Snowy River
Issue: Catchments
This issue is discussed for these areas: [an error occurred while processing this directive]
For more information refer to the following Indicators:
Contaminated Sites | Discharge to Waters | Groundwater | Land Degradation | Land Use | Surface Water Quality
How has Catchment Quality Changed?
Snowy River Shire is located on the Southern Tablelands of New South Wales (NSW). The area is characterised in the east by rolling plains and in the west and south by rugged mountain ranges. The Shire is in the Southern Rivers and Murrumbidgee Catchments and has an area of 6,059 square kilometers. The majority of the Snowy River Shire is subject to snow, ice and high winds during the winter months. The Shire has a population of approximately 7,500.
Insufficient data was available for Snowy River Shire to assess changes to, or impacts on, many aspects of catchment quality over the current reporting period. As a result, changes in erosion and groundwater quality are not reported.
Drought was a significant event impacting on catchment quality in Snowy River Shire over the current reporting period. The drought that commenced in 1997, is as serious if not worse than other major prolonged droughts such as 1895 to 1903 and 1938 to 1945. Previous extreme drought years include 1902, 1914, 1938, 1940, 1944, 1967, 1982 and 2002. The 2006–2007 irrigation season was a record dry season for much of the area.
As water availability has changed, water allocations within the catchment have been adjusted. Water allocations are made in a way that reflects the priority given to domestic and basic rights supplies, then to core environmental needs, then to irrigation and industry. Operational plans for 2007–2008 reflect that the catchment experienced one of the lowest inflow periods in history. In many cases, high security licences were permitted to carryover unused water for the first time.
Drought or excessive water extraction causes water bodies to dry out, water quality conditions deteriorate and the fish within them may die or be eaten by birds. This scenario is unlikely for the main river channels, but is likely for many of the smaller creeks and tributaries. Indeed, many of the smaller creeks have already dried back to a series of disconnected pools.
Algal blooms are also more frequent during drought conditions due to low, slow flows.
During the drought, salinity levels are generally relatively low. This is due to little or no inflows from higher salinity tributaries and no return flows. Groundwater leakages from saline floodplains are generally also lower. However, if dilution flows continue to reduce, river salinity levels increase.
With little water available for irrigation there is the potential for substantial economic impacts. Irrigators who grow annual crops generally adjust their planting area depending on water availability. However, irrigators who grow perennial crops are impacted in the long term if they are unable to ensure crop survival.
Over the current reporting period, water allocations that were assigned in July 2006 had to be suspended in October and November 2006, due to the drought and inflows being below previous recorded low inflows. Domestic water restrictions are currently in the majority towns within the catchment. These are used to raise awareness and understanding of the current drought and encourage people to conserve and use water more efficiently, resulting in lower water consumption.
Where are the ‘Hot-Spots’?
Snowy River Shire’s sewage from Adaminaby, Berridale and Jindabyne is discharged in Locker Creek, Myack Creek and Cobbin Creek, respectively. The NSW Department of Environment and Climate Change (DECC) also licences a number of privately owned sewage treatment plants, such as the Perisher Blue, Thredbo and other resorts in the Kosciuszko National Park snowfields. These plants are also operating under licences to discharge into local creeks.
The discharge volume and the mass load of nitrogen and phosphorous, from the Jindabyne sewage treatment plant released to Cobbin Creek, increased over the reporting period. This was due to an increased number of dwellings in the Cobbin Estate.
The Berridale sewage treatment plant exceeded the daily limit of 250 KL/day on 365 occasions in 2004-2005. However, in 2005-2006 the volumetric limit was only exceeded on one occasion. No figures were available for the 2006-2007 and 2007-2008 financial years.
There was also an accidental discharge of sediment into Snowy River in August 2006 from works at Jindabyne Dam. The discharged volumes are unknown.
Strongly acidic soils occur predominantly within the Murrumbidgee River catchment. However also occurred at Lake Eucumbene and Matong Creek subcatchments of the Snowy River. Impacts of acid soils may include decreased crop yields, and increased erosion, siltation and salinity.
No land use results were available for the reporting period for Snowy River Shire. Over the reporting period it is expected that the rural residential development within the Shire continued to increase. As such it is expected that the related erosion and sedimentation to this development would have also increased.
