I realize there’s some negatives
There is a risk installing a tank below the belly as well.
Many trailer owners have to weld crossmember supports to secure
OEM water tanks installed under TT's. Most water tanks in MH's are resting on solid interior floors.
Is this idea something that you would intend to use while driving on a highway or is it a very short state park campground kind of road you plan to drive on where you don't want to break down your site to go get more water from a spigot ?
On my first search I found a documented case. Most states now have criminal negligence laws regarding DOT and public highways.
In Georgia, A ladder flew off an improperly secured rack mechanism on a privately owned pickup truck and killed another motorist.
The DA made a criminal negligent homicide arrest. The driver was civilly and criminally responsible for 'failure to properly secure a load while operating a motor vehicle on a public highway." He had no defense, he put the ladder there and it was his truck, he was operating it. It was a felony.
