HOUSTON • As officials in Houston struggle to manage the massive catastrophic flood waters unleashed by Tropical Storm Harvey, reservoirs built to handle drainage water have hit over-capacity, which could lead to heavier flooding in the area.
The slow-moving storm has brought torrential downpours to Texas, killed at least nine people, led to mass evacuations and paralysed Houston, the fourth most-populous United States city.
Soaked and desperate, more than 8,000 people were taken to shelters in Houston, a city of more than six million. Some 30,000 people were expected to pour in later.
Officials in Harris County, where Houston is located, said reservoirs built to handle drainage water were beginning to overflow yesterday.
They released water to alleviate pressure on two dams, a move that would add to flooding along the Buffalo Bayou waterway that runs through the area.
"This is something we've never seen before," said Mr Jeff Linder, a meteorologist with Harris County's flood control district.
"We have uncertainty in how the water is going to react" when releases from the reservoirs hit overflowing drainage, he said.
NEVER SEEN BEFORE
This is something we've never seen before. We have uncertainty in how the water is going to react, when releases from the reservoirs hit overflowing drainage.
MR JEFF LINDER, a meteorologist with Harris County's flood control district.
Officials encouraged residents in six neighbourhoods around the reservoirs to evacuate before the water levels around their homes rise.
Officials in Brazoria County, outside Houston, also warned on Twitter yesterday that a levee at Columbia Lakes had been breached by flood waters from the storm, and urged any residents who had not already evacuated the area to leave immediately.
President Donald Trump headed to Texas yesterday to survey the response to Harvey, the first major natural disaster of his White House tenure.
The storm has roiled energy markets and wrought damage estimated to be in the billions of dollars, with rebuilding likely to last beyond Mr Trump's current four-year term in office. The President was scheduled to arrive in Corpus Christi, near where Harvey came ashore last Friday as the most powerful hurricane to strike Texas in more than 50 years. He will later go to the Texas capital, Austin.
Much of the Houston metropolitan area, where 6.8 million people live, remained underwater yesterday, with some parts of the region recording more than 1m of rain since the storm's arrival.
Dangerous rescues went on through the night as police, firefighters and National Guard troops in helicopters, boats and trucks pulled stranded residents from flooded homes.
Some who fled the rising flood waters in the Houston area found they had few options, as roads were washed out and emergency services overloaded.
"I'm still soaking wet and freezing cold and they are short on blankets," said Ms Cheryl Whitely, who sat under a portico outside a Red Cross shelter with her children, mother and six animals.
The group was kept outside because of their pets, Ms Whitely said.
The storm centre was likely to remain just off the coast of Texas till yesterday night before moving inland over the north-western Gulf of Mexico today, according to the US National Hurricane Centre.
Before Harvey, the last Category 4 hurricane to make landfall in Texas was Carla in 1961. Its high winds and torrential rain destroyed about 1,900 homes and nearly 1,000 businesses, the National Weather Service said.
Harvey was expected to produce another 18cm to 33cm of rain until tomorrow, over parts of the upper Texas coast into south-western Louisiana. The floods could destroy as much as US$20 billion (S$27 billion) in insured property, making the storm one of the costliest in history for US insurers, according to Wall Street analysts.
REUTERS, AGENCE FRANCE-PRESSE