出典:Wikipedia
出典:『Wikipedia』 (2010/06/29 04:55 UTC 版)
A needle dam is a weir designed to maintain the level or flow of a river through the use of thin "needles" of wood. The needles are leaned against a solid frame and are not intended to be water-tight. Individual needles can be added or removed by hand to constrict the flow of the river, forming a sluice.