WinDAM C: Analysis tool for predicting breach erosion processes of embankment dams due to overtopping or internal erosion

Authors: Hunt, Sherry; TEMPLE, DARREL - Retired ARS Employee; NEILSEN, MITCH - Kansas State University; ABDELFATAH, ALI - Orise Fellow; Tejral, Ronald

Submitted to: Applied Engineering in Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/20/2021
Publication Date: 6/1/2021
Citation: Hunt, S.L., Temple, D.M., Neilsen, M.L., Abdelfatah, A., Tejral, R.D. 2021. WinDAM C: Analysis tool for predicting breach erosion processes of embankment dams due to overtopping or internal erosion. Applied Engineering in Agriculture. 37(3):523-534. https://doi.org/10.13031/aea.14334.
DOI: https://doi.org/10.13031/aea.14334

Interpretive Summary: Earth dams are considered safe, but if they fail, they most commonly fail from water spilling over the top of dam or by water flowing through a dam opening likely created from animal or tree growth damage on the dam or inadequate dam construction. More than half of the nearly 12,000 dams constructed under the assistance of the United States Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) are more than 50 years old. As these dams age, challenges arise, which is a growing concern among the dam safety community including federal and state dam safety officials, emergency managers, and engineering consultants. These stakeholder groups need reliable technology and tools to predict how well a dam will perform under extreme flood events, and they ultimately want better warning systems and emergency plans to inform and advise the public when there are problems with a dam. The USDA Agricultural Research Service (ARS), USDA Natural Resources Conservation Service (NRCS), and Kansas State University have partnered to conduct research and develop software to predict earthen dam failure. This software is a simplified approach to represent the erosion processes that occur during a dam failure event. This paper highlights assumptions and equations used in the software development and the limitations one may encounter when using the software.

Technical Abstract: Internal erosion and overtopping erosion of earthen embankments are the leading causes for earthen embankment failures. Challenges like reservoir sedimentation, structural deterioration, rodent damage or tree root growth, changing hazard classification from low to significant or high have arisen with aging dams. To address these challenges, new technology and tools for predicting the performance of homogeneous earthen embankments during overtopping or internal erosion are needed. Windows Dam Analysis Modules (WinDAM) is a modular software application developed through collaborative efforts of the United States Department of Agriculture (USDA) Agricultural Research Service (ARS), the USDA-Natural Resources Conservation Service (NRCS), and Kansas State University (KSU) in response to this need. WinDAM incorporates algorithms for predicting the progression of erosion resulting from embankment overtopping or flow through an internal discontinuity in the embankment and software models to simulate flow through a reservoir. These algorithms are based on existing literature and data and observations from physical model experiments conducted by scientists at the USDA-ARS Hydraulic Engineering Research Unit laboratory at Stillwater, Oklahoma. The resulting computational model is a simplified representation of the observed process of progressive erosion that may lead to embankment breach. This paper reviews the components of the erosion/breach process and the way in which these components are quantified and integrated into the current WinDAM software, WinDAM C. The scope of application of the software, limitations, and computational assumptions are also discussed.