Dam Safety 2022: Workshop - Two-Phase Flow Tailings Dam Breach Modeling

Dam Safety 2022: Workshop - Two-Phase Flow Tailings Dam Breach Modeling

Half-Day Workshop: Two-Phase Flow Tailings Dam Breach Modeling

When: September 22, 2022 from 8:30 am - 12:30 pm Eastern

Registration Fee: $200

Assessing mudflow hazard from a tailings dam breach with a 2-D flood routing model is the industry standard, but the uncertainty of the sediment modeling is the primary limitation in the accurate prediction of a downstream flood hazard assessment. A two-phase flow modeling component has been developed in the FLO-2D model. The new 2-phase hyperconcentrated sediment flow component simulates a tailing dam breach with reservoir water storage and predicts both the downstream fluid and mudflow inundation. When a tailings dam with water storage fails, initially there is a distinct fluid floodwave that propagates downstream as the water flow moves overtop the tailings in the reservoir. The fluid phase scours the tailings surface as the mudflow mobilizes through the breach. Over a relatively short distance, the fluid and mudflow phases mix and become a mud flood with some mudflow cessation deposits downstream of the breach. The fluid phase continues in advance of the slower mudflow phase and may initially scour, then deposit on the downstream bed. 

The FLO-2D model is applied worldwide to simulate tailings dam breach failures. This 4-hour workshop will describe these physical processes in detail and will focus on the creation of a tailings dam breach project using the two-phase component. The workshop will include a theoretical presentation (1.5 hrs) and a hands-on project (2.5 hrs). The practical lesson will show how to simulate a tailings dam breach failure and route the breach hydrograph as two-phase fluid flow (water and mudflow) downstream and delineate the hazard mudflow inundation. A new GUI for tailings dam breach studies supported by robust pre- and post-processor tools in the QGIS geographic information software will be used. This 2-phase modeling approach represents a new level of predictive analysis for tailings dam breaches and mudflows.

The workshop will include a 3-month FLO-2D PRO license.  Licensing details will be emailed to registered attendees in advance of the workshop.  To download the software, you will need to have admin rights for your machine.
Workshop Topics:

  • Introduction to the QGIS Plugin Tool and FLO-2D model.
  • Build the detailed flood model components for the tailings dam breach with water storage.
  • Run the model and predict downstream fluid and mudflow inundation.
  • Assess mudflow cessation and sediment scour/deposition.
  • Apply tailings dam tool to verify volume releases.
  • Discuss results.


  • Noemi Gonzalez, Ph.D., FLO-2D Software 
  • Karen O’Brien, FLO-2D Software 
  • Jim O’Brien, FLO-2D Software