To identify 30 popular beaches at the greatest risk of disappearing due to erosion, 24/7 Tempo calculated the compound average growth rate of shoreline length for more than 600 “significant public beaches” between the most recent and oldest years for which data was available for each beach, using beach length statistics compiled by the U.S. Environmental Protection Agency. For the average beach, the change in shoreline was calculated for the period from 2008 to 2017. Significant public beaches, defined as the beaches that coastal and Great Lakes states and territories identify as Tier 1, indicate a high-risk, high-use beach. States and territories must identify their Tier 1 beaches as part of their BEACH Act grant application.
Data on population change from 2013 to 2017 for the county each beach is located in came from the U.S. Census Bureau’s American Community Survey.
Average annual precipitation figures are from the Centers for Disease Control and Prevention’s North America Land Data Assimilation System and are averages for the period 1979 to 2011.
