Hello! All tilesets are located inside the “Tileset” folder, including the water tilesets.
To create the spring water environment like in the spring screenshots, you will need the files "Water Tile", "Tileset Grass Water Spring", "Tileset Grass Cliff Tileset Spring", and "Spring Waterfall". All of them can be found inside the "Tileset" folder.
For the rest of the water decorations, you can find them inside the "Objects" and "Props" folders. If you are looking for beach decorations specifically, check the "Beach" folder instead of "Props".