Emergency workers rescued dozens of trapped residents Monday after torrential rains deluged more than 400 homes in southern Texas and forced the temporary closure of the main road through the Rio Grande Valley.

Officials used any available boat to pluck about 60 people from their flooded homes after more than 13 inches of rain fell on parts of Starr County.

The Department of Public Safety had recommended that U.S. Highway 83 be closed near Rosita, about midway between Roma and Rio Grande City, because a creek was more than a foot above the guardrails, said Starr County Judge Eloy Vera. Not even emergency vehicles were permitted to pass.

"That pretty much isolates Roma from the valley," Vera said. "We're real scared about that."

The highway was reopened Monday evening. About 10,000 people live in Roma, 210 miles south of San Antonio.

The impact of so much rain was compounded by the ground's saturation from Hurricane Dolly, which hit in late July, said county Emergency Management Coordinator Gene Falcon.

"It's really in a bad situation now," Falcon said.

Jose Garcia, fire and police chief in Roma, said floodwaters had started to recede in the city Monday afternoon, but he was not sure it had seen the last of the rain.

Roma received about 8 inches of rain in three hours early Monday, and water pooled at depths of 6 inches to 4 feet, he said.

The National Weather Service on Monday issued a flash flooding warning for communities including Rosita and Rio Grande City.

A flash flood watch also was in effect for parts of southern Texas through Tuesday night.