Healthy beaches offer more than scenery

Healthy beaches are not only important to our quality of life. They also protect people and property along the coasts from hurricanes and coastal storms.

Barrier islands, such as Longboat Key, change shape and move constantly. As the name implies, barrier islands are “barriers” to waves and protect the mainland.

Some people now say: “You should never have built on a barrier island because of the high probability the island will shift and move. Your structures will not withstand this dynamic environment.”

Barrier islands, however, attract people who want to live on them.

Although shoreline erosion was observed in the 1950s on Longboat Key (and Lido Key and Anna Maria), building occurred at a rapid pace. Single-family homes and multifamily condominiums were built close to the shoreline, especially in the 1970s. Threatened with receding shorelines, many private owners constructed seawalls, revetments and other types of shoreline armoring to protect their beachfront investments. It was a losing battle; the beach kept eroding, and those seawalls ended up right against deep water. By 1980, 40% of the Key’s shoreline had been armored and/or covered with other hard coastal structures called groins.

In the mid-1950s, 3,000 feet of groins were installed along Whitney Beach; those groins were damaged by storms and replaced with 3,500 feet of seawall in 1957, which storms, in turn, destroyed in the early 1960s but rebuilt again within a decade all the way south to Gulfside Road. Similar examples include a groin field of more than a mile from Bayport to Longboat Key Town Hall.

Private citizens whose properties were threatened by dynamic natural forces funded the vast majority of these structures. Many were installed without the benefit of competent coastal engineering judgment or consideration of potential adverse impacts.

By the mid-1980s, the town instituted a coastal permitting program that included prohibition of new seawalls and expanded setback line requirements for structures, such as houses, swimming pools, etc., along the beachfront.

Concurrently, the town embarked on its first shore protection project in 1993, placing 3.3 million cubic yards of sand along the beachfront. As part of the original work, the town removed existing groins and seawalls. A few seawalls were left in place where older homes and buildings had been built close to the shoreline.

Stricter beachfront development regulations and a regular, engineered beach management program soon provided a relatively stable shoreline without the need for excessive hard erosion control structures. Still, certain small sections of the shoreline — the north end near Greer (Beer Can) Island, for example — have higher erosion rates than other beaches.

These “hot spots” have such high erosion rates that sand placed on them quickly moves away. For example, in 2011, the town placed 139,000 cubic yards of sand near and around the north-end public beach access at a cost of $4 million. A year later, while other nonerosive sections of the beach (“cold spots”) were stable, this particular hot spot section receded approximately 130 feet from the original 180 feet at the public beach access. Today, no dry beach remains in the area.

All of this happened without any significant storm events. To continue placing sand on this hot spot, without erosion control structures to slow the rapid sand movement, is not a financially sustainable approach.

The town wants to implement the least intrusive, least costly alternative that will meet our objectives and protect homes, facilities and infrastructure.

Barrier islands are important to the entire community. The town contributes millions of dollars each year to Manatee and Sarasota counties. The counties benefit because the islands are developed and well maintained.

In addition to recreational activities beaches provide, the benefits of wide, sandy beaches extend to the area’s imperiled and threatened wildlife.

In early 2014, in collaboration with Manatee County, the town submitted a joint application to state and federal regulatory agencies to dredge Longboat Pass at the north end. The sand extracted from Longboat Pass will be placed along the Key’s severely eroded northern beaches.

For the south end, the town and city of Sarasota submitted a joint permit application to dredge New Pass. The town will receive all sand extracted from the first project, with the city receiving sand from New Pass the next time it is dredged.

In November, construction of two permeable adjustable groins (PAGs) will begin near North Shore Road. These groins will help reduce — but not completely stop — the erosive waves and currents that wash away precious sand from our northern beaches. This $2 million project should be completed just before the 2015 hurricane season.

The commission will hear a presentation from town staff and its coastal engineer at its 1 p.m. Oct. 20 workshop, at Town Hall. The public is invited to attend.

Juan Florensa is director of Longboat Key’s Public Works Department.