Video of Texas Army National Guard soldiers and Texas Task Force One Swift Water Rescue Team prepping for Hurricane Harvey, city of Bryan, 25 AUG 2017:

U.S. Army Corps of Engineers, Galveston District

12th Flying Training Wing T-6A Texan-2 moved inside hangars at Joint Base San Antonio-Randolph
Video of Texas National Guard 176th Engineer Brigade prepping for Harvey to hit Victoria, 25 AUG 2017:

HC-130J Hercules Combat King-2 at Moody Air Force Base, Georgia, stands by for possible rescue operations following Hurricane Harvey
Video of Georgia HC-130J takeoff for Texas:
Video of Georgia HH-60G PaveHawk takeoff for Texas:

T-1A Jayhawk training aircraft were flown from Randolph Air Force Base, Texas, to Tinker AFB, Oklahoma

European made HC-144 Ocean Sentry on standby at Air Station Corpus Christi, Texas
Video of U.S. Coast Guard SeaHawks based at San Diego, California, deploying to Texas for Hurricane Harvey: