HOUSTON, April 18 (UPI) -- Texas Gov. Greg Abbott declared nine counties in the southeastern part of the state a 'disaster area' as the region continues to be dealt punishment from thunderstorms and flooding -- severe weather that has so far killed several people, officials said.
More than a foot of rain had fallen in the gulf region, which includes the populous Houston metropolitan area, by Monday afternoon. Abbott signed the disaster declaration for Harris, Bastrop, Colorado, Fort Bend, Grimes, Montgomery, Waller, Wharton and Austin counties.
At least five people have died, news media reported.
The disaster declaration opens additional resource avenues and expands the state's authority, including the setting of curfews for residents. A federal declaration could follow in the coming days if infrastructure damage is sufficient.
Heavy rain inundated the Houston area with nearly 20 inches by Monday afternoon. The severe rain is expected to continue Tuesday.
"About one half of the state is still under flood warnings," he said at a news conference. "And one of the most important messages I can convey to Texans across the state at this moment is ... it's very, very important for everybody, in whatever community they live in, if you may encounter potential flooding or if you receive any type of warning, heed those warnings."
The weather has damaged hundreds of homes and effectively paralyzed the region, the Houston Chronicle reported Monday.
"Dozens of Water Rescues Underway Near Houston as Floods Continue to Grow. Turn around don't drown," Abbott tweeted.
Officials are comparing the flood to Tropical Storm Allison in 2001, when more than two feet of rain drenched southern Texas.
"This is a major rain event," Harris County judge Ed Emmett said. "I hate to use the word 'Allison' but it's got all the similar features."
Emmett said more than 1,000 homes had already flooded, and emergency workers responded to more than 1,200 flooding emergencies.
Houston's George Bush Intercontinental Airport, which was deluged by rainfall Monday, canceled more than 600 flights and delayed 1,100 others. The city's other airport, William P. Hobby, canceled more than 100 flights. METRO Houston also shut down all rail and bus service.
Officials said one man died after driving an 18-wheeler into high water, but added that a medical condition may have contributed to his death.
Jeff Lindner, a meteorologist with the Harris County Flood Control District, said that "significant widespread flooding" was reported northwest of Houston.
Harris County spokeswoman Rosie Torres advised residents to "stay home and off the roads."
In a statement, Harris County officials warned, "If your home or apartment takes in water, DO NOT LEAVE. You are safer inside your home. Straying into deep or fast moving flood waters means certain death."
Officials warned that the situation could worsen as seven bayous across Harris County had flowed over their banks and two damns were in danger of breaking.
"To everyone in Houston, please stay safe and avoid traveling. Our prayers are with you," Democratic presidential candidate Hillary Clinton tweeted Monday.