Urban Systems Ltd. (USL), established in 1975, specializes in civil engineering, community planning, and landscape architecture. In October 2009, USL completed a sanitary sewer analysis for the City of Surrey’s Newton Town Centre (NTC) area, which consists of western and eastern sanitary catchments. The Western Catchment drained south into the King George Highway sewer main, and the Eastern Catchment drained east towards the Newton Town Centre, seen in Figure 1. It was known to the City of Surrey that there were capacity issues in the King George Highway sewer main. To alleviate this problem, the City of Surrey proposed to reroute flows from the Western Catchment towards the Eastern Catchment. The City of Surrey approached USL to conduct capacity analyses on the King George Highway sewer main under the existing as well as with the proposed diversion to determine if redirecting flow would solve the known capacity problems.
USL asked Alexa Baker, a civil engineering co-op student from the University of Waterloo, to investigate the capacity of the King George Highway sewer main under original and redirected flow conditions. Based on her results, USL intended to provide an appropriate recommendation to the City of Surrey.
This case study is intended to demonstrate urban water systems design concepts in the context of a real-life engineering project. After the completion of the case study, the student will be able to: use urban water system design techniques to calculate the dry weather flow peak factor, dry weather flow, infiltration flow, and peak wet weather flow for a given segment of sewer, determine the capacity of a sewer and decide if that capacity has been compromised, generate a design for rerouting flow within a sewer system, and simulate the effects rerouting flow will have on a particular sewer’s capacity.