Tumut

Issue: Catchments

This issue is discussed for these areas: [an error occurred while processing this directive]

How has Catchment Quality Changed?

The Tumut Shire is located on the foothills of the Snowy Mountains and is in the Murray Catchment. Tumut has an area of 3,767 square kilometers and a population of approximately 11,500.

Insufficient data was available for Tumut 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 Tumut over the current reporting period. The drought dates back to around 1997, and is as serious, if not worse, than other major prolonged droughts such as those over 1895 to 1903 and 1938 to 1945. Previous extreme drought years include 1902, 1914, 1938, 1940, 1944, 1967, 1982 and 2002. The 2006–07 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 2007–08 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 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. Most towns however have sufficient treatment facilities and treat all sewage before discharging to water and, where possible, manipulate flows to break up algal blooms.

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 river flows continue to reduce, then river salinity levels can 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’?

Tumut Shire has four sewage treatment plants and a number of other discharge to waters licences, all discharging into creeks and utilization areas in Tumut. The Tumut Sewage Treatment Plant (STP) is licensed to discharge effluent to Gilmore Creek. The maximum daily volume for this plant was 3.3 megalitres per day. However this limit has increased from 22 September 2008, (after the current reporting period) to 7.5 megalitres per day. The discharge conditions were also changed to discharge to a pit immediately downstream of the ultra violet (UV) disinfection system.

Adelong STP discharges to Adelong Creek, while Brungle STP discharges into the Tumut River and Batlow STP discharges into a storage pond and an unnamed creek, before flowing to Little Gilmore Creek. Some effluent from the Batlow plant is reused at the Memorial Park, Golf Course and Hockey field. The Talbingo Sewerage Treatment Plant is licensed to discharge from the effluent drain into a wetland, and subsequently downstream to Lake Jounama.

The Tumut Water Filtration plant is also licensed to discharge from its settling ponds to the Tumut River. Talbingo Raw Water Treatment Plant is licensed to discharge from the outlet of sludge lagoons to a pondage area.

The Department of Environment and Climate Change (DECC) licences the Jounama Dam Construction Site to discharge to water at a limit of 100 megalitres / year. This license was approved in November 2007 to Snowy Hydro Limited. This company also has a licence to discharge from the Cabramurra Town Sewage Treatment Plant into local creeks.

The reduced flow regime of the Tumut River over the reporting period means that the environmental impacts of these discharges are of greater significance than they would be under a regular flow regime.

Small areas of dryland salinity outbreaks were reported in the Adelong Creek subcatchment.

The Adelong Creek subcatchments had the highest concentration of extreme gully erosion in Tumut. Moderate to severe sheet erosion occurred within the conservation reserves within the Goodradigbee, Goobarragandra and Tumut River subcatchments.

Strongly acidic soils occur predominantly within the agricultural lands in Tumut Shire. Impacts of acid soils may include decreased crop yields, and may indirectly contribute to increased erosion, siltation and salinity.

No land use results for Tumut were available for the reporting period. 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.

Murray Catchment Management Authority identified some of the key challenges facing catchments in the Tumut region namely to:

Continue work already begun to further define environmental objectives and benchmarks for local zones (e.g. local water quality benchmarks based on the work of the Murray Catchment Management Committee Water Quality Working Group).
Continue scientific research, monitoring and reporting on river issues.
Use local knowledge and enthusiasm for social, environmental and economic sustainability - including continuing the Landcare program.
Reverse the loss of native trees and other perennial vegetation across parts of the catchment, which is leading to stream and wetland sedimentation, increased water turbidity, rising watertables and increased salinity levels in waters.
Reduce the causes of unnatural rates of river erosion and manage riparian zones to protect remaining native vegetation.
Increase efforts to reduce faecal contamination of streams by livestock.
Reduce remaining significant point-source pollution; for example, sewage treatment plants.
Address water quality problems caused by unsewered villages.
Further reduce pollution from pesticides, nutrients, salts and sediment.
Improve the quality of stormwater runoff from both urban and rural lands.
Implement land and water management plans and other means of reducing high watertables and maintaining the agricultural productivity of irrigated land.
Increase efforts to control exotic pest plants and animal pests in rivers-particularly carp.
Improve controls on the use of groundwater to avoid impacts on streams and surface environments, including salinisation from deposition of groundwater salts on soil (DECC, 2008).

What has been done to address Catchment Quality?

Groundwater samples are collected at various locations in Tumut and Adelong, and are sent for analysis as part of the Murrumbidgee Catchment Management Urban Salinity Project.

Level 2 Water Restrictions are in force in all towns and villages across Tumut Shire. The Shire Council also actively encourages rainwater tanks to be used and installed through the shire, as a part of the NSW Government’s Climate Change Fund.

Towards the end of the current reporting period, Tumut Shire Council and the Murrumbidgee Catchment Management Authority started a program of tree plantings which will yield benefits to the Tumut community and the local environment. As a part of this project, 102,000 native trees and shrubs will be planted in the Tumut area in 2008, in partnership with local landholders. Plantings have been undertaken on more than 35 properties in the area. These revegetation activities should improve water quality in the catchment area, combat soil erosion, and enhance biodiversity.

The future - What does this mean for Council?

The catchment data supplied from Council and the Department of Water and Energy is lacking for many indicators within Tumut. 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.

The Tumut Shire Council should undertake the following actions to ensure environmental improvement in the catchment:

Continue to work closely with Murray Catchment Management Authority, to implement joint projects and ensure consistency in approach to land and water management and complementary actions.
Continue to build on the effective relationship with NSW State Government agencies to ensure the collection of up to date information regarding the 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) (2008) NSW Water Quality and River Flow Objectives: Murray River (NSW) Community Comment on Objectives, Department of Environment and Climate Change viewed at http://www.environment.nsw.gov.au/ieo/Murray/report-01.htm on 22 October 2008.

Top of page...

Regional State of the Environment Report 2008