Cancun, Mexico — Just six months after Hurricane Wilma erased Cancun's famed white sand beaches in autumn 2005, a massive beach restoration program seemingly did the impossible: It doubled the size of the sandy playground for money-spending tourists.

But as Cancun gears up for its first spring break season since the $23 million restoration project, the new beach at Mexico's top international tourist destination is slipping back into the sea.

NANCY FLORES/Cox Newspapers (ENLARGE)

A lifeguard carves steps into the cliff-like beach near Cancun's northern point.

NANCY FLORES/Cox Newspapers (ENLARGE)

A $23 million project was completed last spring to restore CancunÕs beach, wiped out by Hurricane Wilma in 2005. Sand bags are being used in a bid to keep erosion at bay.

NANCY FLORES/Cox Newspapers (ENLARGE)

Parts of Cancun's beach show signs of erosion. Last spring, a Belgian firm completed a $23 million project to restore the beach, completely wiped out by 2005's Hurricane Wilma.

NANCY FLORES/Cox Newspapers (ENLARGE)

Sand bags are used to keep erosion at bay. Along much of the 8-mile beach the sand has stuck. In other parts it's been swept back out to sea.

In recent months, much of the restored sand has disappeared, leaving steep mini-cliffs that beachgoers have to jump from to reach the water. And while the beach still averages about 60 feet wide, some sections are pitted with rocks and sandbags.

Officials in Mexico are facing what their counterparts in Florida and Texas learned long ago: Keeping up with Mother Nature is expensive. A permanent maintenance program may be needed.

The fortresslike hotels lining Cancun's eight-mile strip of Caribbean beach have undergone a transformation. Most took advantage of the forced break after Wilma to install spas and other amenities.

As American students return for their seasonal invasion, they will find a swankier, and more expensive, Cancun.

Hotel occupancy hovers around 80 percent, in the same ballpark as before the storm, a remarkable comeback for a resort nearly flattened in October 2005. Wilma battered Cancun for two days, and waves scooped sand from the beach.

"It's a totally renovated destination, and that has never happened before in the world," said Jesús Almaguer Salazar, president of the Cancun Hotel Association. "The restoration job gave us the chance to get back into the market quick, which was important for us."

'It's more of a spa thing'

But for all the optimism and money being injected into Cancun, the question mark remains its beach.

"It's pretty narrow," said Angie Rikard, who visited last week with her husband, John, after winning a trip at work.

The Charlotte couple couldn't wait to hit the beach for a romantic nighttime stroll when they arrived, but they were greeted by an unwelcome surprise: waves lapping against the concrete wall of their hotel, the beach nowhere to be seen under the evening high tide.

"It's still a lot better than home," joked Angie, 32, a speech pathologist, on a recent morning as low tide revealed only about 15 feet of restored beach.

Other beachgoers complained that the restored sand isn't nearly as powdery as the original stuff. Carol Germaine, a health care worker from Ottawa, was making her third visit to Cancun and said she was shocked. "I don't think it'll ever be the same," she said. "They've changed the ambience, too. It's more of a spa thing."

Tourism officials are making a conscious effort to shed MTV-fueled images of excess and are marketing the reborn resort as a high-end destination. Many hotels adopted a minimalist, boutique style and added luxury spas.

Gabriela Rodriguez Gálvez, tourism minister for Quintana Roo, Cancun's home state, said hoteliers invested nearly $2 billion to renovate damaged and destroyed buildings.

"Cancun [will appeal to] a more upscale kind of student," she said.

Students are returning in large numbers, although some students have been caught off guard by higher prices, said Dean Goodwin, sales director for Maryland-based Student Travel Services.

Goodwin said Cancun spring break traffic is double what it was last year, but still 15 percent less than pre-hurricane levels.

Lots of work to be done

Investors remain confident about Cancun's future — last week the Cancun Hotel Association announced plans for nine hotels, adding 5,000 rooms.

Officials with Mexico's environmental agency say the beach restoration, paid for by the federal government, only brought back about one-fourth of the sand Cancun's beaches need. And they say the project — overseen by tourism officials and carried out by a Belgian firm — was rushed and damaged coral reefs that help slow beach erosion.

Environmentalists are also criticizing local officials for seeking to bypass a new federal law that prevents development in fragile mangrove swamps south of Cancun, which they argue help combat coastal erosion. Local officials say Quintana Roo needs the jobs and income that development in the mangroves would provide.

Tourism officials say the recent erosion is the result of unusually strong winter winds and waves, and the situation should stabilize during calmer weather in March.

Officials also insist they foresaw the loss of restored sand and say the restoration process is just beginning.

In the project's second stage, engineers will place large, clothlike tubes about 300 feet offshore in hopes of keeping more sand on the beach. Officials are creating a fund for yearly maintenance.

Cancun's beach erosion problems date to the 1970s, when state planners selected an uninhabited spit of flawless beach on Yucatan's coast for an upscale tourism development. In those days, Cancun's beach, on a barrier island, stretched nearly 200 feet wide.

Four natural canals connected the ocean to the lagoon on its inland side and acted as a kind of emergency valve during extreme storms, providing an outlet for monster waves.

The channels were filled in as the barrier island was developed, and erosion has accelerated ever since.