Protocol for Gates and Reservoir Operation Based on Hidro-Social Scientific Evidence: Embalse De “El Guájaro” Case Study

The "El Guájaro" reservoir is part of a hydrosystem located in the north of Colombia, which interacts with the Magdalena River and the artificial channel “Canal del Dique”. This reservoir is used for agriculture, livestock, artisanal fishing, aquaculture, fish farming, and tourism, as well as for flood control and discharge of domestic water pre-treated. The reservoir has a system of gates that operate under protocols that respond to the hydrological conditions of the Magdalena River. However, there have been conflicts of the gates operation among some stakeholders, especially among fishermen, fish farmers, farmers and the environmental authority in charge. Therefore, it has been necessary to explore new protocols that consider not only scientific evidence of the hydrological conditions and climatic variability but also the interests and needs of stakeholders integrating hydrological, economic, social and environmental criteria. For the analysis and definition of the operation protocol, an analysis and numerical modeling were carried out integrating the hydrological and hydraulic conditions of the system and the socio-economic criteria, including: the rainfall-runoff response from the basins afferent to the reservoir, the Magdalena River-Canal del Dique system, the operation of gates and the hydraulic of the reservoir, the water demand and the socioeconomic conditions of the users. Surveys and interviews were conducted in order to obtain inputs on the needs and interests of users. The different demand scenarios and operating criteria were evaluated under different hydrological and climate variability scenarios in order to measure, through indicators, the responses associated with the different proposed protocols that reduce potential social conflicts while complying with the water demand of the system. This article shows the methodology, the analysis, the modeling results and the results of some scenarios evaluated and assed for determining better protocols for the reservoir operation.