Where Does Groundwater Come From?
Water seeps down to become ground water in two main ways:
|
|
|
|
This process is known as "recharge." On a Northern Territory wide scale, climate has a big influence on ground water recharge.
At one extreme is the arid interior where aquifers are replenished infrequently, perhaps only once every several years. Heavy rains occasionally fall in these areas and recharge tends to occur through the beds of the normally dry rivers.
In the humid north, rainfall is high and falls regularly each year. Aquifers are replenished each wet season and the amount added to the ground water is generally greater than in the arid south. Recharge is also more widespread, occurring through the soil and swamps as well as river beds.
The amount and type of recharge varies between these two extremes depending on the location. On a more local scale, recharge is influenced by soil, vegetation and aquifer types.
Groundwater Does Not Come from New Guinea!
There is a widespread myth that some groundwater in the Territory originates from the mountains of New Guinea. The majority of ground waters are recharged within kilometres or tens of kilometres from the bores or springs where the waters discharge.
In some of the larger aquifers this distance may extend up to several hundred kilometres. New Guinea is at least 400km from the Territory and there are no aquifers that are common to both places.
It would be a physical impossibility for ground water to travel from New Guinea to the Northern Territory.
