Session Report Cover Sheet
SESSION CODE: IWRM-11-1
Name of Convener(s): Hiroyuki Kato
DATE:
Session Title: Symposium on Wastewater Treatment
20 - March, 2003
Accommodation:
Contact
information
Contact No.: 077-528-4213
in
Japan
Contact E-mail: s210242@pref.shiga.jp
Session Report
SESSION CODE: IWRM-11-1
Reporter/Rapporteur: Yukinori Kawashima
Contact E-mail : s252972@pref.shiga.jp
1. Key Issues
2. Lake Biwa – Yodo River basin includes Shiga, Kyoto, Osaka prefectural area where
the water used repeatedly for various purposes. Lake Biwa is a significantly
important water resource in this area.
3. Eutrophication of Lake Biwa water has deteriorated rapidly since 1970s, red tides
were first observed in 1977, large-scale blue-green algal bloom occurred in 1983.
The prefecture-wide movement by local residents promoted the activities for Lake
Biwa conservation of local government and residents, such as the ordinance,
enacted in 1980, that restrains the use of synthetic household detergents.
4. Sewerage system is considered an practical method to reduce the pollution load into
Lake Biwa. The population served by sewer has increased at a incomparable rate;
the percentage of the sewered population in Shiga prefecture reached 69.5% at the
end of FY 2001, being ranked the 7th in Japan. In addition, all sewage treatment
plants in Lake Biwa basin have adopted the advanced treatment to remove nitrogen
and phosphorus.
5. Despite of the efforts above, water quality of Lake Biwa has not been improved
noticeably; further reduction of pollution load is required.
For the sewerage system,
therefore, it is required to improve the effluent quality beyond the current advanced
treatment.
6. However, in terms of the cost sharing for water resource conservation in Lake Biwa,
it should be inequitable to charge all of the cost to pollutant. To build the basin-wide
framework for cost sharing and to build the common understanding about it is an
important issue.
2.
Actions on going
1. Based on the Mother Lake 21 Plan, a lot of actions by stakeholders in the basin beyond
fields are in progress.
2. An agreement that includes the framework to build the partnership of local governments,
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residents and NPO/NGOs has made by local governments in the basin.
3. An NPO that acts in sewerage field, positioning between government and residents, has
established in Shiga; it is rare case in Japan. Their main target is to make a suggestion
to realize an adequate water circulation that includes sewerage systems.
3. Recommendations／Commitments for future

Establish the framework of partnership including local residents, NPO/NGOs,
businesses, governments and researchers, to promote the water quality conservation
in Lake Biwa – Yodo River Basin, especially in Lake biwa basin,

Make the common understanding about the desire state of basin environment, and
make the agreement regarding benefit, responsibility and payment.Secure the
accountability of government, and ensure the participation in the policy making
process, to support the framework of partnership.

Apply the economic measures to promote the water quality conservation efficiently.
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