2017-2018

Risk analysis of Cerros Colorados System

ORSEP is the Regulatory National Dam Safety Argentinian Authority and directly  regulates  safety of the national hydropower dams in the country and it is an advisory body for other regional and local dams.

In recent times, ORSEP is developing procedures and knowledge to apply risk analysis techniques in order to inform dam safety governance.

iPresas has collaborated with ORSEP on the implementation of risk analysis to inform dam safety from a regulatory perspective through applying quantitative risk models to integrate available information about hazards, vulnerability and consequences and to inform dam safety decision making by estimating not only the current risk but the impact of different investments.

The first step in this capacity-building process was applying risk analysis techniques to a pilot case: the Cerros Colorados dam system. This group of dams is located in the Neuquen River and is used for hydropower generation, flood control and agricultural water supply, with a total reservoir volume of 41605 hm3 and power capacity of 462 MW.

This system is operated by a private company and belongs to the Negro river basin, which has a basin authority, Interjurisdictional Authority of the Limay, Neuquén and Negro rivers basin (AIC). The AIC has been a strong support for obtain hydrologic information and basin’s data.

This pilot case was chosen due to the uncertainty on the hydrological capacity of the system, since new studies based on recent flood events indicate that extreme floods have a higher magnitude than expected. In addition, this system is located upstream of important cities and villages. Hence, a failure in the flood protection that these dams provide, could produce considerable damages downstream.

The application of risk analysis to Cerros Colorados System presented several benefits from the process itself, including:

  • It allowed creating a working group with the participation of international experts. This exchange of knowledge, combined with the detailed review of the available information, was critically important to characterize the current safety status of the dams during the failure modes identification sessions. Results will be applied to justify future actions on dam safety improvements.

 

  • This pilot case represents the first step towards a portfolio risk management of all dams in Argentina since it is expected that ORSEP will support the application of risk analysis techniques to other dams in the country operated by public and private entities.