This is a remix of the water pump with evaporation slide added to change rate and a second pump added.
The turtles do the drawing of earth, sky, and pump. Then the water in the ground is added with the "create groundwater" procedure using recursion. Next, water gets pulled by the force of gravity, slowly percolating through the ground. Water gets drawn up into the pump (and used but this part of the cycle is not shown). Finally, the water is "recycled" as rain, falling quickly through the sky, where it has a chance of evaporating.