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...

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…