Improvement During the Meiji Period (1867-1911)
During the Meiji period, the government made an improvement plan, aiming at full diversion of the three Kiso rivers. Large-scale river improvement work, involving expenditure of about 12% of the contemporary national budget, was carried out between 1887 and 1912.The work brought the downstream region of the three rivers of Kiso substantially into its present form.
Johannis de Rijke, a Dutch engineer, who was involved in planning the Meiji conservation work and who laid the foundations for the diversion of the three Kiso rivers
Map of the Meiji improvement plan