A hidden resource

Groundwater is water that is found below the surface of the ground.  It may be out of sight, but it is a highly valuable resource which supports various economic, environmental, cultural and social needs of our region and community. 

Groundwater mainly comes from rainfall and is stored in aquifers (layers of fractured rock, gravel, sand or limestone below the ground surface) when the water seeps from the ground surface down to the water table directly or from rivers, lakes and wetlands. The slow discharge of groundwater from aquifers to some rivers, lakes and wetlands is a critical part of their continuous supply of water.

How much groundwater we can sustainably use from an aquifer depends on keeping an equilibrium between the rates of recharge (water flowing into the aquifer) and discharge (water flowing out of, or being extracted from, the aquifer). If we take out groundwater more quickly than it is recharged, groundwater levels and quality can decline. If this continues for long enough, it can have negative impacts on the groundwater reserve, the water users and the local environment. 

This section of the Regional Catchment Strategy summarises the state of the groundwater resources in the Port Phillip and Western Port region. It draws mainly on information provided by the authorities responsible for managing and sustaining the groundwater resources in this region.