How does groundwater move?

Groundwater moves more slowly than water flowing down a river or stream. It moves mainly under gravity from areas of high groundwater levels or pressure to areas of low groundwater levels or pressure – in other words it flows downhill. It is also possible for groundwater to move horizontally across an aquitard and even upwards when it is under very high pressure known as artesian pressure.

How quickly does it move?

This depends on the aquifer material. For example in aquifers made up of porous material it moves faster than in aquifers made up of material that is more tightly compacted. Groundwater moves slowly compared with the faster flowing water of rivers and streams. It can take days, years or even thousands of years for groundwater to travel only one or two kilometres.

For more information about how aquifer material can affect how quickly (or slowly) groundwater moves, visit our What is groundwater yield page.

Flow systems

Groundwater moves as part of local, intermediate or regional flow systems. Local flow systems are short and groundwater moves through them quick quickly. Regional flows systems are very long and groundwater can take decades, hundreds or thousands of years to move from recharge point to discharge point.

Aquifers with different flow systems react different to changes. To find out more visit our How do different aquifers respond to change page.

Characteristics of local, intermediate and regional flow systems

	How long are they?	Where are they found?	How long does it take water to flow through them?	How quickly do they respond to change?
Local flow system	< 5km	Mainly shallow, unconfined aquifers	Weeks to years	Quickly (weeks or months)
Intermediate flow system	5 – 30km	Mainly confined middle and lower aquifers	Months to years	More slowly (months or years)
Regional flow system	>30km	Mainly confined middle and lower aquifers	Decades to thousands of years	Very slowly (impact may not be seen in a lifetime)

This table shows the different characteristics of each flow system.

What is groundwater yield Find out more

FAQs Find out more

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