Florida’s fears of further beach erosion and coastal flooding
Decades after Congress sought to curb the federal costs of coastal management, several agencies are encouraging communities to apply for aid to protect shores with sand replenishment, bulkheads, breakwaters and rock embankments.
“If you don’t have a federal project, we want to talk to you,” Jacqueline Keiser, chief of coastal and navigation projects at the Jacksonville office of the Army Corps of Engineers, told a recent gathering of local officials and sand and dredging industry representatives.
Her job is to look for suitable projects in her area. Last year alone, the corps spent $150 million to replenish sand on 39 miles of Florida beaches. Keiser expects a lot more work.
“There’s going to be an increasing need to actively manage the shoreline,” she said in an interview. “We either need to nourish the sand or harden the coast – or really retreat from the coast, and I don’t think that’s an option.”
Nowhere to go
Walton County’s coast was a rural landscape of rolling green dunes and sugar-white beaches when Florida lawmakers approved new restrictions on coastal development in 1978.
Coker, a surfer, photographer and owner of an import business, pointed to a boxy new house on a dune where he used to lead his daughter on a path through scrub oak and sea oats to the beach.
“It’s insane,” Coker said. “Still building right on the dunes.”
This 18-mile stretch of Atlantic coast was undeveloped when the highway opened decades ago. Now, more than 400 houses line the shore of what is, like so many heavily developed areas in Florida, a barrier island whose natural function is to protect the mainland from the sea by bearing the brunt of storms and high seas. “For Sale” signs top undeveloped lots on the narrow dune between the highway and the shore.
Storms regularly scoured the coast. Beaches retreat and regenerate. Today, a 20-mile wall of villas and resorts pushes right up to the edge of the last dune before the surf. With nowhere to go, the beach – a stretch of rare fine-grained sand that’s almost pure quartz – has been disappearing as summer storms have worsened.
Their erosive effect has been compounded by a separate phenomenon: The normal seasonal increase in sea levels during summer months has intensified along the eastern Gulf Coast since 1990. Scientists aren’t sure why.
A recent study by researchers at the University of South Florida in St. Petersburg (report) found that this trend has doubled the impact of long-term sea level rise on surges during summer storms.
During that period, hurricanes and tropical storms have resulted in 10 federal disaster declarations in Walton County. The worst, Hurricane Ivan, flung 15-foot surges against the Florida coast in 2004, causing an estimated $8 billion in damage and killing more than a dozen people.
When Dennis crashed to shore the next summer, there was too little beach left to stop the waves from grinding away the dunes under the big villas. Rooms and pool decks hung in midair. The storm caused more than $1 billion in destruction and two deaths in Florida. Katrina passed to the south a month later, taking a little more of the beach.
A state report on the aftermath said the storms left homes on a stretch known as Blue Mountain Beach “critically imperiled” by severe erosion. A photograph of the damage shows two battered houses clinging to a 20-foot-high ledge where the storm had sheared off a large dune.
2.2 million new houses
Between 1990 – when warnings were already being sounded on rising sea levels – and 2010, the United States added about 2.2 million new housing units to Census areas, with boundaries near the shore. The analysis did not include Louisiana, Hawaii or Alaska.
That 27% increase is in line with growth nationwide. But it occurred in block groups near some of the country’s most imperiled shores. Florida’s 1,350 miles (2,173 km) of shoreline – the longest in the contiguous 48 states – accounted for a third of new coastal housing built. The number of people living near the Florida seashore has jumped by about 1.1 million since 1990, to 4.8 million