A new study used Twitter posts to measure the frequency of minor and recurring floods — also known as nuisance flooding — along the United States’ East and Gulf Coasts.

The study found that this type of flooding is more common in 22 counties than official data would suggest. These counties include major cities such as New York, Miami and Boston, which combined have a population of more than 13 million people.

“Coastal floods and inundation are projected to produce some of the primary social impacts of climate change, imposing significant costs on communities around the world,” the report said.