## (4) Stimulating sewage maintenance to improve the water environment

We will appropriately formulate and review the comprehensive basin-wide planning of sewage systems, and promote high temperature incineration to remove nitrogen and phosphates which contribute to the eutrophication of enclosed bodies of water. In addition, we are working for early advancement in improving water quality and stratified advanced water treatment by partially renovating equipment and facilities in treatment plants that have not yet reached their scheduled renewal period.

As for the combined sewerage system, we plan to complete implementation of measures by 2022 through controlling the amount of water and the frequency at which untreated water is released in to streams during heavy rains.

## 5 Cultivating water and using it efficiently

## (1) Stable supply of water resources

In order to secure stability in the utilization of water, there must be various policies corresponding to the situation of communities from both standpoints of supply and demand. Specifically, in the facet of demand, we must enhance the recovery and reuse of water, and increase awareness for conserving water. In supply, we must build and improve water resource development facilities such as dams, implement countermeasures for aging facilities related to water resources, develop crisis management measures, and increase the number of water resources by utilizing rainwater and recycled water. In addition to the conservation and use of groundwater, in order to conserve and activate the water source area, based on the “Special Measures for Water Source Area Act”, work is being done to establish the living environment of the water source area and the industrial base, along with prevention of water pollution of the dam reservoirs.

In addition, climate change due to global warming has been pointed out, and as a response to the effects of climate change, such as an increase in the range of rainfall variation in the recent and future years and the early melting as well as reduction in snowfall, work is being done towards risk management of drought, building a water-saving society through demand management, implementing measures for aging and maintenance, earthquake resistance, avoidance of draught risk by promoting the public understanding of the conditions, as well as measures for water resources.

## (2) Efficient use of water resources

### a. Initiatives towards expanding the utilization of recycled water derived from sewage

Stable amounts of recycled water can be secured and is a valuable water resource in urban areas. Of all the treated sewage, approximately 1.4% undergoes treatment according to purpose, and recycled water is used in streams, sustaining water levels of rivers and the sanitation of toilets. We aim to further expand the utilization of recycled water.

### b. Promoting the utilization of rain water

In order to efficiently utilize water resources, initiatives are being promoted to treat and use rainwater and waste water from facilities for sanitation of toilets and sprinklers. There are approximately 1,900 facilities utilizing treated water as of 2010, and they use over 65 million m $ ^{3} $ a year. In order to continue promoting the utilization of rainwater, we are gaining understanding regarding actual conditions, including examples of facilities using rainwater and the considerations for using rainwater, and share this information with users.

## (3) Securing safe and delicious water

Water service has become popular in Japan, and in recent years, the public’s need for safe and delicious water continues to increase. For this reason, improvement measures such as water conservation measures for dam reservoirs, promotion of the sewer system, the introduction of advanced water treatment and combined sewer systems have been implemented.

## (4) Promoting measures concerning the permeation of rainwater

Due to the spread of impervious areas in recent years by urban development of drainage basins, more rainwater flows into rivers in short periods of time instead of being absorbed into the ground. In addition to reducing flood damage from heavy rains by absorbing as much rainwater as possible into the ground, improvement to rainwater storage penetration facilities are being promoted through tax measures, for cultivating groundwater, contributing to the revival of springs, and building a healthy water cycle system.