New viewpoints beyond for managing nonpoint source pollution

Author(s): Keiko Wada
Email (s):
Institution or organization of origin: Institute of Lake Biwa-Yodo River Water Environmental Research, Lake Biwa-Yodo River Water Quality Preservation Organization
Country: Japan


The Lake Biwa – Yodo River basin, a representative river system of Japan, spreads across six prefectures in the Kinki Region. This river system is blessed with abundant nature and clear water, which supports and enriches the lives and economic activities of the local residents. Water pollution became a serious problem between 1954 and 1970, a period of high economic growth in Japan. In recent years, enforcement of regulations for effluents discharged from industries and sewerage gradually improved water quality. Some lakes, marshes, and enclosed coastal seas, however, still do not meet environmental water quality standards. Conserving and restoring water quality in public waters require something more than point source pollution controls, particularly in areas of enclosed water, such as lakes, marshes and enclosed bays. Improving public water quality requires reducing nonpoint source (NPS) pollutant loads discharged from mountains and hills, farmlands, and urban areas in the river basin. To this end, the national and local governments have been developing measures to control NPS pollutant loads. These NPS pollution controls have, however, generally lagged behind point source pollution controls. The effects of some measures implemented in the basin have been largely unrecognized or seldom evaluated. In this study, specific attention was paid to these less-studied effects. This study will hopefully widen the viewpoints of those who can control NPS pollution and comprehensively improve the water environment.

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