Key West ponders a submerged future

KEY WEST, Fla. -- The director of airports here, Peter Horton, puffed a cigarette on a rooftop vantage point outside his office and watched a commercial jet taxiing below before takeoff.

The air was dry on this 90-degree summer day, but water was on Horton's mind. Several days of heavy rains had flooded the grassy infield abutting the runway in Key West International Airport.

For Horton, the water turning the infield into a soppy oval is more than just a nuisance. Because the pool consists of fresh water, it's turning the land into a natural nesting target for birds that pose a threat to incoming aircraft.

It used to be that the infield would rarely flood, and when it did, it would dry out in 48 hours. Now, the field floods several times a year, and the water remains for the better part of a week, Horton said.

"I've been here since 1988, and it's getting harder and harder to move the water out of here," said the 65-year-old Horton, speaking over the sound of roaring jet engines. "I'm very concerned about the long-term prognosis for this airport and the rest of Key West."

Horton is one of a growing number of county and city officials grappling with how to prepare for a slow but steady water intrusion in the Florida Keys, a string of small islands known for their sunsets, snorkeling, laid-back culture and Ernest Hemingway history. Key West, population 24,909, is at the southernmost tip of the Keys. It is the seat of Monroe County, population 74,000, which governs most of the Keys and a largely uninhabited part of the Everglades.

A government-backed advisory committee in Monroe County -- which owns the airport -- is drafting a climate action plan in the next three months that aims, in part, to make recommendations on minimizing the impact of stronger storms and rising seas. Horton is in communication with the advisory committee members about airport conditions.


Among the committee's top concerns is how to protect infrastructure vital to the region's tourist economy.

The 255-acre airport, for one, is a tourist gateway -- more than two-thirds of its 700,000 annual visitors are nonresidents headed to hotels and guest rentals up and down the coast. The airport also faces many of the same water drainage challenges as housing complexes and other facilities from Key West to Key Largo.

Many of the officials here speak with a certain inevitability -- a recognition that their role may be to prolong the quality of life in the Keys for as long as possible, rather than save them entirely. Florida's unique, porous geology generally forbids the idea of building levees or protective sea walls such as those in New Orleans or the Netherlands.

Hoping for a few more years

"In the end, we are going under," said Alison Higgins, sustainability coordinator for Key West. "But if there are things we can do to extend the quality of life for 20 or 30 years or longer than what they would be otherwise, then it is crucial we do that."

Higgins' concerns are not unfounded. In addition to the possibility of heavier rainfall, many existing climate models predict rising temperatures could raise global sea levels by roughly 3 feet by 2100. Some scientists think the number could be several feet higher. In southeast Florida, officials have agreed on the possibility of 9 to 24 inches of rise by 2060, and as much as 7 inches by 2030.

Considering that much of the Keys hovers around 4 feet above sea level, the worst-case scenarios pose a very serious threat.

In December, a coalition of four southeast Florida counties tried to calculate what 1 foot, 2 feet and 3 feet of rise might look like in all of southeast Florida considering land elevation data and limitations of existing models. Rising seas pose a problem for major population centers like Miami and Fort Lauderdale, but in the Keys the inundation is expected to come at a much more rapid pace.

The analysis reported, for example, that 44,885 acres, or 68 percent, of Monroe County's landmass is vulnerable to flooding at high tide under 1 foot of sea level rise. At that level, three of Monroe's four hospitals, 65 percent of the county's schools and 71 percent of its emergency shelters would have vulnerable property.

Raise the projection to 3 feet of sea level rise, and about $15 billion in taxable assets and 86 percent of county land could be saturated at high tide, including the airport where Horton works and buildings like the Marathon wastewater treatment facility.

Long-term engineering solutions like levees or sea walls don't work in the Keys, which, like the rest of south Florida, have a Swiss cheese geology of porous limestone. A short walk through any park reveals holes in the ground between patches of grass.

"If you put in a sea wall, the water would just flow underneath it and seep up through the ground," said Chris Bergh, a Keys-based program director at the Nature Conservancy.

A breaking point for the 'Conch Republic'?

The geology dynamic leaves a short list of options on how to prepare for eventual inundation: Elevate and improve existing infrastructure, move people and species to higher ground, and maximize the functionality of the current water drainage system.

Horton mentioned all three ideas as he descended from the roof overlook and jumped into an official vehicle for a drive around the airport.

The facility greeting visitors with the sign "Welcome to the Conch Republic" on its tiny terminal is a virtual island, surrounded by the ocean and saltwater ponds.

Passing the terminal on a roadway parallel to the runway, Horton said standing water has become a bigger problem at the airport in the past five years -- after a string of rain poured more than the average amount of water onto the grounds in a short period of time. They were the kind of heavier-than-average rainfall events that scientists and computer models predict will become more common with climate change.

Currently, the airport drains rainwater through a series of 12 drainage wells spread out from the runway to the parking lot. Horton said he has been able to get by with the help of evaporation and the existing holes in the ground.

"But it is at capacity with high tide and 2 inches of rain," he said. "It's not going to take much for us to be at a breaking point."

