The results of a yearlong study by an independent external peer review panel to assess the use of risk-informed dam safety practices is now available to the public. The verdict – the way the nation operates its dams across three federal agencies is appropriate and sound but can benefit from some areas of improvement.
The U.S. Army Corps of Engineers (USACE), alongside the Federal Energy Regulatory Commission and the Bureau of Reclamation, contracted with a panel of dam experts, all external to their agencies, to review their dam safety practices at the direction of U.S. congress. The review took place following the 2017 spillway failure at California’s Oroville Dam, which triggered broad industry concerns about the safety of dams nationwide.
“Many agencies including USACE took a much closer look at how we have been evaluating safety at our dams. Congress was also interested in what the Oroville incident meant for the nation and for federal dams specifically. They asked USACE to coordinate an independent review of the risk policies and methods used to assess risk across the three major federal agencies that own, operate, or regulate dams in the U.S. It was congress’ intent to inform improvements broadly in national dam safety practices,” said Risk Management Center’s Director, Nate Snorteland, whose work falls under USACE’s Institute for Water Resources.
The panel, which includes a broad range of experience and expertise, encompassed individuals from the United States, the Netherlands, and Australia, and included academicians and a private sector consultant. In addition to evaluating agencies’ use of risk in dam safety and regulation, the panel also considered how dam safety practices are affected by human factors, as well as how risk informed analysis in other industries may be applicable to dam safety practices.
According to Snorteland, the review consisted of several meetings between the agencies and the panel, where documents provided by the agencies were reviewed and each agency briefed the panel on their policies and methods. “The panel spent more than a year examining the documents and discussing them with the three agencies. Ultimately, they provided a draft report, received feedback from the agencies, and provided an out brief to the agency leadership. The report was finalized in September 2020 and submitted to the Administration,” Snorteland said. The report has now completed clearance and is ready for release.
The review showed that overall, the risk management programs for dam safety in the three agencies are appropriate and sound. Additionally, the agencies’ implementation of risk-informed decision-making are consistent with federal guidance despite differing levels of dam safety program development between agencies. The panel felt the level of cooperation between agencies and progress made by the agencies over the last 10 years was important and improved safety overall.
The report also highlighted issues that warrant attention by the agencies. Specifically, the panel recommended agencies incorporate practices used in other industries more fully, such as incorporating human factors into the risk methods. The team also recommended agencies fully calibrate models used in risk analyses and employ expert judgments to support safety assessments. Other recommendations of note included improving communication with the public on their risk exposure. USACE concurred with each of the recommendations and has developed a plan to implement improvements over the next several years.
According to Carlos Denson, the Risk Management Center’s Director of Operations, the federal dam infrastructure provides a substantial benefit to the nation. “These structures protect the public from floods, provide reliable drinking water, generate clean reliable power, and provide water to irrigate crops across the country. The safety of these structures is important so that they can continue to deliver those benefits to society. The findings from the panel reinforce the stewardship that is currently being provided by the agencies and the commitment to continually improve safety across the nation,” said Denson.
USACE Headquarters Dam and Levee Branch Chief, Travis Tutka, provided his perspective on the report.
“When it comes to the management of our dams, public safety is our top priority. USACE conducts self-assessments of our programs and contracts external reviews periodically. This independent review was requested by congress to assess the use of risk-informed dam safety practices in each of the three federal agencies.” Overall, the review validated our efforts with some room for improvement. By maintaining openness and transparency of our programs with the public through reviews such as this, we hope to increase trust in our management of USACE dams on behalf of the nation.”
For the full digital report, visit: https://publibrary.planusace.us/document/3b6ce218-62d3-447b-c8af-04ad2d2af780
About the Risk Management Center:
The U.S. Army Corps of Engineers (USACE) – Institute for Water Resources, Risk Management Center (RMC) is a center of expertise. It was established in 2009 to improve management controls over infrastructure decisions, serve as an independent advisor to senior leadership, maintain and develop risk competencies, and ensure consistency in processes, application of criteria and decision-making. The mission of the RMC is to support Civil Works by managing and assessing risks for dams and levee systems across USACE, support dam and levee safety activities throughout USACE, and develop policies, methods, tools, and systems to enhance those activities. The RMC serves as a USACE-wide resource for risk-related tools, assessments, knowledge, and methods. It is intended to offer a national perspective as well as support routine District and Major Subordinate Command (MSC) dam and levee safety activities. The RMC offers services to support dam safety; levee safety; and the Modeling, Mapping, and Consequence (MMC) Production Center.
The Institute for Water Resources’(IWR) Hydrologic Engineering Center (HEC), located in Davis, CA, takes home the U.S. Army Corps of Engineers (USACE) Innovation of the Year Award for adding Post-Wildfire Modeling capabilities to its software. These software capabilities provide prediction tools that engineers can use to anticipate a unique type of flooding that can follow a combination of fire and floods.
The software development was led by a USACE project delivery team with collaboration between HEC, the Engineer Research and Development Center’s (ERDC) Coastal and Hydraulics Laboratory, and USACE District Engineers, who incorporated the post-wildfire modeling capabilities into HEC's hydrology and hydraulic software. What resulted was award-winning predictive capabilities that advances the nation’s fight against floods, and especially post-wildfire flooding.
