This book is intended to provide guidelines to engineer, town planner, economic analyst, researcher and authority on how to evaluate the efficiency of flood control schemes using cost-benefit analysis. As flood control project is very expensive, it is crucial to decide on which projects should be implemented in order to gain the most economical solution. The decision making process is based on the projects that provide highest benefit-cost ratio and maximum net benefit. By using this book, one will understand the basics of flood: hydrology, mitigation and implication. The method to assess the damages and the cost-benefit analysis technique are also described in details. Finally, a case study is shown as an example, in order to ensure that the readers will fully understand the necessary steps to calculate the cost-benefit parameters. Case study presented in this book is limited to the locality of the author. However, the readers can always perform another analysis, based on their local condition. By using combination of basic knowledge and case study in this book, the readers can develop their own tools to determine the cost-benefit parameters.