HALLANDALE BEACH, Fla. -- With its fast food restaurants, churches and strip malls, this city in southeast Florida looks like much of America. But on a sunny day last month, city official Hector Castro talked about its resemblance to Italy's slowly sinking Venice.

"At some point in the future, some places may be uninhabitable," said Castro, director of the city Department of Public Works, Utilities and Engineering. "Maybe people could live in the top part of buildings. But what do you do about the roads?"

These predictions about an underwater city may sound dire, but officials here say they already are changing infrastructure with climate change in mind.

Recent storms battered the 4.4-square-mile city -- which sits about 7 miles north of North Miami Beach -- to such a degree that some homes were abandoned for the first time, said Castro, looking at photographs of cars floating in a parking lot. It was the kind of heavy rainfall that could become more frequent with climate change, even though scientists say no one weather event can be tied to warming temperatures.

Simultaneously, the city's freshwater supply is being contaminated by saltwater intrusion -- a problem that was not created by climate change, but that is likely being accelerated by it, according to researchers.

So city officials are spending some $16 million to upgrade their stormwater system, and to move the city's entire drinking supply to the west to get out of the way of the ocean. It is a temporary fix for a problem that is projected to get worse as time goes on.

"We are the canary in the coal mine with climate change," said Hallandale Commissioner Keith London, a ponytailed, athletic politician who attends hydrology work groups in his spare time.

Canary or not, Hallandale Beach is a symbol of several water problems looming over southeast Florida. Its infrastructure and size may be different from Miami or Key West, but the challenges are the same.

Facing tough, expensive questions

For example, a December analysis released by the Southeast Florida Climate Change Compact -- a coalition of four counties -- found that 893 miles of roadway from Miami to Palm Beach could be inundated at high tide with 3 feet of sea-level rise. Some $31 billion in taxable property could be vulnerable with that amount of additional water, the analysis says.

Armed with new maps and data sets produced in the past six months about how climate change could play out on the ground with infrastructure, local government officials in southeast Florida are starting to ask some tough questions: Will some roads have to be elevated or deemed unusable? Will parts of the region be affordable only to wealthy people in the future who can pay for expensive drinking water? At what point is it cheaper to abandon a drinking water or flooding problem rather than fix it?

The debate was on display last month when members of the compact met in Key Largo to release a climate action plan that aimed, in part, to offer preliminary recommendations on how cities in the area can prepare for sea-level rise and more powerful storms.

There are no easy answers, and cost is inevitably part of the conversation, considering that many cities and towns are strapped for cash and already reliant on federal agencies such as the Federal Emergency Management Agency (FEMA) to assist with problems.

"This is an issue that nobody wants to address," said Jack Osterholt, deputy mayor of Miami-Dade County. "This is an issue that if you took really seriously, it would cause such low-level chaos."

Back in Hallandale Beach, city officials do want to address it, but there may be limits on how much they can protect the city from flooding and saltwater intrusion in the drinking supply with existing technologies. No one knows how long they have before facing serious trouble -- it could be 30 years or so, or it could be later.

The city's finances and geology explain some of the knowledge gap.

Sandwiched between Miami and Fort Lauderdale, Hallandale Beach's population of 37,000 swells by a third during the winter months, as young families flock to the city's white-sand beach on the Atlantic Ocean, which is framed by towering condominiums. Like other southeast Florida cities on the coast, it holds a network of man-made canals near the ocean with symmetrical islands of mansions.

On an 80-degree day this winter in the area, a resident fixed a statue on his lawn as his boat bobbed several feet away by a personal dock. Cars sprayed salt water from elongated roadway puddles before moving in and out of a gated community.

Where does the stormwater go?Farther inland are blocks of brown family homes lined with palm trees, and the city's public works building, where city and county officials explained on a December morning how climate change could wreak havoc on the city's existing infrastructure.

The city's flood-control system consists of a series of drainage wells that use gravity to push stormwater underground and off the streets during storms, said Jennifer Jurado, director of the Broward County Natural Resources Planning and Management Division.

The problem with sea-level rise, she said, is that it helps push ocean water not just on top of land, but underneath the ground in a westerly fashion through the region's distinctive, porous geology, which resembles Swiss cheese.

That ocean water then pushes against fresh water already in the ground, causing the fresh water to rise closer to the surface and farther up the drainage wells. The dynamic means that stormwater produced during rains doesn't have as much room to fall down the wells and instead ends up saturating roads and buildings.

This underground system is showing its limitations. During a powerful storm in 2009, multiple streets flooded and insurance claims skyrocketed, including for car owners faced with saltwater damage to their vehicles, according to Castro.

To help resolve the problem, the city obtained $4 million from FEMA to install pumps that not just force water down the drainage wells, but make water fan out into nearby rock to keep it off the surface. The pumps resemble gigantic, upright metal tubes.

City officials also are planning to use $11 million in FEMA money to construct new drainage wells. The city is spending $6 million of its own revenue on the projects.

"Obviously, you can't do other things," said London about the water infrastructure expenses. "I haven't rebuilt my parks."

Additionally, the city is testing duck bill-shaped valves on drainage pipes near the ocean that prevent ocean water during high tides from flowing backward into basements and parking lots.

These solutions may buy the city decades of time, but they won't prepare it for 2 feet or more of sea-level rise, particularly when combined with the prospect of more powerful storm surges, according to Castro.

"The only other thing we could do is raise the heights of sea walls," he said about the prospect of 2 feet of additional water. The area's porous geology prevents construction of levees, he said.