Hydrologic Engineering Center Director, Chris Dunn, highlighted the significance of the achievement. “The team’s efforts culminated in truly groundbreaking capabilities which are of great value to the nation and to the engineers who use the tools. The engineers analyze watersheds where wildfires have occurred, and they attempt to predict what could happen in watersheds where wildfires may occur in the future. The incorporation of these capabilities into HEC-HMS and HEC-RAS will better help engineers, emergency planners, and the public understand their risks and appropriately prepare. A big part of our jobs is to understand and help others understand their risks. These capabilities have helped us to do so in a big way.”
According to Stanford Gibson, HEC’s Sediment Transport Specialist, the modeling tool is increasingly relevant due to an uptick in wildfires in the western United States and the destructive or deadly nature of wildfires, and the potential for mud and debris flows to follow. “Wildfires are kind of a big deal these days. But after the wildfire, the danger isn’t over. The fire changes the landscape, so subsequent rain can cause sudden mud and debris flows. We added analysis tools to our software – which is already industry standard for flood risk – to forecast the impact of these events and plan emergency management actions,” Gibson said.
Specifically, the models are now superpowered by a library of new equations to handle the unique physics of these events which improves the agency’s ability to more anticipate the likelihood and magnitude of a post-fire event, where it will flow and how deep the flooding will be. “This is crucial for emergency assessments and mitigation measures,” said Dr. Jay Pak, HEC Hydraulic Engineer, “as it allows USACE to more accurately predict post-fire flood risk and respond accordingly. Additionally, the establishment of a long-term modeling framework enables USACE to continuously simulate post-fire flooding, debris flow risk, and ecology recovery in downstream ecosystems and communities over a 10-year period,” Pak said.
These capabilities are critical for USACE as the agency has a role in responding to post-wildfire hazards. “As the nation’s premier flood risk agency, our partners turn to us when they face any kind of flood risk, whether the water is blue (traditional flood water) or brown (mud and debris-filled flood waters). They expect us to have the capabilities to forecast their flood risk and evaluate mitigation alternatives, no matter the scenario, which requires increased analysis since the physics of mud and debris flows is more complicated than water. This effort got the tools our Corps districts need into their hands to meet these expectations for post-wildfire hazards,” Gibson said.
In addition to increasing predictive capabilities and response efforts, the software also increases opportunities for collaboration among key partners, thanks in part to the research and development touchpoints occurring between state, local and federal agencies utilizing the software. Pak emphasized that such cross-agency collaboration can lead to more effective and efficient emergency response and risk mitigation measures, such as was recognized in the innovation award. “The team behind this innovation can be proud of the fact that we developed new capabilities in the HEC-Hydrologic Modeling System (HEC-HMS) and the HEC-River Analysis System (HEC-RAS) from scratch through research, software development, technical transfer, and applications. This is a significant achievement that required a lot of hard work, collaboration, and expertise from multiple organizations and individuals. The fact that we were able to develop these capabilities from scratch demonstrates our innovation, creativity, and dedication to improving emergency assessments and mitigation measures for post-fire hydrological phenomenon. This award is a recognition of our hard work and a testament to the impact that our innovation can have on protecting communities and infrastructure from the effects of post-fire flooding,” said Pak. He also added, “Personally, this was a dream come true for me as it provided a once-in-a-lifetime opportunity to utilize my previous Ph.D. research in developing new capabilities for post-wildfire hydrology and debris flow.”
Gibson also reflected upon the team’s achievement, acknowledging the truly innovative approach required. “The hydraulics include some pretty “crunchy” math. Mud and debris flows aren’t water and require new physics and theory. It delves into the world of rheology (which partly studies the flow of complex liquids) and non-Newtonian physics (which studies fluids that depart from Newton’s viscosity assumptions), both of which are fun for someone like me,” said Gibson. “But by getting it into HEC-RAS, the flood risk model that our agency (and ~100,000 people around the world) already use, we got these capabilities into the field, and they were used in planning and emergency management studies in four different USACE districts within a year of release. We trained more than 40 people on these tools at the first class in late April, which means that within a couple years of their release they are just part of the Corp’s wildfire response,” Gibson added.
Gibson also addressed key players in the achievement saying, “We collaborated with USACE Engineer Research and Development Center (ERDC) to develop the algorithms and library…particularly Dr. Ian Floyd, ERDC research physical scientist, and Dr. Alex Sánchez, senior hydraulic engineer at HEC did a lot of the HEC-RAS development.
The PDT is also releasing web videos on the theory and practice behind these new methods. The post-wildfire team has developed seven videos on these topics that have been viewed over 7,500 times since their release. The team has embedded these videos directly into the online user help features, making them directly accessible from the software.
Visit https://www.hec.usace.army.mil/confluence/rasdocs/rasmuddebris to learn more about this innovative capability or https://www.hec.usace.army.mil/software/hec-hms/training.aspx to access a training material link which is a portal to the HMS capabilities and videos.
About HEC:
The primary goal of the Hydrologic Engineering Center (CEIWR-HEC) is to support the nation in its water resources management responsibilities by increasing the U.S. Army Corps of Engineers (USACE) technical capability in hydrologic engineering and water resources planning and management. One way CEIWR-HEC accomplishes this goal is by bringing state-of-the-art research and development into state-of-the-practice, which advances hydrologic engineering and water resources planning.
