Goulburn Mulwaree
Indicator: Groundwater
Results for this indicator are also available for [an error occurred while processing this directive]
What the results tell us for Goulburn Mulwaree
Groundwater in the Goulburn Mulwaree Council area is of a moderate quality (DLWC 1999), with a steadily decreasing water table (DWE 2008). Groundwater is of poor quality for human consumption but can be used for some livestock, domestic and limited industrial uses without treatment.
Groundwater supplies
Groundwater flow in the Council area is mostly from intermediate flow systems in predominately sedimentary Palaeozoic rock with some small areas of intrusive and extrusive igneous rock of the same era (DPI 1998). Bore hydrograph data indicates a consistent seasonally adjusted drop in water levels for the reporting period 2004 to 2008, continuing a trend observed since 1991. A low natural rainfall is likely to be the most significant factor which is further compounded by an increase in extraction (Beale et al. 2004).
Groundwater use
Total groundwater extraction in the Goulburn Mulwaree Council area is less than 10 GL/yr compared with a natural recharge of more than 500 GL/yr (AWR 2000). This is considered a low level of extraction (extraction is 0 to 29% of recharge), and sustainable for the Council area.
Goulburn Mulwaree Council supplies 2.3GL/yr of water to its customers (DWE 2006). Previous extraction from four groundwater bores at Kingsdale ceased in June 2007, due to easing of water restrictions from Level 5 to Level 3. Additionally groundwater is supplied to selected allotments in the Tallong Park Estate by a privately-operated groundwater supply scheme.
The State Water Corporation (SWC), on behalf of the Department of Water and Energy, administers much of the water allocation in rural NSW. To recover the cost of administration, infrastructure and future investment, the SWC charges each licensed user. Base charges are either $51.46 for non-monitored or $118.56 for monitored areas, plus a per megalitre access charge. As part of the Lachlan and Macquarie groundwater area, Goulburn Mulwaree is charged a $2.10/ML access charge and $1.09/ML usage charge. Although base charges are consistent throughout the state, access and usage charges vary. Lachlan and Macquarie access and usage charges are approximately average for the State (SWC 2008).
Groundwater quality
As part of its obligation under Public Health Act 1991 the Goulburn Mulwaree Council has an obligation to monitor potable water supplied. The following information was reported in a Parsons Brinckerhoff Drilling and Pump Test Groundwater Investigation Program:
- hardness - samples typically exceeded the Australian Drinking Water Guidelines (ADWG) for hardness, ranging between 417 and 517.5 mg/L.
- pH - samples ranged between 7.1 and 7.7 (laboratory) and 7.3 and 7.6 (field measurements).
- turbidity and colour - samples contained elevated amounts of suspended material, with milky colour water sampled from the bore head. Turbidity decreasing during the tests to generally <0.1 NTU.
- nutrients - total phosphorous levels were generally <0.01 mg/L, with slightly higher values in some airlift samples.
Groundwater salinity in the Goulburn Mulwaree Council is moderate (1,000-3,000 mg\L) (DLWC 1999) with little variation throughout the region. Water is considered suitable for livestock and limited domestic and industrial use only. Groundwater in the area is generally unsuitable for human consumption without treatment.
Managing groundwater demand
Water conservation measures
Goulburn Mulwaree Council is covered, approximately 50/50, by two Catchment Management Authority’s; the Southern Rivers CMA (SRCMA), and, the Hawkesbury-Nepean CMA (HNCMA). A small area to the south-west is administered by the Lachlan CMA. The CMA’s were established to guarantee the protection and sustainable development with each catchment, including impact on water quality and use. With regard to groundwater, the SRCMA and the HNCMA have in place water management targets (SRCMS 2007, HNCMA 2007) for the Goulburn Mulwaree Council. They are:
Southern Rivers CMA
- By 2008, 80% of priority groundwater will be managed according to a water sharing/management plan.
- By 2016, the quality of priority water bodies will be maintained or progressively improved
- By 2016, all water utilities will manage water systems consistent with best practices
- By 2016, residential consumption will progressively be reduced to a set benchmark
- By 2016, a 20% reduction in water use on 2005 usage by irrigators.
Hawkesbury-Nepean CMA
- Putting in place incentive programs to support achievement of targets
- Developing, implementing and reviewing a comprehensive reporting, monitoring and evaluation framework
- Preparing and implementing a strategy that ensures effective communication with the community
- Developing and implementing sub-catchment plans are for the nine priority sub-catchments
- Initially treating and/ or fencing 200 ha of saline discharge sites; then identifying recharge sites in priority sub-catchments and treated 2400 ha of recharge areas
- In non-acidic soils, reducing the rate of induced soil acidification due to agricultural practices
- Not increasing area affected by acid sulphate soils.
