HOUSTON -- With flood waters continuing to rise and more Texas residents in need, Gov. Greg Abbott activated the entire Texas National Guard for hurricane relief efforts along the Gulf coast.

"We want to be sure we are doing all we can to maintain safety and security for all of Texas," the governor said in a press conference Monday.

As rainfall continues to pound Houston and the Gulf Coast, an additional 9,000 Texas National Guard members will join the 3,000 who had been on duty over the weekend conducting search and rescue operations. They will join 30 state agencies, FEMA and the Department of Homeland Security. Army and Air National Guard troops from Oregon, New York, Connecticut and Nebraska have also been sent to help.

"The need is massive now," said Lt. Col. Travis Walters, public affairs officer for the Texas Military Department. "It's hard to overstate how many people are in dire need."

Guard members have already supported a wide range of operations, from aiding elderly and residents with limited mobility to providing transport for residents who were stranded from rising flood waters.

Many Guard members have deployed to the Houston area and others are fanning out across the state's southeastern coast to help with problems caused by the hurricane's winds and rain.

"This will not be over today or tomorrow," Walters said. "We are committed to being here to be on duty, to help our fellow Texans as long as we are needed."

In addition to flood evacuation, National Guard and Air National Guard members are also performing medical evacuations with helicopters and a C-130 aircraft.

Residents stranded in the flood waters or on rooftops are being rescued by the Texas National Guard and pulled into helicopters. In addition, Guard members are helping residents find adequate shelter.

"We are just beginning the process of responding to the storm," Gov. Abbott said. "We are still involved in the search and rescue process. Our No. 1 goal from Corpus Christi all the way to east of Houston is still protecting and preserving life and rescuing every person that we can find."

Walters stressed that the storm and flooding are still ongoing and more residents will need assistance in the coming days. Many residents lack adequate necessities, including food and water.

"This is not going to be a single agency effort," Walters said. "It's not just going to be the Texas Department of Public Safety or the Texas National Guard or FEMA that responds to really the dire needs of an unprecedented event. This is going to take a full national and community effort."

(An interview by Kayla Cain for Soldiers Radio News contributed to this report.)