The relationship between Man and Nature can be divided into three ‘eras.’ The first era refers to a time when Man was dominated by Nature, governed by her fluctuating seasons and at the mercy of her erratic moods. Man’s advancement brought into being the Machine, which enabled Man to move into a second era. This era brought about a brief state of equilibrium between Nature and Man, before Man advanced even further and faster into a third era in which Man and Machine dominated Nature. Man’s appropriation of Nature’s resources is his most intimate experience of the Natural world. However, in this third phase of development, Man has negated the ‘natural’ source of Nature’s resources and has thus disconnected himself from her. As a result of this disconnection, the third era is characterised by an imbalance which is leading towards the possibility of Man tipping off the scales entirely. This thesis explores the possibility of a fourth era in which Man and Nature once again achieve an equilibrium of mutually beneficial symbiosis. A fourth era would be the setting of a mend in the severed Man-Nature relationship. A ‘reconnection’ could be achieved through a renewed understanding of the systems, both natural and technological, that supply Man with Nature’s resources. The ‘Machine’ that is the Vaal Dam Wall and its surrounds was chosen as a locus for the theoretical application of a form of inhabited resource infrastructure that takes steps towards a fused Man-Nature entity. The dam wall is a significant piece of existing infrastructure that plays a major role in the capture, storage, and distribution of water to people in Gauteng, South Africa’s economic powerhouse. A legible, multi-use intervention sensitively placed on this site could reconnect the water-users to the natural water resource that is so vital to their livelihoods. The intervention is in the form of a visitor centre which incorporates water purification and hydroelectric power generation as well as a management facility for the Department of Water Affairs, the entity with jurisdiction over the Vaal water system and dam wall site. The Vaal Dam Visitor Centre could provide much-needed infrastructure to the chosen site in its un-realised capacity as a locus for tourism, education, research and management. In doing so, the Centre could be the ‘Machine’ that reconnects Man to Nature through responsible use and understanding of her resources.

A l’échelle d’une agglomération, réfléchir à une gestion durable de l’eau amène à s’interroger sur les liens entre les usages et les ressources : quelle qualité de l’eau est nécessaire pour quels usages ? Le contexte parisien est un terrain propice pour mener ce type de réflexion, grâce à l’existence d’un RENP, datant de la fin du XIXe siècle. Alimenté par les eaux sommairement traitées de la Seine (20%) et du canal de l’Ourcq (80%), ce réseau sert principalement aux usages municipaux : nettoyage des trottoirs, curage des égouts, arrosage des espaces verts et alimentation des lacs artificiels. Un modèle alternatif de gestion de l’eau à l’échelle parisienne devient aujourd’hui possible grâce à la décision de la Ville de Paris en mars 2012 de maintenir et de réhabiliter son RENP. Cette décision a été confirmée par l’approbation par le Conseil de Paris en septembre 2015 du schéma directeur des usages et du réseau d’eau non potable de Paris, pour la période 2015-2020. L’entreprise publique Eau de Paris, responsable du service de l’eau à Paris, a pour mission de mettre en œuvre les décisions et les orientations de ce schéma directeur. Dans une logique de moindre pression sur la ressource naturelle, une évolution possible de la gestion du RENP est la diversification de ses ressources. Les ressources potentielles considérées sont les eaux d’exhaure, les eaux usées traitées, les eaux de pluie et les eaux de piscine. La recherche vise à étudier la question suivante : Comment et à quelle conditions l’alimentation du RENP peut être gérée de manière durable sur le territoire parisien ? Pour ce faire, on réalise d’abord un état des lieux de la situation actuelle, puis on identifie les ressources potentielles et les enjeux associés. Puis deux approches sont menées. La première approche consiste à définir plusieurs choix de répartition des ressources du RENP, appelés scenarii. Les scénarii sont évalués et comparés grâce à la construction d’indicateurs de performance. La deuxième approche consiste à caractériser les positions des acteurs par rapport à la diversification des ressources du RENP. La caractérisation des positions est réalisée grâce à la conduite d’entretiens semi-directifs. Les résultats des deux approches sont enfin discutés. Les résultats de la recherche permettront de reposer la question du lien entre usages et qualité des eaux requise. Elle permettra de mettre en lumière les freins et les leviers pour la valorisation des ressources alternatives à l’eau potable. Enfin, elle alimentera les réflexions sur le statut même de l’eau potable dans un contexte de gestion durable de la ressource / At the scale of a city, a sustainable water management raises questions about the links between uses and resources: what water quality is needed for what purpose? The Parisian context is a favourable ground for conducting such type of reflection thanks to the existence of a non-potable