Estimating seawater intrusion impacts on coastal intakes as a result of climate change

Climate change and sea-level rise threaten the intakes of coastal utilities with seawater intrusion that will be of greater frequency, magnitude, and duration. This article describes a method that utilities can use to assess the risk to their intakes and details its application in two estuaries that supply freshwater to municipalities in Georgia and South Carolina. The method uses long-term weather and hydrologic data to develop an empirical model that represents the intrusion process near an intake. Data available from past droughts and storms provided sufficient variability to model the expected ranges of future weather and hydrologic conditions. The model's inputs can be varied using permutations of historical conditions or climate change forecasts to estimate potential impacts at an intake. The data and models are deployed in a spreadsheet-based decision support system that can be easily used by utility personnel.