[wehadfun]

Is there a toilet that isn't water based? Or are you talking about using tree/hole/... as toilet?

[fulafel]

Yes, UDDT toilets work so well that environmentally conscious people install them in homes even in places with good access to water. https://en.wikipedia.org/wiki/Urine-diverting_dry_toilet

In arid third word countries people have low tech outdoor arrangements like pit toilets.

[fizgig]

Composting or incinerating toilets.