| 摘要 |
Culvert ends are commonly dammed by beavers, especially if water dribbles out of the culverts in small quantities. The problem is solved by means of a culvert end structure defined by an L-shaped tube connected to the inlet end of a culvert and containing an inlet opening in one side thereof; a valve normally closing the opening; a tubular rod carrying the valve; and a pair of floats connected to the rod by arms above the valve for moving the valve upwardly when the water level at the inlet end of the culvert rises above a predetermined level. |
