Where does groundwater come from and where does it go?

How do aquifers receive recharge?

Groundwater stored in aquifers comes mainly from rainfall. Depending on the type of aquifers this could be rainfall that occurred recently or up to thousands of years ago. Water can also seep through the ground surface and down to the water table from streams, lakes, rivers and other surface water bodies. Deep confined aquifers can also receive recharge from the aquifers that exist around them through downward leakage, throughflow and even upward movement from underlying aquifers (as a result of artesian pressure).

How does groundwater discharge from aquifers?

Groundwater flows through an aquifer until it reaches a discharge point such as a stream, river, wetland, spring or even the ocean. It can also flow into another aquifer that is either alongside, above or below. Where groundwater is stored very close to the surface it can evaporate directly into the atmosphere or be used by plants and trees. It can also be extracted from aquifers via pumping from a bore.  To view a simple diagram showing recharge and discharge visit our What is groundwater page.

Water balances

Water balances are used to describe the relative importance in the major inflows (recharge) and outflows (discharge) of an aquifer.

Groundwater inflows and outflows

This diagram shows the primary inflows and outflows of aquifers.  Blue arrows represent inflows, red arrows represent outflows. Diagram: ©Spatial Vision Innovations Pty Ltd (2015)