Last summer, violent waves from hurricanes Irma and Maria battered Puerto Rico’s beaches and washed tons of sand out to sea. Then, six months later, a winter storm pummeled the island with 30 foot waves that knocked down trees and flooded roads.

Aurelio Mercado is with the Department of Marine Sciences at the University of Puerto Rico in Mayagüez. He says that one reason the damage was so bad was that years of erosion had made the shoreline especially vulnerable.

Mercado: “The width of the beaches are decreasing.”

And that’s a problem, because …

Mercado: “Beaches serve as a buffer area for wave energy.”

So as beaches lose sand and become narrower, they provide less protection from the waves. That leaves buildings and roads more vulnerable when a storm hits.

Mercado says one of the biggest causes of beach erosion is sea-level rise, which has sped up over the past decade. Since 2010, sea levels around Puerto Rico have been rising about three times faster than they were for the 50 years before.

As the island rebuilds, Mercado says people need to plan for rising seas and decide if or what to build along the changing shoreline.

Mercado: “On the long term, people will have to move inland.”

Reporting credit: Sarah Kennedy/ChavoBart Digital Media.