Introduction Introduction The economic development has always been the core of European affairs and one of the main factors whether in the European Community (EC) or in the European Union (EU), from the beginning of the integration in Europe. At the beginning of the Treaty Establishing the European Community (TEC), Article 2 provides that the Community has to promote the development of economic activities as its task. It was the economic activities of the EC that had been the main focus of attention. From 1950s, Economic growth in Europe has been steady, but the steady growth may also bring related pressures on the environment. As a result, the environmental pollution and ecological stress has been attracted by the society, even if there were wide variations between the regions and countries in the scale and range of environmental pressures and in the balance between positive and negative impacts. Actually, in the early 1970s, the EC had recognized that the protection of environment would not be neglected and would be valued seriously. "A true starting signal for the development of a European environment policy was given in 1972 when a Summit meeting of the Heads of State of Government of the Member States of the EC declared that economic expansion must as a priority help to attenuate the disparities in living conditions." 3 However, at the level of Treaty on EC, the base for environmental policies had not been established until 1987 when the Single European Act came into force and continued until the date the TEU entered into force. The TEC then designed a series of provisions specifically to protect the environment, for example, Articles 174, 175, 176, and 95. From the beginning of the 1990s, the EU had set itself an ambitious agenda for deepening the integrational links between its member states. The agenda was embodied within the terms of the Treaty on European Union (TEU) which envisaged some form of economic and monetary union (EMU) by the end of the 1990s. In fact, The EU formally came into existence after final ratification of the TEU on 1 November 1993. And later, a key event happened. It was the adoption of a single European currency by all but four of the members of the EU on 1 January 1999. When it keeps focusing on the economic affairs, EU has been considering the environment as a serious matter as well. With the TEU entry into force in 1993, the EU environmental law came into a new era. It began to provide some new principles, especially concerned on the 'sustainable development'. With the development of EU economic activities, environment has also been improved gradually. As an important ingredient of environment, water, our very existences as well as our economic activities, is totally dependent upon this precious resource. Clean fresh water is always essential to life. Unfortunately, since the Industrial Revolution, most of Europe's rivers have been treated more like a convenient way of transporting waste to the sea, destroying the biodiversity of thousands of kilometers of waterways, harming human health, and polluting coastal waters in the process. The past decades have seen significant progress in treating the sewage and industrial wastes which are being pumped in o Europe s river systems. This progress has finally resulted in lower levels of most pollutants and a measurable improvement in water quality. The agricultural sector, on the other hand, has not made as much progress. Nitrate levels in Europe's rivers are still as high as they were at the beginning of the last decade. And not only the quality of water but also the quantity available for human use is of importance. Yet, water is often a limited resource, even at global level.8 More and more frequently, there are problems with water scarcity around large cities and in southern Europe. Facing such numerous and increasing pressures on the limited water resources, the protection of water is one of the important parts in the process of EU development. It is vital that effective legislative instruments clearly address the problems and help secure these resources for future generations.