Which part of town goes underwater first?Part of the challenge for city officials is that climate models are uncertain, and unable to give a precise picture of impacts on a local area. The difference between 1 foot and 3 feet of rise on Hallandale is huge, according to an analysis finalized in December by the compact, which worked with the federal government and the South Florida Water Management District to predict the future as much as possible.

The analysis, which used land elevation and tidal data, found that 460 acres, or about a sixth of Hallandale Beach, would be below sea level during high tide under a 3-foot scenario of rise, according to Nancy Gassman, a natural resources administrator for Broward County's Natural Resources Planning and Management Division who worked on the assessment. The main impact with 1 foot of rise, on the other hand, would be in pockets of the city and a parking lot.

The 3-foot scenario raises many financial questions, as some of the worst-hit areas of the city would be in the man-made canal area, which also happens to hold much of the city's most expensive real estate.

In addition to hosting million-dollar homes with boat access, the area is close to the city's entertainment hub, the Gulfstream Racing and Casino Park, which helps provide Hallandale Beach with substantial revenue from sales and property taxes. Property taxes provide about 37 percent of city dollars.

But the pumps that the city is currently installing farther inland to force water into the ground are not an option for the canal area, because there is "too much water" there, said Castro, bringing up Venice again.

"You can get to a point of diminishing returns," he said, where the cost of valves and raised sea walls far exceeds the values of properties. "At that point, it may be time to say, 'Move west.'"

One thing the city is already trying to move west is its drinking water wells, which are being contaminated with salt water. Like the rest of southeast Florida, the city depends on an ample supply of fresh groundwater to extract drinking supplies.

For decades, ocean water has been moving westward underground toward these existing drinking supplies for reasons other than climate change, including historical drainage of inland areas for agricultural development. Since fresh water acts as an underground barrier against the ocean, the drainage has helped the salt water seep in.

"The system is still responding to drainage since the 1920s," said Jurado.

Moving drinking water sources inlandBut climate change may be making this problem much worse.

Preliminary analyses the county conducted with the U.S. Geological Survey of Pompano Beach -- 20 miles north of Hallandale -- show that climate change may speed up the movement of the saltwater intrusion line and take it much farther west than it would be otherwise, according to Jurado. The county is working on a similar analysis of Hallandale Beach specifically, she said.

The analysis raises the question of what the city will do in the future, even if it succeeds in moving its current drinking supply to the west. Hallandale Beach officials currently are hoping to spend $10 million to move its well fields to a golf-course area if the deal comes through this month.

But if climate change helps move the saltwater intrusion line far enough west, new supplies also could be threatened. In that case, the city would be forced to move to extremely expensive desalination treatments that turn salt water into drinking water, said Castro.

"I worry about a day when people's water bills are quadruple what they are now," said Castro.

City and county officials from other southeast Florida cities expressed similar sentiments about climate change and its potential effects on worsening drinking water and flooding issues during a December tour of the region.

In Fort Lauderdale, county officials are testing valves in a four-block neighborhood similar to those in Hallandale Beach that keep out salt water. The area -- which resembles Hallandale Beach's canal area -- was experiencing flooding severe enough during monthly high-tide events that residents were wading to their cars.

"I couldn't take it anymore," said Tamara Tennant, a homeowners association president in the area. The county will reimburse residents in several years if the valves work.

For now, the problem is confined to a small area, but other city officials -- including in Hallandale Beach -- are looking to the neighborhood as an example of what could become a common, and very expensive, scenario across south Florida.

In Key West, city officials are planning to build a new fire station several feet higher than originally planned, because of worries about climate-driven sea-level rise.

In Pompano Beach, officials are using an engineering firm to incorporate climate change into their master plan, so they can begin to plan for possible elevations of new roads and buildings.

During a recent storm, flooding got so bad that the "city could not keep up" and water poured into manholes, said Maria Loucraft, utilities laboratory manager for the city. Thus, the city is awaiting a decision on a grant from the federal government that would pay for more than 4,000 new manhole covers that keep water out of the sewer system.

Expecting 'real winners and losers'"It's a short-term solution," said Loucraft.

The long-term drinking-water issues for cities in the area could be alleviated by a proposal for a regional drinking water reservoir that captures storm runoff currently lost, Jurado said. The reservoir -- if constructed -- would be built outside of the region, where the rock is not porous, and pipe some 60 million gallons of water a day into Broward County. The decision on whether to build it depends on financing, among other things, and the idea has many critics who think the state should be doing more with water conservation.

With flooding, one of the key suggestions from the action plan released in December is for localities to make use of a 2011 state law. That law that allows them to designate official "adaptation action areas."

The goal of the new rule is to help local governments identify vulnerable areas affected by climate change that they can show to federal and state officials as a way to obtain money for things like road rebuilding. Without an official "action area," it would be easier for grant applications to get lost in the shuffle, regional officials say.

Land-use decisions will be key for cities like Hallandale Beach, said Jurado, since municipalities have power to decide where much new construction can and cannot occur.

But as Miami-Dade County Deputy Mayor Osterholt noted, those land-use decisions could be very tough to make, even with the compact's efforts.

Many city officials across the region are preoccupied with decisions that needed to happen three weeks ago, he said, so getting them to focus on 10 years from now, much less 100 years from now, is a tough sell. There is "comfort" in thinking climate change might not happen, he said.

"There are real winners and losers here," he said. "They don't want to have to say, 'This area here, we're going to continue to habitate. Everyone else must get out.'"

Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC. www.eenews.net, 202-628-6500