Watered Down = Precipitation
Precipitation is made up of any type of water that falls to the earth like snow, hail, mist, or rain. Here in Wisconsin, we get about 30-32 inches of precipitation every year. Most of it (80 percent) evaporates or transpires through plants and never reaches lakes, streams, or ground water. The rest, about 6-10 inches of precipitation, runs off the land into lakes, streams, wetlands or rivers (also called "surface water"), or, it soaks right into the ground.
For every inch of water that runs off the land into surface water, three inches seep into the ground to the water table in southern Wisconsin. In the middle of the state where we have sandy soil, nine inches of water seeps into the ground for every one inch that runs off the land into surface water.