You shoot out a stream of water, which slams into the door, ricochets right back into you, and knocks you across the hallway into the door on the other side of the wall (which has a handle).

You take 1 damage.
You are wet.
You drop the sponge.

By the way, these hallways are 15 foot wide and these doors with the grids are 10 ft wide. The doors with the handles are usually 5 ft wide.

The door is dinted.