Well, it's because South Carolina is famous for its peach production, and the town of Gaffney wanted to create a landmark that would showcase their pride in this fact. It's kind of like how has the Statue of Liberty - it's a symbol of the city's identity. And let's be real, a giant peach is way more fun than your average water tower, right?
I mean, can you imagine if other cities started creating water towers that looked like their claim to fame? Like, a giant pineapple in Hawaii or a massive cow in Wisconsin? It's a fun thought to imagine, and who knows, maybe one day we'll see more creative water towers popping up around the country.