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

Abstract

Problem, research strategy, and findings

Sea-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 practice

Left 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.

Keywords:

• climate adaptation
• drinking water
• plan review
• salinization
• water quality

Acknowledgments

Thanks to the many people who contributed to this study. I am most indebted to my team of research assistants. Kellie King and Lily Cheng expertly created a database of drinking water intakes and associated it with sea-level rise scenarios. Kellie King and Saiya Sheth downloaded and searched for keywords in climate adaptation plans. Henry Feinstein provided summary statistics on water suppliers and well owners. In addition, thanks to colleagues Tom Daniels, Erick Guerra, and John Landis for insightful comments on an early draft and the anonymous reviewers for their careful and helpful critical feedback.

Research Support

This work was supported by PennPraxis and the Wharton Risk Management and Decision Processes Center.

Data Availability Statement

Data on the 3-ft sea-level rise scenario are publicly available through NOAA’s sea-level rise viewer at https://coast.noaa.gov/slr/#. Data on CWS systems are publicly available from SDWIS at https://www.epa.gov/ground-water-and-drinking-water/safe-drinking-water-information-system-sdwis-federal-reporting. Due to the secure nature of drinking water intake locations, data on drinking water intake and well locations are not available. All climate adaptation planning documents are publicly available through GCC (https://www.adaptationclearinghouse.org/), CAKE (http://www.cakex.org/), and the Office of the Federal Chief Sustainability Officer (https://www.sustainability.gov/adaptation). State water planning documents are publicly available through the relevant state agency (Florida: https://floridadep.gov/owper/water-policy/content/florida-water-plan; Georgia: https://waterplanning.georgia.gov/state-water-plan; New Jersey: https://www.nj.gov/dep/watersupply/pdf/wsp.pdf; Pennsylvania: https://www.dep.pa.gov/Business/Water/PlanningConservation/StateWaterPlan/Pages/default.aspx; South Carolina: https://scdhec.gov/south-carolina-state-water-plan; Texas: https://www.twdb.texas.gov/waterplanning/swp/index.asp; Virginia: https://www.deq.virginia.gov/our-programs/water/water-quantity/water-supply-planning/virginia-water-resources-plan).

Supplemental Material

Supplemental data for this article is available online at https://doi.org/10.1080/01944363.2024.2305882.

Additional information

Notes on contributors

Allison Lassiter

ALLISON LASSITER ([email protected]) is an assistant professor of city and regional planning at the University of Pennsylvania Weitzman School of Design.