Dam Safety Interest Group (DSIG)

Many of the dams around the world were designed and built over 35 years ago.
As these structures age, the level of safety becomes more difficult to evaluate, particularly where original design details are not known.
Moreover, safety and design standards have changed over the years and many of these aging structures must be upgraded to meet current standards.
Research is required for the development and evaluation of new diagnostic monitoring tools and techniques for the assessment of the stability and safety of existing dams.
New repair materials and techniques can reduce the cost of required dam safety improvements.

The Dam Safety Interest Group (DSIG) is composed of dam owners who jointly sponsor research & development projects designed to help assess and improve the safety of dams.
Today, the DSIG is represented internationally by participants from Canada, the United States, Australia, Sweden, France, the United Kingdom, and Germany.

Topics and Issues:

• Risk assessment for dam safety
• The use of geophysical methods in the diagnostics and monitoring of embankment dams
• Erosion and piping in dams
• Reliability of discharge facilities
• Ice loadings
• Probability (frequency) of extreme floods
• Emergency preparedness
• Testing of embedded dam anchors

Project Highlight: Comparison of Flood Hazard Estimation Methods for Dam Safety – Phase 1

Hydrology was of course one of the first civil engineering disciplines to benefit from modern statistical thinking. Sophisticated descendants of these early statistical methods are now used worldwide within the dam industry to estimate the flood hazard. Such methods, if applied correctly, provide powerful tools capable of exploring the extremes of hydrological hazard whilst at the same time honestly acknowledging the uncertainty in these estimates.

In addition to statistical methods, the Probable Maximum Precipitation (PMP) and Probable Maximum Flood (PMF) approaches aims to define a “maximum” design event that is a reasonable worst combination of meteorological and hydrological factors for a particular reservoir project.

As a result, a plethora of approaches now exist, each with its perceived advantages and disadvantages, and hence a wide diversity of practice exists. In some cases this reflects the differing demands of regulation and physical setting, whilst others simply reflect analyst preference.

Beyond the established approaches, the dam safety community throughout the world has a growing interest in moving towards a risk-informed management paradigm. This is not an easy transition. It is however clear that fundamental to its success, as in traditional approaches, is a transparent and reliable means of estimating extreme flood flows.

This project will provide an unbiased and structured review of the available and evolving methods, how and why they are used in across the world and, importantly, how they perform.

Current Projects

• Dam Safety Inspection Procedures, Guidance and Training for Plant OperatorsDevelopment of a dam safety training guide specifically focused for hydropower operators that includes the following: Non-engineering introduction to the design and structural characteristics of dams, failure mechanisms, and dam performance monitoring; Guidance, including general procedures, for dam safety inspections; Guidance on understanding the difference between maintenance and dam safety issues; A basic understanding of what potential failure modes are and how that knowledge can be applied to operators� specific locations; and Guidance, including general procedures, for reporting dam safety concerns and implementing emergency response plans.
• Investigating the Structural Safety of Cracked Concrete DamsThe main purposes of this study will be to provide owners, operating staff and engineers with a basic framework and practical tools for making appropriate decisions in the field and managing cracks that is consistent with good international practice.
• Comparison of Flood Hazard Estimation Methods for Dam Safety - Phase 1The proposed project aims are clearly and simply stated as to: Improve the knowledge on flood hazard estimation methods used, and emerging, for dam safety worldwide (with a focus on those countries using more advanced approaches). Provide a state-of-the-practice report on existing methodologies and regulatory frameworks that will be a benchmark of the available methods.
• Modeling Evaluation of CSEM Techniques including MMR Technology for Seepage Delineation in Earth Embankment DamsThe main objective of the project is to evaluate the ability of CSEM/MMR to detect and delineate preferential seepage within earthfill dams.
• Dam Safety Performance Monitoring and Data Analysis Management - Best PracticesThe objectives of this project include documenting best practices in order to develop an instrumentation program for dam surveillance, inspection, instrumentation needs and maintenance, data collection, data analysis, and data management for performance monitoring and understanding. This includes identifying the responsibilities of management and the key components for managing the overall performance monitoring program along with proper coordination and communications between and among program components.
• Erosion and Breaching of Embankment Dams (Phase 2: Development of Erosion Model)The primary objective of the project is to develop a state-of-the-art numerical model that will simulate the erosion and breach of embankment dams of varying types (e.g., homogeneous, zoned, cohesive earthfill, rockfill), with erosion initiated by overtopping flow, internal erosion, or piping erosion.

Recently Completed Projects