Economic Analysis and Comparison of Flood Control Projects During the Construction of Diversion Dams: A Case Study

Floods have caused extensive damages in the floodplain every year. An important issue in regions with construction sites of diversion dams is how to protect the project during the construction. In implementating flood management schemes, both non-structural and structural flood control options should be considered. The experiences show that nonstructural options are more effective than structural methods in reducing the damages of flood at a lower cost. In this paper, an algorithm is developed to define the best management scheme for flood protection. An economic analysis is undertaken which combines the analysis of probable floods and expected damages for different flood control options as well as a flood warning system. The case study is Shirgovaz diversion dam which is located 44 kilometers downstream of the Pishin Dam in South Baloochestan in southeast of Iran. The results show that considering a flood warning system for the Pishin Dam is an effective method to reduce the flood damages. This system could provide early warning to the Pishin Dam and the rest of the area. A simple flood warning system has been designed and could utilize the information obtained from upstream synoptic and hydrometric stations. This study shows the significant value of planning flood control schemes for flood damage reduction.