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Why is groundwater
important?
Groundwater makes up nearly 70%
of all the world’s freshwater; only 0.2% is found in lakes,
streams or rivers and 30% is bound up in snow and ice on mountains
and in the polar regions. As rivers and lakes tend to be supported
by groundwater, it is not exaggerating to say that almost all
the water we use for agriculture, industry and drinking water
is either groundwater or has been groundwater at some point
in the water cycle. Groundwater
plays a number of very important roles in our environment
and in our economies. In the environment it supports rivers,
lakes and wetlands, especially through drier months when there
is little direct input from rainfall. The flow of groundwater
into rivers as seepage through the river bed, known as baseflow,
can be essential to the health of wildlife and plants that
live in the water.
Many
reasons make groundwater a good choice for a water supply:
 It
is often present in those areas where there are limited
surface water sources.
- The quality of groundwater is usually very good, and
it does normally require much less treatment than river
water to make it safe to drink. The soil and rocks through
which the groundwater flows helps to remove pollutants.
- The quality doesn’t change much through the year,
which can be important for industry.
- Groundwater also responds slowly to changes in rainfall,
and so it stays available during the summer and during droughts
when rivers and streams have dried up.
- Groundwater is relied on in many parts of Africa and
the developing world, because it can often be found close
to villages and it does not require the large costs which
may be associated with capturing, treating and piping surface
water.
- Groundwater doesn’t require expensive reservoirs
to store water in before it is used.
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