water network (RENP) dating from the late nineteenth century. The network is currently supplied by summarily filtrated water from the Seine river (20%) and the canal de l’Ourcql (80%). It is mainly used for municipal purposes: Parisian streets and sewers cleaning, water supply of artificial lakes and green areas watering. An alternative model of water management at Parisian scale is today possible thanks to the decision of the City of Paris in March 2012 to maintain and rehabilitate its RENP. This decision has been confirmed by the approval by the Council of Paris in September 2015 of the master plan of the RENP and its uses (“Schéma directeur des usages et du réseau d’eau non potable de Paris”) for the period of 2015-2020. The public company Eau de Paris, responsible for the water service in Paris, is mandated to implement the decisions and orientations of the master plan. In the context of pressure reduction on natural resources, one potential evolution of the RENP management is its resources diversification. The considered potential resources are mine water, treated wastewater, rain water and swimming pool water. The research raises the following question: How and under what conditions can the RENP supply be sustainably managed on the Parisian territory? In order to answer this question, one first carries out a description of the current situation, then one identifies the potential resources and the associated risen questions. Two approaches are proposed afterwards. The first approach involves the definition of several choices of RENP resource repartition, called scenarii. These scenarii are assessed and compared through performance indicators. The second approach consists of the characterization of the actors’ positions regarding the RENP resource diversification. The characterization of the positions is achieved through conducting semi-structured interviews. Results of both approaches are finally discussed.The results of the research will enable to re-examine the question of the relationship between the water uses and the required water quality. It will highlight the brakes and levers for the valorization of alternative resources to drinking water. It will enrich the reflections on the status of drinking water in the context of sustainable water management

Esta Tese analisa os condicionantes, os limites e as possibilidades postos à efetivação de uma gestão efetivamente integrada em bacias hidrográficas de dupla dominialidade, contextualizando tais questões ao modelo de gestão em implantação no Brasil a partir do início da década de 90. O trabalho está focado na gestão das águas da bacia do Rio Paraíba do Sul, analisando o processo histórico de construção do sistema e seus impactos nas estratégias de convivência entre os dois diferentes organismos atuantes no trecho paulista da bacia: o Comitê da Bacia Hidrográfica do Rio Paraíba do Sul (CBH-PS), responsável especificamente pela gestão no trecho paulista da bacia; e o Comitê para a Integração da Bacia do Rio Paraíba do Sul (CEIVAP), com jurisdição sobre a totalidade da bacia. O marco conceitual deste estudo apóia-se, principalmente, nas contribuições de autores situados no campo reconhecido como neoinstitucionalista. Promoveu-se um minucioso resgate do processo de implantação das diferentes “instituições políticas" relacionadas à gestão das águas da bacia, contextualizando assim o “processo político" de convivência entre os dois modelos de gestão retratados, abrindo-se dessa maneira perspectivas mais amplas para a análise dos conteúdos e dos impactos decorrentes dessas políticas. Para o adequado desenvolvimento deste estudo foi realizado o acompanhamento – tanto documental, quanto presencial - das atividades de ambos os Comitês. A pesquisa está também apoiada em entrevistas com um amplo conjunto de informantes centrais. O relato do histórico da gestão no trecho analisado foi organizado em cinco períodos, retratando movimentos de conflito e cooperação entre os atores. Apesar dos diversos desafios ainda a serem enfrentados rumo à integração, os dados coletados apontam para um gradual avanço na maturidade do sistema de gestão de recursos hídricos, com perspectivas positivas rumo à implantação de ações coordenadas e cooperativas na bacia. Esse movimento também explicita a dimensão temporal como um importante fator a ser considerado no processo de mudança institucional. / This study examines the possibilities and the restraints of the estabilishent an effective Integrated Water Resource Management System in the Paraiba do Sul River Basin in the context of the new Brasilian water management policy started in the 1990s. The research focused on the institutional an jurisdictional complexity of this management, particularly in the São Paulo State section. This study analyzes those institutional frameworks, their articulations and overlaps, and the outcomes on sustainable water use. The research was based on documental analysis and interviews. The management history report of the analyzed section was organized into 5 moments, depicting points of contention and cooperation among the ones involved. The gathered data point to a gradual improvement in the evolution of Integrated Water Resource Management System with positive perspectives towards the implementation of coordenated and cooperative actions in the Basin.

