| 摘要 |
PURPOSE:To increase the amount of drainage in the early period of inflow by a method in which a small water tank having an overflow portion on its upper part is provided at the inlet and outlet of a regulating reservoir, the lower parts of both small tanks are connected with a water conveyance pipe and the lower part of the water tank on the outlet side is provided with a drain port. CONSTITUTION:When rains start to fall, great amounts of rain water flows through an inflow pipe 1 into the first regulating tank 2, and the rain water concurrently flows into a drain tank 4 through a drain port 22 and a water conveyance pipe 23 and is discharged to downstream from a discharge pipe 5. In this case, in the first regulating tank 2, the water level is raised and the amount of drainage passing through the water conveyance pipe 23 is increased, but when the amount of inflow water becomes too great to handle, the water flows from the overflow portion into the second regulating tank 3. The rain water is discharged through the drain tank 4 from the drain port 32, but during the period, the water level of the second regulating tank 2 is raised to regulate the amount of drainage to the river. By this, the amount of drainage through the water conveyance pipe 23 even in the early period of inflow can be increased. |
