Captiva conducts second year beach monitoring project
To preserve the shoreline, every eight to 10 years, Captiva renourishes the stretch of sand of the entire island to the north end of Sanibel, near Blind Pass.
After the renourishment project is completed, the Captiva Erosion Prevention District conducts a physical monitoring survey annually for three years. After that, they are done bi-annually until the next beach renourishment event or the expiration of the project design life. The most recent beach monitoring project began on June 20 and lasted the entire week.
“People on the island are very much in favor of doing the projects. They see the success of the projects. As one said to me, it’s expected and accepted. We try to keep people very well informed with what we’re doing,” said Kathy Rooker, administrator of the Captiva Erosion Prevention District. “We’re very fortunate that the people of Captiva realize the value of what we’re doing.”
CB&I Coastal Planning & Engineering is in charge of conducting the survey. They will perform topographic and bathymetric profile surveys of the beach. They will look for patterns, trends and changes between annual surveys and cumulatively since project construction that was completed on Dec. 26, 2013.
“We look at where do we need more sand, where do we need less sand. It helps us design our next project,” Rooker said.
Each year, the beach renourishment project is slightly different, depending on what the needs are. In 2013, they spent $20 million on the project, which took a little over two months to complete. In 2015, after conducting an annual physical monitoring project, they found that 84 percent of the volume of the sand remained intact.
To help speed up the process, the Captiva Erosion Prevention District obtained a permit from the State of Florida in December of last year, to take care of troublesome hotspots that need sand brought in immediately. The permit is good for 15 years.
“If there’s a real significant issue, the permit lets us deal with that issue at that time,” she said.
Since 1988, 2.8 million cubic yards of sand remained, according to a survey that was done last year. The two main things they look for, according to Rooker, are the volume and width of the sand.
“The monitoring really helps us get a better project for the next time that we do one and it tells us when we need to do another project. It’s a clock. It lets us know how much sand we’re losing and how fast,” she explained.
When doing the survey, engineers look for copper monuments that are buried in the sand from the Florida DEP. Each monument has a number that corresponds as to where they are on the beach. The engineers also take adjacent beaches into consideration to make sure the project isn’t causing any harm.
“Captiva goes from monument 83 to 109. These are placed strategically on the beach. The surveys the engineers take are at every single one of those monuments. So, the numbers they come up with are how much volume and width are left,” Rooker said.
After they’re done, they graph the numbers and do an analysis. The engineers have 90 days to present the report to the Florida DEP. Rooker plans to have results of the study by October.
“We expect to see volume changes, but what we want to see is what is the average per year and how this project is performing over the years. It will also give us an expectation of how long this project will last,” Rooker said.
The project is funded by the State of Florida, Lee County Board of County Commissioners and Captiva property owners.
For more information or questions about the project, give CEPD a call at (239) 472-2472, or send them an email at firstname.lastname@example.org.