Update as of 9:19 a.m. May 2: First Street Foundation clarified its study to Community Impact Newspaper. Comments from First Street have been added to the original story below.

A recent study shows tidal flooding caused by sea level rise has cost some Bay Area communities, including Nassau Bay, millions in home value appreciation.

According to research from Columbia University and First Street Foundation, which includes scientists who study and quantify flood risk nationwide, rising sea levels have cost 3 million coastal properties in Texas about $76.4 million in relative property values between 2005 and 2017.

Galveston homes were most affected, losing $9.1 million in relative appreciation. Nassau Bay homes lost $4.1 million, with one Nassau Bay home at Back Bay Court losing $81,296 in appreciation over the 12-year study, according to a First Street Foundation press release.

Most of the affected homes did appreciate over the studied period, but they did so at a significantly lower rate than comparable homes not affected by tidal flooding, the release reads.

“From Maine to Texas, we have seen the same phenomenon,” Jeremy Porter, Columbia University professor and First Street Foundation statistical consultant, said in the release. “Increased tidal flooding has led to a loss in home value appreciation. We expect this trend to not only continue in the coming years but to accelerate along with the accelerating rate of sea level rise.”

In an email to First Street, City Manager Jason Reynolds asked for clarification on the study, saying his perception is its data were “misguided or skewed.”

“Nassau Bay has suffered through many storms and has been impacted by storm surge and extraordinary rain events, but homes have not flooded due to high tides or large rain events,” Reynolds wrote. “I am not aware of a single instance that the city has flooded due to high tides, nor a single incident of a home flooding due to high tides.”

According to city data, the highest tide Nassau Bay has seen since 2012 was 5.04 feet, which is still almost a foot beneath the 6-foot banks that surround the city. The Army Corps of Engineers predicts the sea level at Nassau Bay will rise 7.56 inches over the next 15 years, but that still would not put the highest tide about Nassau Bay’s banks, Reynolds wrote.

Southeast Texas has suffered heavy rains over the last decade, but none of them outside hurricanes Ike and Harvey have flooded Nassau Bay homes, Reynolds wrote.

First Street Foundation clarified its study to Community Impact Newspaper.

Some Nassau Bay roads, such as Upper Bay Road, are at a low elevation and close to bodies of water such as Clear Creek. Gravity-based drainage systems lead to those bodies, but when there is high tide, made worse by sea level rise, the drainage systems can be blocked, said Steven McAlpine, the foundation’s head of data science.

If it rains heavily during a high-tide event, flooding occurs. Road flooding can have a greater negative effect than property flooding because it affects commutes, can be easily seen and sometimes leads to negative reputations for flood-prone neighborhoods, McAlpine said.

Road flooding is the leading cause of home value loss in many areas. In Nassau Bay, it is the only cause, McAlpine said.