School/Public Education

What is Groundwater?

When rain falls to the ground, the water does not stop moving. Some of it flows along the surface in streams or lakes, some of it is used by plants, some evaporates and returns to the atmosphere, and some sinks into the ground. Imagine pouring a glass of water onto a pile of sand . Where does the water go? The water moves into the spaces between the particles of the sand.

Groundwater is water that is found underground in the cracks and spaces in soil, sand, and rocks. The area where water fills these spaces is called the saturated zone. The top of this zone is called the water table… just remember the top of the water is the table. The water table may be only a foot below the ground’s surface or it may be hundreds of feet down.

Groundwater is water that is found underground in the cracks and spaces in soil, sand and rock. Groundwater is stored in – and moves slowly through – layers of soil, sand and rocks called aquifers. Aquifers typically consist of gravel, sand, sandstone, of fractured rock, like limestone. These materials are permeable because they have large connected spaces that allow water to flow through. The speed at which groundwater flows depends on the size of the spaces in the soil or rock and how well the spaces are connected.

Source: Groundwater Foundation

What is the Hydrologic Cycle?

The Water Cycle or Hydrologic Cycle is a series of movements of water above, on, and below the surface of the earth. The water cycle consists of four distinct stages:

  • Storage
  • Evaporation
  • Precipitation
  • Runoff

Water may be stored temporarily in the ground; in oceans, lakes, and rivers; and in ice caps and glaciers. It evaporates from the earth’s surface, condenses in clouds, falls back to earth as precipitation (rain or snow), and eventually either runs into the seas or re-evaporates into the atmosphere. Almost all the water on the earth has passed through the water cycle countless times.

Source: “Water Cycle,” Microsoft Encarta Online Encyclopedia 2003. All Rights Reserved.

Educational Resources

  • TWDB Kids Web Site – This web site features interactive games and a new 6th grade curriculum. The games reinforce concepts taught in the Major Rivers program and the new 6th grade curriculum.