Water Kit - Hunter Water

Impacts on groundwater
quality in the hunter
Groundwater is vulnerable to human
impacts. Even small changes to the
groundwater catchment can create a
slow but significant change to water
quality and quantity over time.
There are a variety of impacts on
groundwater management, including:
• Water extraction: overuse of
groundwater can affect the level
of water stocks and potentially
remove the natural buffer between
the aquifer and saline sea water,
allowing a flow of sea water into the
freshwater sandbeds.
• Industrial land use: industrial
development can result in
deforestation, water pollution and
compaction of the sandbeds, and
reduce the storage capacity and
quality of the aquifer.
• Urban development: pesticides
and fertilizers used in urban areas
can infiltrate the soil and move into
the aquifer. Large areas of the land
sealed as roads, roofs, driveways
and paths cause a decrease in
infiltration and thereby reduce
replenishment of groundwater
supplies.
• Sewerage disposal: leaking septic
tanks can seep into groundwater
and cause contamination.
• Mineral and sand mining: can
cause damage to groundwater by
exposing the water to the air. This
begins as a series of chemical
reactions which can result in ‘grey
water’ and increased concentration
of minerals, such as iron.
Managing Groundwater in the
Lower Hunter
The sustainable management of
groundwater will ensure that this resource
is available for continued human use, and
remain an important factor in sustaining
local ecosystems.
Up until 1991, Hunter Water managed
Tomago Sandbeds to provide water to
Newcastle. Under Hunter Water’s
management, some groundwater sources
were classified as special areas and
attract a high level of protection. In other
areas licences were necessary to access
a specified volume of water. These
strategies ensured that the quality of
water remained high.
Since 1991 the management of the
sandbeds has been controlled by the
Department of Infrastructure, Planning
and Natural Resources. New legislation
empowered DIPNR to manage the
resource to maximise benefits and
minimise impacts.
The Hunter Water (Special Areas
Regulation came into effect in 2003,
replacing the 1997 regulation. This
regulation gives power to the Director
General to issue directions for the
management, disposal or removal of any
substance that may harm any waters in
the Special Area.
The Water Management Licence issued
to Hunter Water under the Water Act
1912 is administered by DIPNR. The
licence authorises Hunter Water to take
and use water, and places rules on
extractions from Chichester and the
Williams River, and groundwater from
Tomago and Tomaree Sandbeds.
The licence requires Hunter Water’s
management of water resources to
follow the principles of sustainability
and to manage its land in order to
protect water quality. Management of
the Sandbeds is guided by the
following principles:
• Water levels in the aquifer should
be managed in a way that maintains
the health of wetlands and other
ecosystems
• Unacceptable salt water intrusion
is prevented by maintaining
appropriate water levels
• Unacceptable changes in the
levels of chemical ions in the
groundwater must be prevented
• The amount of groundwater
extracted annually should not
exceed the average annual recharge
(ie the amount of water entering the
aquifer on average each year)
• maintaining a management plan
for the area
Raw water is primarily extracted from the Inner Barrier zone
Water from the sandbed is extracted by
sinking bores underground
Water kit . ssS . 001 . april 2010
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