Tropical Storm Gaston struck the South Carolina coast near Charleston early Sunday, blowing down trees and flooding streets before moving slowly inland and soaking the state’s interior.

The storm, worse by some accounts than Hurricane Charley two weeks ago, prompted flood watches while causing widespread power outages in Charleston and Berkeley counties.

About 175,000 people were without power at one point in those areas, which bore the brunt of the storm. By 10:30 p.m., more than half had had service restored.

By late Sunday night, there was only one initial report of a serious injury — a resident injured when a tree fell on a house.

Gaston’s landfall — making this the busiest tropical storm month in the state’s history — heightened concerns about Hurricane Frances, which is churning toward the southeastern U.S. coast.

It’s too early to determine whether Frances will affect South Carolina, National Weather Service forecasters said, but flooding from Gaston might. Forecasters were keeping a close watch on rising rivers in eastern South Carolina, where some waterways are expected to spill their banks this week.

The Santee River in the Francis Marion National Forest will exceed flood stage near Jamestown this morning, according to the National Weather Service, which also reported rises in the Little Pee Dee, Waccamaw and Great Pee Dee. Weather service forecaster Michael Caropolo said flood warnings could be posted in a few days, depending on how rain upstream affects those rivers.

Tropical Storm Gaston prompted Gov. Mark Sanford to declare a state of emergency Sunday and urge Lowcountry residents to stay home as damage assessment crews looked at the storm’s impact.

Gaston’s damage appears “greater than Charley,” Sanford said. “People have described it in some areas as comparable to Hurricane Floyd in terms of the level of damage.”

Floyd caused major damage in South Carolina in 1999, dumping heavy rains over both Carolinas that caused several rivers to flood.

Gaston was unlike many tropical weather systems that affect the South Carolina coast because it formed just offshore, rather than far east in the Atlantic near Africa, according to the National Hurricane Center. It also formed in a matter of days, giving the state less time to prepare.

LINGERING STORM

Sunday’s tropical storm, while nowhere near as forceful as major hurricanes such as Hugo 15 years ago, was nonetheless felt because it lingered for so long over the state.

It made landfall in the Awendaw-McClellanville area about 9:30 a.m., but remained over South Carolina well into Sunday evening. During that time, the storm’s winds and heavy rains took a toll.

In some places, about 10 inches of rain fell from midnight Saturday through late afternoon Sunday. Roads flooded in many areas, including Berkeley and Charleston counties and as far inland as Clarendon County.

Wind gusts of more than 80 mph were recorded at Isle of Palms and downtown Charleston. Steady rain pelted Mount Pleasant for hours after the storm and tree limbs littered flooded roadways, some of which were impassable.

Gaston knocked down utility lines and flooded streets in Charleston, Mayor Joe Riley said. In Charleston Harbor, several boats broke free from their moorings and sank.

Nonetheless, Debbie Rice-Marko spent part of the day Sunday cleaning up limbs and other debris from in front of her 250-year-old home on Charleston’s historic Battery.

“We didn’t see anything like this with Charley,” she said.

Donny Browning, who oversees the Cape Romain National Wildlife Refuge at Awendaw, said the storm might have hurt already damaged nesting sites of endangered sea turtles at Cape Island. The island contains a third of the state’s loggerhead sea turtle nests, but Charley already had washed away thousands of eggs when it blew through earlier this month.

Other than some damage to a public boat dock, McClellanville appeared to have escaped major storm damage, Browning said. Hurricane Hugo blasted the fishing village in 1989.

POWER KNOCKED OUT

Power companies scrambled Sunday night to restore electricity to about 175,000 customers in Charleston and Berkeley counties, which bore the brunt of the tropical storm’s fury. The power outages topped those reported by utilities for Hurricane Charley the weekend of Aug. 14. Electricity wasn’t expected to be fully restored for several days.

About 125,000 SCE&G customers were without power for parts of the day Sunday. By 10:30 p.m. power had been restored to all but 50,000 customers, the company reported.

Another 7,000 customers of Santee Cooper lost power.

Two-thirds of the 66,000 customers served by the Berkeley Electric Cooperative lost power Sunday, spokesman Eddie McKnight said. The co-op reported that it had restored power to about 21,000 homes by 9:30 p.m.

“This thing just kind of sat over Berkeley County,” McKnight said. “We had trees through the middle of houses here in Berkeley County.”’

Sanford said he won’t know the full extent of the damage until work crews have assessed coastal areas. Some crews were unable to begin such assessments for hours after the storm made landfall because it continued to hover over the state.

WARY OF FRANCES

Sunday’s storm also produced anxiety about the potential impact of Hurricane Frances, a major storm that would dwarf the impact of Gaston’s 74-mph sustained winds.

At 11 p.m. Sunday, Frances was carrying maximum sustained winds of more than 125 mph and could make landfall Labor Day weekend, most likely on Florida’s Atlantic Coast, according to the National Weather Service.

But some worried that the forecast could change, as hurricane predictions often do.

In recent years, many hurricanes have moved up the coast from the spot they were originally forecast to hit. Even if Frances hits Florida as now projected, the storm is so wide that tropical storm-force winds could be felt in South Carolina, according to the National Weather Service.

“It’s something to be worried about,” Riley said. “I see this experience with Gaston as good preparation and scrimmage to be ready for a huge storm.”

Gaston’s landfall Sunday apparently makes August 2004 the busiest tropical storm month in the state’s history.

While none caused major damage, four tropical storm systems have impacted South Carolina this month, causing beach erosion and spawning heavy rains. Other tropical weather systems this month were Hurricane Charley, Hurricane Bonnie and Tropical Storm Alex.

According to records kept by the state climate office, only once since 1871 have four tropical systems caused damage in the state in a full season. That was in 1893, when the storms were spread out from June 15 through Oct. 13.

Staff Writer Joey Holleman, The Associated Press and Reuters contributed to this report.