Garcia, R, Artigas, J, Martinez, S, Garcia-Navarro, P, Murillo, J & Correa, A 2026, 'Rheology matters: simulating dilute-to-dry tailings dam breaks', in AB Fourie, M Horta, M Oliveira & S Wilson (eds), Paste 2026: Proceedings of the 28th International Conference on Paste, Thickened and Filtered Tailings, Australian Centre for Geomechanics, Perth, pp. 1-10, https://doi.org/10.36487/ACG_repo/2655_37 (https://papers.acg.uwa.edu.au/p/2655_37_Garcia/) Abstract: Mine tailings dam failures generate complex flows composed of water, multiple solid phases of varying sediment sizes, organic matter, chemical solutes, and metals. These flows can rapidly entrain soil from surrounding terrain, and under lower-energy conditions, deposit material or even come to a halt. Accurately predicting affected areas requires models that incorporate rheological formulations capable of representing both dilute suspensions and dry tailings. In many cases, these models must also capture interactions between tailings flows and existing water bodies such as rivers or reservoirs. This paper presents a practical application of a two-dimensional model for tailings dam risk assessment that integrates rheological formulations for non-Newtonian fluids, spanning dilute-to-dry tailings. The model accounts for variability in soil properties of both the terrain and tailings, as well as the spatiotemporal evolution of fluid properties, including density, viscosity, and yield stress during flow and interaction with the environment. Results highlight the critical role of selecting appropriate rheological formulations and accounting for dynamic interactions with terrain and water bodies. The findings provide valuable insights for professionals involved in risk assessment and the design of mitigation measures for tailings dam failures. Keywords: tailings rheology, dam break modelling