Yes
Yes 17 dollars on up per day depending on size.
17 for the small but you can fit a fairly large backpack in it. Twenty something for a medium, and 35ish for a huge locker. Don't get a locker in the water park as they close at 7 and will lock your stuff in. The lockers near the entrance of Carowinds stay open till 10. Also they will let you leave the park and come back in so don't be afraid of leaving/getting stuff from the car.
Yes, $17 for a day of use.
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