Author(s): Nicolas Cortes-Torres; Maria Camila Fernandez Berbeo; Laura Estefania Laverde Mesa; Karen Ortega Tenjo; Martin Perez Pedraza; Carlos Cubillos Pena; Sergio Salazar Galan

Linked Author(s):

Keywords: Environmental management; Water resources; Hydrological alteration rate; Environmental flow

Abstract: In Colombia, around 70% of the energy is from hydropower source, and its associated hydraulic infrastructure is located in the macro-basin of the Magdalena and Cauca rivers. These projects are generating a drainage network fragmentation and a significant alteration of the natural flow and sediment regime, which is having negative impacts on freshwater ecosystems and their ecosystem services. Nowadays, there is no regulation to estimate the Environmental Flow in Colombia, thus, it is defined in many cases by the subjective criteria of the actors involved, creating wide gaps in the integrated water resources management and in many cases conflicts between water users. Further, Colombia has a great potential to expand hydropower generation as well as a growing demand from sectors such as agriculture. Therefore, it will generate new issues and challenges for water governance. In 2018, the Colombian Ministry of Environmental and Sustainable Development published a draft related with environmental flows allocations which must be applied by two set of stakeholders: environmental authorities to distribute water at local scale in a context of integrated water resources management at regional scale and for holders of new projects with high impact on the natural flow regime of rivers. This implementation is a novel fact and, therefore, there is no precise idea about its effectiveness in terms of reduction of both environmental impacts and social conflicts. The opportunity to carry out a validation of its premises for a wide variety of contrasting case studies has emerged in order to provide solid support and consistent recommendations for practical applications. That is why we have developed a computer model (HeCCA 1.0) which is composed of the most important methods contemplated in the methodology proposed by the mentioned Ministry. Based on it, and using hydrometeorological data of different river systems, the methodology in question is being tested. As a worldwide robust referent, we use the IHA (indicators of hydrologic alteration) approach to compare results in terms of river flow alteration considering environmental flow allocation rules. These references can help identify weaknesses, strengths and opportunities for improving the methodology that is being developed. After the validation of the tool, any interested person or entity can use it without difficulty with the help of the user manual that was developed. The tool would allow performing a detailed analysis of the components to be taken into account in the development of river intervention works and the calculation of percentages of the water resource for different uses, without altering the ecosystem and its dynamics.

DOI: https://doi.org/10.3850/IAHR-39WC252171192022362

Year: 2022