* Route 4: There's a small chance you might find one by searching the tall grass.
* Reversal Mountain: You can find one on the floor inside the mountain.
* Driftveil Drawbridge: Search the tall grass along the bridge.
* Undella Bay: Search the tall grass along the beach.
* Undella Bay (North): Search the tall grass in the northern area of Undella Bay.
Keep in mind that finding Water Stones is a bit random. You may have to search these locations multiple times before you find one. Good luck!