An already-swollen reservoir west of downtown Houston overtopped its spillway Tuesday, sending an “uncontrolled release” of Harvey’s floodwaters into nearby neighborhoods, as a separate levee breach south of the city prompted an urgent warning for residents to leave immediately.
Floodwaters in the the Addicks Reservoir, located about 19 miles west of downtown, went over the top of the 108-foot spillway for the first time in history, threatening immediate surrounding subdivisions.
Jeff Lindner, a meteorologist with the Harris County (Texas) Flood Control District, said it was “something we’ve never seen before” at a morning news conference.
“This is not going to happen fast, this is a slow rise,” Lindner told reporters, adding the flow of water going over the reservoir into neighborhoods will increase as the levels in the reservoir behind continue to rise.
Hours after the Addicks Reservoir was overtopped, officials in Brazoria County, located south of Houston, warned that a levee at Columbia Lakes had been breached by floodwaters and urged any residents who had not already evacuated the area to leave immediately, writing “GET OUT NOW!!”
The level of water in Addicks Reservoir and neighboring Barker reservoir in Houston is so high the flood gages have themselves flooded, according to Lindner, who added the flood control agency is working quickly to repair them and has law enforcement on scene to provide readings.
“The biggest challenge we face right now is to determine how the flow interacts with the system, and how the water will go as it comes out of the spillway,” he said.
Lindner said the agency believes the additional water will flow towards the Sam Houston Tollway, then south to the area around Interstate 10, known as the Katy Freeway and, eventually, Buffalo Bayou, which leads to downtown Houston.
County officials said they are monitoring six neighborhoods around the reservoirs, and encouraged residents in those areas to evacuate before the water levels rise.
“Once the water comes into the street you aren’t going to be able to leave,” Lindner said.
Lindner earlier told Fox News the spillover will cause “serious flooding in immediate areas,” starting as a trickle, then becoming an uncontrolled release of water. Second-story homes also will be at risk, Linder added.
Lindner said this does not mean that downtown Houston will necessarily be greatly impacted, but officials don’t fully know what will happen because they’ve never faced this situation before.
The meteorologist described the situation to Fox News as “uncharted territory” for the city.
The Army Corps started releasing water Monday at the Addicks and Barker reservoirs because water levels were climbing at a rate of more than 6 inches per hour, Corps spokesman Jay Townsend said.
The move was supposed to help shield the business district from floodwaters, but it also risked flooding thousands more homes in nearby subdivisions. Built after devastating floods in 1929 and 1935, the reservoirs were designed to hold water until it can be released downstream at a controlled rate.
In Houston’s southwestern suburbs, officials in Fort Bend County, Texas, warned Tuesday the Brazos River is projected to crest at 59 feet, FOX 26 Houston reported.
The Fort Bend County Office of Emergency Management issued a new advisory Tuesday warning subdivisions where residents should prepare to be affected by the floodwaters.
With nearly two more feet of rain expected on top of the 30-plus inches in some places, authorities worried the worst might be yet to come from Harvey. As of Tuesday, at least 14 people have died in the historic storm, including a family of six trying to escape the floodwaters, authorities said.
“We know in these kind of events that, sadly, the death toll goes up historically,” Houston Police Chief Art Acevedo told the AP. “I’m really worried about how many bodies we’re going to find.”
The storm is generating an amount of rain that would normally be seen only once in more than 1,000 years, said Edmond Russo, a deputy district engineer for the Army Corps of Engineers.
Rescuers meanwhile continued plucking people from inundated neighborhoods. Mayor Sylvester Turner put the number by police at more than 3,000. The Coast Guard said it also had rescued more than 3,000 by boat and air and was taking more than 1,000 calls per hour.
Fox News’ Griff Jenkins and the Associated Press contributed to this report.