Planning is currently underway for the final phase of the Treasure Island and St. Pete Beach nourishment project, conducted by Pinellas County and the U.S. Army Corps of Engineers, with the next improvement project not contemplated for another five years.
John E. Bishop, coastal management coordinator for Pinellas County Environmental Management, explained to Tampa Bay Newspapers that Treasure Island, including Sunshine and Sunset beaches, are scheduled to be nourished in the summer of 2023, along with Upham Beach and Pass-a-Grille in St. Pete Beach.
“The order in which they will be renourished won’t be known until a contractor is selected,” he advised. “The current plan is to control erosion though continued beach nourishment.”
The project is expected to cost roughly $20 million to $25 million. The good news for local cities is neither Treasure Island nor St. Pete Beach will have to pay a percentage of the beach renourishment cost.
The Army Corps will fund 64.25% of the project. Pinellas County pays the remaining 35.75% using tourist development tax funds. Coastal management officials noted one-half of 1% of the tourist development tax is set aside annually for beach projects, generating nearly $4 million per year.
“This project is expected to renourish the beach similar to what was done in the past, which is about 155 feet of added beach width,” Bishop said. The Corps “is in the process of collecting beach profiles to assess the volume needed to fill the beach.”
The project is expected to take several months to complete, during which approximately 1,000-foot sections of beach where renourishment construction is taking place will be closed off.
“The closed length of beach may vary depending on the available space at the time of construction. The beach not within the active work zone should remain open,” he said.
Dune renourishment will not take place during this project. Dune renourishment will have to wait until the next beach project, if federal funding is allocated, around 2028, Bishop said.
The project includes another 50-year authorization for the Treasure Island and Long Key, which includes Upham Beach and Pass-a-Grille. If passed and funded, the next project would be scheduled for about 2028, and will include a beach as well as a dune feature that would be constructed to an elevation of 10 feet.
“Prior to beach nourishment, many beach municipalities had thin, non-protective beaches or no beach at all,” Bishop said. Over successive nourishments, the beaches from Clearwater to St. Pete Beach have been built up with 10 million cubic yards of sand, according to a County Coastal Management study, which concluded, “The preservation of the beaches is essential in maintaining the quality of life that residents value and which attracts visitors throughout the year.”
Beach renourishment protects coastal communities during storms by providing a buffer to coastal storm surge and flood waters. It also serves to have an environmental impact by providing nesting areas for sea turtles and shorebirds, and a foraging habitat for shorebirds, officials noted.
According to the coastal management element of the county Comprehensive Plan, researchers found south of Indian Rocks Beach the transport of tidal sand is generally from north to south, while north of Indian Rocks Beach the sand movement is from south to north. Estimates of the amount of sand transported along the Pinellas County coast range from 15,000 to 100,000 cubic yards of sand per year.
The report states, “It is important to understand this sand transport mechanism, because if this sand supply is interrupted for any reason (such as inlets, groins, or jetties), then the downdrift beach may be starved of sand. There is also sand movement offshore and onshore, perpendicular to the shore. Gentle waves tend to push sand up on the beach. Stronger waves, more typical in the winter and when a hurricane passes nearby, carry sand offshore from the beach.”
The report states that beach renourishment is particularly important to preserve the barrier island beaches, because “the sand contained in the County’s barrier islands is a closed system; there is little contribution of sand from outside the system (such as rivers or lagoons). With no new sand entering the system, the County’s barrier islands are dependent upon the existing sand supply along its coast.”
From 1873 to the latter 1970s, erosion on Honeymoon Island, the beaches on the central and southern portions of Clearwater Beach Island, and on the beaches on Sand Key, Treasure Island, Long Key and Mullet Key has been “severe,” the study noted.
When it comes to Treasure Island beach, the Coastal Management report explains “between 1873 and 1950, the shoreline receded, with the exception of the island’s northern end. Since then, the shoreline has generally advanced over the entire island. This advance is primarily due to a federal beach erosion control project, dredging at John’s Pass, and two jetties.”
In St. Pete Beach, part of Long Key, the study noted, “Since 1950 the shoreline has advanced. The advance primarily reflects the effects of the terminal groin at the south end of the island and the fill placed on the south end of the island by local interests.”
