symposium research meeting:2007.12.12

General Strategic Project Research Meeting
" A New Wave for Designs of Rivers and Coasts"

Date：12, Dec. 2007 (Wes) 15:00-17:00
Place: Common Study Room, Koganei Campus, Hosei University

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　　A statement of Creative Rebellion against Public Works in Ohata-cho, Aomori Prefecture
" New Wave for Designs of Rivers and Coasts"
Takao Tsunomoto (Sustainable Communities Research Institute, Ohata, Aomori)
　We were awarded the Grand Prix of Design Award by Japan Society of Civil Engineering in 2006, and Gold Prize of Good Design Award in 2007. These results show that our process and way of thinking were evaluated, implying the determination of academic society and good design award to change their frameworks of evaluation.
　Because Ohata is the product district of squid, we held "Cultural Forum of Squid" in 1994 to revaluate the culture of squid. In that year, we launched "Forum in Ohata". We also organized "Committee of Forest, River and Ocean", and "Committee of History and Myth" in that forum. We continued research meetings and observation meetings, to integrate the results into "Ohata Principle" as the philosophy of community development in 1997.
　The Ohata River has become frequently swollen after the straightening of the channel, and creatures of the river were dramatically decreased. In 1996, we started study meetings with river section of Aomori Prefecture, and proposed a renovation project based on Neo-Natural River Reconstruction Method. We launched the improvement work on that method in the name of training. A hundred and more people including civil engineers, architects, officers, and inhabitants gathered to construct water control structure surrounding both banks of the river. In neo-natural method, we have to restore a flow with minimum intervention so that the river would be regenerated by itself. River environment could be dramatically transformed at low cost. The construction, without self-assertiveness, will disappear within five to ten years. We often throw stones into rivers. As a result, during recent eight years, salmon run, which means the river has been regenerated.
　The proposal of coast improvement project from the prefecture in 1999 triggered the regeneration of Kinop coast. In 1999, Seacoast Law was revised to include environment and utilization as its concept, adding to protection. To examine three concepts of Seacoast Law, we had meetings eighteen times with Aomori prefecture, municipalities, NPOs, villages, consultant companies, and specialists of ocean engineering. We expected those specialists to explain characteristics of the seacoast to inhabitants. In the meeting, old Kinop coast was introduced. Though there was no picture of landscape, commemorative pictures showed the rich rocky shore. People had rich daily life throughout the year. In the process as described above, consensus was built on restoration of the shore.
　There was a gently slanted dyke on the shore. The shape was popular at the time of construction and it was built for protection purposes. Some of the members proposed to demolish this dyke in the meeting because it prevented to go directly to the seacoast, and high tides rose along the dyke. Because the construction of the dyke was funded by nation, the demolishment could lead to be incompatible with the law defining the appropriateness of subvention. Therefore we used broken blocks as wave absorbing structure, both for protection and environment. We had already noticed the wave dissipating effect of the rocky shore. For the restored rocky shore, we considered the improvement work should be kept minimum. However, the promoter ordered the work on the ordinary construction cost due to the lack of experience of similar projects. As a result, the builder carried out excessive construction works. The porosity was specified to 50% in the design drawing. We applied surface compaction because it did not pass the inspection. Though Seacoast Law and River Law proclaim citizens' participation, and consensus building, what inhabitants can do was to offer their opinion in reality. Once the project was determined, inhabitants were not invited to the related meetings. There are supervision processes for architecture; however, for civil engineering works, the design would be ordered to consulting companies without supervision processes. I wonder to what degree citizens' consensus was guaranteed. Finally we demanded to modify the wave absorbing structure which differed from the consensus. I wrote the necessities of this work on the paper for Japan Society of Civil Engineers. We improved the structure two times to restore the flow of tide. Based on the old picture, we decided the positions of stones; "a stone will become stable by moving". People are getting attracted to the shore. The seabed was also re-naturalized. We have continued the monitoring of seawater temperature, saline concentration, and creatures for more than three years. The buried rocky shore became exposed. We are studying to scientifically generalize the case of Kinop. We will develop activities to change coastal lines of Japan which unfortunately became unattractive by offshore breakwaters.