Failure Knowledge Database / 100 Selected Cases

The fishery damage by National Isahaya Bay Reclamation Work【 At the Isahaya Bay in Nagasaki Prefecture from April 14 in 1997〜 】

Masahiko KUNISHIMA・Michihide MIURA (*1)

In spite of the opposition from many people involved in the fishing industry andlocal people, the water gate of the Isahaya Bay salt pan embankment was closed onApril 14 in 1997. The subject areas of this plan are Isahaya City, Moriyama Town,Takaki Town, Agatsuma Town, and Aino Town in Nagasaki Prefecture (Fig.3 reference).
Following this National Isahaya Bay Reclamation Work was started whose content of
the construction is creating the reclamation farmland of about 700 hectares inside( Fig.1〜3 reference ). The total cost is about 250 billion yen. Completion is due
in fiscal 2006, and over 90% of the construction already ended by 2004. According
to "the national Isahaya Bay land improvement work changing plan" announced in theyear-end of 1999, the purpose of this project is “① Making come true the agriculture
with the high productivity by developing the large-scale flat superior farmland which
has the regulating reservoir and the water whose source is the regulating reservoir.
② strengthening the disaster prevention function against the storm tide, the flood,and the poor-drainage in the back swamp. ". But National Isahaya Bay Reclamation Work
is told that it has affected something unusual in the Ariake Sea, and it has also
caused the large disturbance of the fisheries promotion that has resulted in thedecrease in the laver harvest and so on ( Fig. 4,5 reference ). Comparing the increasein the agricultural yield by making the new farmland with the transition of decreased
harvest, there are some comments that it is a failure in terms of being the national
work contributing to upgrading the degree of self-sufficient food. In addition, though
they have declared the prevention of disasters as one of the work's purpose, floods
have not decreased or rather there are even some reports that the new types ofinundation disasters have happened. Nation and Nagasaki Prefecture should carry out
the proper reevaluation for this project, and distribute the information. And theexamination of stopping the project has also been required.
The judgment was transferred to the field of the judiciary. The national Isahaya
Bay reclamation work which typifies the public works about which it is said “Oncepublic work starts, it never stops” was carried out under the provisional disposition
application of the suspension of the construction. This was applied for by 106
fishermen of coastal 4 prefectures because the fishery damage by the unusualness of1

Failure Knowledge Database / 100 Selected Cases

Ariake Sea was caused by the effect of the national Isahaya Bay reclamation work.
On August 26th, 2004, Yoshiyasu Enomoto (the presiding judge of Saga District Court)
initially decided that the construction would be forbidden. At last the provisional
disposition of the suspension of the construction was decided. However, the Stateobjected as it is natural to rule according to past precedents as in the past justiceof public work. The sterile combat has continued. Will it be possible to stop thenational Isahaya Bay reclamation work, which typifies the public works about which
it is said “Once public work starts, it never stops”? Or will it be reversed in
the future justice and will it be ended with the temporary joy of local area
inhabitants? The outcome of the trial and government measures attacked great publicattention. The result… In May, 2005, Fukuoka High Court removed the statement ofthe fishermen because the general proof was needed to judge the suspension of theconstruction. In addition, on September 30th, 2005, the Supreme Court rejected thecomplaint of the fishermen. By the judgment, the decision of Fukuoka High Court whichcanceled the decision of Saga District Court which prohibited the remaining
construction was determined.

Outline of the plan
Isahaya
BayFig.1 (Source: Home Page by Ministry of Agriculture, Forest and Fishery)2

Failure Knowledge Database / 100 Selected Cases

Fig.2

Fig.3

(Source: Home Page by Ministry of Agriculture,Forest and Fishery)(Source:HomePageby(Source: Ministry of Agriculture,Forest and Fishery)(Source: Home Page by "Come Back, the Ariake Sea!")(Source: Home Page by "Come Back, the Ariake Sea!")

Fig.4

Fig.5

1. Event
The content of the construction is isolating the end of the Isahaya Bay by the salt
pan embankment and creating the reclamation farmland of about 700hectares inside.
About the cause-and-effect relationships between National Isahaya Bay Reclamation
Work and something unusual in the Ariake Sea, the investigation work has still beencontinued. (①The loss of the water purification function and the increase in thebad influence ②The change of the flow ( tidal level, velocity of flow, and flow
direction ) ③The increase in the red tide ④The generation of the anoxic watermass ⑤The decrease in atrina pectinatas, ruditapes philippinarum, and so on, Thepoor growth of them, The death of young shellfish ⑥The change in the nature of thebottom in the Isahaya Bay ( accretion of floating mud and becoming fine-grained )and the decrease in benthos. )3

