Exponential growth of private coastal infrastructure influenced by geography and race in South Carolina, USA

Homeowners in coastal environments often augment their access to estuarine
ecosystems by building private docks on their personal property. Despite
the commonality of docks, particularly in the Southeastern United States,
few works have investigated their historical development, their
distribution across the landscape, or the environmental justice dimensions
of this distribution. In this study, we used historic aerial photography
to track the abundance and size of docks across six South Carolina
counties from the 1950s to 2016. Across our roughly 60-year study period,
dock abundance grew by two orders of magnitude, the mean length of newly
constructed docks doubled, and the cumulative length of docks ballooned
from 34 to 560 km. Additionally, we drew on census data interpolated into
consistent 2010 tract boundaries to analyze the racial and economic
distribution of docks in 1994, 1999, 2011, and 2016. Racial composition,
measured as the percentage of a tract’s population that was White,
positively correlated with dock abundance in each year. Median household
income and dock abundance were only correlated in 2011. Taken together,
these metrics indicate the growing desire for direct estuary access,
however, that access does not appear to be equally spread across racial
groups. Because docks enhance estuarine access and demarcate private
property, our study provides longitudinal insights into environmental
justice concerns related to disparate private property ownership. We found
a persistent correlation between the racial characteristics of an area and
dock abundance, strongly indicating that White South Carolinians have had
disproportionately greater private water access for the past two decades.