Journal cover Journal topic
Hydrology and Earth System Sciences An interactive open-access journal of the European Geosciences Union
Hydrol. Earth Syst. Sci., 22, 2839-2865, 2018
https://doi.org/10.5194/hess-22-2839-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
Research article
08 May 2018
Basin-scale impacts of hydropower development on the Mompós Depression wetlands, Colombia
Héctor Angarita1,2, Albertus J. Wickel3, Jack Sieber4, John Chavarro5, Javier A. Maldonado-Ocampo6, Guido A. Herrera-R.6,7, Juliana Delgado1, and David Purkey3 1The Nature Conservancy, Bogotá, Colombia
2Grupo de ecología y territorio, Facultad de estudios ambientales y rurales, Pontificia Universidad Javeriana, Bogotá, Colombia
3Stockholm Environment Institute US Center, Davis, California, USA
4Stockholm Environment Institute US Center, Somerville, Massachusetts, USA
5Centro de Investigación en Ciencias y Recursos GeoAgroAmbientales CENIGAA, Neiva, Colombia
6Laboratorio de Ictiología, Unidad de Ecología y Sistemática (UNESIS), Departamento de Biología, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia
7Laboratoire Evolution et Diversité Biologiques (EDB), Paul Sabatier University, Toulouse III, France
Abstract. A number of large hydropower dams are currently under development or in an advanced stage of planning in the Magdalena River basin, Colombia, spelling uncertainty for the Mompós Depression wetlands, one of the largest wetland systems in South America at 3400 km2. Annual large-scale inundation of floodplains and their associated wetlands regulates water, nutrient, and sediment cycles, which in turn sustain a wealth of ecological processes and ecosystem services, including critical food supplies. In this study, we implemented an integrated approach focused on key attributes of ecologically functional floodplains: (1) hydrologic connectivity between the river and the floodplain, and between upstream and downstream sections; (2) hydrologic variability patterns and their links to local and regional processes; and (3) the spatial scale required to sustain floodplain-associated processes and benefits, like migratory fish biodiversity. The implemented framework provides an explicit quantification of the nonlinear or direct response relationship of those considerations with hydropower development. The proposed framework was used to develop a comparative analysis of the potential effects of the hydropower expansion necessary to meet projected 2050 electricity requirements. As part of this study, we developed an enhancement of the Water Evaluation and Planning system (WEAP) that allows resolution of the floodplains water balance at a medium scale (∼ 1000 to 10 000 km2) and evaluation of the potential impacts of upstream water management practices. In the case of the Mompós Depression wetlands, our results indicate that the potential additional impacts of new hydropower infrastructure with respect to baseline conditions can range up to one order of magnitude between scenarios that are comparable in terms of energy capacity. Fragmentation of connectivity corridors between lowland floodplains and upstream spawning habitats and reduction of sediment loads show the greatest impacts, with potential reductions of up to 97.6 and 80 %, respectively, from pre-dam conditions. In some development scenarios, the amount of water regulated and withheld by upstream infrastructure is of similar magnitude to existing fluxes involved in the episodic inundation of the floodplain during dry years and, thus, can also induce substantial changes in floodplain seasonal dynamics of average-to-dry years in some areas of the Mompós Depression.
Citation: Angarita, H., Wickel, A. J., Sieber, J., Chavarro, J., Maldonado-Ocampo, J. A., Herrera-R., G. A., Delgado, J., and Purkey, D.: Basin-scale impacts of hydropower development on the Mompós Depression wetlands, Colombia, Hydrol. Earth Syst. Sci., 22, 2839-2865, https://doi.org/10.5194/hess-22-2839-2018, 2018.
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Short summary
The Magdalena River basin has great hydropower potential. A number of large dams are proposed in the upstream reaches of the two largest rivers that converge in the lowland floodplains. While these dams are expected to more than double national electricity production, the implications for the wetlands and the people that depend on them are highly uncertain. Our assessment of these implications provides insights to guide basin-level infrastructure development and ecosystem conservation projects.
The Magdalena River basin has great hydropower potential. A number of large dams are proposed in...
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