Mounting recognition of the socio-political context of the management of water resources has rendered the application of technocratic approaches in isolation insufficient in addressing future management challenges with participatory approaches increasingly promoted in response. Against this background, new regulatory mechanisms in the water sector in England and Wales promise an increased role for the views of customers in water utility planning and decision- making. Yet, existing scholarship on the institutionalisation of participative approaches in water utility planning and decision-making in England and Wales is sparse. This thesis contributes to an improved understanding of factors that hold potential to impact institutionalisation of participative approaches in this context by focusing on three specific aspects of effectiveness; motivational clarity, the influence of participative mechanism design, and the use and influence of water utility customer contributions in water sector planning and decision-making. This has been achieved through the deployment of participatory research in collaboration with the sponsoring organisation (a water utility operating in England and Wales) utilising group discussion and semi-structured interviews with domestic water customers and water utility practitioner respectively. Findings demonstrate that preference elicitation vehicles embedded within participatory mechanisms hold the potential to influence participants expressed preferences thus representing a key design consideration where multi- mechanism approaches are deployed in planning and decision-making contexts. Furthermore, useful design considerations for multi-attribute presentation in participatory mechanisms are presented. Findings also identify a dominance of instrumental and legalistic practitioner motivations for the use of participative approaches in water utility decision-making. Foremost, it identified the significance of the regulator in driving water utility practices for the management and influence of customer contributions in planning and decision- making, and more fundamentally illustrates the significant barrier posed by a legacy of technocratic practices for the institutionalisation of participatory approaches in water utilities.

Esta tese desenvolveu um Sistema de Suporte a Decisão para auxiliar na concessão de outorga de lançamento de efluentes, através do qual é possível avaliar estratégias de outorga visando facilitar o processo de análise e a efetivação do instrumento. O SSD utiliza em seu processo de análise algoritmos evolucionários para a otimização do processo de alocação de demanda e de carga efluente, visando a maximização dos usos e a minimização dos custos das medidas de tratamento de efluentes, respeitando os limites estabelecidos pela classe de enquadramento dos corpos dágua. Os algoritmos evolutivos analisados foram os Algoritmos Genéticos, Particle Swarm Optimization e o Differential Evolution. Entre as estratégias de outorga consideradas estão o atendimento da legislação ambiental para o lançamento de efluentes, a isonomia entre os usuários, o atendimento aos padrões de qualidade estabelecidos pelo enquadramento dos corpos hídricos e as restrições impostas pelo órgão gestor aos usuários ou as finalidades de uso. Para avaliar o desempenho do SSD foi realizado um estudo de caso na Bacia Hidrográfica do Rio Atibaia, no Estado de São Paulo. O Rio Atibaia foi escolhido por apresentar problemas de disponibilidade hídrica e conflitos pelo uso da água, o que permite avaliar os resultados do SSD para as diferentes estratégias em um caso real. Os resultados obtidos pelos três algoritmos para as estratégias analisadas foram satisfatórios atendendo as restrições e penalidades impostas à função objetivo. Observou-se que a estratégia de outorga que não considerou a Legislação Ambiental para lançamento de efluentes e a questão da isonomia entre os usuários apresentou o menor custo global das medidas de tratamento de efluentes. Este resultado se deve ao fato desta estratégia ser menos restritiva que as demais analisadas, e pelo melhor aproveitamento da vazão disponível no trecho para diluir os efluentes. As estratégias propostas neste estudo tiveram como principal objetivo avaliar o comportamento do SSD na obtenção das análises, assim como analisar a flexibilidade dos algoritmos na introdução de restrições e penalidades. Para a escolha das estratégias de outorga, destaca-se o importante papel do Comitê de Bacia e do órgão gestor para definir as prioridades, tendo em vista que os critérios de outorga, a legislação ambiental e a isonomia, podem acarretar em investimentos mais elevados para a implementação das medidas de tratamento. O Sistema de Suporte a Decisão proposto nesta tese representa um avanço no processo de gestão de recursos hídricos, uma vez que envolve importantes critérios e estratégias na análise da outorga de direito de uso da água, sem dissociar os aspectos de quantidade e qualidade da água e aspectos econômicos para sua efetivação. / This study presents a Decision Support System (DSS) to assist in the issuing of wastewater discharge and water abstraction rights, including the evaluation of alternative pollution control strategies used to facilitate the analysis and implementation of the instrument. The DSS substantiates its analysis with the use of evolutionary algorithms for the optimization of water demand and wastewater discharge allocation. It intends to maximize the uses and minimize the costs of wastewater treatment measures, according to the limits imposed by the water quality standards. The evolutionary algorithms investigated in this study include Genetic Algorithms, Particle Swarm Optimization and Differential Evolution. Among the strategies considered for the issuing of water rights were the compliance with environmental legislation for wastewater discharge, the equality between water users, the water quality standards et by the water bodies classification, and the restrictions imposed by the responsible controlling agency. The SSD was evaluated on a case study area, at Atibaia River, located in the State of Sao Paulo. The Atibaia River was chosen because of the existence of innumerous conflicts of over water use and availability. It allows the