Yeah so that exists and it's not going so well for the UK. I will edit with some links.

Edit:

Very broadly water utilities in the UK and north America largely started off private but public ownership is still the norm for centralized system of idk > 100 people?

Tbh I'm high and not bothering to look stuff but but I'm guessing that it was sewage treatment which lead water utilities (handling both potable and sewage) being public. You can charge people for water, but unless the government is forcing people to connect to a sewer and get rid of pit latrines etc there is no market for it. (Fun fact domestic connections to sewers predate the widespread use of septic tanks)

Migration to urban centres due to industrialization and the industrial processes themselves were the main loading of sewage, which overwhelmed natural systems that had previously been able to support the community.

Someone had to treat the sewage because it was fucking up the drinking water. Who has to deal with stuff like that? The government! So they run the sewage plants. And because the private drinking water plants were run for profit and not for health, a lot of them were extremely bad they got shut down. Once again, the government had to step in because they needed to enforce standards.

Toronto and Ottawa have very interesting and very divergent experiences with that relationship. If someone is interested I can see if I can dig up an article someone wrote about it.

Anyways, sometimes the government made developers pay directly for the construction, operations and maintenance of a plant, but now in Ontario for the most part they just charge development fees. Small communities like trailer parks or ski villages typically have their own little plant or over glorified septic tank.

I came here to argue that there are in fact private sewage companies and they are often disasters, but I think the above kind of proved that the origin of public water utilities was the failure of the private sector to get their shit together.

Well that's awkward.

Anyways, fuck Thames Water : https://en.wikipedia.org/wiki/Thames_Water