Sérgio R. Leite, Ludimila L. Silva & Luiz R. Gomes
dependent on this type of energy on the continent[1]
infrastructure and energy and water security strategies are not adequate to respond to climate change[2] According to Belt[3]
, are becoming increasingly severe, suggesting that critical .
, higher temperatures and changing weather patterns are altering evaporation, river
flow, rainfall patterns, frequency of extreme weather and glacial melting rates. Although the response of flood magnitudes to precipitation extremes is not entirely clear due to the still large uncertainties associated with climate models[4]
systems and reservoirs. In Brazil, according to data from the Dam Safety Report[5]
, studies indicate an increasing trend of vulnerability to flooding in urban , 2023 edition, prepared by the National Water
and Sanitation Agency (ANA), there are at least 26,000 dams, from small to large. Most of them were built based on pre-climate change hydrological assumptions, i.e. without considering the risks arising from the intensification of extreme events. The effects of this potential fragility were observed in May 2024, when the Brazilian state of Rio Grande do Sul faced climatic events that impacted on the safety of its dams, causing partial collapse and flooding of its powerhouses. This context triggered a series of actions by the Brazilian Electricity Regulatory Agency (ANEEL) and other government entities involved, which highlighted the importance of preventive inspection in standardizing emergency procedures and updating safety standards. The aim of this exploratory article, from the perspective of the dam safety policy in force in Brazil, is to discuss the events recorded in the state of Rio Grande do Sul, their impact on the procedures adopted by ANEEL to mitigate their effects, and to present the initiatives adopted to deal with this critical scenario.
2. The National Dam Safety Policy and ANEEL’s Responsibility On September 20, 2010, Federal Law No. 12.334[6]
was passed in Brazil, establishing the National
Dam Safety Policy (NDSP) for the accumulation of water for any use, the final or temporary disposal of tailings and the accumulation of industrial waste. The NDSP establishes that the public authorities are responsible for overseeing the safety of dams, according to their purpose, by the bodies that grant or authorize the exploitation of the hydraulic potential. The regulation of Law 12.334/2010 with the specificities of the electricity sector is currently governed by ANEEL Normative Resolution no 1.064 of May 2, 2023 – REN 1064/2023[7]
.
These regulations define that the safety conditions of structures are checked by means of inspections and by following up with the recommendations proposed by the technicians responsible for submitting the safety reports. The law subdivides safety inspections into regular and special. The regular one is carried out by the dam’s own safety team, and the resulting report must be made available to the inspection body and civil society. The special one must be drawn up as directed by the inspection body, by a multidisciplinary team of specialists, depending on the risk category and potential damage associated with the dam. The reports resulting from the safety inspections must indicate the actions to be taken by the developer to maintain the safety of the dam. The regulation also provides for Periodic Safety Reviews (PSRs), the aim of which is to check the overall safety status of the dam, taking into account the current state of the art for the design criteria, updated hydrological data and changes in conditions upstream and downstream of the dam.
158 | Dam Engineering | Vol XXXIII Issue 3
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