Validation of Fuse Plug Design and Guidance using a Simplified Physically Based Breach Model

January 7, 2026

Fuse plug embankments may be used to provide additional spillway capacity at elevated reservoir levels. For a fuse plug to meet its design intent, the embankment must operate as a stable dam embankment for the range of expected conditions until such time as the reservoir level exceeds a predetermined level, at which time the fuse plug embankment should activate and breach according to the intended design. Should the fuse plug fail to activate at the intended reservoir level, prematurely fail or fail to breach, or breach at a rate that exceeds the bounds used in the design, the results can range from loss of reservoir capacity and reconstruction costs to uncontrolled overtopping, dam failure and downstream impacts. The industry guidance for the design of fuse plug embankments typically involves the use of empirically based relationships to determine the geometric arrangement, internal zoning and the selection of construction material. The methods are also limited in terms of the expected hydraulic conditions that initiate the fuse plug embankment. These simple relationships are based upon a limited number of laboratory and prototype tests, and as a result present a narrow range of design. For a given project application, the design of a fuse plug embankment often requires modification to accommodate appropriate slope stability, seismic, and piping design aspects. These departures from the empirical guidance are typically beyond the ranges tested or recommended within the available guidance, and consequently, there is little ability to validate that the modified designs will still function as intended. This study investigates the use of a simplified physically based breach model to validate and support fuse plug design. Various published laboratory and prototype scale fuse plug designs are represented within the model, allowing estimates of breach initiation and progression to be evaluated against the reported results. By providing guidance on model arrangement and parameters, this study aims to deliver an additional design tool that can be used for fuse plug embankment design.

Palmen, L. 2025 “Validation of Fuse Plug and Design Using a Simplified Physically Based Breach Model,” in Proceedings of the NZSOLD/ANCOLD Conference 2025, 19 – 21 November 2025, Ōtautahi Christchurch, New Zealand: NZSOLD/ANCOLD