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Japan's marginal villages can help solve water issues in Japan and across the world

2012.10.04 Junji Hashimoto


Small-scale water supply facility run by the local residents built in the Kurotsuchi district.

Japan's water supply coverage is 97.5% (as of 2010). There are some prefectures such as Tokyo and Okinawa with 100% coverage. Having said that, there are also prefectures with a lower coverage like Kumamoto (86.1%) and Fukushima (89.6%). In other words, there are approximately 3 million people in these regions who do not have a water supply.

This does not mean that they do not have any drinking water. These areas are mostly mountain villages with an abundance of clean spring water, underground water, etc.

But in recent years, the situation has begun to change. Due to the aging population, it has been getting more and more difficult to maintenance and manage water facilities. Moreover, in many regions the water quality has worsened and the quantities have become unstable.

The Kurotsuchi district in Bungotakada City, Oita Prefecture is a small community of 223 people. They do not have a good water supply. The surface water and shallow groundwater levels are poor, and the deep groundwater contains much iron and manganese, making it unsuitable for daily use. Residents source their water from a spring located 10km away, but "This is only possible while we can still drive. Eventually it will be difficult to secure water." Some people go to the Bungotakada City regularly to use the laundromats there.


Coffee-colored water with high concentrations of iron and manganese(left) must be filtered to create water suitable for daily use(right).

Water projects are facing financial difficulties, so there are currently no plans to lay down new pipes to supply water to small communities. Many of the residents feel "abandoned." This is not a story about a developing country. It is not widely known, but actually there are quite a few places like this in Japan.

The alternative is to have a small-scale water supply facility managed by the local community. But in order to build one, a few conditions must be met.

First of all, the construction and maintenance-management costs must be low. Many elderly live in the Kurotsuchi district of Bungotakada City (the population aging rate is 55.2%), and for the most part their income comes purely from pensions. So they cannot afford to pay a high fee for facilities.

Secondly, the facility must be easy to maintain and manage. Because there are many elderly, it would be difficult to maintenance and manage if heavy labor and complicated processes (such as using chemicals) are involved.

That is why the "NPO Oita No Mizu To Seikatsu Wo Kangaeru Kai (Let's Think About Oita's Water and Lifestyle Group)" proposed adding a water purification facility that uses biological processes (slow filtration) to the existing facility.

This system offers 4 key benefits:
1. With this type of filtration, the biotic community invisible to the naked eye on the surface of the filtration layer purifies the water. It is a chemical-free, small-scale reproduction of the process by which nature (and the soil in the forest) purifies water. It is a simple, yet very reliable purification method.
2. When the system becomes clogged, the sand will need to be removed, but it is light, easy work even the elderly can perform.
3. The system does not require the use of any chemicals, so it is very easy to maintenance and manage.
4. The construction and maintenance-management costs are relatively low, so the residents do not have to bear a high financial burden.

With subsidies from Bungotakada City, Oita Prefecture, the community was able to build a small facility that can purify 8 tons of drinking water a day that began operation in April 2011. The facility cost 7 million yen to build, but the residents only had to pay approximately 50,000 yen per household. The residents manage the facility themselves. More specifically, they take turns managing the amount of water filtered per day, cleaning the coarse soil every 2 weeks, and unclogging the purification system every 2 months.

The NPO also visits the facility nearly once every month to check on the status, water quality, and propose improvements for maintenance-management of the facility.

It is quite a new endeavor, where an NPO and the local community are working together to fill the gaps in the public service.

Tsuyama City in Okayama Prefecture, with a population of 110,000, has a water supply coverage of 99.4%, yet there were 254 households (approximately 730 people) without drinking water. This region, too, faced similar problems as Bungotakada City.

That is why Tsuyama City established a system that provided subsidies for the construction of small-scale water supply facilities. This system will provide subsidies from the allocated budget to help build small-scale water supply facilities in order to improve the quality of life and health and hygiene of areas without water supplies.

The key premise of the subsidy is that the local water management group will take responsibility for the establishment and management of the facility. In other words, as was the case in Oita, the residents will be in charge of managing the water supply. In addition, the following conditions have to be met to become eligible for the subsidy.

- Meet the safety standards as prescribed in Article 4 of the Waterworks Act.
- The (Waterworks Act non-applicable) area must contain more than 10 households with a population of over 20 and less than 100.
- The subsidy application must have the agreement of over 90% of households in the area.

The subsidy will cover 60% of the construction costs of the water intake-purification system, 30% of the construction costs of water supply pipes, costs that are beyond the community's payment capacity, and 50% (up to 10%) of the water quality examination costs. So far, small-scale water supply facilities managed by local residents have begun operation in 3 districts.

When the water is really muddy, for example when there is heavy rain, biological purification methods (slow filtration) is insufficient, so the water must also be pre-filtered in a facility that uses small stones and gravel.

These case examples will be great references for small communities and local governments experiencing similar problems. These solutions can also be applied overseas. In the past, there was a tendency to prefer the implementation of cutting-edge technologies to address water issues all around the world. State-of-the-art water supply facilities often found in developed countries were constructed, however, it was very difficult to maintenance and manage, and when something broke down, parts could not be sourced, there were no engineers that had the necessary understanding of sophisticated technology, and the maintenance-management costs were too high. Many of these facilities eventually had to be shut down and were often abandoned. These are indeed the same issues small communities in Japan are facing, and therefore the same solutions may be applicable. Some may call these solutions low-tech, however solutions that can easily provide safe drinking water at low costs are in demand. So these systems that have been adopted by Japan's marginal villages may also prove to be quite useful for many areas around the world.

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The area of this news

Oita,Okayama,Japan (Japan

Junji Hashimoto

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