Unmetered water service is (or was) common in, of all places, California's Central Valley, including the cities of Sacramento, Bakersfield, Modesto, Merced, and Lodi, legacy of the state's rather arcane (and highly nonscientific and environmentally hostile) Spanish-based water rights laws. Unsurprisingly, when meters were installed, even where billing wasn't based on usage, massive wastage through broken infrastructure was rapidly discovered, an interesting example of "what isn't measured cannot be managed".

See: <https://www.kqed.org/science/15191/california-communities-th...> and <https://www.sacbee.com/news/local/article201568164.html>

Other regions without use-metered water include parts of the UK, and Asia where the concept is called "non-revenue water (NRW)":

UK: <https://www.ofwat.gov.uk/households/your-water-bill/unmetere...>

Asia: <https://www.jstage.jst.go.jp/article/jscejer/76/7/76_III_277...> (PDF).

NRW: <https://en.wikipedia.org/wiki/Non-revenue_water>

Our service is metered over on the other side of the lake (Grand Rapids, MI), but I can only remember a couple of times we've had to restrict water usage (odd-even sprinkling was the worst of it) in the almost 40 years I can remember. Lake Michigan is a hell of a reservoir.

Water is metered now, but still extraordinarily cheap.

Most forever-on fountains in the city are that way not because the water is abundant but rather as a means to reduce the amount of lead consumed by users.

Each spring all fountains run continuously for about a month to flush the system from winter stagnation.