Water removal: not easy anymore

Sea level rise is poised to make this worse in two ways.

The drainage wells work by gravity. Currently, there is about a foot between the top of the wells and a large pool of salt water underneath the ground. If the sea level rises as expected, it's going to push against this pool underneath the surface and send the water higher into the drainage holes.

Horton said there needs to be additional assessment of exactly how much sea level rise would completely clog the drains, but he said even a few inches could create "serious issues."

And there's another problem. High tides are increasingly bringing salt water from the surrounding ponds directly onto the airport premises. In those cases, the stormwater drains operate backward and bring water up through the ground and onto the airport's surface.

That was the case on the day of Horton's drive. Just past the runway's edge, Horton stopped in front of a pond streaked with grass patches like a marble cake. The salty pool has not yet breached the runway on the occasions it formed but is not far from doing so, considering the runway sits about 2.5 feet above sea level at its high point, Horton said.

After a full moon and extreme tide in early May, salt water also seeped up storm drains into the grassy infield and onto pavement to create a large puddle near the airline taxiway.

A document Horton prepared for the Monroe County climate task force estimated that a 1.6-foot rise in sea level would be "near catastrophic," with the aircraft parking ramps and taxiways flooding "on a routine basis."

The challenge for Horton is that water removal is not as simple as pumping water back out to sea with a hose.

South Florida Water Management District regulations require that standing water at an airport be cleansed of pollutants -- such as those that seep from jet exhausts -- before it's sent to a natural waterway for disposal. The idea is to protect the whole ecosystem, so it is not contaminated from gasoline, silt or other toxins that gather on pavement.

The airport's current method for pollutant removal is to let the water sit on grass, a natural filter. "Large inflows of salt water are going to kill the grass," Horton noted. "I'm really not sure if there is a solution to that."

A $40M option

Horton said he can deal with increasing numbers of landing birds on the infield by shooting propane cannons in the air that scare them off with noise.

The Federal Aviation Administration also agreed this summer to provide $250,000 for four or so new drainage wells to the facility. That will help in the short term but will not solve the long-term problems, he said.

For that, Horton said, he may have to explore the idea of transforming an old bunker area into a reservoir where more and more water could be collected, piped and filtrated before being pumped out to sea. But he's not sure the engineering would work considering the volumes of water that would be involved, or whether the airport could find enough real estate for storage.

There's also the option of raising the runway, and the airport's surrounding grounds, but it would take at least 20 years to permit, Horton said.

Runway elevation would come at a hefty cost, at least $40 million, according to the document Horton prepared for the county climate task force. The FAA, which funds most of the airport's drainage system, would have to pay 90 percent of the cost via various airport fees, unless "we bonded it," Horton said.

"But if the surrounding roads are not dealt with, it won't matter, he said. "There's no point in having an airport if people can't get here."

The airport is in many ways a microcosm of the water challenges facing the broader Florida Keys. As is the case with Horton's facility, the islands drain stormwater out through a series of holes, or ditches.

In the case of heavier storms, the county could add pumps in select locations to push more water out through the wells, explained Kevin Wilson, an engineer in the Monroe County Public Works & Engineering Division.

Rising above it all?

But that, along with the addition of more holes, is not a widespread option, he said. The pumps are expensive, and they wouldn't solve the problem of underground seawater coming up the drainage wells.

"They wouldn't help at all with sea level rise," he said.

Pumps also add the dynamic of having to pipe water to a central location and treat it there -- rather than letting it naturally filtrate out all over the islands. "We would get into a permitting issue, because of single-point discharge," Wilson said, echoing Horton's concerns.

That puts county officials back in the realm of considering elevation of infrastructure that could be in place for 50 years or more.

The county advisory committee is figuring out how to do this via the soon-to-be-released county climate action plan, which contains phrasing such as "elevate flood-proofed buildings to a minimum of 2 feet above the road elevation."

But officials also have to contend with the uncertainty of climate models. Not knowing whether sea level rise will hit 9 inches, 24 inches or some other number by 2060 puts them in a state of planning limbo.

County officials discovered this when they recently decided to build a new fire station 1 foot higher than originally planned on Stock Island as a result of the early deliberations of the county climate task force.

The design worked well at 1 foot but would not make it at a 2-foot elevation, Wilson said.

"If we had changed the design to raise it higher to 2 feet, the ramp from the building to the street became too steep," he said. "The fire trucks would have scraped the pavement." If the county had wanted 2 feet, it would have had to buy more land to extend the ramp or "start over," he said.

While the station should be fine at its planned height, it raises questions about the kind of mundane details that are going to come up when officials start debating 1-foot vesus 2-foot elevations, he said.

Similarly, simply raising county roads is not a widespread option, unless connecting houses are raised simultaneously, he said. If they were raised everywhere, the roads would then act as dams and flood people's yards and any wiring infrastructure underneath homes, he said.

"If sea level comes up and roads are higher but the houses aren't, all we have is a series of saltwater rice paddies," he said.

Tomorrow: Will Monroe County's climate action plan save the Keys?