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

Water is an essential element for life and crucial to survival. South Africa is a semi-arid country and therefore water should be protected and managed effectively by all residents of the country. In the 1830s the Mooi River was the key reason for the Voortrekkers to establish Potchefstroom at a locality adjacent to this river. The Voortrekkers noticed the dolomitic outcroppings in the vicinity, but still opted to reside next to the river for it provided easily accessible water and fertile soil. Since the 1830s water legislation regulating the management and use of the water in the Mooi River has been amended innumerable times to bring us to the current situation of Potchefstroom’s water (mis)management by the role-players and stakeholders of the water source. As a resident of Potchefstroom, the researcher has a keen interest in the origin of the city’s water sources, the re-routing of the water from the origin to the water purification unit via the open-on-top cement canal system, and the overall management of these canals and their servitudes. In order to conduct a research study on the Mooi River’s water re-routing canals and servitudes, the following research methods were applied: The researcher performed a comprehensive literature review, conducted fieldwork, held interviews with landowners and experts in the geographical area of the Mooi River Valley, and performed statistical analyses as well as content analyses of the findings. Some of the most alarming findings include the lack of co-operative governance between water users and – authorities, and the current public management and disaster risk management challenges in the re-routing of water from Klerkskraal Dam down to the water purification plant of Potchefstroom. It is recommended that the major stakeholders of the Mooi River Valley, e.g. the disaster management centre in Potchefstroom, the Department of Water and Sanitation’s (DWS) regional offices in Potchefstroom, as well as the Tlokwe Local Municipality need to join forces for a combined effort to accomplish the overarching research objective of achieving improved cooperative municipal governance and Integrated Water Resources Management (IWRM) to eventually ensure the safe and effective re-routing of water from the Klerkskraal Dam to the Potchefstroom water purification plant. Note: Since July 2014 the Department of Water Affairs (DWA) has changed to the Department of Water and Sanitation (DWS). / MA (Public Management and Governance), North-West University, Potchefstroom Campus, 2015

Water is an essential element for life and crucial to survival. South Africa is a semi-arid country and therefore water should be protected and managed effectively by all residents of the country. In the 1830s the Mooi River was the key reason for the Voortrekkers to establish Potchefstroom at a locality adjacent to this river. The Voortrekkers noticed the dolomitic outcroppings in the vicinity, but still opted to reside next to the river for it provided easily accessible water and fertile soil. Since the 1830s water legislation regulating the management and use of the water in the Mooi River has been amended innumerable times to bring us to the current situation of Potchefstroom’s water (mis)management by the role-players and stakeholders of the water source. As a resident of Potchefstroom, the researcher has a keen interest in the origin of the city’s water sources, the re-routing of the water from the origin to the water purification unit via the open-on-top cement canal system, and the overall management of these canals and their servitudes. In order to conduct a research study on the Mooi River’s water re-routing canals and servitudes, the following research methods were applied: The researcher performed a comprehensive literature review, conducted fieldwork, held interviews with landowners and experts in the geographical area of the Mooi River Valley, and performed statistical analyses as well as content analyses of the findings. Some of the most alarming findings include the lack of co-operative governance between water users and – authorities, and the current public management and disaster risk management challenges in the re-routing of water from Klerkskraal Dam down to the water purification plant of Potchefstroom. It is recommended that the major stakeholders of the Mooi River Valley, e.g. the disaster management centre in Potchefstroom, the Department of Water and Sanitation’s (DWS) regional offices in Potchefstroom, as well as the Tlokwe Local Municipality need to join forces for a combined effort to accomplish the overarching research objective of achieving improved cooperative municipal governance and Integrated Water Resources Management (IWRM) to eventually ensure the safe and effective re-routing of water from the Klerkskraal Dam to the Potchefstroom water purification plant. Note: Since July 2014 the Department of Water Affairs (DWA) has changed to the Department of Water and Sanitation (DWS). / MA (Public Management and Governance), North-West University, Potchefstroom Campus, 2015