Draining of the Lake Shinai, Miyagi Prefecture

Abstract

Daishichi-chiku is the last polder reclaimed from the former Lake Shinai, a retaining pond that has been drained since the 17th century for the purpose of using it as rice fields. Draining of this area, 370ha. large started in 1940 and was finished in 1948. Because the retaining pond has disappeared as the result of this draining, floods occur frequently in and around this area, for the improvement of the rivers which flowed through it was imperfect. To protect the land around this area from the floods, an over-flow weir along the embankment encircling it was built, so that certain amount of water flows into this area when the rivers stand above normal level, that is to say, its function of retaining water was preserved notwithstanding reclamation. So this polder is submerged once or twice a year and rice is somewhat damaged. But in accordance with recent progress of the revision of the channels, it was desided to raise the height of the over-flow weir in near future.