Abstract
Tsugaru Dam is a gravity dam under construction in the direct downstream of the existing Meya Dam. The functions of the Meya dam are required to be maintained during the construction of the Tsugaru dam. The design flows for the temporary diversion facilities were defined as following: 1) A flow not to affect the construction of the Tsugaru dam; 2) A flow not to endanger the safety of the Meya dam. Multiple-stage diversion plan was adopted due to its economical efficiency and the gate operation of Meya dam is possible with it. In addition, facilities have been designed based on hydraulic model experiments reproducing the discharged water from the Meya Dam.
