PROBLEM TO BE SOLVED: To reduce a polluted-matter load imposed on a river by combined overflow water in rainy weather.;SOLUTION: Flushing water supply means 10a-10e for allowing the inflow of flushing water for cleaning the inside of sewer piping from the outside of a sewer piping net are arranged in a decentralized manner in upstream-side small-diameter combined sewer piping 30a-30c and midstream-position midsize-diameter combined sewer piping 31; and a central control unit 50 for performing the remote control of the means 10a-10e is provided. The flow-down speed, a time of a concentration, and a flow rate of water in the piping are estimated by numerical simulation, and the timing of the start of the supply of flushing water from each flushing water supply means is determined so that leading sections of water flowing from respective tributary sections can almost concurrently reach a combined section each time water flows downstream. Rainwater or water which is poured from a river is stored in the water storage tank 14 of each of the means 10a-10e, and the flushing water is made to flow into the sewer piping on the basis of the timing before the start of a rainfall, when the estimated amount of the rainfall equals or exceeds a reference value.;COPYRIGHT: (C)2006,JPO&NCIPI
展开▼
