Couple of thoughts, first I dont know what kind of truck you have and if you have any experience hauling but 275 gal of water is 2200 lbs. Be sure your truck can handle that, then the water will splash around if you go to fast and cause more trouble.

What I would do is get a 35-50 gal plastic drum from the local fertilizer plant (thats where I get mine) then fill them with water and attach a small solar panel and pump system to each. My neighbor has done this with several tress on his creek property. He does not have to fill it up that much, and the trees were fine last time I checked.

I need to take a closer look at the set up but that is how it looks like he does it and he has them on about 8 trees and trust me its cost effective or this guy would be toating the water himself, not useing the lazy man set up.

Get out and fish.