Japanese Watersheds an Island Nation\'s Freshwater Resources

Japanese Watersheds

An Island Nation's Freshwater Resources

We think of Japan as an island nation, a nation defined by its shoreline with the Pacific Ocean. And, of course, this is a perfectly legitimate way to envision the country: It certainly is dwarfed by the Pacific. However, like all areas that sustain permanent human populations, it is also home to a number of fresh water sources. And while it is impossible to underestimate the importance of the Pacific to Japanese culture, economy, and psychology, its internal freshwater watersheds are no less important. Simply because its lake and rivers are no less important in terms of the country's psyche does not mean that they are not vital to its people. And yet, like the people of other nations, the Japanese are at times careless of their water sources. Water may be the essence of life, but this does not mean that we protect it as the vital essence that it is.

This paper examines two of the watersheds in Japan, their current state of health (that is, environmental health) and the possible pathways that they may follow in the future. Of course, the future is never set in stone, and these possible paths can be disrupted or rerouted by a change in attitude and policy. However, water is becoming increasingly scare in our world and its health is likely to become worse and worse over time.

It is important to define first of all what a watershed is since the term is not one that is used in common conversation. A watershed is more than a lake or a river, although it is most likely to include at least one of these and probably both. The United States Environmental Protection Agency, which overseas the health of watersheds in the United States defines a watershed as: "A watershed is the area of land where all of the water that is under it or drains off of it goes into the same place" (United State Environmental Protection Agency, 2012).

Another, more poetic definition but one that is easier to understand because it frames a watershed in terms with which we are all familiar is the following:

I think of a watershed as a large bathtub. When a drop of water hits anywhere in that bathtub it eventually finds its way to the drain. The bathtub defines the watershed boundary. On land, that boundary is determined topographically by ridges, or high elevation points. Water flows downhill, so mountains and ridge tops define watershed boundaries. A watershed can be as large as the Mississippi River Watershed (that is one big bathtub) to as small as the little creek running through your back yard being a watershed. We can talk about watersheds and sub-watersheds, with a sub-watershed just being a smaller watershed in the bigger watershed (Mansfield University, 2012)

Every watershed presents its specific challenges because none of them is exactly alike. However, there are also common challenges faced by all watersheds due to their common features, such as pollutants from human activities and stress created from lowering water levels due to climate change and over-use by humans.

The stresses faced by Japanese watersheds are primary the result of the fact that Japan is a very densely populated country. Whenever a land area is densely populated then there will be extreme demands made on the water that is available. This will be true even if there is a substantial amount of local water. In simpler terms: If there are a lot of people, even large watersheds will be stressed.

Japan, which has significant stresses on its watersheds because of its dense population, also has significant advantages. These include primarily a well-educated population and one of the world's finest infrastructures. The Japanese government has spent decades putting safeguards in place against another of the major watershed risks in Japan: The possibility that there will be substantial floods. The following provides an overview of the ways in which Japan has prepared its land and its people:

Japan has the means -- and the skills -- to manage these risks using infrastructure such as dams, levees and underground floodways.

There is also great emphasis placed on public awareness and disaster preparedness. The authorities have developed early warning systems that rely on the Internet, Geographic Information Systems (GIS) and hazard mapping, and there are shelters where people can take refuge.

Such continuous efforts have ensured that one of the world's largest economic developments has been able to safeguard its population in the high-risks region. (Greater Tokyo, 2004)

The above description demonstrates one of the ways in which watersheds (in this case, the one that exists under the city of Tokyo) come to be endangered by human activity.

When humans view water as a danger then in turn they become a danger to the water. Of course it is if we look at water vis-a-vis its power to kill people and destroy its buildings -- a danger that we saw all too well with the tsunami that struck Japan last year. However, floods and the human responses to it are not the most serious dangers that face the watersheds in Japan today. These far more serious dangers include "a degraded natural environment and pollution of groundwater, and many efforts, such as river restoration works" (Greater Tokyo, 2004). However, and this is appropriate to Japanese culture and in it lies the possible future rescue of the watersheds, there is also significant effort "being implemented with wide public participation" (Greater Tokyo, 2004)

The following map shows the complexity of the river system that underlies Tokyo. Rivers flow in and out of the city's watershed, and each one of these is impacted by the density of one of the world's most crowded cities. Despite the meticulous planning of the Japanese government and a keen awareness of the ways in which conservation of watersheds is imperative to future quality of life, http://www.mediatinker.com/blog/upload/2006/12/10-year-roads.jpg the number of people alone makes it impossible for human interaction with this watershed.

Another aspect of watershed protection and endangerment is exemplified in the Tokyo watershed: Most watersheds (at least in the developed world but often in the developing world as well) are placed in future peril because of the tangle of regulations and legal claims that can be made on them. The complexity of claims on the Tokyo watershed are an example of this:

The water of Japan's rivers has historically been dominated by a large number of river users with vested water rights, conferring the right to use water, both public and private. With the development of human society and disputes arising over water rights, the need arose for a legal system to regulate water use. (Greater Tokyo, 2004).