Green lawns and brimming canals returning to South Florida mask the water supply worry spreading along the coast.

This year's drought brought a saltwater scare that poses a long-term threat to South Florida's water supply, and that threat lingers even as summer rains turn landscaping green again.

Water managers shut down "at risk" wells in four coastal communities in Broward and Palm Beach counties in May, not because the wells were on the verge of running dry, but because salt water threatened to seep in and spoil underground drinking water supplies.

The shutdowns are temporary, however. Long-term solutions involve expensive alternative water sources, which in many cases remain years away from getting water flowing.

In the meantime, water providers warn that the pumping required to meet the demands of a growing population, along the coast and to the west, allows salt water to keep forcing its way inland.

"That salt water is coming in. I don't think wild horses can stop that," said Hal Elsasser, water plant manager for Hallandale Beach. "Whether we use our wells or don't use our wells, that salt water is coming in."

Not so, according to the South Florida Water Management District.

The district contends that targeting the most susceptible areas can stop salt water from fouling the underground fresh water South Florida shares. And the agency says developing alternative sources can meet the water needs of a growing population.

"Saltwater intrusion is directly related to the pumping of those well fields closest to the coast," said Pete Kwiatkowski, the district's director of resource evaluation.

Lantana, Lake Worth, Dania Beach and Hallandale Beach form the front line in the defense against salt water moving into South Florida's drinking water supply.

Rising salt levels detected in wells used for monitoring in those four communities prompted the district in May to call for a 60-day shutdown or at least reduced pumping from wells closest to the coast.

Salt levels had not spiked in the wells that produce drinking water, but identifying rising levels in the monitor wells was enough to call for the cutbacks, according to the district.

"When you start seeing it in the production wells, it's almost too late," Kwiatkowski said.

Hallandale Beach started sacrificing wells 20 years ago to head off a saltwater threat that just won't go away.

The city used to have six wells at its water plant on Northwest Sixth Avenue, but only one remains after the rest were shut down in the 1980s.

That last well, wedged between buildings at the plant, was temporarily shut down in May, requiring the city to buy water from Broward County to meet its needs. The city takes about 2 million gallons per day from county wells at Brian Piccolo Park and mixes it with 3 million gallons per day it produces from a well field in northwest Hallandale Beach.

Plant Operator Al Martinez watches the computer readings that flicker on the control room wall, providing continual updates on water pressure and other measures showing the daily demands on the city's supply. Martinez said he understands the district's caution in shutting down wells, but he says that creates more of a challenge for utilities that didn't anticipate the towering condominiums rising along the coast and the amount of development spreading to the west.

"We have something they don't have to do," Martinez said about the district. "We have to provide water."

Most of South Florida taps into the Biscayne aquifer for drinking water, using wells that reach 80 to 150 feet deep.

Pumping too much water from the Biscayne can allow salt water to push its way in from the coast.This saltwater intrusion already reaches more than 3 miles inland along some parts of the coast, according to district estimates.

Eighteen months of below-normal rainfall heightened the risk of salt water seeping into the Biscayne aquifer. The district responded by imposing once-a-week watering limits in Broward and Palm Beach counties, the toughest restrictions in South Florida history, and shutting down or cutting back pumping at wells in the four at-risk communities.

Summer rains have helped water supplies rebound faster than the district gives utilities credit for, said Bevin Beaudet, Palm Beach County's Water Utilities Department director.

Beaudet said water restrictions in place now are based on a "man-made drought" that resulted from decisions last year to lower Lake Okeechobee in advance of hurricanes that never materialized.

"There is no longer a drought on the East Coast of Florida. I don't care what [district officials] say," Beaudet said. "All of the utilities had plenty of water. We met all our demands."

Hallandale Beach didn't create saltwater intrusion and it is the water needs of development west of the city that worsen the problem, Mayor Joy Cooper said. Adding to the strain was the decision to lower Lake Okeechobee, Cooper said.

"It was compounded, regretfully, because of some mismanagement at the water management district," Cooper said.

The Army Corps of Engineers, with support from the district, last year decided to lower the lake because of forecasts for a busy hurricane season and concerns about the stability of the earthen dike that protects South Florida from lake flooding.

District spokesman Jesus Rodriguez said that even if the lake had not been lowered, the below-normal rainfall would have left South Florida in a drought. "Our charge is to protect the aquifer and these well fields," Rodriguez said. "Even if it means erring on the side of being conservative."

Lingering saltwater concerns had already prompted Hallandale Beach to build a $25 million plant, expected to open by the end of the year. The membrane filtering plan will allow the city to use more of the county water that comes from the inland wells farther from the reach of saltwater.

As the population continues to grow, more South Florida communities will have to find alternative water sources, Elsasser said. For Hallandale Beach and others that could mean digging deeper wells that can tap into the Floridan aquifer, a more plentiful source below the Biscayne with water that requires more extensive, and expensive, treatment.

"The [more] people we have down here, the more acute the droughts will become," Elsasser said.

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