Meanwhile, officials and local reports have indicated that there have been 19 flood-related deaths in Harvey's wake.
Numerous facilities in Houston's Theatre District have sustained damage.
The release of the water means that more homes and streets will flood, and some homes will be inundated for up to a month, said Jeff Lindner of the Harris County Flood Control District. Last night, four cargo planes filled with 137 Galveston residents landed at Love Field, and Rawlings said more planes could be on the way.
"All the cots are lined up, and it's going to be a little tight", the mayor said, but he's confident that the "little city" Dallas has built will provide adequate shelter for southeast Texans who choose to head north in the coming days.
I-10 from Houston to New Orleans is one of the most heavily traveled roads in the country, normally carrying tens of thousands of vehicles each day. As of early Tuesday morning, 9,021 evacuees had checked into the sprawling convention center on the east side of Houston's downtown. Since the storm hit she said she's already waited in many long lines for help.
The Red Cross has also set up other shelters throughout the area.
Osteen said on Twitter that the church was inaccessible due to flooding.
Cots and belongings have been abandoned on the civic center floor, which is under about a foot (30 centimeters) of water. Some have been at the civic center since Monday.
For those waiting out the rain at the convention center, many say they are just thankful to have a dry place to stay but are anxious for the future. Beaumont is just northwest of Port Arthur.
And I think just the ongoing concern would be what to do as more and more people come here. On Monday, rumors swelled that officers were checking the immigration status of those arriving at the convention center.
Harvey is expected to weaken as it slogs through Louisiana and makes it way northward, with Arkansas, Tennessee and Missouri on alert for flooding in the next couple of days.
"Once we lifted off there was applause, and it was a good feeling", Garb said. The number of evacuees is certain to rise further, with the town of Dickinson issuing a mandatory evacuation order on Monday afternoon.
Jefferson County Sheriff Zena Stephens tells the station that county resources can not get to Port Arthur because of the flooding and some residents have gone into survival mode.
Dallas Office of Emergency Management says it's taking lessons learned from Hurricane Katrina in 2005. He also urged residents to get to higher ground and to avoid becoming trapped in attics.
Deputy Marcus McLellan says city's 911 system has been inundated with calls, which are bouncing to other law enforcement agencies.
Meanwhile, there's an end of the rain and a sunny day nearly in sight for the Houston area.
Residents are rescued from their homes surrounded by floodwaters from Tropical Storm Harvey on Sunday, Aug. 27, 2017, in Houston, Texas.
Police Chief Art Acevedo said violators will be stopped, questioned, searched and arrested.
Vaz said he expects the Dallas shelters to remain open for several weeks, even if they are sparsely populated.
The zoo is also offering free admission to visitors impacted by Harvey through September 4.