Video shows the bridge crumbling as it was overrun by the bloated, roiling Llano River in Kingsland, about 65 miles northwest of Austin. The Llano and Colorado rivers meet at Kingsland, and the National Weather Service said both were experiencing "major flooding."
The body was found in Lake Lyndon B. Johnson, situated where the Llano flows into the Colorado. Local officials say they have yet to identify the person, but that many homes along the lake and rivers have been flooded. A flash flood warning was in effect.
Residents were evacuated from homes in Kingsland and in nearby Marble Falls, which was being overwhelmed by the Colorado River. Several school districts closed for the day, and emergency personnel blocked access to more than 150 low-water crossings.
Bill and Laura Villella awoke early Tuesday to about 12 inches of water in their home in Llano, a town just northwest of Kingsland. The rising water forced them to stand on their kitchen counter before emergency personnel in a boat pulled them to safety.
"We honestly did not believe it would go up that high," Bill Villella told the Austin American-Statesman. His wife added: "I've been through a lot in my life, but that's the scaredest I've ever been."
Gov. Greg Abbott released a statement urging "all Texans to take their safety into their own hands by closely monitoring changing weather conditions and heeding warnings from local officials."
The governor's warning came little more than a week after four people were washed away when the South Llano River, which becomes the Llano River downstream, overran an RV park in Junction, Texas. Three bodies have been recovered. The search for the fourth has been suspended due to the heavy rain.
The body found Tuesday doesn't appear to be the person still missing from the RV park, which is along the South Llano River about 90 miles away, said Burnet County Sheriff's Capt. Tom Dillard.
Flooding sweeps away RV park in Texas Hill Country
The most dramatic scenes Tuesday played out in Marble Falls, where an extraordinary amount of water poured over the Starcke Dam, carrying with it riverside docks and other large debris.
Homes also were being evacuated in nearby Granite Shoals, and people were sheltering at a middle school.
Water levels along the Llano River at Llano have subsided but are still well above major flood stage. Levels rose to just under 40 feet on Tuesday but fell as the morning progressed, settling at little more than 35 feet, according to the National Weather Service. Major flood stage is 23 feet, and the river isn't expected to drop below that stage until Wednesday.
Heavy rains were also impacting other parts of the state.
Flood warnings were issued for areas north of Houston, and the Fort Worth Fire Department said it responded to some 80 traffic accidents blamed on slick roads and poor visibility Tuesday morning. Officials in Dallas said the rain was causing sewer overflows in several parts of the city but added that its water supply wasn't affected.
In Austin, fire officials temporarily banned all watercraft. Flooding was also occurring in Kerr County, northwest of San Antonio, and other parts of Texas Hill Country, according to the Texas Department of Transportation. The Guadalupe River at Comfort, northwest of San Antonio, was forecast to rise from about 5 feet up to more than 28 feet.
Patricia Sanchez, a meteorologist for the National Weather Service in Fort Worth, said the transition from fall to winter usually brings elevated levels of rainfall - but nothing compared to the amount of precipitation over the last month.
"The ongoing multiple days of rain and the extraordinary amount is of course not normal," she said. "Not for this time of year."
Recent tropical systems and moisture from the Gulf of Mexico are contributing to the amount of rain Texas has seen, she said. Light to moderate rain will continue for the next couple of days but taper off as the weekend approaches, she said.