assessment of the SSD performance, to different strategies, in a real case scenario. The SSDs results, using all three introduced algorithms, were satisfactory to the strategies analyzed, as they complied with the restrictions and penalties imposed to the objective function. Strategy one, with no restrictions or penalties, had the lowest overall cost of wastewater treatment measures, in comparison to strategy two, equity between water users, and three, compliance with Environmental Laws. This result is due to the fact that strategy one is less restrictive than the two others, and because of the best use of the available flow, in each respective reach, to dilute the wastewater discharge. The main objective of the proposed strategies is to evaluate the performance of the SSD in getting the results, as well as to analyze the flexibility of the algorithms when new restrictions and penalties are introduced in the decision making process. Water users, other stakeholders and the responsible controlling agency have an important role in the selection of suitable strategies and priorities of uses. Higher investments to implement water treatment measures may become necessary according to the strategy chosen. In addition, when a strategy is not well defined, it may cause unnecessary investments. The DSS proposed in this study represents an advance in water resources management. It involves important criteria and strategies used in the analysis of wastewater discharge and water abstraction rights, without disassociating water quality and quantity aspects as well as economic factors for its implementation.

China, the world's most populous country, has been experiencing a severe water crisis. This has manifested itself through water shortages, water pollution and natural water disasters, and has been exacerbated by the rapid social and economic development that has taken place in the last two decades. To deal with these problems, an integrated water resources management programme, within which an effective and enforceable water rights system can play a key role, should emerge as soon as possible under the principle of sustainable development. However, there are many problems under the water rights system in the current Chinese water law, involving the property right of water resources, the human right to water, and the environmental right to water. ... this dissertation recommends a well structured water rights system under which the economic, social and environmental values of water resources co-exist equitably in harmony.

This thesis improves the understanding of adaptive water governance in the policy process, and draws lessons of policy relevance for flood management. Scholars using the concept of adaptive water governance posit that factors influencing the governing activities of social actors are of critical importance to improve society’s capacity to better respond to the on-going water crisis. They developed a set of principles for adaptive water governance, in particular the need for polycentric forms of governance, where power over decision-making is not held by a single social actor but distributed across society, and the use of participatory processes, promoting collective action and enhancing collective reflection. Empirical evidence on the validity of these principles remains sparse, in particular in public policy processes.The thesis uses established research on the policy process to better conceptualise the governance of complex water problems. It examines empirically the emergence of integrated, ecosystem-based flood management in Scotland, a typical Western democracy though characterised by an interesting history of institutional design and flood policy dynamics. First, factors influencing the formulation and integration of the approach in national environmental policies are identified, drawing on an inductive, thematic and historical analysis of documents and interviews with key policy actors. Second, factors influencing the implementation of the approach, in particular the role of policy instruments and public participation, are then identified in the Eddleston and Bowmont-Glen catchments. A combination of documentary analysis, interviews with local actors, and Q Methodology are used. The thesis supports the general principle that polycentric governance can improve the adaptability of governance systems. Horizontally, multiple actors with decision-making power may encourage greater reflexivity in the policy process. Having multiple policy regimes may also foster innovative interventions. Vertically, significant autonomy between governance levels may help better adapt policies to the appropriate scale of intervention. The devolution of legislative powers from the British to the Scottish level is presented as an example. At a more local level, providing greater autonomy to implementers can enhance their capacity to enforce policies. The thesis also provides evidence for critics of polycentric governance. In particular, polycentric governance may result in a lack of coherence between policy regimes, heterogeneous implementation, and potentially status-quo, rather than change. The thesis supports the idea that a strong participatory approach may help overcome the limitations of polycentric governance. Findings indicate that critical factors for success are the institutional context in which it occurs, its inclusive nature, adequate resourcing, time available, and the willingness of participants to reach compromise and learn. Individual entrepreneurship is clearly fundamental to increase the adaptability of governance systems.Overall, the thesis shows that attention to the public policy process is an important analytical approach to the study of adaptive governance. Past research on the policy process provides constructive theories to explore principles of adaptive governance in an empirical context. Main policy recommendations, for Scotland and beyond, include, amongst others, a call for strong governance arrangements to accompany the work of multi-actor groups for policy integration, the use of instrument mixes across policy regimes to influence land managers, and greater support for non-governmental catchment organisations to foster local collaboration and improve policy implementation.

