Risk Management

Best Practices and Risk Methodology

The Bureau of Reclamation has been using risk analysis as the primary support for dam safety decision-making for about 15 years, and has developed procedures to analyze risks for a multitude of potential failure modes. Manuals, guidelines, standards, and practical reference material on how to perform risk analysis for dam safety applications are lacking. The Best Practices Training Manual contains what are considered the "Best Practices" currently in use for estimating dam safety risks at the Bureau of Reclamation. Risk analysis at the Bureau of Reclamation has evolved over the years and will continue to evolve. Therefore, updates to this manual are planned in the future as significant improvements are developed.

From the outset of implementing risk analysis, Reclamation recognized that procedures and data available for dam safety risk analysis, while quantitative, do not provide precise numerical results. Therefore, this manual strives to present useful information, tools, and techniques, while stopping short of a "cookbook" approach. This allows the risk analyst(s) to use the proper balance of engineering judgment and calculations in estimating risks, and to understand and "build the case" for what is influencing the risks the most. Thus, the numbers, while important, are less important than understanding and documenting what the major risk contributors are and why.

The Bureau of Reclamation conducts risk analysis at different levels, from screening level analyses performed by an individual (with peer review) during a Comprehensive Facility Review (CFR), to full blown facilitated team risk analyses, which include participation by field personnel. It is envisioned that the tools presented in this manual can be used for any level of risk analysis. The primary difference will be the level of detail to which the analyses are carried. These differences are noted where appropriate.

Contact for course information: Jeanne Major (jmajor@usbr.gov)

Best Practices Chapters

Please note that these documents are intended to serve as instruction material during the training course of the same name and should not be used as a stand-alone reference. In many cases, additional details should be sought from the available references or an experienced risk analyst. 
 
Chapter Title
Latest Update
A-1
Basics of Probability and Statistics
Presentation 
July 2018
A-2
Geologic and Geotechnical Information Required for Risk Assessments
Presentation 
July 2018
A-3
Potential Failure Mode Analysis
Presentation
July 2018
A-4
Semi-Quantitative Risk Analysis
Presentation 
July 2018
A-5
Event Trees
Presentation
July 2018
A-6
Subjective Probability and Expert Elicitation
Presentation 
July 2018
A-7
Probabilistic Stability Analysis (Reliability Analysis)
Presentation 
July 2018
A-8
Combining and Portraying Risks
Presentation
July 2018
A-9
Risk Guidelines
Presentation
June 2017
A-10
Building the Case
Presentation
June 2017
A-11
Facilitator Considerations
Presentation
June 2017
B-1
Reservoir and River Stage Exceedance Probabilities
Presentation
July 2018
B-2
Probabilistic Hydrologic Hazard Analysis
Presentation
July 2018
C-1
Consequences of Flooding
Inundation Modeling, Breach Parameters, and Consequences (Introduction) - Presentation
Reclamation's Life Loss Estimating Methodology (RCEM) - Presentation
Inundation Modeling, Breach Parameters, and Consequences (USACE Approach) - Presentation
June 2017
D-1
Erosion of Rock and Soil
Presentation
July 2018
D-2
Spillway Erosion
Presentation
June 2017
D-3
Flood Overtopping Failure of Dams and Levees
Presentation
June 2017
D-4
Riverine Erosion
Presentation
June 2017
D-5
Embankment Slope Instability
Presentation
June 2017
D-6
Internal Erosion Risks for Embankments and Foundations
Presentation
Internal Erosion Table 1
Internal Erosion Table 2
Internal Erosion Table 3
Internal Erosion Table 4
Internal Erosion Table 5
Internal Erosion Table 6
Internal Erosion Table 7
Internal Erosion Table 8
Internal Erosion Table 9
July 2018
D-7
Foundation Risks for Concrete Dams
Presentation
June 2017
D-8
Seismic Risks for Embankments
Presentation
June 2017
E-1
Concrete Properties Considerations
Presentation
July 2018
E-2
Reinforced Concrete Failure Mechanisms
Presentation
June 2017
E-3
Risk Analysis for Concrete Gravity Structures
Presentation
June 2017
E-4
Risk Analysis for Concrete Arch Dams
Presentation
June 2017
E-5
Risk Analysis for Concrete Buttress Dams
Presentation
June 2017
E-6
Seismic Pier Failure
Presentation
June 2017
E-7
Seismic Evaluation of Retaining Wall
Presentation
June 2017
E-8
Levee Floodwalls
Presentation
June 2017
F-1
Hydraulic Failure of Spillway Chutes
Presentation
June 2017
F-2
Overtopping of Walls and Stilling Basin Failure
Presentation
June 2017
F-3
Cavitation Damage Induced Failure of Spillways
Presentation
June 2017
G-1
Failure of Radial (Tainter) Gates under Normal Operational Condition
Presentation
June 2017
G-2
Gates other than Radial Gates
Presentation
June 2017
G-3
Seismic Failure of Spillway Radial (Tainter) Gates
Presentation
June 2017
G-4
Probability of Failure of Mechanical or Electrical Systems on Dam Gates
Presentation
June 2017
H-1
Operational Risks
Presentation
June 2017
H-2
Landslide Risks
Presentation
June 2017
H-3
Construction Risks
Presentation
June 2017
H-4
River System
Presentation
June 2017
H-5
Levee Closure Systems
Presentation
June 2018

 

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Last Updated: 3/29/19