WASHINGTON – The National Guard is prepared to activate between 20,000 and 30,000 troops to assist southeast Texas with deadly flooding, swamped bridges and overrun levees as Tropical Storm Harvey continues bring devastation to the area.

“It’s hundreds of thousands of homes” that are surrounded by floodwaters now and need help, said Air Force Maj. Gen James Witham, the National Guard Bureau director of domestic operations. “I just can’t put a magnitude on the square mileage.”

On Tuesday the scope of the storm and flooding raised questions as to whether Texas has activated enough military assets to assist all of the residents trapped, and whether additional federal military forces could be pulled in to help with the rescue.

The greater Houston area has a population of about 6 million people. 

Texas Gov. Greg Abbott announced Monday he had activated 12,000 Texas National Guardsmen, however to date only about 3,000 were on the ground in the Houston area assisting. 

“As far as I am aware of, Texas to date has been given everything they have asked for,” said Witham, who briefed reporters at the Pentagon on the military’s response.

As of Saturday, the U.S. Coast Guard had reported conducting 3,600 rescues, and Witham said the Texas National Guard had conducted about 3,500 rescues. It was not immediately clear if some of those figures overlapped, Witham said.

National Guard to activate up to 30,000 troops in response to Texas flooding

The National Guard is preparing to activate up to 30,000 troops as Tropical Storm Harvey continues bring devastation to the Texas Gulf Coast.

Federal military forces that have already begun assisting with search and rescue include members of U.S. Northern Command and U.S. Marine Corps reservists from Charlie Company, 4th Amphibious Assault Vehicle Battalion. The amphibious assault ship Kearsarge, which would be needed to support scores of additional helicopters Texas is requesting, is also headed to the area.

The additional federal military forces, which would have to be requested by Abbott, would be used to augment Texas’ National Guardsmen. 

So far the majority of  Texas’ response to the storm has come from its National Guardsmen who have mobilized and worked around the clock over the last few days as well as from private citizens assisting each other, Witham said.

National Guard responds to Texas flooding after Harvey

As those first responders begin to wear out, Witham said he expected that additional troops would be brought in. The National Guard bureau is now planning for the weeks after Harvey, when fresh guardsmen and military troops with expertise in engineering and security will be needed, he said.

“At the height of [Hurricane] Katrina, there were approximately 50,000 guardsmen and a little over 20,000 active component forces. I anticipate … there will probably be a similar ratio,” Witham said.

The National Guard has more than 450,000 service members to call upon, Witham said.

Marine Corps Times correspondent Jeff Schogol contributed to this report.