WASHINGTON—The deterioration of water infrastructure is a widely acknowledged concern. In a new discussion paper posted by Resources for the Future (RFF) that deals with water main breaks in the Washington, DC area, the researchers state that, “… the number of water main breaks, and the corresponding age of the mains, … is alarming.” The authors, however, identify one exception: the costs associated with such breaks on traffic congestion.
In the new paper, “Clustered Into Control: Causal Impacts of Water Infrastructure Failure,” the research team of Jacob LaRiviere from Microsoft and the University of Tennessee, RFF Fellow Casey J. Wichman, and RFF Research Assistant Brandon Cunningham observe 515 DC main breaks between July 1, 2014 and June 30, 2015, focusing on 278 where resultant traffic impacts could be measured along 2182 road segments comprised of small city streets.
They find that water main breaks may have slowed traffic down by as much as 1.9 percent, which is statistically significant but regarded as economically small. Specifically, they calculate $1,350 in congestion costs for an average break. Given that the total population of Washington, DC is roughly 700,000, that works out to about $1 per person annually.
Their data also reveal that of the 278 breaks used in the study, roughly 46 percent occurred in water mains that were over 100 years old. The oldest break was from a main installed before the Civil War, in 1859. The authors note that their sample is similar to the median age reported on DC Water’s website, approximately 79 years old.
The authors warn that their finding may be unique to DC or at least to large urban areas: The report states that using these effects of water main breaks on traffic “for other urban areas is somewhat plausible but they probably do not transfer to less urban areas. Washington, DC is a dense urban area with various alternative transport options.”
The authors further note that their results “do not suggest that infrastructure investment is not important. … We provide evidence that a single indirect economic cost (increased congestion) from distributed water infrastructure failure is small. Other direct and indirect effects could be large.”
Read the entire discussion paper:
Read a new blog post by Wichman and Cunningham highlighting the paper:
The authors are grateful for research support from the US Department of Homeland Security (DHS). Findings expressed here do not represent official positions of DHS.