In 2015, Barr conducted a storm sewer system vulnerability analysis for the City of Minnetonka to assess failure risk and identify higher-risk pipes and culverts in the city’s aging storm sewer system. Risk is defined in many ways but can generally be described as the combination of the likelihood of something occurring and the magnitude of impacts. This risk definition provided a framework for an analysis to help identify higher-risk stormwater infrastructure and prioritize monitoring, inspection, and maintenance improvements to mitigate or adapt to risk and facilitate resiliency.
Barr’s assessment included a two-step GIS-based analysis. First, we identified pipe segments with a higher likelihood of failure due to pipe characteristics (e.g., age and material) and other site-specific factors such as soil conditions (e.g., corrosion susceptibility) and topography (e.g., steep slopes). Then, we assessed the consequences of pipe failure, including the potential for roadway inundation and washout, disruption of emergency routes, flooding of critical buildings and infrastructure, and slope failures. A scoring system was developed to identify higher-risk storm pipes based on likelihood of failure, failure consequences, and combined risk. As part of asset management, the city plans to develop a targeted inspection and replacement program based on the results of this analysis.
Vice President Senior Water Resources Engineer
Vice President Senior Water Resources Scientist
Water Resources Engineer