Abstract: The riparian improvement structure for use upon riparian protection, shore and bank protection, wave control, water control, etc. of a river, lake, sea, etc. is composed of a plurality of blocks and a structural body or bodies composed of a plurality of wooden materials or mass materials. The riparian improvement structure also provides an environment suitable for the habitation of aquatic life such as fish, crustaceans, e.g., crabs, shrimps, aquatic insects, etc., and for the growth of aquatic plants, etc. The blocks are each provided with a water passage, such as a through-hole formed therein or a plurality of grooves formed on the bottom thereof, through which fresh water can flow, when they are disposed on the structural body or bodies or on a riparian area such as a river-bed, shore, bank, bottom, etc. of a river, lake, sea, etc. The blocks are disposed for fresh water to flow through the water passage and to be supplied to the structural body or bodies inhabitable for aquatic life.

Abstract: The riparian improvement structure unit for use in construction work for water control and protection is composed of the first tubular member and a plurality of stick-and-twig members tied in a bundle with a bundling member, the first tubular member being formed with a plurality of holes through which to allow fresh water with dissolved oxygen present in water flowing through the first tubular member to pass into spaces and gaps formed within the plurality of the stick-and-twig members. The riparian improvement structure unit may have the second tubular member disposed along and in parallel to the first tubular member and tied together with the first tubular member and the plural stick-and-twig members in a bundle with the bundling member. The riparian improvement structure units are laid on a riverbed or a bottom of a riparian area along or in parallel to a flow of water so as to allow water to flow and pass through and within the riparian improvement structure units.