Dam, Right! Using Screening Level Risk Analysis for Dam Risk Reduction and Safer Communities.
In 2016, the Water Infrastructure Improvement for the Nation Act introduced the Rehabilitation of High Hazard Potential Dams (HHPD) Grant Program under FEMA’s National Dam Safety Program. This program provides states with technical, planning, design, and construction assistance to support HHPDs with improving safety. Amid Part 2 of the HHPD application process, FEMA requires a risk assessment for each potential project dam to demonstrate risk reduction. North Carolina developed a risk-based portfolio of eligible HHPDs, utilizing a Screening Level Risk Analysis (SLRA). An SLRA aims to identify potential failure modes and create relative risk estimates for each dam. The results correlate the likelihood of failure and resulting consequences, providing a total risk categorization. The process can be completed on individual dams, and results from multiple dams can be compared within a select portfolio for further prioritization. This framework helps communities and regulators prioritize dam work, ensuring resources are allocated effectively to address the most critical risks. Risk reduction involves measures and actions aimed at decreasing the likelihood of dam failure. Once a specific measure is verified as effective in reducing risk, estimated costs can be developed for each measure. Multiple measures may be needed to reduce risk to the desired level. These costs can then be compared to other measures within a dam project or across multiple dams in a portfolio. This comparison enables the state dam safety program to assess the efficacy of each risk reduction measure and prioritize dam projects accordingly. Effective dam safety management requires understanding risk factors and making informed decisions that balance safety, cost, and practicality. This presentation aims to demonstrate that State dam safety programs or dam owners can use SLRA as a tool to support Part 2 of the HHPD application process, develop cost estimates for reduction strategies, and prioritize dam rehabilitation efforts. This presentation will highlight:
- An example of how the SLRA process is applied to evaluate various failure modes.
- Exploration of risk-informed decision-making processes in dam safety management to prioritize and address potential failure modes.
- Development of measures to assess the risk reduction and associated cost for state dam safety programs and dam owners to evaluate best approaches to improve the safety of dams.
Author Bio
Sophia Guzman graduated from North Carolina Agricultural and Technical State University with a bachelor’s degree in Biological and Agricultural Engineering. She joined Freese and Nichol’s Water Resource Design team in Raleigh NC in late 2022 and is where she’s gained her experience in water resource design focusing primarily on helping support her team’s hydrology and hydraulic efforts on many projects throughout the southeast.
