Hydrological and hydraulic studies, instrumentation of the basin and elaboration of a Management Plan for the waters of the micro-reservoir generated at the river mouth of the Aguapey Stream, located on the Paraguayan edge of the Yacyretá Reservoir, which was diverted and closed through the construction of the Aguapey dam, to prevent the flooding of important areas due to the extension of the Yacyretá reservoir. The Management Plan contemplates the relationship between the levels of the micro-reservoir with the safety of the Aguapey dam and the preservation of adequate environmental conditions.
Due to the implementation of the Yacyretá Project and later due to the elevation of the reservoir level from +78 to +83 meters above sea level, a series of hydraulic works have been built for the diversion of the Aguapey Stream and a closing dam at its river mouth in order to avoid the flooding of an important surface on the right bank and upstream of the mentioned stream. The main works of the system are the following:
- Aguapey Dam
- Aguapey Canal:
- Complementary structures with gates for the control of the Aguapey canal and water intake in the dam.
EIH carried out a series of technical studies related to different problems that affect the hydraulic system and the ecosystem at the river mouth of the Aguapey Stream. The general objective was the elaboration of a Management Plan for the waters of the micro-reservoir, taking into account mainly the relationship of its levels with the safety of the dam and the preservation of adequate environmental conditions.
• PART I: Instrumentation and Hydrometeorological and Water Quality Monitoring.
A Telemetric Network for measuring and controlling the Hydrological, Hydraulic and Quality operation of Aguapey Stream was projected and installed, aimed at knowing the operation of the Stream and providing information in real time
It included the provision and installation and start-up of a network of four (4) remote hydrological and quality stations and three (3) meteorological stations, together with the training for its maintenance and operation.
• PART II: Hydrological – Hydraulic and Management Study of the Ecosystem of the Aguapey Stream Micro-reservoir – Management Plan.
An adequate characterization of the functioning of the Aguapey Stream system and the interaction of hydrological and hydraulic aspects with the behavior of the ecosystem was carried out.
The study of the hydrological characteristics of the system, that is, basin, stream, micro-reservoir, diversion channel and complementary works, sought to define its response to large-scale rainfall events or periods of drought, and in particular the study of evolution micro-reservoir levels. The working conditions of the works were analyzed, mainly in low water conditions where the preservation of the fish fauna is put at risk.
Field measurements and studies were carried out in hydrological mathematical models of the input basin, modeling of the hydraulic behavior of the reservoir and the discharge channel, using HEC-HMS and HEC-RAS tools. Adaptations to existing works or new complementary works were proposed to achieve an adequate Management Plan.
• PART III: Analysis of Dam Behavior, Adjustment of Auscultation Thresholds and Verification of Protective Rock.
In view of the modifications of the hydrological conditions in the environment of the dam and taking into account the elevation of the reservoir in 5 m, the safety conditions of the same were verified. Field inspections and studies on the runoff and stability of the Dam were carried out through the application of mathematical models and the threshold values for auscultation under the new operating conditions were analyzed. Additionally, the status and design of the Rip Rap defense of the reservoir side of the Aguapey Dam was verified, in view of the changing weather conditions and the occurrence of some damage to the shell of this protection due to wave action.