This thesis is a comparative law study of the national water laws of four jurisdictions - Scotland, England, South Africa and Queensland Australia. The purpose of the research was to develop an analytical framework for reform of national water law. The management of the water resource is a pressing global concern and law is one of the disciplines working to achieve this. As part of the global policy agenda for water, many states are reforming their national laws; many other actors are also engaged in these processes. However there is no framework for this area of law reform, no structure against which reform proposals can be assessed. This thesis attempts to draw out such a framework, by a primarily positivist and pragmatist analysis.

A otimização do uso da água é um desafio para os gerenciadores, pois o planejamento da irrigação requer cuidados especiais, a fim de compatibilizar o balanço hídrico com a demanda, tanto no que se refere à quantidade como a sua repartição espacial e temporal. Técnicas de otimização têm sido empregadas nas recentes décadas para tratar problemas de planejamento e manejo de sistemas de recursos hídricos. O objetivo do presente trabalho consistiu em propor planos ótimos de cultivos, utilizando modelos de programação linear que proporcionem a maximização do retorno líquido do Perímetro de Irrigação Formoso, especificamente quanto a área de lotes familiares. Os modelos utilizados neste estudo foram baseados nos dados que compõem os Relatórios de Monitoria Ano Agrícola de 2008 e 2009 da 2ª Superintendência Regional da CODEVASF, Relatório do Distrito de Irrigação do Projeto Formoso e em informações adicionais fornecidas pela referida empresa pública. O modelo estudado é uma formulação-padrão de programação linear, cuja função-objetivo consistiu em maximizar a receita líquida do projeto, utilizando-se as culturas mais cultivadas nessa área, sob regime de irrigação. Com base nas culturas consideradas e suas respectivas funções de resposta à água, nas restrições de área cultivada, nos preços e nos custos de produção, os resultados permitem as seguintes conclusões: A maximização da receita líquida no Perímetro Irrigado Formoso foi obtida com o modelo de lâminas alternativas, com um retorno financeiro de R$ 68.384.956,53, utilizando o seguinte padrão de cultivo: 30 ha de abóbora, 30 ha de feijão Phaseolus, 977 ha de melancia, 1868 ha de banana, 1200 ha de mamão e 300 ha de limão Tahiti, para o volume anual de 79.649.300 m3. Em qualquer nível de volume de água disponível os valores das lâminas de água foram maiores no modelo lâminas fixas do que no modelo lâminas alternativas. / The optimization of water use is a challenge for managers, because the planning of irrigation requires special care to reconcile the water balance with demand, both in terms of quantity as spatial and temporal distribution. Optimization technique have been employed in recent decades to address problems of planning and management of water resources systems. The aim of this study was to propose optimal crop plans, using linear programming models, providing the maximization of net return on Formoso Irrigation District, regarding the area of farming family. The models used in this study were based on data of the Reports Agricultural year 2008 and 2009 of the 2th Regional Superintendent of CODEVASF and additional information submitted by that government department. The studied model is a traditional linear programming formulation, in which the objective function consisted into maximizing the net income of the project using the most cultivated crops in the area, under irrigation conditions. Based on the crops considered and their response functions to water restrictions on acreage, prices and production costs, the results allow the following conclusions: the maximization of net revenue in Formoso Irrigation District was obtained with the model of alternative irrigation depths, with a payback of R $ 68,384,956.53, using the following crop pattern: 30 ha of squash, 30 ha of Phaseolus beans. 977 ha of watermelon, 1868 ha of banana, 1200 ha of papaya and 300 ha of Tahiti lime, for the annual volume of 79,649,300 m3. At any level of available water the irrigation depths in the model fixed was higher than the irrigation depths in the model alternatives.

