Cost-Effective Resilience - The Grey, the Green and the Ugly - WEAO Influents Article Examines Infrastructure Technology 'Bang for the Buck'

New article in the Water Environment Association of Ontario's Influents Magazine explores the cost-effectiveness on infrastructure technologies, including conventional 'grey' and emerging 'green' approaches for achieving extreme weather resiliency by reducing flood losses in existing communities.

See: article link.

The article provides a brief history of Low Impact Development Best Management Practices (LID BMPs) in Ontario and the assessment of cost in infrastructure projects. New requirements for benefit-cost analysis for flood mitigation projects, such as through Infrastructure Canada's Disaster Mitigation Adaptation Fund, are also discussed. A previous post identifies some of these significant projects (

Results of a case study comparing grey, green and blended grey and green technologies are summarized. Details of this analysis are included in a previous post ( and were presented at the 2019 WEAO Annual Conference. The case study confirms the cost-effectiveness of conventional grey technologies, consisting largely of storm and sanitary sewer upgrades, and cast doubt on the cost-effectiveness of emerging green infrastructure or LID BMPs, considering full lifecycle costs. Limitations in the assessment of technical effectiveness green infrastructure in insurance industry research, as summarized in a previous post ( and in my NWWC2018 presentation Storm Warts, the Floods Awaken ( are briefly touched upon.

The move toward more rigorous assessments of project cost effectiveness is keeping with the Made-in-Ontario Environment Plan that intends to avoid the frustration of "policies and programs that don't deliver results". Such assessments are also consistent with Ontario's Long Term Infrastructure Plan 2017 that suggests that infrastructure proposals should be "supported by robust and consistent business cases".