Conservation and Management of Water Environment in Metropolitan Areas – Focusing on the Development of Sewerage Systems and Waterfront Space –

摘要

This paper aims to show the true state of the conservation and management of water environment in the world’s major metropolitan areas by focusing on “sewerage systems” as well as on “rivers” and “ports and coastal zones” which are strongly affected by development of sewerage system. These three aspects constitute the three most important points of urban water environment, and to introduce some leading examples of successful urban development in the major metropolitan areas, chiefly based on the results of literature research as well as field surveys (2001-2008) and interviews (2001-2008). In the world’s major metropolitan areas, the need for the development of sewerage systems has been almost fulfilled and their endeavor to conserve and manage water environment has entered a new stage where the improvement of urban rivers as well as of ports and coastal zones is called for. Especially in Japan, behind this development are the amendments of river laws in the later half of the 1990s that have brought increased attention to rivers as precious waterfront space in urban areas and enhanced public awareness of the importance of basin management along the water flow from forests through rivers into the sea.