Cost-Benefit Analysis of Mangrove Restoration for Coastal Protection and an Earthen Dike Alternative in Mozambique

With support from USAID/Mozambique and the USAID Global Climate Change Office, CEADIR prepared cost-benefit analyses (CBAs) of mangrove restoration for coastal protection and an earthen dike alternative in Quelimane, Mozambique. The purpose of the analysis was to inform decisions of USAID/Mozambique-funded Coastal City Adaptation Project (CCAP) and the Government of Quelimane to protect the most climate-vulnerable residents in the peri-urban areas of this coastal city from climate change impacts, including frequent flooding and high storm surges. 

Using CCAP data, primary field research, and local stakeholder consultations, CEADIR estimated both the financial and economic impacts of mangrove restoration and an earthen dike alternative—two strategies to combat flooding and coastal erosion that arise from climate change. The report identified that the earthen dike was not financially or economically viable due to the alternative’s net negative present values because of high capital costs to build and maintain the earthen dike combined with the low benefits from storm protection. The low benefits from storm protection resulted from the low average value of the informal sector housing in the study area communities, which are typically made of mud and mangrove poles. Mangrove restoration had positive financial and economic net present values that exceeded the earthen dike alternative primarily because it provided substantial additional benefits that the earthen dike did not.  

CEADIR found the primary benefits of mangrove restoration are carbon sequestration and fish production. Storm protection benefits from both alternatives would have been higher if it included values for the reduction in human health and safety impacts. CEADIR conducted this cost-benefit analysis in a Microsoft Excel workbook, which allows users to examine additional scenarios.