Planning for Drinking Water Salinization in the U.S. Atlantic and Gulf Coast Regions

Problem, research strategy, and findingsSea-level rise will bring ocean salts inland and salinize the drinking water sources of some coastal communities. How are municipalities, regions, and states preparing for salinization? In this study I evaluated 264 climate plans and seven state water plans from the Atlantic and Gulf coasts of the United States. Of these, 65 climate adaptation plans engaged with salinization in the context of drinking water; 21 made salinity adaptation recommendations, 6 discussed implemented monitoring or modeling, and 11 discussed implemented adaptation strategies. In state water plans, some states showed considerable salinization adaptation activity, but not all linked these actions to climate adaptation. Despite seawater intrusion and salinization being widely recognized, actions were concentrated in fewer states. Maryland, Delaware, Virginia, Florida, and Texas exhibited high degrees of engagement. Louisiana, Mississippi, Alabama, and Georgia showed little evidence of planning for salinization in climate or state water plans. In the absence of federal or state governments leading on managing sea-level rise–driven salinization, evaluating and preparing for the challenge of salinization is likely to become the de facto responsibility of coastal water suppliers and well owners, who may not have the capacity, budget, or jurisdiction to adequately monitor and protect supplies.Takeaway for practiceLeft to individual drinking water suppliers and well owners with varying capacity for adaptation, water supply salinization driven by sea-level rise has the potential to exacerbate existing inequities in drinking water provision. Planners can contribute to adapting coastal drinking water systems by integrating monitoring and modeling into climate adaptation plans, creating partnerships that enable drinking water adaptation actions, and supporting new approaches to water funding and financing.