Home built water tanks

Sine my trailer is going to be more Vardo shaped I wont have many curves to deal with I was thinking of using PVC pipe within the top sections of the wall and on flat spots on the ceiling so I could have my water tank as stealthy as possible and to help take up very little space.....Would this work?? I'd only fill it when I got to my destination so while traveling it would be mostly empty. I like the idea of gravity fed system so that it would be quiet in the middle of the night if you had to turn it on you wouldn't be walking anyone with a pump kicking on and off...and I thought that possibly the PVC pipe would add some extra structure to my build.....Looking forward to hearing your input Thanks