Proposição de diretrizes de segurança hídrica na bacia hidrográfica do rio Meia Ponte com foco no abastecimento da Região Metropolitana de Goiânia/Goiás
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Data
2019-02-21
Autores
Raiser, João Ricardo
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Universidade Estadual Paulista (Unesp)
Resumo
A água está ligada a praticamente todos os processos e atividades, entretanto, apesar de ser um recurso renovável, sua disponibilidade é limitada. Interferências antrópicas e degradação ambiental contribuem para reduzir a capacidade de infiltração, acumulação e armazenamento nas bacias, consequentemente, reduzindo a vazão nos mananciais. A expansão dos usos, deficiências na gestão e governança das águas comprometem o balanço hídrico e o atendimento aos múltiplos usos, inclusive os prioritários. Eventos hidrológicos críticos agravam esses processos, sendo necessário atuar para evitar ou minimizar impactos econômicos, sociais e ambientais. A bacia do Rio Meia Ponte é a principal bacia goiana, onde se concentra 40% da população em menos de 3,5% do Estado. A situação é agravada no trecho das nascentes do rio Meia Ponte até o ponto de captação para o abastecimento da Região Metropolitana de Goiânia, área de estudo desta pesquisa, que representa 0,4% do Estado e é responsável por abastecer aproximadamente um milhão de pessoas. Este trecho está severamente antropizado, restam 13,6% de vegetação remanescente e 63,47% das áreas de Preservação Permanente no entorno dos mananciais comprometidas. Aproximadamente 94,67% da vazão já está alocada para os usos e o abastecimento público capta 80% desta. Os pequenos usos não são considerados no cálculo do balanço hídrico e há uma grande quantidade de usos irregulares. O somatório desses fatores compromete a capacidade de atender aos múltiplos usos, colocando em risco o abastecimento da população e o desenvolvimento da bacia. A situação foi agravada por um evento hidrológico crítico, 2015 a 2018, com redução das precipitações e das vazões, inclusive secando o rio em agosto e setembro de 2017, o que colocou o abastecimento público em risco de colapso. A atuação dos Sistemas de Gestão de Recursos Hídricos e de Meio Ambiente, envolvendo o Comitê de Bacia, a Secretaria de Estado e os Conselhos Estaduais de Recursos Hídricos e do Meio Ambiente de Goiás foi crucial para enfrentar o período de escassez. Foram aprovadas a redução da vazão e o volume outorgado para os usos, definição de um trecho de vazão reduzida, intensificação do monitoramento e fiscalização. Entre as experiências de enfrentamento à escassez hídrica e eventos críticos destacam-se: uso, ocupação e conservação do solo; recuperação das bacias; regularização dos usos; aprimoramento e integração da gestão; uso racional da água; controle de poluição; soluções baseadas na natureza; e programa produtor de água. As bases para propor as diretrizes foram: deliberações dos colegiados; institucionalizar as ações; reduzir o risco de desabastecimento; reorganizar os usos; e atuar de forma sistêmica e integrada. O resultado foi apresentado em 19 eixos de ação, divididos em dois conjuntos de Diretrizes de Segurança Hídrica: disponibilidade hídrica – ampliação da vazão ou redução das pressões sobre as fontes, com 10 eixos; e Gestão e integração - aprimoramento da gestão, monitoramento e políticas públicas, com 9 eixos. Os 19 eixos foram detalhados e foi elaborada uma sugestão de priorização. Os produtos gerados foram apresentados ao Comitê da Bacia Hidrográfica, que aprovou a proposta, visando a sua implementação na bacia.
