In recent years, the topography of affected areas has undergone dramatic changes due to the increasing frequency of large-scale floods and landslides associated with heavy rainfall. Large-scale floods not only induce landslides and mudslides but also cause river breaches and widespread flooding, leading to significant landform modifications. In this context, accurate topographical information is essential for effective recovery planning and the prevention of disasters. Therefore, the automation and labor-saving measures for surveying operations have been advanced by the deployment of robots and drones. In addition, amphibious robots can flexibly conduct surveying and environmental monitoring in diverse topographical conditions. In this paper, we propose a two-step optimization method for wide-area monitoring using amphibious robot. We optimize the waypoint locations to maximize the monitoring area. Then, we optimize the travel route to minimize the electric energy consumption. We carried out simulations to evaluate the proposed method. The simulation results show that the proposed method increases the monitoring area and minimizes the robot’s electric energy consumption.