The increase in streamflows and its impact on the probability of failure by sliding of the Santa Clara HPP dam using Monte Carlo method

Abstract

Rainfall behavior has been affected worldwide, probably because of climate change. In several cases, this modification generated more intense river streamflows. Risk assessment is essential to check the security of existing dams, and it provides guidance for the design of future hydraulic structures. The risk analysis approach helps new projects to comply with safety criteria, or it is a reliable method to guide the need for safety interventions or repairs and to help in the decision to increase their discharge capacity. A case study of the Santa Clara Hydro-Power Plant was carried out to analyze if there were changes in the design flood and the impact that these variations could have on the dam failure probability. The maximum streamflows determined at the time of the dam construction were compared with the streamflows found in the update of the hydrological studies. Analyzing the results, it was possible to find out there was an increase in streamflow rates. The Monte Carlo method was used to establish a curve correlating the affluent streamflow with the probability of failure, allowing to verify the update of the hydrological study of the project implied an increase in the probability of failure of 18.1% for the millennial flood.