View Summer 2022 issue

Summer 2022

Risk assessment has been a key part of redesign for this high hazard dam in Minnesota. Deficiencies in the dam could impact performance and increase safety risks, so Barr performed a semi-quantitative risk assessment on the design concept for replacing the dam’s spillway and repairing its embankment.

Q&A: Spotlight on safety

July 25, 2022

Dams are a vital part of our world’s infrastructure, and global or environmental forces can affect how we assess their safety. Risk, climate change, and sedimentation and sustainability are three such factors driving recent changes and developments in how we assess, modify, and design dams for water supply, flood control, and power generation.

Brian Becker spent 35 years in dam engineering positions with the U.S. Bureau of Reclamation (USBR) and U.S. Fish and Wildlife Service before joining Barr. Brian, a delegate to the International Commission on Large Dams’ Committee on Dam Safety, discusses how these trends could impact facility design, operations, and planning.

Q: How will changes in risk analysis and risk-informed decision making (RIDM) affect owners and operators?

A: The Federal Energy Regulatory Commission (FERC) recently updated regulations, making formerly voluntary risk assessments mandatory. The reason was the benefits: the work that goes into risk analysis leads involved parties to gain a deeper understanding of a dam and its strengths and weaknesses; it helps owners and agencies know what needs to be mitigated.

As far as clients, they may not completely understand risk analysis themselves. They may have questions about what will be expected. They’ll need information about what risk analysis entails; training on dam inspection and making risk-related business decisions; assistance conducting the analysis; and help working risk analysis into their business model.

Our dam engineering team can help clients understand and perform risk analysis and RIDM, as well as Potential Failure Mode Analyses and semi-quantitative and quantitative risk assessments. Our strength is helping owners and operators truly understand the resulting information and how to use it to make or prioritize decisions.

Q: Let’s turn to climate change. How is that affecting safety trends?

A: Climate change—and extreme weather and floods—will affect how we operate facilities, store water, and generate power; it will also affect irrigation supply. The challenges include making water available, anticipating extreme storms, and planning for and managing a fluctuating water supply. Twenty years ago, when we called it global warming, I worked with hydrologists to try to better understand climate change impacts on dam safety; even now, there’s still a lot to learn. One continually maturing aspect is the creation of resilient structures. Barr understands the latest developments, and we consider resilience when designing dam modifications or new structures and assisting with operations plans.

Q: What about sedimentation and sustainability—what are the trends there?

A: Sedimentation in a reservoir impacts the amount of water that can be stored and supplied, and reservoir sustainability is affecting the economics and viability of many facilities. In future planning, owners and operators need to account for storage loss and include it in their economic analysis; design must accommodate how a dam or reservoir will handle sedimentation. Barr can help clients understand sedimentation effects and determine the best mitigation measures, such as design modifications, dredging, or other methods to restore volume. For a new facility, we can help anticipate sustainability needs.

For more information on dam safety and risk assessment, contact us.

About the author

Brian Becker’s extensive 35-year background in dam engineering was gained in positions with the U.S. Bureau of Reclamation (USBR) and U.S. Fish and Wildlife Service (USFWS). A specialist in dam safety and risk assessment and management, he served as the USBR’s Dam Safety Chief and is a current U.S. delegate to the International Commission on Large Dams’ Committee on Dam Safety.