Integrating social, economic, and environmental risk into flood management of aging dam infrastructure by combining cost-benefit and multi-criteria decision analyses

Abstract

Abstract. Management planning for aging dam infrastructure is typically conducted through the lens of a traditional cost-benefit analysis, in which flood characteristics are related to implementation costs while lacking endogenous consideration of environmental risks (i.e., pollutant dispersion, habitat disruption) and social impacts (i.e., vulnerability, community buy-in, hazard resiliency). To address this gap, we integrate cost-benefit ratios into a spatial multi-criterion decision analysis framework that amalgamates a suite of social and environmental criteria with stakeholder-defined weights and inundation outputs from standard flood control modelling. We use this framework to assess the costs and trade-offs for eight (8) alternative mitigation strategies associated with the Addicks and Barker Reservoir System in Houston, Texas, USA under extreme rainfall conditions. This case study illustrates how the total effectiveness of flood management scenarios may shift when flood modelling outputs are combined with spatially distributed environmental and social risks. We merge quantitative and qualitative data for high-risk decision-making, thereby fostering stakeholder collaboration amongst conflicting goals.