I. Title of the Best Practice

II. Overview of the Best Practice

A. Features of Promotion of efficient use of rainwater in Sumida ward
1. Background
The local government has promoted the efficient use of rainwater in cooperation with citizens and commercial enterprises in Sumida Ward (Tokyo). It is based on the idea that efforts to secure the city's water resources, improve the hydrological cycle, and to obtain water for fire fighting, help reduce the burden on the environment and, consequently, limit CO2 emissions.

2. The contents of practice
(1) Introduction of rainwater storage facilities at public facilities in the ward
In principle, public facilities in Sumida Ward are to be equipped with rainwater storage facilities. In 1995, there were rainwater storage facilities at 14 facilities, including the ward office, schools, libraries, and cultural centers; the stored rainwater was utilized for flushing toilets, sprinkling gardens and cooling water in air conditioners. Water storage capacity of these facilities amounted to 3,118 cubic meters in total. Furthermore, water collection tanks, like oil drums, were provided for all 45 public primary schools and junior high schools, and 7 kindergartens in the Ward.
(2) Promotion of rainwater storage facilities at private facilities
In order to promote efficient utilization of rainwater without excessive financial burdens on those who introduce the facilities, measures being considered include subsidies, and provision of guidance, advice and information.
(3) Promotion of rainwater storage facilities in communities
There are six "Rojison" rainwater utilization systems invented by citizens in the Ward, which use a hand-operated pump to pump stored rainwater collected from the roofs. The water stored is used for both emergency and daily use. Installations were financially supported by Tokyo Metropolitan Government and the Ward. Measures to promote them further are under discussion.
(4) Establishment of network
In July Sumida Ward invited local governments nationwide to join in establishing the Liaison Committee of Local Authorities Promoting Rainwater Utilization. It enabled them to exchange information and discuss the implementation of appropriate measures. In addition, the Ward has (a) supported NGOs supporting these initiatives in the Ward, (b) held seminars in cooperation with the building sector, (c) supported intersectoral organizations to develop facilities that can selectively collect clean water, and (d) held the "Forum for Local Authorities and Citizens Utilizing Rainwater" in 1998.

B. Reasons for Inclusion as a Best Practice

• It is a challenging and emerging approach. This is a progressive practice in Japan.
• It can contribute to the formation of future policies to prevent global warming. This is useful for other local authorities in considering the measures to prevent global warming.
• It is useful for consideration by social actors other than G8 countries implementing domestic initiatives in developed countries. This is an effective practice that contributes to sustainable urban development.
• It can be appropriate for application in, or technical transfers to, developing countries:
• It is suitable to the natural environment and society of the country or area where they are implemented. It can work as a measure against water shortages where little rain falls, while it can provide a means to prevent floods where rainfall is high
• It has far-reaching effects. The "heat-island effect" (caused by excess warming in urban areas due to heat absorption by man-made surfaces) can be alleviated by the promotion of greening by utilizing rainwater and the filtration of rainwater into the ground.
• It is promoted through the cooperation. It has been promoted through networks among the municipal government, citizens, commercial enterprises and other local governments.

C. Problems and their Solutions
As the attitudes toward this practice differ from one social actor to another, it is essential to establish firm leadership and for all social actors to build networks in order to promote the practice. In the case of Sumida, the Ward took the initiative, along with the cooperation of existing networks of citizens and commercial enterprises, which play an important role.

III. Categorizing the Best Practice

1. Classification(s)
( ) Regulatory Approach (Policy approaches-regulations, incentives, etc.)
( ) Practical Action (Action undertaken independently by a social actor)
( X ) Social Network Mechanism (Cooperative structure)

2. Social Actor(s) Involved
( X ) Citizens
( X ) Central government
( X ) Local government
( X ) Business

3. Sector(s)
( X ) Energy
( X ) Residential
( ) Industrial
( ) Transportation
( X ) Commerce
( ) Agriculture/Land Use/ Forestry
( ) Others ( )

4. Target Greenhouse Gas(es)
( X ) CO2
( ) CH4
( ) N2O
( ) HFC
( ) PFC
( ) SF6
( ) Other ( )

IV. List of Attachments

Omitted

V. Please indicate a person to contact for more information about this Best Practice.

Contact Person:	Makoto Murase
Title:	-
Organization:	Environment Conservation Division, Sumida Ward
Email:	-
Tel:	+81-3-5608-6209
Fax:	+81-3-5608-6405
Address:	1-23-20, Azumabashi, Sumida-ku, Tokyo 130-8640
Note:	sumikan@Sepia.ocn.ne.jp