Inland Waters
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aquifer is more saline than the T1 aquifer and exhibits a salinity of around
<1,000 – < 3,000 mg/L.
Condition Indicator:
Groundwater extraction versus water availability
In order to maintain a sustainable environment, the need to allocate water to the
environment as well as for extraction uses is essential. This indicator provides
information about the sustainable balance between water recharge and water
use.
The South Australian Department of Environment, Water and Natural
Resources assesses groundwater recharge and groundwater use and provides
estimates of the sustainable limits within the Torrens major sub-catchments,
however has no data available on Port Adelaide Enfield groundwater recharge
and the sustainable limit estimate. Groundwater Allocation Plans are currently
being developed for the Northern and Central Adelaide Groundwater areas,
which will enable greater measurement and monitoring of these indicators.
Observation wells
Observation wells managed by the Department of Environment, Water and
Natural Resources monitor the depth of the water in aquifers and the salinity.
The results from these wells are available to the general public via the Water
Connect website. This data forms part of the investigation for the prescription of
water resources as discussed above.
The following graphs demonstrate the Standing Water Levels (SWL) measured
since the last Port Adelaide Enfield SoE 2007 report. As indicated some records
go back as far as the 1960s within the City of Port Adelaide Enfield. Generally
the salinity in most observation well locations is increasing. The SWL (Standard
Water Level) is the distance in metres from the ground surface to the water
surface.
The water level in aquifers fluctuates naturally as indicated in the graphs below.
Rising water levels could indicate that land could be at risk from dry land salinity
and provides an early warning system. Salinity problems can occur when
groundwater is within 2m of the soil surface.
Pressure Indicator:
Trend of Standing Water Levels (SWL) of observation
wells.
This indicator shows the trend of water and/or salinity levels over time as a
measure of dry land salinity, and is an important tool for resource management.
