Dams are integral to many communities and critical to watershed management. The U.S. Army Corps of Engineers (USACE) operates and maintains approximately 740 dams and associated structures that provide significant, multiple benefits to the nation.
In order to effectively operate and maintain those dams, USACE applies risk-informed decision making to evaluate, prioritize and justify dam safety decisions. Using risk information allows the organization to repair its dams in the most effective manner within a constrained budget. To streamline this process, USACE researchers have developed a systemwide approach for assessing risk in flood risk management watersheds.
“A lot of these structures were built 70 to 80 years ago — and in some cases 90 to 100 years ago — and the design lives for most of them was 50 to 75 years,” said Willie Brown, a research civil engineer at the U.S. Army Engineer Research and Development Center. “Some of these structures have outlasted what they were supposed to be able to provide — and that's a great thing — but as that continues to be the case, the risk of failing becomes greater and greater. For the communities surrounding them — from a flood risk management perspective — if we don't keep our facilities in good shape, the consequences could be dire.”
Brown’s team is specifically focused on the probability of failure, or how likely the facility is to fail within a set number of years.
“The current system is very subjective,” he said. “Whereas the new method gives us the ability to compare facilities from across the country by having a more consistent, more transparent way of assessing risks. In providing a fair playing field, we will be able to maintain our infrastructure better because we're allocating resources to the things that are the highest risk. That was our goal — to generate risk data that decision makers can use so that our limited civil works dollars get allocated to those assets with the highest risk.”
The innovative approach has already been applied in several case studies in four different watersheds across the enterprise, and the team is currently working with USACE headquarters to roll it out nationwide.
In addition, the USACE Risk Management Center (RMC) has developed the quantitative risk analysis software, or RMC-TotalRisk, to enhance and expedite risk assessments within the flood risk management, planning and dam and levee safety communities of practice.
“It can do simple things all the way to the most complex projects,” said Haden Smith, a senior hydrologic engineer with the RMC.
The RMC-TotalRisk software tool provides several features that greatly improve quantitative risk analyses and is part of the comprehensive RMC risk analysis software suite.
“In terms of value-added, this tool stands to significantly reduce study costs,” Smith said. “It has an intuitive user interface with very fast runtimes. It allows users to run more alternatives and really dive in. Because it's so fast, they can quickly see cause-and-effect on inputs and outputs. It stands to not only improve the quality of studies going forward, but also reduced the overall time to develop a model.”
The software provides several risk measures that can better support the evaluation of risk reduction alternatives and provides many features that will enhance dam and levee safety activities and improve investment decisions.
The RMC-TotalRisk tool is actively being used on all new starts for dam and levee safety studies in the risk management center and is freely available to the public and downloadable from the RMC website (https://www.rmc.usace.army.mil).