Failure Knowledge Database / 100 Selected Cases

2. Course
The national Isahaya Bay reclamation work is based on “national Isahaya Bay
reclamation work plan” announced in 1985. After some delays such as the scale
reduction etc in 1992, it started. On April 14th, 1997, the water gate of the embankment
was closed. However, the tideland in the Isahaya Bay was dried up by the nationalIsahaya Bay reclamation work. The organisms which lived in the bay received thedestructive damage. The environment problem called “the unusual event in Ariake Sea”
became serious. The discussion on the appropriateness of Isahaya Bay reclamation work
increased. The laver culture industry of the whole Ariake Sea received enormous damage
by the generation of the red tide from December, 2000, which was of the biggest scale.
The crop of the laver was record-breaking bad. The sharp decrease of seafood in Isahaya
Bay and Ariake Sea started from the commencement of the work. Many people in Japan
became to know the unusualness of Ariake Sea because of the bad crop of the laver.
To stop the fishery damage, each fishermen cooperatives in the coast of Ariake Sea(Saga, Fukuoka, Kumamoto) insisted that the unusualness of Ariake Sea was mainly
caused by the construction of the reclamation work, in November, 2002, demanded thesuspension of the construction of the reclamation and took first filing suit to Saga
District Court. The judgment was transferred to the field of the judiciary. The
national Isahaya Bay reclamation work was subjected to the provisional disposition
application of the suspension of the construction which 106 fishermen of coastal 4
prefectures had applied for. On August 26th, 2004, Yoshiyasu Enomoto (the presiding
judge of Saga District Court) initially decided that the construction would beforbidden. At last the provisional disposition of the suspension of the construction
was decided. However, the State objected as it is natural to rule according to past
precedents as in the past justice of public work. As the result, in May, 2005, Fukuoka
High Court removed the statement of the fishermen. In addition, on September 30th,
2005, the third petty bench of the Supreme Court rejected the complaint of thefishermen. By the judgment, the decision of Fukuoka High Court which canceled thedecision of Saga District Court which prohibited the remaining construction wasdetermined.
3. Cause
・The holes ,which were dug in order to pick sea sand, have been a hotbed of the anoxic
water mass.
・The salt pan embankment has caused a weakening the tidal current and a raising of
the tidal level.
・"Foul water" discharged from regulating reservoir has contaminated the whole Ariake
Sea.
4Failure Knowledge Database / 100 Selected Cases

・The Isahaya Tideland Mud Flat , which had retained the high clarification function,
decreased because of the closing the salt pan embankment. Because of the drainage
from the regulating reservoir, the discharge volume of organic matters, phosphorus,
nitrogen, and so on have increased.
・The holes, the embankment, and the foul water, have caused generation of the redtide.
・Since there had not been countermeasures against the high water at all at the Oura
Harbor, the dangers in typhoon ( , storm tide, or flood tide ) increased after thecompletion of the salt pan embankment.
4. Immediate Action
When the crop of the laver was bad, some fishermen have carried out the acid treatment
which began at the middle of the 1970's. But it is said that the acid treatment may
cause the further vicious circle.
Against the background of the national criticism which was "Once public work starts,
it never stops", in December of 1997 Prime Minister Ryutaro Hashimoto directed the6 public work relations of 6 ministries and agencies concerning public works tointroduce the reevaluation system of public works. That was why, the Ministry ofAgriculture, Forest and Fishery introduced its own reevaluation system, starting fromfiscal 1998. However, the following are being mentioned as a problem of thereevaluation system: That they do not guarantee fact, information disclosure andcitizen participation of the evaluation content has narrowly been limited, and mostof the reevaluation in a past becomes the business ratification, etc...

It isstrongly desired that it looks at social conditions and environmental problems of
the actuality directly, and that the specialist carries out the fair evaluation, andthat it demonstrates the function as a rational evaluation system which also contains
the judgment of the business review in visual field without ending as a resultjustifying the business continuation, of which this reevaluation system is merely
a formality.
5Countermeasure
In February of 1998, Nagasaki Prefecture set the numerical target of the water quality

protection about the environmental impact assessment, the review and the predictionof the water quality in the regulating reservoir. Nagasaki Prefecture settled on theInitial Stage Water Quality Protection Plan, and promoted the systematic and synthetic
water quality protection countermeasure in order to achieve this numerical target.
It is necessary that the administration steadily carry out the plan on the basis of5

