TOPSAIL BEACH — Two days of stiff winds and high waves clawed at the North Carolina coast this week, eroding as much as 20 feet of the beach in places, officials said.

By Wednesday, the system that battered the coast had developed into Subtropical Storm Andrea. Sustained winds of 46 mph were recorded off the coast of Georgia as the system crawled in a south-southwesterly direction toward Florida.

The low-pressure system churned off the Outer Banks on Monday and Tuesday, creating waves as high as 40 feet and wind gusts of 35 to 40 mph.

"The winds just pounded the coast over the past 48 hours," WRAL meteorologist Elizabeth Gardner said.

Topsail Beach Town Manager Jim Carter said as much as 20 feet of beach has been washed away. Sand fences were left in splinters, and dunes were carved out next to houses, he said.

"In some areas, we're precariously thin with what's left," Carter said. "We're going to be open for business. I don't want to be overdramatic about it. The beaches will be fine this summer, but we are concerned about the dune structure."

Water didn't breach any dunes to damage beachfront homes, but 70 homes are "imminently threatened," meaning the dune line is within 20 feet of their foundations, he said.

John Gresham, who has lived at Topsail Beach for 20 years, said he has never seen the island's dunes eroded so much so early in the year.

"I hate to lose the sand, but that's what we have pilings under the house for, so the water can come and go," said Gresham, who spent much of Wednesday repairing his boardwalk to the beach. "We don't sweat the small stuff."

The heavy erosion puts the coast at a disadvantage with three weeks left until the start of the 2008 hurricane season, Carter said.

"We felt pretty good going into the hurricane season that our dunes were in fairly good shape. But as it stands (Wednesday), a lot of that has disappeared," he said.

Topsail Beach has been planning its own beach renourishment project because federal funds have been scarce in recent years for a Army Corps of Engineers program. Carter said the town efforts are still at least a year away, however.

"Hopefully, we can get back on the beach and repair the dunes that were most significantly hit," he said.

A $25,000 emergency renourishment program, which officials hope to finish by June 1, will involve bulldozers' scraping sand off the beaches at low tide to rebuild the dunes.