New research shows that increased tidal flooding caused by sea level rise has eroded $76.4 million in relative property values along the Texas coast between 2005 and 2017.

That’s according to a peer-reviewed housing market study by data scientists from First Street Foundation and Columbia University that was expanded to include approximately 3 million coastal properties in Texas.

Coastal homes in Galveston were hit hardest, losing $9.1 million in relative appreciation. Homes in Jamaica Beach saw $8.6 million in unrealized value, followed by Bolivar Peninsula at $8.1 million, Surfside Beach at $5.7 million, and Nassau Bay at $4.1 million. One of the area’s significantly impacted properties, a single-family home on Back Bay Court in Nassau Bay, lost $81,296 in appreciation over the 12 year study period.

Analysis of Texas brings the total loss among 18 East and Gulf Coast states, from Maine to Texas, to $15.9 billion.

Steven A. McAlpine, head of Data Science at First Street Foundation, and Dr. Jeremy R. Porter, a Columbia University professor and First Street Foundation statistical consultant, first established their peer-reviewed methodology with an analysis of the Miami-Dade County real estate market. That study, published in the journal Population Research and Policy Review, showed $465 million was lost from 2005 to 2017 due to tidal flooding driven by sea level rise.

McAlpine and Porter have since created 19 housing market-specific models. By analyzing approximately 13.7 million real estate transactions, and applying the results to 28.6 million properties, the researchers have found a $15.9 billion loss in home value appreciation across 18 states.

McAlpine and Porter’s research quantifies the observed negative impact of increasingly frequent tidal flooding, driven by sea level rise, on the housing market. By taking into account characteristics associated with home value, such as square footage and proximity to amenities, and accounting for economic trends like the 2008 housing recession, the scientists were able to isolate the impact that increased frequent tidal flooding caused by sea level rise has had on home value.

While most of the affected homes did appreciate over the studied period, they did so at a significantly lower rate than comparable homes unaffected by tidal flooding. The research also found that in addition to direct property-lot flooding, nearby road flooding has a major impact on home value.

First Street Foundation is a 501(c)(3) tech nonprofit that quantifies and communicates the impacts of sea level rise and flooding. Its web-based application, Flood iQ, gives coastal residents, homeowners, and prospective homebuyers access to comprehensive flood risk and property value loss information.

Source: First Street Foundation