Gravity fed sinks?

[witchywoman]

So , I am planning to install a gravity fed sink. Has anyone done this and have pictures and /or ideas they can share?
This is not a full time home so I’d rather keep costs down.

Thanks!

[BeNimble]

I had same idea, put tank on the roof. Water pressure goes uphill to fill them, gravity empty them. As long as tank isn't too big (and thus heavy) should be ok.
I found tanks made for horse trailers to water horses that go on the trailer roof, bus roof can handle the weight. Only concern is trees etc can poke holes in them up there.