State of watermain infrastructure: a Canadian case study using historic pipe break datasets

Abstract

Over the last two decades, a variety of reports have suggested that watermains in Canada are deteriorating, and break rates are increasing. However, these reports are often limited as the years of break records being utilized are brief; this paper revisits those assessments using over 45 years of break records and shows that three of the five utilities investigated are experiencing significant decreases in break rates over the past 10 years while the two other utilities are maintaining consistent break rates. These results indicate that these utilities are effectively managing their watermain infrastructure, and suggest watermain infrastructure throughout Canada may be performing better than suggested by cross-sectional survey results. Analyses indicate that on average, 22% of the watermains analyzed have exceeded the 0.125 breaks per km per year break rate threshold and may be considered for pipe replacement or rehabilitation. In particular, 50% of cast iron pipes installed post-WWII have exceeded a break rate threshold of 0.125 brks/km/year, suggesting large pipe replacement or rehabilitation of this pipe cohort is required.