Southern Rivers Catchment Management Authority identify some of the key challenges facing catchments in the Snowy River Shire as:
- conserving, rehabilitating and sustaining aquatic and terrestrial biodiversity
- protecting the soil,
- maintaining sustainable production and development,
- developing healthy urban environments,
- recognising and protecting cultural heritage, and
- maximising community participation in catchment health (Southern Rivers CMA, 2008).
Murrumbidgee Catchment Management Authority identify some of the key challenges facing catchments in Snowy River Shire as:
- use local knowledge and enthusiasm for social, environmental and economic sustainability, including continuing land care and improving water management.
- continue scientific research, monitoring and reporting on river issues.
- reverse the loss of native trees and other perennial vegetation across parts of the catchment that is leading to stream and wetland sedimentation, increased water turbidity, rising watertables, increased salinity levels in waters, and urban salinity.
- reduce the causes of unnatural rates of river erosion and manage riparian zones to protect remaining native vegetation.
- reduce remaining significant point-source pollution (e.g. sewage treatment plants, unsewered villages).
- further reduce pollution of stormwater runoff from both urban and rural lands, and contamination of surface or groundwater with pesticides or other chemicals.
- enable continuing improvements in efficiency of agricultural and urban water uses.
- increase efforts to control exotic plant and animal pests in rivers, particularly carp (DECC, 2008).
What has been done to address Catchment Quality?
The Berridale sewerage scheme was designed over the reporting period, and will be completed over the next reporting period. The scheme comprises of the augmentation works of the existing treatment plant, a pumping system to pump effluent at the Coolamatong Golf Course Dam and an irrigation system of reclaimed water at the golf course. The augmentation works will comprise:
A) Sewage Treatment Plant -
- New Inlet Works;
- Effluent Pump Station;
- Two sludge lagoons;
- UV disinfection facility;
- A Storm detention pond;
- Power supply upgrade; and
- Miscellaneous works including Access Road and Fencing.
B) Effluent Re-use System -
- Rising main from the Treatment Plant to Coolamatong Golf Course;
- Construction of new Irrigation Storage Dam;
- Connecting pipework, inlet and outlet structures; and
- Irrigation system for the Golf Course.
The proposed augmentation works will increase the capacity of the existing treatment plant to 2000 Equivalent Population, as well as increasing the quality of the resulting reclaimed water. The construction of the irrigation system will allow the reclaimed water to be beneficially reused, instead of being discharged to Myack Creek.
Snowy River Shire also adopted voluntary water restrictions for the Shire in the current reporting period. The Council also adopted a new Snowy River Rural Local Environmental Plan which was prepared and enforced over the reporting period.
What does this mean for Council?
The catchment data supplied from Council and the Department of Water and Energy is lacking for many topics within Snowy River Shire. This means that only partial assessment of the catchment quality is ever possible.
There is limited Council monitoring of erosion, sedimentation, salinity and ground and surface water quality. Therefore impacts from urban and rural development and significant natural pressures such as drought cannot be fully determined. The monitoring of the implemented Council strategies and associated actions is also necessary to determine their effectiveness in achieving the desired catchment management outcomes.
Snowy River Shire should undertake the following actions to ensure environmental improvement in the catchment:
- continue to work closely with Southern Rivers and Murrumbidgee Catchment Management Authorities, to implement joint projects and ensure consistency in approach to land and water management and complementary actions.
- continue and build on the effective relationship NSW State Government agencies to ensure up to date information regarding condition of the catchments environmental drivers such as salinity, and associated management issues relevant to them.
- monitor and adapt to the impacts of climate change to ensure no significant detrimental catchment effect is sustained from the changing conditions and any future actions.
- continue to ensure impacts on ground and surface water quality are considered in landuse zoning, development applications, sewage and water supply treatment.
- implement appropriate environmental monitoring programs to measure the effectiveness of Council's policies, strategies, and management activities.
- support and encourage sustainable land use and water management in the urban and rural communities. Approach business and industries regarding sustainable practices and monitoring.
References
DECC - Department of Environment and Climate Change
Department of Environment and Climate Change (2008) NSW Water Quality and River Flow Objectives: Murrumbidgee River Community Comment on Objectives, Department of Environment and Climate Change viewed at http://www.environment.nsw.gov.au/ieo/Murrumbidgee/report-01.htm on 20 October 2008.
Southern Rivers CMA (2008) Southern Rivers Catchment Management Authority, viewed at http://www.southern.cma.nsw.gov.au/index.html on 20 October 2008.
