The appeal is dismissed.

The costs of appeal are assessed against the plaintiff (appointed party) and the appointed party.

The grounds of appeal are examined (to the extent of supplement in case of supplemental appellate briefs not timely filed).

1. As to the ground of appeal No. 1, since the former River Act (amended by Act No. 5453 of Dec. 13, 1997) has adopted the so-called statutory system concerning the method of determining the river area which is the crossing area of a river, the area falling under Article 2 (1) 2 (a), (b) and (c) of the same Act shall be the river area as a matter of course, except where the designation of the river management agency in the latter part of the same item is required.

Therefore, in order for the bank to be excluded from the land or the area located on the side of the lower court from the bank to the river area stipulated in the above item (b) or (c) above, it is sufficient that the bank is established by the river management agency or the person who is permitted or entrusted by the river management agency as a river appurtenances under the above item (c) of Article 3 of the same Act, and it is not incorporated into the river area which requires separate procedures such as designation of the river management agency or public announcement of the river works.

In addition, even if the land was legally incorporated into the river area to which Article 74 of the Act applies mutatis mutandis, even if the owner suffered damages by being restricted in the exercise of private rights to use and benefit therefrom, the owner may not claim the return of unjust enrichment on the ground that the possession of local government, which is the river management agency, is the same as that of the possession without the title.

(See Supreme Court Decision 93Da30686 delivered on November 18, 1994. The court below held that since the land of this case was legally incorporated into a river area according to the River Act according to the "Yecheon Reinforcement and Hado Maintenance Work" implemented by the defendant around December 1996, the land of this case was legally incorporated into a river area according to the "Yecheon Reinforcement and Hado Maintenance Work" and thus, the plaintiff (appointed party) and the designated parties (hereinafter referred to as "Plaintiffs").