Portage County Groundwater
What is the Water Cycle?
Water can be found on Earth in three different states: liquid, solid (ice), and vapor. Not only does water cover three fourths of the Earth's surface, but it also flows underground, and floats in the air. The following percentages show the water distribution on Earth:
| Ocean | 97.2% |
| Ice Caps/Glaciers | 2.14% |
| Groundwater to depth of 13,000 ft. | 0.61% |
| Fresh Water Lakes | 0.009% |
| Inland Seas/Salt Lakes | 0.008% |
| Soil & Subsoil Moisture | 0.005% |
| Atmosphere | 0.001% |
| Rivers | 0.0001% |
| Biota (within living plants, animals, & humans) | 0.0001% |
| (Source: Fetter, C.W. (1994). Applied Hydrogeology, 3rd ed. Prentice Hall Inc.: NJ, p. 4. ) | |
The water cycle, also known as the hydrologic cycle, describes the movement and interrelationships of surface water, groundwater, and water in the atmosphere. The water cycle is the continuous circulation of water from the atmosphere to the earth and back to the atmosphere including condensation, precipitation, direct runoff, infiltration, groundwater, evaporation, and transpiration.
Portage County receives an average of 31 inches of rain and snowmelt per year. In the sand plain and sandy glacial drift areas, 1-2 inches of this precipitation becomes direct runoff, and 29 inches infiltrates into the ground. Of this 29 inches, 20-22 inches evapotranspire and 10-11 inches becomes groundwater. For the northwest part of the County, which is comprised of silt and clay soils, 6-8 inches becomes direct runoff, and 22 inches infiltrates into the ground. Of this 22 inches, 20-22 inches evapotranspire and 1-4 inches becomes groundwater.4, 7, 8
To learn more about precipitation and runoff, click here
Additional information on the water cycle can be found on the following websites:
Italicized words are defined in our glossary