Rock was added in the chapter: Meet Swampy
Rock is a key asset in Where's My Water, It is similar to dirt, but cannot be cut by the player. Any fluid the touches it will bounce of it or can act as an obstacle. However, it can be destroyed by the combination of Ooze and Poison Water, or by the explosions of Bombs. It can also be created when Ooze hits algae. In Where's my Water 2?, rock can be cut by the player in Driller Challenges.