(Updates are Central Time)
1:45 p.m. A boil water notice has been issued for Hays County residents east of Interstate 35 and western Caldwell County.
Water needs to be boiled at 212 degrees Fahrenheit for one minute to decontaminate and purify the water, Hays County officials said.
“It is very important to do so in case there is/was any accidental contamination introduced into the water supply, due to the recent flooding event,” Hays officials wrote in a statement.
Officials advised people to consult this link for further instructions: http://traveltips.usatoday.com/long-boil-water-purification-62933.html
11:25 a.m. update: The Hays County cities of San Marcos and Wimberley were hardest hit after torrential rain swelled the normally scenic Blanco River into a destructive wall of water early Sunday.
At least 1,000 people remained in Hays County shelters Sunday morning after losing their homes or being stranded in a part of the Hill Country dotted with low-water crossings. As a result, Hays County officials ordered a nighttime curfew beginning at 9 p.m. for San Marcos, Wimberley and unincorporated areas south of RM 150.
At least 400 homes in San Marcos and Wimberley were destroyed, and many more are damaged, officials said even as rooftop rescues continued into the late morning.
The Blanco River runs through both towns, and it was swollen by nearly 10 inches of rain that fell Saturday night over neighboring in Blanco County. Upstream in the town of Blanco, the river ran roughshed over its banks through Blanco State Park and reached the U.S. 281 bridge.
In Wimberley, the river crested at 40 feet — 27 feet above flood stage. The flow of the river that had been measured at 400 cubic feet per second at midday Saturday had accelerated to 69,000 by 4:30 Sunday morning.
When the river reached San Marcos further downstream, it swept into houses and up over Interstate 35, closing the highway for several hours Sunday morning.
In Austin, Barton Creek flooded and sent muddy water spewing over the dam at Barton Springs Pool, which will require considerable cleanup before reopening.
On the Highland Lakes, officials at the Lower Colorado River Authority opened gates at Max Starcke Dam in Marble Falls to relieve floodwaters and allow water to rush into Lake Travis, which was reported to be more than half full for the first time since 2012.
The Lake Travis basin at Mansfield Dam was at 645.56 feet above sea level at 11:15 Sunday, 14 feet higher than the same time a week ago.
The storms that brought the heavy rainfall also delivered strong winds, with one gust measuring 75 mph at Austin-Bergstrom International Airport. Winds knocked down power lines, trees and damaged several buildings, including a Northeast Austin apartment complex where residents thought they had been hit by a mini-tornado late Saturday night.
10:14 a.m. update: At least 1,000 people are in shelters in Wimberley and San Marcos, officials said in a news conference Sunday morning.
At least 400 homes in the two communities have been destroyed and many more are damaged, officials said.
Dozens of water rescues are underway in Wimberley and San Marcos, including efforts by National Guard troops.
“Right now is not the time to try to return to your homes,” San Marcos Fire Marshal Ken Bell said.
In a Sunday morning news conference, San Marcos Mayor Daniel Guerrero said more rains are expected in the next 48 hours and the situation remains dangerous.
Meanwhile, Kyle Police officers are in the process of removing barricades and reopening the Interstate 35 business route within Kyle.
But on the outskirts of the urban areas, drivers faced frustrating traffic obstacles.
Trucker John Airhart started his day off north of Austin at 4 a.m., his 18-wheeler laden with a dozen diesel engines. At 8:15 a.m., around the time he was supposed to be approaching Laredo, he instead found himself smoking a cigarette in his cab on the shoulder of Texas 21 South, beside a soggy San Marcos field.
Texas 21 by San Marcos Municipal Airport had been closed in the latest in a series of detours he had endured.
He said he was staying off the toll road because he didn’t want to pay the fee, which he heard was about $46.
“What’s irritating is they don’t lift the toll during adverse conditions,” said the Pittsburgh-based driver.
6:40 a.m. update: Interstate 35 at the Blanco River is open again in both directions, San Marcos and TxDOT officials said.
6:25 a.m. update: San Marcos officials said the city’s Activity Center is at capacity with more than 300 people seeking shelter there.
Residents displaced by flood waters are being encouraged to go to Maria Hernandez Elementary School on Stagecoach Trail.
The San Marcos neighborhoods of Blanco Gardens, Crepe Myrtle, Pecan and Hackberry streets as well as parts of Blanco Vista near the Blanco river have been evacuated.
Meanwhile, about 250 people have sought shelter at Wimberley High School, where volunteers say blankets and food are in high demand.
Earlier: San Marcos residents on Riviera, Riverside, or anywhere in the Rio Vista subdivision have been ordered to evacuate, San Marcos city officials said.
A temporary shelter has been set up at the San Marcos Activity Center.
Interstate 35 is being closed at the Blanco River between the cities of Kyle and San Marcos, starting at Center Street. San Marcos Fire Department rescue boats are responding to the flooding of I-35 at the Blanco River.
Kyle Fire officials said I-35, Texas 80 and Texas 21 are now closed. Water rescues are ongoing near those highways, the National Weather Service said.