Triple Bottom Line Cost Benefit Analysis of Mirabeau Water Garden Manuscript

Triple Bottom Line Cost Benefit Analysis (TBL-CBA) was conducted for the proposed Mirabeau Water Garden, an urban stormwater park, in the City of New Orleans in Louisiana. The project is among a suite of green infrastructure (GI) projects in New Orleans seeking to reduce flooding and subsidence, while providing environmental, social, health, educational, and economic co-benefits to communities. The TBL-CBA approach broadens traditional financial analysis to incorporate, and value social and environmental factors within an expanded CBA framework. The TBL-CBA for the proposed Mirabeau Water Garden assessed financial (e.g. capital expenditures, operations and maintenance costs), environmental (e.g. air pollution, water quality), and social (e.g. avoided flood damage, property value uplift/aesthetic, and recreational value) impacts. The proposed Mirabeau Water Garden is expected to generate a triple bottom line net present value (TBL-NPV) over its life in the order of 79 million. When uncertainty is incorporated through Monte Carlo, both lower and upper bound TBL-NPV estimates continue to be positive.