This builds on the the base model of a water pump for the Shared Water Resources module, which was remixed from the Project GUTS starter model. My models are intended for my 6th grade science class.
Project GUTS model:
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.
Additions:
This model starts with a data box that counts the "groundwater." For simplicity's sake, it includes all water on the screen, not just the water in the ground at any given moment. This also includes a data box to count how much water has been pumped. There are two pumps, #1 and #2. There is a drip pipe to return treated wastewater to the ground. Sliders have been added to control the evaporation rate, precipitation rate, pavement, permeability, and wastewater recovery rate.
I have added the evaporation slider to test whether the model continues to run smoothly with various configurations for the slider.