Flood control measures for the Hinokawa River

The Hinokawa River is a small river located in the upper reaches of the Hinokawa River, a second-class river managed by the headwater near housing complex in Konandai. It is connected to the Hinokawa River in Hino 5-chome, Konan-ku (Hinobashi) and the Hinokawa River in the second-class river Hinokawa River.

The watershed of the Hinokawa River, a quasi-use river, is a plateau and hill with convenient transportation to Yokohama Station and central Tokyo via the JR Negishi Line and the Municipal Subway Blue Line. As a result, the amount of spills to Hinokawa increased due to the decline in the water retention and drainage function in the basin, and drastic flood control measures were required to increase the safety against flooding from rivers.

On the other hand, the lower reaches of the Ooka River, a second-class river that flows through the center of the city, is the central part of Yokohama, which has various characteristics such as administrative agencies and sightseeing spots, and it is difficult to widen the river channel due to the progress of urbanization. Therefore, as a flood control measure for the Ookagawa River, almost all of the outflow during the flood is cut in the upper part of the Hinokawa River, and discharged directly to Okagawa River, and discharged to Okagawa River 9 to Okagawa River, and Okagawa River 1.

In addition, for the mutatis mutandis river Hinokawa, a renovation project was started in 1989, and full-scale Hinokawa renovation work was carried out in 2001, and the immediate maintenance goal is that it will not overflow with an hourly rainfall of 50 mm. We are proceeding.

State of renovation work

Gwangmyeong Hashigami style	Gwangmyeong Hashigami style after maintenance
The water diversion tunnel beside the Hino three-dimensional intersection	Ookagawa Branch Waterway