Global warming spurs new flood worries

Jun 12, 2008

Water management officials studying ways to protect water supplies, structures from rising threat

Naples Daily News--June 11, 2008

Will global warming cause the sea level around Florida to rise quicker than expected?

If so, officials from the South Florida Water Management District are concerned about what would happen to flood control structures and water supplies.

Some studies show the water would only rise 5 feet in the next 200 hundred years. Others show it rising much higher, and at a much quicker pace.

In its next budget, the district has asked for $100,000 to study the effects of sea rise on flood control structures.

“If the dollars are allocated, a scope of work will be created that will define what the study will cover,” said Susan Sanders, a spokeswoman for the agency. “There is really nothing to discuss in detail at this point as staff has to perform some groundwork and then go back to the board with specifics.”

Existing research on anticipated sea level rise throughout South Florida will be used to help employees decide the implications on the structures and water supplies.

Some of that research could come from Dan Trescott, a planner with Southwest Florida Regional Planning Council.

He and others, through a 2001 grant from the U.S. Environmental Protection Agency, conducted studies aimed at looking at how much the sea will rise, ultimately covering what is now dry land.

“In Florida, we assumed a 5-foot rise in roughly 200 years, or roughly 2200,” Trescott said.

However, other studies show the sea could rise anywhere from a foot to 10 feet.

“It’s all over the place,” he said. “You see one article one day, another article the next day” showing how much the sea may rise during the next several hundred years.

The study by the state’s regional planning councils looked at comprehensive plans, future developments plans and other factors regarding land uses. Planners developed a color-coded map which points out wetland areas, uplands, where seawalls are placed and other items.

“It’s an analysis of land uses impacted by this 5-foot rise,” Trescott said. “We assumed a 2-foot rise this century and a 3-foot rise next century.”

For coastal communities, such as in Lee and Collier counties, tidal and non-tidal wetlands were looked at, along with uplands, or areas where water doesn’t typically stay.

What the planners found: “It’s rising and it’s going to rise rapidly,” he said.

For about the past 3,000 years, the rise leveled off. Then, in the past 100 years, the rise began. The seas rising can take away wetlands and upland or dry areas.

“There’s very little being done to address the issue,” Trescott said. “This mapping we started was an attempt to get everyone talking about it.

“It’s an issue of which land uses are going to hold back the sea and which aren’t,” he said. “We’re already holding back the seas (using beach renourishment, fill and sea walls).”

Also, the Federal Emergency Management Agency regulates where some structures can be built — if they are in a floodplain.

“So, we’re prepared to a great degree, but are we for the long term? No,” he said. “At some point, it’s not going to work. It works for shorter and shorter periods of time.”

Wetlands can be greatly affected by the sea rise.

“The Everglades is a classic case,” he said. “They are going to get sea rise from the Atlantic and Gulf. Even those areas in freshwater, flood-prone areas are going to get more funding. There’s no way to get it out. Freshwater floats on top of saltwater.”

And, those scenarios could affect the structures and freshwater supplies, in addition to parks and other publicly-owned land such as Lovers Key State Park and Rookery Bay National Estuarine Research Reserve.

Those scenarios likely will be used by South Florida Water Management District personnel to determine what could happen to infrastructure.

“I’m sure they’ll be looking at different scenarios,” Sanders said. “What they are more interested in is our flood control structures. I’m sure they will use existing data.”

As for the publicly-owned property, Mother Nature wants to change Lovers Key, but humans intercede to keep the beach intact.

“All of the buffer lands, like at Rookery Bay, the uplands, those would be wetlands,” Trescott said. “The sad thing about this whole projection: we’re going to lose our wetlands. Those are going to get squeezed between uplands and protection structures.

“Humans want to keep everything the same and not adjust to the environment pushing on them. I guess we are going to have a lot of places filled,” Trescott said. “I don’t know where we’re going to get the fill. Assuming gas is cheap, but gas isn’t cheap anymore, are we going to get a dump truck to go to Sebring and bring it (fill dirt) back to the coast?

“I personally don’t think we’re going to do it ourselves,” he said of keeping the sea at bay. “I don’t think we can beat this.”