Failure Knowledge Database / 100 Selected Cases

the specialistʼs view and opinion, and properly maintains the water quality in theregulating reservoir throughout the future. In addition, the water quality
protection plan must be revised at every regular period, and reviewed by having its
basis in the progress of the various countermeasures and the change of the newsituation. But the result of review in 2001 was very different from the predictionof the environmental impact assessment of National Isahaya Bay Reclamation Work in
1986, and it has been said that it is doubtful whether the water quality protection
plan will be achieved.
6. Generalization
National criticism and anger for public works which are said “Once public work starts,
it never stops” were begun by the case of Nagaragawa river mouth barrier andaccelerated by the image of the guillotine of the Isahaya Bay. The decision by thejudiciary about the national Isahaya Bay reclamation work was hard to accept for theplain tiffs. They were very sad. However, in the Kawabekawa River dam plan (sameKyusyu), on May 16th, 2003, the party which opposed the construction won in wateruse hearing of the intermediate appeal, even though the State applied theexpropriation vote of fishing right. In Kawabekawa River dam, the construction ofthe dam had not started at the time of writing (2005) though the Ministry ofConstruction (the Ministry of Land, Infrastructure and Transport) announced the planin 1966 (40 years ago).
However, the State does not change completely. Kitagawa (the Ministry of Land,Infrastructure and Transport) says “it is necessary to complete as soon aspossible.” The anger and the opposition movement of the local areasʼ citizens formany useless public works such as the Isahaya Bay reclamation work, the Nagaragawa
River mouth dam, the Yoshinogawa River movable weir and the Kawabekawa River dam
attract the attention of Japanese people and change the rigidity of public works.
7. BackgroundWe can cite Nagasaki Prefecture, the Ministry of Agriculture, Forest and Fishery,
Nagasaki Great Reclamation Resolution Alliance Association, and the area's farmers
as the promoters of the reclamation work. Each has promoted the reclamation workfor the following reason.
・Nagasaki Prefecture :In order to get out of the inefficiency of the small-scale reclamation system, which
had been carried out in the past, at the Ariake Sea Coast.
In order to drastically prevent the typhoon disaster occurred in the coastal area
frequently.
6Failure Knowledge Database / 100 Selected Cases

In order to upgrade the self-sufficiency degree of the prefectural people's food・The Ministry of Agriculture, Forest and Fishery :In order to attempt to increase the food production nationally・Nagasaki Great Reclamation Resolution Alliance Association :Because the area's people recognized that it was very important from the point of
the modernization of agriculture, the regional development, the prevention ofdisasters, food self-sufficiency.
・The area's farmers :Because it can solve the bad drainage
Because they expected the effect of the increase in the agricultural income and soon
Nagasaki Prefecture has disasters frequently, and has experienced the damages ofstorm tide and the flood. Especially, the Isahaya Huge Flood in 1957(Figure-6) brought
about great damage. The heavy rain which attacked the Isahaya district from July 25th
to 26th in this year was over 588 millimeter. Therefore, all rivers such as Honmyogawa
River which flowed into Ariake Sea overflowed. The earth-flow was generated here andthere in the upstream. In addition, the debris flow smothered many farms with rocks
and it swallowed a large number of houses and people. In the Honmyogawa River watershed,
flood damage in detail is described as follows.
Fatalities: 494 persons
Missing person: 45 persons
Complete collapse and washed away: 727 houses
Half collapse: 575 houses
Complete collapse (non-dwelling): 176 houses
Half collapse (non-dwelling): 320 houses
Damage the total amount: 87 hundred million yen
People expected the Isahaya Bay reclamation work to protect the high water disaster,
to dispel the worry of ill-drainage in the hinterland and to develop large farmland
which has desired in the district. People also expected the Isahaya Bay reclamation
work to contribute as a flood countermeasure since the sad experience like the Isahaya
Huge Flood should not be repeated.

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Failure Knowledge Database / 100 Selected Cases

The Isahaya Bay Reclamation has the long history. The durable reclamation had been
carried out by the technology which skillfully utilized the natural environment called"the sight frontage reclamation" since about 600 years ago. Today's plan of thelarge-scale and compound reclamation was started by "the Nagasaki Large Reclamation
Plan" in 1952. The project done at present was named after "the Isahaya Bay Disaster
Prevention Total Reclamation Project" planned in 1983. The plan was changed in 1999.
The drastic extension in the construction period (the completion schedule: fiscal2006) and the increase in the cost (249 billion yen) have been expected.

Figure-6 (Source: The Ministry of Land,
Infrastructure and Transport Kyushu district
improvement station Nagasaki river national roadoffice)(Photograph: Isahaya history story association)

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Knowledge・ When the Government plans and undertakes projects, it should consider the latest
socioeconomic situations, environmental problems, and so on.

And the Government

should carry out the strict evaluation, which is based on fair and proper
information, in the transparent process.
・ According as the change of the socioeconomics situation, the administration should
carry out the reevaluation anytime.
・ If they take makeshift action on situations without examining the basic measure,it may cause the vicious circle.
9On the Side
Closing the salt pan embankment in Isahaya Bay in April of 1997 has been called the"guillotine". The guillotine was the beheading stand for the executions, used mainly
during the French Revolution. We were overwhelmed by the image of what is called the"guillotine”; 293 steel plates were dropped like dominoes. It is not difficult toimagine that a lot of people opposing it have never been able to forget the image
as a detestable memory.

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Failure Knowledge Database / 100 Selected Cases〈Reference〉
・"Assessment Of The Time" of the Isahaya Reclamation by the citizens
・Home Page by Ministry of Agriculture, Forest and Fishery・The Web site of the formal data of National Isahaya Bay Reclamation Work・Home Page by "Come Back, the Ariake Sea!"・"The Power Structure about National Isahaya Bay Reclamation Work"
http://www.geocities.jp/joho̲triangle/isahaya/isahayawan03.html
・ISAKANhttp://nonki.cside5.com/isahaya/nagasaki/Nindex.html(*1) Department of Civil engineering, Univ. of Tokyo

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