Abstract In Brazil, 65% of the electric power production comes from hydroelectric power plants (HPPs). In some cases, these power plants divert the course of rivers, resulting in regions impacted by the absence of water, which are known as reduced fow sections (RFS). These sections are regulated by legislation and aim to maintain the minimum fow necessary to preserve the fauna, flora, fish, and human consumption in the region. Depending on the time of year, this minimum flow, also known as ecological flow (residual flow), can reach significant values, resulting in the interruption of power generation in these HPPs. This article presents a study case of two hydroelectric power plants located in different Brazilian states. The objective of this study is to explore the feasibility of implementing auxiliary generator groups that can operate uninterruptedly at different drop heights while ensuring the preservation of residual flow during low flow periods or taking advantage of the overflow flow by spillways during high flow periods. This auxiliary system would use the same set of structures and transmission systems as the main power plant, minimizing environmental impacts and implementation costs, allowing this solution to be implemented in HPPs that face this type of problem in Brazil. The results obtained indicate that HPPs with larger reservoirs have a greater ability to maintain residual flows with minimal generation loss and that run-of-the-river power plants are the most impacted by the maintenance of residual flow.

RESUMO O estudo da interação entre estruturas hidráulicas em sistemas fluviais de leito móvel é complexo pois envolve transporte de sedimentos e mudanças dinâmicas nas condições de contorno, sendo necessário o uso de modelos físicos. Este artigo apresenta o procedimento para o desenho e construção de um modelo físico do reservatório e da barragem da Pequena Central Hidroelétrica (PCH) de Salto Paraopeba. Na fase de desenho, foi utilizada a modelagem computacional de transporte de sedimentos para a reconstituição da geometria primitiva do rio, também foram realizadas simulações do regime do escoamento e da capacidade de transporte ao longo do curso do rio; ambos os resultados permitiram delimitar a extensão do modelo. Considerando a escolha da escala e os critérios de semelhança entre o modelo e o protótipo, foi proposto o uso de um novo material alternativo, composto por partículas de borracha de pneu trituradas, de massa específica menor e diâmetro maior do que o sedimento do protótipo. Na fase de construção, foi aplicado um novo método construtivo do modelo físico empregando fibra de vidro, o método apresenta vantagens construtivas como melhor representação da morfologia, menor peso, instalação e desinstalação simples mediante módulos, e reparações simples e rápidas, entre outras. contorno físicos PCH (PCH Paraopeba rio protótipo alternativo trituradas vidro morfologia peso módulos rápidas outras

ABSTRACT The study of the interaction between hydraulic structures in mobile bed river systems is complex because it involves sediment transport and dynamic changes in the boundary conditions, requiring the use of physical models. This article presents the procedure for the design and construction of a physical model of the reservoir and dam of the Small Hydroelectric Power Plant (SHPP) of Salto Paraopeba. In the design phase, computational modelling of sediment transport was used to reconstitute the primitive geometry of the river, and simulations of the flow regime and the transport capacity along the course of the river were also carried out; both results allowed to delimit the model extension. Considering the choice of scale and the similarity criteria between the model and the prototype, the use of a new alternative material was proposed, composed of crushed tire rubber particles, with a lower specific mass and a larger diameter than the prototype's sediment. In the construction phase, a new constructive method of the physical model was applied using fiberglass, the method presents constructive advantages, such as better representation of the morphology, lower weight, simple installation and uninstallation through modules, and simple and fast repairs, among others. conditions models SHPP (SHPP Paraopeba phase out extension prototype proposed particles prototypes s fiberglass advantages morphology weight modules repairs others

ABSTRACT The dam safety depends heavily on the organizational structure, the developer’s philosophy, and the involved actor’s technical responsibility. In this context, the present research aimed to: introduce the concept of Engineer of Record (EoR); discuss their influence on the continuous improvement of dam safety, propose a work plan for this professional applicable to water storage dams, and estimate the costs associated with their team. Since mining dams have experienced recent accidents, safety laws, and methodologies are more stringent for these structures. Therefore, based on this experience, a list of actions for the EoR was proposed, targeted explicitly at water storage dams, divided into two stages: the first to comply with the National Dam Safety Policy (NDSP); and the second focused on the continuous improvement of the safety of these structures. Additionally, a cost estimate was conducted, resulting in a value of $ 0.15 per m3 consumed for implementing an EoR team.

RESUMO A segurança de uma barragem depende fortemente da estrutura organizacional, da filosofia do empreendedor e da responsabilidade técnica dos atores envolvidos. Neste contexto, a presente pesquisa teve como objetivos: apresentar o conceito de Engenheiro de Registro (EoR); discutir sua influência na melhoria contínua da segurança; propor um plano de trabalho para este profissional, aplicável às barragens de acúmulo de água e estimar os custos associados à sua equipe. Considerando que as barragens de mineração têm enfrentado acidentes recentes, as leis e metodologias de segurança são mais rigorosas para estas estruturas. Portanto, com base nesta experiência, propôs-se uma lista de ações para o EoR, especificamente voltada para barragens de acúmulo de água, dividida em duas etapas: a primeira, para atendimento da Política Nacional de Segurança de Barragens (NDSP); e a segunda, voltada à melhoria contínua da segurança dessas estruturas. Adicionalmente, realizou-se uma estimativa de custos, chegando ao valor de R$ 0,15 por m3 consumido para a implantação de uma equipe de EoR.