"Very well done! Dam Breach Analysis provides practical knowledge that can be applied to real-world situations." - John Simcik, Associate, Kasberg Patrick & Associates, Temple, Texas

Purpose and Background

This intensive, workshop‐oriented, two‐day seminar will prepare the engineer and water resource professional to use the HEC‐RAS computer program for creating and running one‐dimensional unsteady models and dam breach simulations. Led by experts from WEST Consultants with practical experience in dam breach modeling, participants will learn how to approach and conduct a dam breach problem, estimate breaching parameters, construct a HEC‐RAS unsteady flow model of the dam breach, and eliminate errors and instabilities in the model run.

The HEC‐RAS modeling system was developed by the Hydrologic Engineering Center of the U.S. Army Corps of Engineers. HEC‐RAS incorporates various aspects of 1‐D and 2D hydraulic modeling, including dam and levee breaks. HEC‐RAS is user friendly, computationally efficient, and runs within, and fully supports, the Microsoft Windows environment. It uses the latest graphical user interface (GUI) technology for data entry, graphics, and display of program results. Complete context‐sensitive help screens are available for every program feature and option. Software includes the following functions: file management, data entry and editing, hydraulic analyses, tabulation and graphical displays of input and output data, reporting facilities, and on‐line help.

Includes advances in open channel hydraulic analysis such as:

• Setting up and debugging one‐dimensional unsteady HEC‐RAS models
• Pre- and post-processing of one‐dimensional results
• Modeling dams, levees, culverts, and bridges in one‐dimensional unsteady modeling
• Dam and levee breach analysis including multiple dam and/or levee breaching
• Selecting the appropriate dam breach parameters

HEC‐RAS is one of the most extensively‐tested civil engineering computer programs ever developed. In addition to extensive in‐house testing at the Hydrologic Engineering Center and at other offices of the
U.S. Army Corps of Engineers, the program has been tested by thousands of engineers in the private and public sectors.

Learning Outcomes

• Students will learn how to use the U.S. Army Corps of Engineers HEC‐RAS (River Analysis System) computer program to conduct dam breach analyses. Assessment Criteria: Students will work in pairs to create several HEC‐RAS unsteady and dam breach models.
• Students will gain hands‐on HEC‐RAS experience with the most common problems that arise when doing one‐dimensional unsteady and dam breach models. Assessment Criteria: Students will participate in practical computer workshops using HEC‐RAS and will be tasked with setting up the models, running them, and analyzing results.
• Students will gain an overview of hydraulic principles for rivers, waterway bridges, and culverts and how they work within one‐dimensional unsteady and dam breach models. Assessment Criteria: Students will work in pairs to gain hands‐on experience with HEC‐RAS that will require them to understand and apply hydraulic principles discussed in class.
• Students will gain understanding of breaching parameters and how to choose them. Assessment Criteria: Students will work in pairs to gain hands‐on experience with HEC‐RAS that involves selecting and applying dam breach parameters to the model.
• Students will obtain valuable insights in methods for minimizing computation errors and instabilities commonly associated with unsteady hydraulic models Assessment Criteria: Students will work in pairs to gain hands‐on experience with HEC‐RAS that involves setting up a dam breach HEC‐RAS model, diagnosing instabilities and errors with dam breach models, and fixing dam breach models.

Assessment of Learning Outcomes

Instructor(s) will observe student performance during multiple computer workshop problems, and students will take a test at the end of the class with questions addressing these items. The test will be graded in class by their classmates as the instructor goes over each question and answer.

Special Features

Via email, approximately 5 days prior, workshop participants will receive links to websites/FTP containing the HEC-RAS software, the manuals in PDF format (User's Manual, Hydraulic Reference Manual, and Applications Guide), input files for the workshops, as well as workshop solution files.

Workshop participants receive links to download the following publications and software:

• HEC-RAS software (latest version)
• HEC-RAS Hydraulic Reference Manual (digital copy)
• HEC-RAS User Manual (digital copy)
• HEC-RAS Course Notes

Consulting engineers, water resource planners, engineers employed by local, state, or federal government agencies who are currently, or at some point plan to execute and/or review dam breach hydraulic studies. Participants should have sound experience in HEC-RAS steady flow computer modeling and some experience in HEC-RAS unsteady flow computer modeling. They should also be able to follow simple computer instructions.

Seminar Outline

TIME: 8:00 a.m. - 5:00 p.m.

DAY 1

• Introduction to Flow Modeling with RAS
• Unsteady Model Setup and Review
• Workshop & Review: Introduction to Unsteady Flow Modeling
• Modeling Inline and Lateral Weirs
• Advanced Unsteady Flow Features
• Workshop & Review: Pre-processing for Unsteady Flow Models
• Overview of Dam Failure Modeling Using HEC-RAS

DAY 2

• Overview of Dam Failure Modeling Using HEC-RAS
• Setting Up a HEC-RAS Dam Breach Model
• Workshop and Review: Adding an Inline Structure and Breach
• Fixing a HEC-RAS Dam Breach Model
• Selecting Dam Break Parameters
• Workshop & Review: Building a HEC-RAS Dam Breach Model