Japan Water Resources

Japan's water resources are characteristically plentiful mainly during the tsuyu, typhoon, and spring thaw seasons.Although annual precipitation far exceeds the world average, this does not mean abundance of water resources. Due to Japan's dense population the per capita precipitation in Japan is only about one-sixth of the world average. Furthermore, since the rivers have small basins and steep channels, rivers flow erratically and relatively little of their water is actually available for use.Compared with cities in other countries, Japan's major cities store surprisingly little water reserves, and every year there are water shortage problems somewhere in the country.The annual volume of water for municipal and agricultural use taken from rivers is estimate at about 78.21 billion cubic meters, and that from groundwater about 13.15 billion cubic meters. It is apparent from these figures that river water is the important water resource in Japan and that its efficient use is essential.

For more details check: http://www.mlit.go.jp/river/english/land.html