers from National Renewable Energy Laboratory. Evan Bredeweg, Ivan Arismendi and Sarah Henkel from Oregon State University. Alex Cagle, Bella Alvarado, and Alex Meyer from Noria Energy. Dan Berger, Dana Olson, and Daniel Pardo from DNV. Meghan Bringolf, Jose Zayas, and Neal Simmons from Eagle Creek Renewable Energy. January 2026. INL/RPT-25-82657 Revision 0. Solar Energy Technologies Office and Water Power Technologies Office
Satellite observations reveal widespread alteration of river thermal regimes by US dams. Emily A. Ellis, George H. Allen, Christian E. Torgersen, Katie A. McQuillan. Sci. Adv. 12, eaeb5193 (2026) 8 July 2026.
www.science.org on July 29, 2026
22 | September 2026 |
www.waterpowermagazine.com
awareness of responsibilities and tasks, communication needs, and coordination efforts in the case of a dam emergency or high releases,” said Haywood Manciel, emergency management specialist in the USACE-Albuquerque District. Participants were from Emergency Management, Water Management, Dam Safety, Operations Division, the Geotechnical and Environmental Engineering Branch, and Public Affairs, as well as maintenance staff from Abiquiu Dam. There were also representatives from the N.M. Dept. of Homeland Security and Emergency Management, Bureau of Reclamation, the City of Abiquiu, and Rio Arriba County. Attendees were given a scenario where weather conditions increased the water level of the reservoir to higher than previously recorded levels. The discussion centred on what would trigger an emergency and how the various stakeholders would respond to the situation, including which agency would be responsible for which actions, as some things require specific authority. One of the primary outcomes of the event was establishing the vital importance of creating personal emergency action plans to integrate with the comprehensive overarching plans. Along with recognition that the district must do such drills, seminars, and table-top exercises every two years.
Changing temperatures A new study claims to be the first to identify widespread
warming of river surface temperatures downstream from US dams. Dams can impact river thermal regimes by impeding the natural flow of water and altering mixing within the water column, which can lead to thermal heterogeneity, stratification, and the release of warm or cool water downstream. Such changes can have wide-ranging consequences for aquatic ecology and biogeochemical processes. Previous assessments of downstream temperature changes have been constrained to single dams, single basins, or specific seasonal windows, limiting knowledge of their impacts. However, a new study by Ellis et al has used satellite-based thermal infrared observations to quantify river surface temperature differences up- and downstream of 287 large US dams, across all seasons from 2013 to 2024. Using Landsat 8 TIR imagery, the research team sought to describe the differences in river temperatures downstream from dams, the extent of their alterations, and how those downstream effects vary seasonally. The study found downstream river temperature
differences for the majority (71%) of longitudinal river profiles. These downstream changes were typically warmer (60%) and, on average, were sustained or continued to increase within 20km downstream of the dam. The magnitude and frequency of downstream alterations varied by dam type, with 91% of extreme (≥±4°C) differences occurring at dams with reservoirs. Using remote sensing, Ellis et al were able to identify instances of cooling downstream from large dams and provide a potential means of locating areas where important cold-water refuges can be created through dam operations. As climate change continues to compound the pressures placed on riverine ecosystems, the authors note, it will become increasingly important to find ways to mitigate temperature changes within rivers.
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