Japan: Tsurumi River Basin Water Master Plan (#302)

The Tsurumi River Basin, located in the suburbs of Tokyo, extends over an area of 235 km2 and a river length of 42.5km. The Tsurumi River Basin is regarded as one of the most important and representative river basins in Japan. The basin was largely developed by the rapid urbanization since the 1960s. 

The transition of the urban area increased from 10 % (1958) to over 84% in late 2000. The total population in the basin reached about 1.9 million in 2004 (density of 8,000 people/km2).

The process of the rapid urbanization in the basin generated a great concern to keep advancement of flood control for the region. To formulate adequate solutions, the basin management authority called for the establishment of a committee consisting of experts from the academia, basin municipalities and river administrations.

The committee undertook the efforts of simultaneously advancing river development and flood control measures in the basin with the aim to solve water problems basin-wide. In this effort, measures such as those against urban rain runoff increase were addressed in the basin from the stages of the city planning and development by the basin municipalities.

This initiative set a precedent for integrated flood control measures in Japan. Although the integrated flood control measures showed some effects, the continuing rapid urbanization in the basin brought to the surface various additional problems regarding environment, disaster prevention, and flood control.

Therefore, while aiming to regain the rich river-human relationship that was lost in the process of urbanization, it was necessary to look at cities from the viewpoint of “the whole basin” and to integrate concerned measures under the concept of the “Revitalization of a Sound Water Cycle”.

Lessons learned

The agreement on the water master plan was reached through cooperation and discussion among various administrative sectors (river, sewage, water-supply, roads, parks, cities, environment, agriculture, construction, disaster prevention and education), citizens, enterprises and NGOs. Particularly, the Tsurumi River Basin Commission invited public participation and up to present over hundred individuals from the residents of the basin are registered. 

To implement the Tsurumi River Basin Water Master Plan, which involved the large number of concerned parties as participants, many years (6 years) were needed. To implement action plans steadily, it was important to set short-term targets and to conduct continued reviews of its progress.

Monitoring by measurable indicators and the reporting of its results were essential tools for concerned parties to share the effects of the implemented measures. 

Importance of case for IWRM

The formulation of a comprehensive and integrated master plan with the aim to revitalize a sound water cycle that is lost in the process of rapid urbanization is an extremely time and effort consuming process. In order to ensure a stead progress towards targets, it is vital for the process of actions to include, in addition to long-term objectives, short-term targets (e.g. to be achieved in a specific period of. five years).

Furthermore, it is imperative to define and adopt a set of measurable indicators to monitor the progress of implementing each individual action plan of the master plan. The Tsurumi River Basin Action Plan shows that to ensure success the first priority should be given to feasibility and involvement of all stakeholders from the early stages of the formulation and also during the implementation of the actions.

Thus it is believed that this good practice example for the formulation and implementation of the Tsurumi River Master Plan would serve as a useful reference on steady implementations of integrated management and action plans.

Photo credit: Toshihiro Gamo