A segment-based optimization model for water pipeline replacement

Abstract

By looking at valve-enclosed segments of a pipe rather than at each pipe as an independent unit, this research examined the extent and degree of water shortage resulting from pipeline damage. Two computer programs were developed to identify all segments of a pipe network that can be isolated with valve closure and to determine which segments are critical, i.e., pipe failures within them will result in a complete shutdown of water supply in any connected downstream segments. A third program was written using the EPANET 2 toolkit to estimate water shortages that would result because of pipe failures within noncritical segments. Results from these programs were used within a segment-based pipeline replacement optimization model to determine which pipes within a system should be replaced first in order to achieve the highest improvement in system reliability. Two case studies were implemented to demonstrate the effectiveness of the strategies derived from the proposed model for improving water supply reliability.