Affordable housing at risk of coastal flooding

Affordable housing serves as a lifeline for millions of individuals and families in the United States. Stable, secure housing is known to support better health outcomes, economic mobility, and employability. But there is a severe shortage of homes that are affordable or available to low-income renters. Scientists at Climate Central analyzed the risk coastal flooding poses to affordable housing—both subsidized and naturally occurring—as sea levels rise. They found that more than 7,600 apartments, townhomes, and houses nationwide are currently exposed to at least one “coastal flood risk event” in a typical year, and more than 24,500 units may be so threatened by 2050.  

The combination of physical vulnerability of affordable housing, socioeconomic vulnerability, and more frequent flooding due to sea-level rise presents a triple threat within the next 30 years to residents and owners of the country’s already scarce affordable housing.

Key concept

• A new analysis conducted by scientists at Climate Central and published in Environmental Research Letters highlights the equity implications of sea-level rise in the first nationwide assessment of risk to the country’s affordable housing supply.
• The number of affordable housing units at risk from coastal flooding and sea-level rise is expected to more than triple over the next three decades.
• By 2050, virtually every coastal state is expected to have at least some affordable housing exposed to more than one “coastal flood risk event” per year, on average—up from about half of coastal states in the year 2000.  (A flood risk event occurs when local coastal water levels reach higher than a building’s ground elevation, and any known barriers do not provide full protection.)  
• New Jersey, New York, and Massachusetts have the largest share of affordable housing stock and a number of units at risk; projections for New York City, Atlantic City, and Boston show that each city could have thousands of units exposed to chronic coastal flooding by 2050.
• Climate Central has introduced a new interactive online mapping tool showing the vulnerability of affordable housing to coastal flood risk now and in the future.