Integrating social data and engineering solutions for developing resilient water infrastructure against coastal climate change.

This study combines responses from a social survey with compound flood modeling in a marginalized coastal community to assess implementation of green infrastructure, such as rain barrels and rain gardens, in a city scale. This research focuses on the City of Imperial Beach, CA, which is an underserved coastal community located near the border with Mexico. A principal objective of the present research was analyzing social survey responses and the public's perceptions to estimate the extent to which decentralized water infrastructure might be accepted by and feasible for the target underserved coastal community. The feasibility of the proposed solution is strengthened through a collaboration with the City of Imperial Beach, which has led to the results of this study being presented in various public sources and forums. The social survey revealed that more than 4/5 of respondents are interested in receiving a rain barrel for free, and the needed financial incentives for rain barrel and rain garden installation can be the whole cost of the practice. Results of the social survey provide promising prospects for the community's adoption of decentralized water infrastructure, but public awareness and engagement still need to be improved through appropriate outreach activities, particularly in areas at risk of future flooding and sewer overflows. The effectiveness of our proposed solution is assessed through hydrologic-hydraulic model outputs, deploying a fine resolution 2-dimensional overland flow model, present that for a stormdrain system with typical defects (e.g. 0.25% porosity), working under current sea levels (i.e., sea level rise = 0 m), and a typical storm (e.g., 1-year rainfall), the flood volume may decrease 56-99% after implementing a rain barrel system and adding a rain garden system.