So i get that with fire and lightning style you generally create a flame or electric current by turning the chakra into energy and with wind style you breathe in air but how does chakra create earth and water for those styles? we see that some use water that they drink much like gamatatsu and other jutsu depend on water near you but what about the shinobi who just spit out massive amounts of water without having any around or without being able to store it inside of them by drinking? is it like summoning from somewhere else or is it more along the lines of creating actual mass out of nothing?
In the Naruto-verse, chakra can be converted into all forms of nature. That's the logic of the Anime. A user with affinity to any chakra nature can create that element using his/her chakra. Water release is no exception. Ninja's with an affinity to water nature type can use their chakra to create water. However, the amount of water they create depends on how much chakra they have.