Also, some local governments have subsidy program for rainwater tank installation. People in the densely populated area had always collected rainwater against such disasters. Rainwater recycling systems have been installed in 17 public facilities such as City Hall and public schools. There is a 1,000m3 underground cistern in Kokugikan. Flushing toilets and cooling water for air conditioning are the main applications.
Rainwater is used for plants and in case of disasters.
It also can be a drinking water with adequate sterilization. Some people placed rainwater tanks at their houses for miscellaneous water supply. The available system for the household use is simple enough to collect rainwater from the roof and store it in cistern through gutter. In other areas of Tokyo, rainwater has also been used for facilities such as garbage and sewage plants, public schools, and worksites. Tokyo Metropolitan Government has announced Water Environment Master Plan, which includes the plan to set up council housings with rainwater cistern underneath the parking areas.