## (4) Improvement of the water environment in enclosed coastal sea

Owing to the fact that many organic pollutants, nitrogen and phosphorous are flowing from the continent, and marine purification ability is being reduced due to the disappearance of tideland and algae habitation in Tokyo Bay, Ise Bay and Seto Inland Sea, red tides and blue tides have been occurring and the fishery industry has been adversely affected. Moreover, the problems of hindrance to ship navigation and environmental deterioration caused by floating waste are also appearing.

In order to improve such situations, measures for restoring beautiful water is being pushed forward effectively, including 1) seabed quality improvement through mud dredging and sand capping; 2) the creation of organism habitation through tidelands and algae habitation regeneration as well as the development of organism-compatible banks; 3) the collection of floating waste and oil through environmental development ships; 4) the burden reduction of pollutants flowing into the water through sewerage development.

## (5) Promotion of sewerage development for improvement of the water environment

Appropriately carrying out the formulation and review of the River-Basis Sewerage Development Integrated Plan, the sophisticated processing of sewerage for the removal of nitrogen and phosphorous, which causes eutrophication in stagnant water, is being pushed forward.

Regarding junction-type sewerage, the completion of measures towards quantity and frequency control of non-processed sewage flowing from rainwater floods during rainy days is being targeted for FY 2013 for medium and small-size cities and FY 2023 for metropolises.

## (6) Regeneration of water flow routes in response to regional needs

Recently, water flow to neighboring rivers and water flowing routes have increased water friendliness and purified water routes. In addition, regional needs for protecting and preserving habitats and reproduction environments for organisms and historical and cultural heritage are continuing to increase. Therefore, according to the “details of approved water usage related to environment-use water $ ^{1} $ ”, the annual approved usable water amount was approved and the approval standard was made clear for working on the regeneration of “Local Clear Streams”.

### 3. Cultivating Water and using Water Skillfully

## (1) Stable supply of water resources

## 1 ) Ensuring the stability of water usage and invigorating water resource districts

In order to ensure the stability of water usage, it is necessary to take diversified measures according to the actual regional situation for both supply and demand. In the supply aspect, measures include the construction and management of water resource facilities (e.g. dams), and the increase in the number of water resources. In the demand aspect, measures include the enhancement of reclaiming and reusing water, and raising awareness of water-saving. Based on these measures, the Basic Plan on Water Resources Development for the Yodogawa River system was changed in April 2009. In addition, in order to alleviate the effect caused by dam construction, preserving and invigorating region with water resources, the development of living environments and industrial foundation are being carried out based on the “Law Concerning Special Measures for Reservoir Areas”.

Moreover, as measures against the risks caused by climate change to the realization of a society with a sustainable water supply and the Establishment of Sound Hydrological Cycles are being aimed at. While water-relating parties are cooperating and adjusting the unit of river basins relying on a single water system, the measures for implementing “Integrated Water Resources Management” were carried out in an appropriate order with the appropriate combination by comprehensively and unitarily considering the water volume and quality, the surface water and underground water, and normal and emergency conditions.

## 2 ) Recycling of processed sewage

Processed sewage is a valuable water resource for ensuring a stable water volume throughout the year in the city. Around 1.5% of processed sewage is being re-used for small streams, river maintenance, toilet flushing etc. Additionally, it is also being used for sprinkling roads and watering gardens, which are the measures against heat islands.

## (2) Securing Safe and Tasty water

The water supply system of our country has become popular and drinkable tap water is a specialty that not many countries in the world are capable of providing. Recently, the need for safe and tasty water from citizens has been increasing further. Therefore, in order to deal with the strange smell caused by water quality deterioration and toxic substances flowing into rivers, the water from tributaries bypass the lower stream of the purification plant intake. In order to ensure tasty water supply, avoid and reduce risks in water quality, dam and river water purification in tap water source regions, popularizing promotion, the promotion of the introduction of the sophisticated processing of sewage and the improvement measures of junction-type sewerage are being implemented.