Watersheds and Aquifers

Watershed

An area of land where all of the water drains off and collects in the same place, such as a creek, river, bay, or ocean. They are also called drainage basins

Tributaries

The streams and smaller rivers that feed into a main river

Watershed Divide

An area between two different watersheds. It is often marked by higher terrain or ridges that separate the flow of water into distinct drainage basins.

Reservoir

A lake that stores water for human use.

Groundwater

Water that has seeped down into the soil and collects in the spaces between soil and rocks underground.

Aquifer

An underground layer of permeable rock or sediment that holds water

Porosity

The amount of empty space in rocks or soil where water can be stored, similar to the holes in a sponge.,

Permeability

How easily water can flow through a material, determined by the size and connectivity of its pores.

Impermeable

Water cannot pass through easily

Saturated Zone

The layer of soil or rock where all the pores are filled with water, located below the water table.

Unsaturated Zone

The layer of soil or rock above the water table.

Water Table

The top of the saturated zone in an aquifer.

Percolation

The process by which water moves downward through soil and rock layers due to gravity, recharging aquifers.