Martín Duque, JF, Lacy, H, Russell, M, Lozano, JP, Gómez, A, Tejedor, M, Sánchez Donoso, R, Hancock, GR & Bladé, E 2026, 'Outcomes and lessons learned on the initial application of 
geomorphic rehabilitation at the Cerrejón mine, Colombia', in AB Fourie, G Boggs, J Heyes & M Tibbett (eds), Mine Closure 2026: Proceedings of the 19th International Conference on Mine Closure, Australian Centre for Geomechanics, Perth, pp. 1-15, https://doi.org/10.36487/ACG_repo/2615_57
(https://papers.acg.uwa.edu.au/p/2615_57_Martin_Duque/)
Abstract: To support its rehabilitation and closure activities, the Cerrejón mine in Colombia, one of the largest open pit mines in the world, is evaluating the feasibility of applying geomorphic rehabilitation (GR), generally referred to as geomorphic landform design (GLD). The scenarios where GR-GLD has been applied or is being evaluated for implementation at Cerrejón are designing, building and evaluating GLD a pilot project; localised site reshaping of existing waste rock dumps (WRDs) to address gully erosion problems; reshaping existing WRDs to enhance ecological value or to mitigate high visual impact; and incorporating GLD into WRDs that have not yet been constructed. GLD was carried out with GeoFluv-Natural Regrade. To supplement this work, landscape evolution modelling (SIBERIA), hydraulic modelling with Iber (a 2D model for the simulation of free surface flow) and mine planning optimisation (DumpSolver) have been applied to the geomorphic designs. As of June 2026, a 4.8 ha pilot project has been built; 34.8 ha are currently under construction; 2,833 ha were designed both for existing and projected WRDs, and 2,410 ha have been modelled with SIBERIA landform evolution software and Iber hydraulic software. Finally, 34.8 ha have been planned with DumpSolver. The monitoring program has been established but monitoring data from the field are not yet available. The focus of this paper is primarily on the early implementation and feasibility of GLD at Cerrejón. 
The pilot project has validated GLD as feasible for integration into mine plansin terms of cost and construction. The main lessons learned from the GLD implementation process were specific training for building GLD is needed for machinery operators; changing deeply embedded earthmoving practices brings some inherent challenges; for implementation at large mines, designs need to accommodate the existing equipment and operational requirements; GLD needs to simplify design outcomes to incorporate planning and building efficiently; as the ‘dump to design’ comparison demonstrates, GLDs are best constructed from the outset rather than retrofitted – reinforcing the case for early adoption of geomorphic design (new WRDs); and in all cases, GLD needs to incorporate erosional and hydraulic modelling. SIBERIA and Iber were particularly useful for understanding, mapping and quantifying the run-on from the top of the WRD and flows and discharge management at the WRD landscapes.
The scenarios where GR-GLD has either being implemented or is being evaluated for implementation at Cerrejón are designing, building and evaluating a GLD pilot project; localised site reshaping of existing WRDs to address gully erosion problems; reshaping existing WRDs to enhance ecological value or in areas of potential high visual impact; and incorporating GLD into WRDs that have not yet been constructed. Of these GLD activities, as of June 2026, 4.8 ha have been built at the pilot project, 34.8 ha are currently under construction, and 2,833 ha were designed both for existing and projected WRDs. An extensive independent assessment has been conducted with 2,410 ha modelled with SIBERIA and Iber, and 34.8 ha have been planned with DumpSolver. The monitoring programs are still being established, and monitoring data are therefore not yet available. 
The outcome of the pilot project validated GLD as a feasible approach in terms of cost, construction and integration into mine plans. The main lessons learned were that specific training for building GLD is needed for machinery operators; it is inherently difficult to change deeply embedded earthmoving practices; for implementation at large mines, designs need to accommodate larger equipment and operational requirements; GLD needs to simplify design outcomes to incorporate planning and building efficiently; GLDs are best constructed from the outset rather than retrofitted – reinforcing the case for early adoption of GLD at Cerrejón where it is still possible (new WRDs); and GLD needs to incorporate erosional and hydraulic modelling – SIBERIA and Iber were particularly useful understanding, mapping and quantifying the run-on from the top of the WRD and flows and discharge management at the WRD landscapes.