Esta tese desenvolveu um Sistema de Suporte a Decisão para auxiliar na concessão de outorga de lançamento de efluentes, através do qual é possível avaliar estratégias de outorga visando facilitar o processo de análise e a efetivação do instrumento. O SSD utiliza em seu processo de análise algoritmos evolucionários para a otimização do processo de alocação de demanda e de carga efluente, visando a maximização dos usos e a minimização dos custos das medidas de tratamento de efluentes, respeitando os limites estabelecidos pela classe de enquadramento dos corpos dágua. Os algoritmos evolutivos analisados foram os Algoritmos Genéticos, Particle Swarm Optimization e o Differential Evolution. Entre as estratégias de outorga consideradas estão o atendimento da legislação ambiental para o lançamento de efluentes, a isonomia entre os usuários, o atendimento aos padrões de qualidade estabelecidos pelo enquadramento dos corpos hídricos e as restrições impostas pelo órgão gestor aos usuários ou as finalidades de uso. Para avaliar o desempenho do SSD foi realizado um estudo de caso na Bacia Hidrográfica do Rio Atibaia, no Estado de São Paulo. O Rio Atibaia foi escolhido por apresentar problemas de disponibilidade hídrica e conflitos pelo uso da água, o que permite avaliar os resultados do SSD para as diferentes estratégias em um caso real. Os resultados obtidos pelos três algoritmos para as estratégias analisadas foram satisfatórios atendendo as restrições e penalidades impostas à função objetivo. Observou-se que a estratégia de outorga que não considerou a Legislação Ambiental para lançamento de efluentes e a questão da isonomia entre os usuários apresentou o menor custo global das medidas de tratamento de efluentes. Este resultado se deve ao fato desta estratégia ser menos restritiva que as demais analisadas, e pelo melhor aproveitamento da vazão disponível no trecho para diluir os efluentes. As estratégias propostas neste estudo tiveram como principal objetivo avaliar o comportamento do SSD na obtenção das análises, assim como analisar a flexibilidade dos algoritmos na introdução de restrições e penalidades. Para a escolha das estratégias de outorga, destaca-se o importante papel do Comitê de Bacia e do órgão gestor para definir as prioridades, tendo em vista que os critérios de outorga, a legislação ambiental e a isonomia, podem acarretar em investimentos mais elevados para a implementação das medidas de tratamento. O Sistema de Suporte a Decisão proposto nesta tese representa um avanço no processo de gestão de recursos hídricos, uma vez que envolve importantes critérios e estratégias na análise da outorga de direito de uso da água, sem dissociar os aspectos de quantidade e qualidade da água e aspectos econômicos para sua efetivação. / This study presents a Decision Support System (DSS) to assist in the issuing of wastewater discharge and water abstraction rights, including the evaluation of alternative pollution control strategies used to facilitate the analysis and implementation of the instrument. The DSS substantiates its analysis with the use of evolutionary algorithms for the optimization of water demand and wastewater discharge allocation. It intends to maximize the uses and minimize the costs of wastewater treatment measures, according to the limits imposed by the water quality standards. The evolutionary algorithms investigated in this study include Genetic Algorithms, Particle Swarm Optimization and Differential Evolution. Among the strategies considered for the issuing of water rights were the compliance with environmental legislation for wastewater discharge, the equality between water users, the water quality standards et by the water bodies classification, and the restrictions imposed by the responsible controlling agency. The SSD was evaluated on a case study area, at Atibaia River, located in the State of Sao Paulo. The Atibaia River was chosen because of the existence of innumerous conflicts of over water use and availability. It allows the assessment of the SSD performance, to different strategies, in a real case scenario. The SSDs results, using all three introduced algorithms, were satisfactory to the strategies analyzed, as they complied with the restrictions and penalties imposed to the objective function. Strategy one, with no restrictions or penalties, had the lowest overall cost of wastewater treatment measures, in comparison to strategy two, equity between water users, and three, compliance with Environmental Laws. This result is due to the fact that strategy one is less restrictive than the two others, and because of the best use of the available flow, in each respective reach, to dilute the wastewater discharge. The main objective of the proposed strategies is to evaluate the performance of the SSD in getting the results, as well as to analyze the flexibility of the algorithms when new restrictions and penalties are introduced in the decision making process. Water users, other stakeholders and the responsible controlling agency have an important role in the selection of suitable strategies and priorities of uses. Higher investments to implement water treatment measures may become necessary according to the strategy chosen. In addition, when a strategy is not well defined, it may cause unnecessary investments. The DSS proposed in this study represents an advance in water resources management. It involves important criteria and strategies used in the analysis of wastewater discharge and water abstraction rights, without disassociating water quality and quantity aspects as well as economic factors for its implementation.