Japanese Water Management Systems from an Economic Perspective: The Agricultural Sector - Water and Agriculture: Sustainability, Markets and Policies - page 44

Not only investments in irrigation facilities and technological progress for an efficient
water use, but also the conservation of watershed areas and improvement of economic
efficiency are needed particularly in developing countries. Food production should catch
up with the increase in domestic demand. Although the situation in most OECD countries
seems to be improving, water pollution, soil salinity in agricultural areas and decreasing
groundwater levels in several countries, and other environment-related problems
excluding deforestation, are relatively important. Challenges to improving water-use
efficiency and equitable cost recovery are yet to be solved. Both require effective and
pragmatic instruments in government policy and social infrastructure.
This paper aims at evaluating agricultural water use in Japan from economic
perspectives, focusing on paddy field irrigation that demands vast amounts of water and
requires collective management and allocation among a number of farmers with small
holdings. Infrastructure development in the post-war period has attained stable water
supply for rice production, at the same time avoiding serious stress on the environment
and conflicts between non-agricultural sectors. Japan's experience could be a good
example for many developing countries depending heavily on paddy production under a
monsoon climate to establish management systems for sustainable, efficient and socially
acceptable water uses.
In the following section, we show the history and overall situation of agricultural
water use in Japan. Section 3 summarises an economic theory and recommended policy
measures for effective use of irrigation water. The Japanese case of agricultural water use
is discussed from the standpoint of economic efficiency in Section 4, and finally we
conclude the paper and give some recommendations to developing countries for
economically, environmentally, socially and politically sustainable sound managements
of irrigation water uses.
2. Agricultural water use in Japan: situation and historical background
2.1 History of agricultural water use
Paddy field agriculture and rice production have had, for more than a millennium, an
essential role in Japanese society. That is the case in many other Asian countries under
the conditions of warmer climate and higher precipitation. Paddy field agriculture is
resistant to continuous planting of rice in the same ground, and has higher carrying
capacity of population. In some cases, the facts reflect a clear contrast among populations
in Asian countries and some European countries based on grassland farming or extensive
use of upland. For example, the population density in Viet Nam and the Philippines was
about one person per hectare (ha) of total land area while that in Ireland and France was
0.4 and 0.8 persons, respectively, in the early 1960s, despite the fact that the former
countries were still covered with forests by 44% and 58% respectively in that period.
Ireland and France had considerable forest loss by hundreds years ago ( FAOSTAT , FAO,
http://www.fao.org & Westoby, 1989).
In most parts of Japan, rice production is restricted by geological and climatic
conditions. Cultivation should be completed during the period from April to October due
to low temperatures in the other months. The land is mountainous and seasonal rainfalls
run very fast along with short rivers into the seas. These features make it easy for floods
and droughts to take place. Controlling water supply and irrigation management have
been necessary for Japanese rice production, because depending solely on rainfall or