## (3) Promotion of measures for rainwater penetration

Recently, rainwater has not been penetrating into the ground and has been flowing into rivers within a short period of time due to the expansion of impervious areas caused by urban development in river basins. By making rainwater penetrate as much as possible, flood damages caused by heavy downpours can be reduced. At the same time, promotional tax schemes for converting facilities for storage to facilities for river-basin storage and infiltration is also being utilized and pushed forward for contributing to the cultivation of underground water and the revival of springs.

## (4) Promotion of measure for underground water

As the result of the overdrawing of underground water for industrial purposes until now, the ground in the regions has sunk and underground water problems (e.g. increase in salt density of the underground water) has been noted. Based on the Summary of the Preventive Measures against Sunken Ground etc., the preservation of underground water and the enhancement of appropriate usage are being worked out in regions with wide-area underground water problems, i.e. the Nobi Plain, the Chikugo/Saga Plain and the northern part of the Kanto Plain.

## (5) Promotion of the use of rainwater and recycled water

As part of the comprehensive water resources measures, the promotion of the utilization of recycled sewage and rainwater for toilet flushing, and the promotion of the utilization of rainwater and recycled water for sprinkling are being worked on. At the end of FY 2007, the number of facilities that had applied for this was 3,290 and the proportion was around 0.3% of the national total water usage. In order to push forward further utilization, the actual situation of those facilities was clarified. At the same time, information is being shared with users, including the sample usage of those facilities, the water quantity and quality of usable processed sewage water, and the points of note for usage.

### 4. Realization of Comfortable Life through the Promotion of Sewerage Development

Sewerage is an indispensable infrastructure for healthy urban development through sewage processing and flood control measures. Recently, it has been required to play a new role in the formation of a low-carbon recycling society and healthy water recycling.

## (1) Popularization of sewage processing in sewerage

At the end of FY 2008, the popularization rate reached about 73% in the national average, but there is a great difference between regions. Especially in the medium and small-size municipalities with populations lower than 50,000 people, popularization has remained at a low level of only 44%. For future sewerage development, at the same time as intensively developing population concentrating districts, efficient development according to the actual regional situation is being pushed forward and it is important to work out the correction of the differences in popularization.

Materials provided by Ministry of Land, Infrastructure, Transport and Tourism, Ministry of the Environment, Ministry of Agriculture, Forestry and Fisheries

## 1 ) Project cooperation for efficient sewage processing facility development

Regarding the development of sewage processing facilities, it is economical to use individual-processing septic tanks for general houses in low-population districts. Following the increase in population density, there has been a tendency toward the economical use of central processing sewerage and farming village drainage facilities. Therefore, for performing the development, prefectures are formulating the “Prefecture Framework” that is a comprehensive development plan on sewage processing reflected fully in regional characteristics such as the economy and the importance of water quality maintenance. According to the recent decreasing trend in population, the immediate review of the prefecture framework is being pushed forward. Moreover, efficient development is also being actively pushed forward through introducing cooperative measures with other sewage processing facilities (e.g. wide-area sludge processing).