- Increasing area of non-urban land managed within its capability
- Increasing the number of properties being managed through a whole-farm management system
- Improving the ability of groundwater systems to support groundwater-dependent ecosystems and beneficial uses
Laws and policy
Outside of regional CMA policies, the use and treatment of groundwater is generally the same throughout NSW. Specifically water management and use is covered under:
- NSW Water Extraction Monitoring Policy (2007): Designed to increase the extent of active monitoring of water extraction to cover 90% of the total volume of water extracted for each water sharing plan.
- NSW Water Extraction Monitoring Standards (2005): Designed to increase the quality of groundwater extraction monitoring.
- National Water Initiative (2004): NSW is a party to the National Water Initiative (NWI), a national initiative to coordinated Australia's water supply to guarantee the greatest possible social, economic, and environmental benefits.
- NSW NWI Implementation Plan: Addresses the initiatives set out in the NWI specific to the State of NSW.
- Living Murray and Snowy Initiatives (2002): Initiative between Federal and State governments concerned predominately with surface water, however, may indirectly impact on groundwater.
- Water Management Act 2000 (NSW): Aim is to protect the supply of water to the environment and water users. Its introduction has been gradual and once fully implemented will largely supersede the Water Act 1912.
- NSW Groundwater Quality Protection Policy (1998): Aim is largely to protect groundwater resources against pollution.
- Local Government Act 1993(NSW): Covers the quality of water supplied for human consumption by local Council, including groundwater as a source.
- Water Act 1912 (NSW): Largely superseded by the Water Management Act 2000 but some provisions still apply.
- Australian Constitution (1901): Section 100 of the Constitution outlines the States primacy over the Commonwealth in terms of laws and regulations affecting the use and conservation of water.
About the data
Data was supplied by Goulburn Mulwaree Council and the NSW Department of Water and Energy. Threshold salinity values of 800 µS/cm and 1,600 µS/cm were used for water quality assessment. They represent the maximum desirable water standard set by the World Health Organisation for human consumption (800 µS/cm) and a threshold at which adverse environmental changes can be expected (1,600 µS/cm) (NHMRC and ARMCANZ 1996).
Groundwater with less than 1,000 mg of salt per litre is also considered good quality and suitable for drinking water and most uses; groundwater with 1,000–3,000 mg of salt per litre is considered fair to poor and suitable for livestock, some domestic and limited industrial uses (DLWC 1999).
mg/L = milligrams per litre
References
Australian Water Resources (2000) National Land and Water Audit.
Beale G, Miller M, Barnett P, Summerell G, Gilmore R and Hoey D (2004) NSW Coastal Salinity Audit, Department of Infrastructure Planning and Natural Resources, Sydney, online at http://www.dnr.nsw.gov.au/salinity/science/pdf/coastal_audit1.pdf.
Department of Land and Water Conservation (NSW) (1999) Groundwater Quality Protection Policy, Department of land and Water Conservation, Sydney, on line at http://www.dnr.nsw.gov.au/water/pdf/nsw_state_groundwater_quality_policy.pdf.
Department of Land and Water Conservation (NSW) (2001) Groundwater Vulnerability Map and Explanatory Notes, Department of Land and Water Conservation, Sydney, on line at http://www.dnr.nsw.gov.au/water/pdf/lachlan_vulnerability_map.pdf.
Department of Primary Industries (NSW) (1998) Geological Map of New South Wales (1:250000 scale)
Department of Water and Energy (NSW) (2006) 2005/06 Water Supply and Sewage Benchmarking Report on line http://www.deus.nsw.gov.au/Publications/dwe_nsw_water_supply_and_sewerage_
benchmarking_report_2005-06.pdf
Department of Water and Energy (NSW (2008) – Bore Location Information supplied in GIS format.
DLWC – see Department of Land and Water Conservation
DPI – see Department of Primary Industries
DWE - see Department of Water and Energy
Goulburn Mulwaree Shire Council 2007 (NSW) (2007) Annual Report, online at http://goulburn.local-e.nsw.gov.au/council/1124/5596.html
Hawkesbury-Nepean Catchment Management Authority (NSW) (2007) HNCMA Annual Report 2006/2007 online at http://www.hn.cma.nsw.gov.au/multiattachments/3828.html
NHMRC and ARMCANZ (National Health and Medical Research Council and Agriculture and Resource Management Council of Australia and New Zealand) (1996) Australian Drinking Water Standards, National Health and Medical Research Council and Agricultural Resources Management Council of Australia and New Zealand, Canberra.
Parson Brinckerhoff Stage 2 Groundwater Investigation — Test Drilling and Pump Test Program, Pages 22-24.
Southern Rivers Catchment Management Authority (NSW) (2007) SRCMA Annual Report 2006/2007 online at http://www.southern.cma.nsw.gov.au/pdf/SRCMA_AR2007body.pdf
State Water Corporation (NSW) (2008) Water Management Charges for Licensed Water Users on line http://www.statewater.com.au/watdel/water_mgt_charges_for_licensed_water_20080124.pdf
