Extreme weather events and the aging dam infrastructure are making dam-related emergency action plans more critical than ever.
There are more than 90,000 dams registered in the U.S. National Inventory of Dams across the country. But we rarely hear about them until the worst happens: one of them fails.
In 2020, record-breaking rainfall in Central Michigan caused the breach of two aging dams along the Tittabawassee River within hours of each other. The result was historic flooding. The failed dams — both nearly a century old — displaced thousands of residents and caused millions of dollars in damages.
“Local jurisdictions do not have access to the resources or expertise needed to fully assess the risks and potentially devastating impacts associated with the dams in their communities. They also often lack the plans vital for an effective response.” — Molly Finster, environmental health systems scientist, Argonne’s Decision and Infrastructure Sciences division
Such incidents are rare. But extreme weather events like ﬂoods and storms are putting added pressure on the aging U.S. dam infrastructure that provides essential functions like water storage, hydropower generation, flood control and recreation. The age of the dams combined with the force of the water they hold back presents potential hazards to downstream communities.
Regardless, many communities are not prepared for a dam-related emergency, said Molly Finster, an environmental health systems scientist in the Decision and Infrastructure Sciences division at the U.S. Department of Energy’s Argonne National Laboratory.
“Local jurisdictions do not have access to the resources or expertise needed to fully assess the risks and potentially devastating impacts associated with the dams in their communities. They also often lack the plans vital for an effective response,” said Finster. “Emergency managers understand that a dam failure could be potentially devastating. However, they are often, and understandably, occupied with other more immediate issues, such as a pandemic, hurricane or wildfire. For that reason, dam safety might not be a top priority.”
To help communities better understand their risks and the potential consequences of a dam-related incident, Argonne experts are working with the Federal Emergency Management Agency (FEMA) on its Collaborative Technical Assistance Program. The program provides at-risk communities with the expertise, coaching and tools needed to develop emergency action plans. It is offered through FEMA’s National Dam Safety Program, in conjunction with the National Integration Centers.
Communities learn through modeling, flood maps
Through the FEMA program, Argonne experts work with dam owners and operators and emergency planners to create dam-related emergency action plans that are ready for real-world use.
Finster presents in-person and virtual sessions on dam safety topics including risk-informed decision making, infrastructure dependencies and flood inundation modeling and mapping. Mustafa Altinakar, an Argonne senior computational hydroscience engineer, trains participants on a web-based, dam-break flood-simulation model called Decision Support System for Water Infrastructural Safety (DSS-WISE™) Lite.
Altinakar developed the DSS-WISE™ Lite model about a decade ago at the University of Mississippi through funding from the Department of Homeland Security. Since 2016, FEMA has used this web-based, integrated software package that combines a state-of-the-art, 2D numerical flood model and a series of geo-graphic information system (GIS)-based decision support tools.
“Participants don’t need expertise in modeling to run this simulation software,” Altinakar said. “I teach them to use DSS-WISE™ Lite in a step-by-step process, explaining what the software does and how to run simulations for various scenarios. We can set up simulations in a matter of minutes with minimum input data provided by the user.”
Visualizing flood scenarios is key to understanding the potential consequences of a dam failure. Simulations created through the DSS-WISE™ Lite model generate flood maps for different dam failure scenarios. These simulations also estimate the potential impact on lives and property in downstream communities based on the speed and depth of the floodwater. Users from more than 40 states have performed approximately 40,000 simulations since 2016, Altinakar said.
Finster uses the flood maps to help communities create dam-related emergency plans. “I walk participants through the steps for applying dam-related risk analysis principles to their planning efforts,” she said. “The contacts, relationships and products developed during the Collaborative Technical Assistance program can also help communities apply for grant funding for much-needed improvements.”
Argonne dedicated to strengthening dam safety and resilience
The Dam Safety CTA program has been implemented in nine U.S. locations, including Snohomish County, Wshington; San Diego County, California; South Carolina, and Puerto Rico.
“In Snohomish County, our analysis showed that the first community downstream of the dam would be underwater within 45 minutes of a catastrophic dam failure. The Collaborative Technical Assistance program supported the development of evacuation and shelter-in-place plans for a dam-related emergency,” Finster said.
In addition to the technical assistance process, the DSS-WISE™ Lite model has been used in numerous dam-related emergencies as a real-time simulation and decision-support tool to assist response efforts. Following Hurricane Maria in 2017, program leaders used the tool to simulate all dams on the island of Puerto Rico. Users deployed the tool to assess potential risks and consequences associated with the failed dams.
Argonne’s work in strengthening dam safety and resilience extends to its research on hydroelectric dams that use a reservoir, a large natural or artificial lake as a water supply.
Altinakar and Vladimir Koritarov, Argonne’s director of the Center for Energy, Environmental and Economic Systems Analysis in the Energy Systems and Infastructure Analysis division, are reviewing liner systems to improve safety and minimize storage loss for reservoirs of closed-loop pumped storage hydropower plants. Lining materials are used to minimize water leakage or seepage losses and reduce the need for makeup water. The work is being done through DOE’s HydroWIRES program.
These plants generate electricity when water is released from an upstream reservoir through turbines into a downstream reservoir. At night, when electricity is cheaper, the turbines are reversed to pump water back up into the elevated upstream reservoir. These plants offer an efficient way of storing energy.
“The reservoirs of pumped storage hydropower plants must be designed with a suitable liner system to minimize water leakage and seepage. The liners also ensure the stability of the embankment slopes against repeated cycles of rapid filling and drawdown of water during normal operation,” Altinakar said.
“Because of the evolving nature of downstream conditions, dam safety should be an on-going process,” Altinakar continued. “You cannot create an emergency action plan and then forget about it. Plans must be revisited and updated regularly.”
Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.