Optimal design of multilevel branching sewer systems

The problem of determining a minimum cost design of a multilevel branching storm sewer system is formulated by using a serial approach to describing the system and proceeding through the computational algorithm. Discrete differential dynamic programing (DDDP) is the basic search technique employed. Results for an example using the serial approach are compared to those achieved by using an earlier nonserial DDDP approach. The several advantages of the serial approach become increasingly important as the size and level of branching of the system increase. These advantages are outlined and discussed, the superiority of the serial over the nonserial approach being demonstrated.