Drink Diocletian's Water
When I guide my guests in Split, usual situation is that they will carry around a bottle of water they just bought (in some cases it's some kind of cantine), while I do what people in Spliti usually do; drink from some of many public fountains scattered around the city. And that's what I always suggest to guests, too. My apologies to all bottled water producers, but if there is anything the one should spend money while staying in Split, water is not among those things. We are proud about a water we drink, and even such a simple thing as water in Split has deeper story. And it's a great story.
Split gets its water from the same source for the last 17 centuries, because main supply route is actually a Roman aqueduct built by Emperor Diocletian as a supply route for his palace. A system of tunnels and pipes going underground and on top of bridges went from the spring of river Jadro to today's center of Split. Waterline was renovated in the late 1880s, but some 40 percent of it still go same route like in Roman times. And it's still as fresh and clear as always. OK, sometime heavy rain makes it a little bit blurred, but it's fine even then.
So, your job is just to get a bottle. Preferably not one of those for single use, and refill it from any given source you run onto. You can do it in your rented apartment, hotel room, even in a toilet in some bar or a restaurant. It's always the same. What if you get thirsty while sightseeing, or hiking on Marjan (maybe on my Nature and Spirituality of Marjan Hill tour), or swimming at one of Split beaches? Just find a fountain, work of Diocletian's engineers and nature will do the rest, with a little help of generations of Splićani (people living or originated in Split) who made public fountains around the city. You need some assistance? Here is the complete map with all Split fountains and public faucets where it's possible to re-hydrate, or refill a bottle. Cheers.