The water is linked to almost all the processes and activities, however, despite being a renewable resource, it is of limited availability. Anthropogenic interferences and environmental degradation contribute to reduce their capacity of infiltration, accumulation and storage of water, consequently reducing the flow in the basin. The expansion of the uses and the deficiencies in the water management and governance, compromise the water balance and the attendance to the multiple uses, including priority uses. The occurrence of critical hydrological events aggravates these processes, and it is necessary to act to avoid or minimize the economic, social and environmental impacts. The basin of the Meia Ponte River is the main basin in Goiás, concentrating 40% of the population in less than 3.5% of the State. The situation is aggravated in the section of the sources of the Meia Ponte river until the point of abstraction for the water supply of the Metropolitan Region of Goiânia, a study area of this research, which represents 0.4% of the State and is responsible for water supplying approximately 1 million people. This section is severely anthropized, only 13.6% of the remaining vegetation and 63.47% of the Permanent Preservation areas around the rivers are compromised. Approximately 94.67% of the flow is already allocated for the uses, and the public supply captures 80% of this flow. The small uses not only considered in the calculation of the water balance and there are a lot of irregular uses. The sum of these factors compromises ability to serve multiple uses, putting the population's supply and basin development at risk. The situation was aggravated by a critical hydrological event, from 2015 to 2018, with reduction of precipitation and flow, including drying the river in August and September 2017, which put the public supply at risk of collapse. The performance of the Water Resources and Environmental Management Systems, involving the Basin Committee, the State Secretary and the Goiás State Water Resources and Environment Councils, was crucial in facing the period of scarcity. Decisions were approved to reduce the flow and volume granted for the uses, to define a river reduced flow segment and to intensify the monitoring and inspection. Among the experiences of coping with water scarcity and critical events the most important are: use, occupation and conservation of soil; basins recovery; regularization of uses; improvement and integration of management; rational use of water; pollution control; nature-based Solutions; and water producer program. The bases to propose the guidelines were: councils’ deliberations; institutionalize the actions; reduce the risk of water shortages; reorganize uses; and to act in a systemic and integrated manner. The result was presented in 19 axes of action, divided into two sets of Water Safety Guidelines: water availability - increase in flow or reduction of pressures on sources, with 10 axes; and Management and integration - improvement of management, monitoring and public policies, with 9 axes. The 19 axes were detailed and was made a prioritization suggestion. The products were presented to the Hydrographic Basin Committee, which approved the proposal, aiming at its implementation in the basin
The water is linked to almost all the processes and activities, however, despite being a renewable resource, it is of limited availability. Anthropogenic interferences and environmental degradation contribute to reduce their capacity of infiltration, accumulation and storage of water, consequently reducing the flow in the basin. The expansion of the uses and the deficiencies in the water management and governance, compromise the water balance and the attendance to the multiple uses, including priority uses. The occurrence of critical hydrological events aggravates these processes, and it is necessary to act to avoid or minimize the economic, social and environmental impacts. The basin of the Meia Ponte River is the main basin in Goiás, concentrating 40% of the population in less than 3.5% of the State. The situation is aggravated in the section of the sources of the Meia Ponte river until the point of abstraction for the water supply of the Metropolitan Region of Goiânia, a study area of this research, which represents 0.4% of the State and is responsible for water supplying approximately 1 million people. This section is severely anthropized, only 13.6% of the remaining vegetation and 63.47% of the Permanent Preservation areas around the rivers are compromised. Approximately 94.67% of the flow is already allocated for the uses, and the public supply captures 80% of this flow. The small uses not only considered in the calculation of the water balance and there are a lot of irregular uses. The sum of these factors compromises ability to serve multiple uses, putting the population's supply and basin development at risk. The situation was aggravated by a critical hydrological event, from 2015 to 2018, with reduction of precipitation and flow, including drying the river in August and September 2017, which put the public supply at risk of collapse. The performance of the Water Resources and Environmental Management Systems, involving the Basin Committee, the State Secretary and the Goiás State Water Resources and Environment Councils, was crucial in facing the period of scarcity. Decisions were approved to reduce the flow and volume granted for the uses, to define a river reduced flow segment and to intensify the monitoring and inspection. Among the experiences of coping with water scarcity and critical events the most important are: use, occupation and conservation of soil; basins recovery; regularization of uses; improvement and integration of management; rational use of water; pollution control; nature-based Solutions; and water producer program. The bases to propose the guidelines were: councils’ deliberations; institutionalize the actions; reduce the risk of water shortages; reorganize uses; and to act in a systemic and integrated manner. The result was presented in 19 axes of action, divided into two sets of Water Safety Guidelines: water availability - increase in flow or reduction of pressures on sources, with 10 axes; and Management and integration - improvement of management, monitoring and public policies, with 9 axes. The 19 axes were detailed and was made a prioritization suggestion. The products were presented to the Hydrographic Basin Committee, which approved the proposal, aiming at its implementation in the basin
Descrição
Palavras-chave
Gestão integrada de recursos hídricos, Recuperação de bacias, Integração e articulação de políticas públicas, Integrated water resources management, Recovery of basins, Integration and articulation of public policies