Beyond energy production: A local perception about the drivers of change in land-water systems for cash crops production surrounding Colombian water reservoirs.

Hydropower dams can lead to changes in the access and use of surrounding natural resources, such as land and water. However, in complex socio-ecological systems (SES), taking into consideration different temporal and spatial scales, dams can be just one of the shocks suffered by the SES. Changes in a SES are not linear and can be part of a cycle of causes and effects in a large chain of system processes. We explore these connected processes in the context of Colombia’s Andean region, one of the hotspots of hydropower expansion in the world. This area is also responsible for 70% of the Colombia's agricultural production. We investigated two large hydropower dams: El Quimbo (Huila Departament) and Hidrosogamoso (Santander Department). This study aims to analyze the changes in land-water systems related to cash crops production and the drivers of these change from the commissioning of the dams until recent years (2009 to 2020). Our goal is to understand how perceived changes in the land-water system are induced (or not) by the construction and operation of the dam and how this influence interacts with other global and regional shocks. We conducted 80 semi-structured interviews with representatives of the agricultural sector from the main food chains (palm oil, coffee, cocoa, and rice), and with government representatives responsible for managing the land and water systems. Regional land use and land cover change maps, national agricultural data and hydropower licenses were used to sample design. The influence of the dams in land use patterns regarding crops was different depending on the geographical location of the crops (downstream or upstream dams, and north or south of the Andes), and on the water and land demands for these crops. For example, in the case of rice, an irrigated crop, interviewees declared that the effects of the dam were minimal, unlike the case of coffee, which predominantly uses rainwater for production. In addition, there are some evidence that the influence of the dams in certain crops had indirect effects in some ecosystems, such as the case of oil palm and the wetlands ecosystems. These indirect changes also increased inequalities, as interviewees from large oil palm owners reported that they were switching to an irrigated system, while smallholders would keep relying on rainwater. We also found that global drivers might be able to mask the effect of local drivers, e.g., climatic variability and the variation in commodities prices in comparison to the influence of the dams. Another example are the changes in agricultural practices induced by the increase in prices of fertilizers due to the war in Ukraine, which illustrates the fact that several drivers, including external ones, are concomitantly influencing transformations in land-water system. This study highlights that the influence of certain shocks in SES, such as large infrastructures, cannot be analyzed separately from other concomitant processes, but in a broader perspective, investigating how these processes interact with each other. Different shocks, such as dams, can also aggravate disputes over land and water resources and increase inequalities.