Interbasin water transfer in Totsukawa River and Kinokawa River Integrated Development Project

摘要

The Totsukawa River and Kinokawa River Integrated Development Project (TKDP) was one of the national projects planned for reconstruction of Japan's war-torn economy just after the Second World War. The target area of TKDP was spread over Nara and Wakayama Prefectures, the Middle West of Japan (see Figure 1). The project was undertaken for the following objectives: (a) Irrigation water supply for a 21,000 ha of agricultural land in Nara and Wakayama Prefectures; (b) Domestic water supply for 400,000citizens in Nara Prefecture; (c) Water supply for industrial use in Wakayama Prefecture; and (d) Generation of electricity. The following construction works were implemented in the project, which was begun in 1952 and completed in 1984 (see Figure 2): (a) Construction of a diversion dam (Yoshinogawa Bunsui) at Shimobuchi, the midstream of the Kinokawa River, to bring water to the Nara Basin for irrigation and drinking; (b) Construction of irrigation canal networks for delivering water from the KinokawaRiver to agricultural land in the Nara Basin; (c) Reorganization of a number of existing primitive weirs into four new barrages in the downstream area of the Kinokawa River in order to improve the irrigation systems in the Wakayama Plain; (d) Construction of Nishiyoshino Barrage and its irrigation canals for agricultural development of the higher land surrounding the Wakayama Plain; (e) Construction of Osako Dam and Tsuburo Dam for controlling stream flow of the Kinokawa River; (f) Construction of Sarutani Dam at the upstream area of the Totsukawa River as the source for water transfer (Totsukawa Bunsui) from the Totsukawa River to the Kinokawa River, compensating for the diversion of water from the Kinokawa to the Nara Basin; and (g) Hydropower generation at Osako Dam and Sarutani Dam. The details of these facilities are shown in Table 1.