Gundagai
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?
The Gundagai Shire is located on the South West Slopes of New South Wales (NSW) in the Murrumbidgee Catchment Management Authority. The Shire has an area of 2,458 square kilometers. Gundagai is traditionally known as a farming area, which yields a wide variety of produce. In the south and east, higher rainfall and cooler seasons see large forestry plantations and rolling hills producing wool, lambs and beef. Along the valley floors, the rich alluvial flats produce excellent hay and horticultural products. Cereal crops are grown in the north and west of Gundagai. Most recently, viticulture has also become a significant crop in Gundagai with several vineyards operational and more planned.
Insufficient data was available for Gundagai 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 Gundagai over the current reporting period.
The drought which dates back to around 1997, is as serious if not worse than other major prolonged droughts such as 1895 to 1903 and 1938 to 1945. The 2006–07 irrigation season was a record dry season for much of the area. Previous extreme drought years include 1902, 1914, 1938, 1940, 1944, 1967, 1982 and 2002.
Water allocations within the catchment are constantly adjusted, as water availability changes. 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 2007–08 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 causes water bodies to dry out or when they are pumped down, 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’?
The Gundagai sewage plant discharges to the surrounding golf course and sports fields. As such no limits on volume or nutrient loads are placed on the sewage treatment plant. The Department of Environment and Climate Change (DECC) has also licensed Gundagai Meat Processors with a protection licence that has a clause relating to Abattoir Effluent Irrigation. The plant’s effluent is reused to irrigate pasture and no non-compliance notes were issued in relation to exceeding the volume limits.
No land use results were available for the reporting period for Gundagai. 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.
Along the Murrumbidgee River, erosion of stream banks is occurring due to river regulation within Gundagai. In addition, a large area of moderate sheet erosion, occurred on the Murrumbidgee River. Areas of severe sheet erosion also occurred almost entirely within the Muttama Creek.
The upper Muttama Creek subcatchment, also recorded dryland salinity outbreaks. The electrical conductivity readings, which are an indicator of salinity, from Muttama Creek were greater than three times the default trigger value. This value however, has significantly improved since the previous reporting period. Of the nine water quality monitoring sites within the Shire, Muttama Creek at Coolac had the poorest water quality rating.
Murrumbidgee Catchment Management Authority identify some of the key challenges facing catchments in Gundagai 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?
Gundagai Shire Council is currently in the process of formulating a Local Environmental Plan (LEP) to provide a framework for future development.
Gundagai Shire also promotes the NSW Governments Rainwater Tank program to be used by residents to reduce potable water demand. It also adopted a Water Restriction Policy for the Shire over the reporting period.
What does this mean for Shire Council?
The catchment data supplied from the Shire Council and Department of Water and Energy is lacking for many indicators within Gundagai. This means that only partial assessment of the catchment quality is ever possible.
Over the entire Shire Council there is a lack of ongoing 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 Shire Council strategies and associated actions is also necessary to determine their effectiveness in achieving the desired catchment management outcomes.
Gundagai should undertake the following actions to ensure environmental improvement in the catchment:
- continue to work closely with Murrumbidgee Catchment Management Authority, 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 Shire 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 - see 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 17 October 2008.
