CORRECTION: This story incorrectly reported where Miami gets the sand to rebuild its beaches. As it draws down its own reserves, Miami hopes to import sand from the Bahamas but the bid process for buying foreign sand won't begin for more than a year.

TEXT OF STORY

Scott Jagow: Sunday is the start of the hurricane season. Every year about this time, states along the coast start eyeing the Weather Channel. But even when there's not a direct hit, beach erosion can be tremendous. And after the storms, states spend millions of dollars shoring up those beaches. Dan Grech reports from Miami on why coastal cities go to such lengths.

Dan Grech: The beach at 29th and Collins is wide and peaceful, perfect for a family picnic. Six months ago, it had all but disappeared.

Carlos Espinosa: We had some erosional problems in this area here. It got down to close to where the dunes are.

That's Carlos Espinosa. He directs the Miami-Dade County agency that oversees beach renourishment.

Espinosa: And then we started a project that essentially relocated sand from the South Beach area over to this area here.

It took three months and $2 million to pipe in that sand. As hurricane season approaches, that sand will be a buffer between an angry ocean and about $1 billion in real estate just over the dunes.

More than 485 miles, or nearly 60 percent of Florida's beaches, are eroding. That threatens the state's $65 billion a year tourism industry.

Rolando Aedo is with the Greater Miami Convention and Visitor's Bureau. He says half of all visitors to Miami go to the beach.

Rolando Aedo: It's not just what it physically does, because ultimately it's silicon or it's sand. It's the ambience that it creates beyond the sand.

Tourist Heather Marie visited from Detroit:

Heather Marie: Honestly, I came here for a music festival, so the beaches have been a ginormous bonus. I stayed three days longer than I was supposed to, to come down and see the beaches.

That's three more nights in a hotel, lots of meals out, hundreds of extra dollars.

Stephen Leatherman, aka Dr. Beach, is with Florida International University. He says beach renourishment is a necessity, like fixing potholes in the road. It's also an exercise in futility.

Stephen Leatherman: When you put the sand out there, and people don't like to use this term, it is a sacrificial beach. Sooner or later that sand is going to be moved offshore and it will not come back.

After years of drawing down its own reserves, Miami now imports sand from the Bahamas -- at nearly twice the cost.

From Miami Beach, I'm Dan Grech for Marketplace.