Mr. Keisuke Hata
Manager, Planning Division
Sewage Works and Management Department
Construction Projects Bureau
Kobe City Government

Kobe was just a small fishing village when it was opened to the world in 1868. It soon attracted a number of foreign traders who established a 'foreign enclave' near the newly constructed port. It was Scottish engineers who laid the first sewage lines in the foreign enclave as early as 1872. This was a well built series of pipes made of brick that simply carried wastes directly into the sea, which are still in operation.

Urbanization followed rapidly as the port expanded. The development of an extensive centralized sanitation system lagged, however, until the reconstruction of Kobe began after its near total wartime destruction in 1944-45. In 1951 a full scale sanitation service began with both flood control and sewage treatment in the central part of the city. Sewage lines and treatment plants followed, though slowly. By 1970 most of the houses used individual septic tanks for wastes. It was not until Mayor Miyazaki began a major push for an extensive sewage system in 1970 that the situation began to change dramatically. At that time only 35% of all households were connected to the central system.

Largely due to Mayor Miyazaki's efforts, and sometimes against the resistance of the population, the system grew until by 1985 more than 90% of all households were connected to the central system. In the next few years that figure rose to near 100%. Today 4,560 kilometers of pipe carry 550,000 cubic meters of sewage per day through 23 pumping stations to 7 treatment plants. In those plants efficient high technology processes pass the sewage through settling tanks, bioreactors, and chlorination plants to discharge clean water, partly into the sea, and partly into irrigation and other systems designed to use recycled water. The sludge that settles out is further digested, dehydrated and incinerated. The ash is used in the construction of paving bricks. In the process, methane gas is produced which is now being used in a new experiment to power the city buses.

Flooding can be especially destructive since extensive underground malls have been built under the city center.

This extension of the sewage system has had two highly visible environmental impacts. BOD levels in Kobe’s rivers, lakes and reservoirs have dropped dramatically.  In addition, the number of red tides has also declined. Managing human wastes immediately cleans natural waterways.

An especially heavy typhoon together with a sea surge could have disastrous effects on human life and property. Recently the frequency and severity of the typhoons has increased, some believe due to global warming and climate change. Whatever the cause, it has led the city to increase the number of pumping stations to remove the heavy rains to prevent flooding.

The great Hanshin-Awaji earth quake of January 1995 caused extensive damage to the sanitation system. Future developments will be built with an eye to making them quake proof.

In 2006, Kobe developed a new five year plan, Kobe Aqua Plan 2010, with five substantive and one administrative goal.  They are as follows:

• To support a pleasant civil life and sound urban activities;
• To create a flood resistant city with enhanced safety and security;
• To create good water environments;
• To form a recycling-oriented society and preserve the global environment; and
• To promote information disclosure and publicity.
• The administrative goal is to reduce the accumulated budgetary deficit of the system by half without increasing the burden on the citizens.

Kobe Sewage Treatment Plant explained

The Bureau in charge of these activities has developed a picture of a tree whose roots lie in sewage and whose message is that processing and recycling this sewage can produce a large number of products and benefits, represented by the branches and leaves of the tree.  Products include plastic additives, bricks and road building materials; water for irrigation, fire fighting and flushing public toilets; and heat to warm swimming pools and produce power for air conditioning and other power uses.

Typical of the approach Kobe takes to these problems is a close integration of highly technical developments, and mobilization of the citizens and neighborhood groups to build public participation into the process of creating a better environment.

Active citizens cleaning and flowering their environment