It's interesting how a lot of newer countries just put the right to water directly in the constitution. South Africa says some stuff about the government having an obligation toward "progressive realization" of the goal [1], whereas Slovenia just straight says water is a right [2]. [1]: https://www.gov.za/documents/constitution/chapter-2-bill-rig... [2]: https://www.uradni-list.si/glasilo-uradni-list-rs/vsebina/12...
South Africa has one of the best constitutions in the world on paper because the authors very recently had to reconcile with and forgo their apartheid past. And they had a number of templates to adapt from, including the US, France, Germany, India, etc. Older countries tend to have shittier constitutions.