Application of metaheuristic algorithms in optimal design of sewer collection systems

Sewer collection systems are essential but the most expensive infrastructures in every modern city. Hence, many researchers and engineers have continuously investigated the optimal design of these systems. The decision variables of these networks include the layout, pipe diameters, and pipe slopes, each of which has its individual complexities. As an optimization problem, the main objective function is to minimize the system’s cost, which is highly dependent on the pipes’ diameters and cover depth. However, hydraulic equations and design constraints, such as minimum and maximum allowable values for velocity, relative flow depth, Froude number, slope, and cover, could increase the complexity of the optimization problem. Metaheuristic algorithms have proven to be some of the best tools for solving the optimal design problem of sewer collection systems. Yet, the available metaheuristic algorithms must be modified to fit each system perfectly and require many constraints to yield acceptable results. This chapter reviews the use of metaheuristic algorithms for the optimal design of sewer collection systems.