Heuristic Design of Sewer Networks

Abstract

This paper presents a heuristic approach for the design of sewer networks that can handle the introduction of lift stations and the use of standard diameters. This heuristic provides good and logical (rather than optimal) designs of sewer networks. The necessary and sufficient conditions to determine the position of a lift station are presented in a theorem. Based on this theoretical result, a heuristic design algorithm, using either the Manning or the modified Hazen‐Williams hydraulic equation, is developed. The proposed heuristic design algorithm takes into account all the structural and hydraulic requirements. The approach is validated and illustrated by designing several hypothetical and two real large sewer networks on a microcomputer. The CPU time for designing sewer networks using the proposed heuristic is less than 10% of the time required for the optimization procedure. Such application indicates the effectiveness of the heuristic in rapidly providing “good” sewer network designs that are comparable to the optimal ones.