January 25, 2017
By Ashley Goodman
Many residents of Captiva and Sanibel gathered at South Seas Island Resort Friday, Jan. 13, to hear about the effects of sea level rise from geologists, biologists, engineers and other experts.
"Now In My Back Yard" was orchestrated by the Captiva Community Panel and Max Forgey, who is president of Zoning Technologies which is based in Cape Coral. The event was sponsored by Sanibel & Captiva Islands Association of Realtors and the Florida Chapter of the American Planning Association.
Dr. Harold Wanless, chair of the geological department at the University of Miami, said that the sea level is rising is due to the ocean warming. According to Wanless, 93.4 percent of global warming heat is transferred to the ocean and because of this, the water is expanding.
"Water has an amazing ability to hold heat. Because of our huge population, this is an accelerated problem. We actually see it (global warming) beginning right after the Industrial Revolution," Wanless said.
Aside from the ocean's rising temperature, Wanless said that the melting of glaciers are a contributing factor to sea level rise as well.
"Beginning in 1990, we saw a further acceleration because of ice melting in Greenland and Antarctica. We've never seen a warming like this before," he said.
Wanless also noted that the melting of alpine glaciers could contribute six to eight inches of rising sea level.
"Accelerated melting causes us to lose our floating glaciers," Wanless said.
During his presentation, he proposed that by 2100, the ocean will rise between 4.1 to 6.6 feet, causing Sanibel, Captiva and other parts around Florida to lose a significant amount of land mass.
"Because we've warmed the oceans, this is not going to turn around. This is going to continue through the century and the next even if we do what we have to do and that's not burning fossil fuels and start pulling out carbon dioxide and the other gases out of the atmosphere," Wanless said. "Florida is very susceptible to a rising sea level."
The second speaker, Hans J.M. Wilson, professional engineer and president of Hans Wilson & Associates of Fort Myers, said that sea level rise can be managed. Wilson said that some of the ways we can manage it on Sanibel and Captiva is by incorporating proper street drainage, sea walls, irrigation wells, septic sewers and having a stormwater management plan. He also mentioned that the sea level rises by approximately 3.3 millimeters per year.
"I think we have time to prepare but we're going to have to be thinking about it a lot harder than we have in the past," Wilson said. "We are going to have to work hard on educating our policy makers."
James Evans, director of natural resources of the city of Sanibel, focused on what options Sanibel and Captiva residents have when facing sea level rise and what some of the direct impacts will be.
"We can anticipate the flooding of public and private property, we can expect higher flood insurance rates, we can also expect a decline in property values as less people would want to take that risk. We are also looking at a loss of natural storm buffers such as mangroves," Evans said.
To plan ahead for sea level rise, Evans has joined forces with Lee County to develop a flood plain management planning and mitigation advisory committee to make Sanibel and Captiva more resilient.
"We've done some flood plain mapping, we're working with FEMA and also some of our consultants are working on the CRS program, the community rating system and really, that is what determines your flood insurance costs. It's all based on risk. We also have some of the most strict building and zoning codes in the state and that helps us to reduce the amount of infrastructure and developed area which by reducing the amount of developed area you're reducing the risk overall," Evans said.
Currently, Evans is working with the Lee County Visitor & Convention Bureau and others on updating a document that addresses sea level rise.
Evans said that the single greatest impact will be to the coastal interior wetlands and that mangroves will be one of the first things to be impacted. Evans also expects that as Sanibel moves into a higher sea level predicament, the city will have to plan on how to treat saltwater instead of brackish water.
Another way Evans is combatting sea level rise on Sanibel is by implementing three living shoreline projects on the east end of the island where erosion is taking its toll. Evans explained that a living shoreline is made from natural materials and concrete.
"These will help to create habitat and a resilient shoreline. The idea is that we move people away from the shoreline and create a natural buffer," Evans said.