Cootamundra

Issue: Catchments

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How has Catchment quality changed?

The Cootamundra Shire is located in the Lachlan and Murrumbidgee Catchments. The Shire has an area of 1,524 square kilometers.

Insufficient data was available for Cootamundra 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 significantly affected the catchment quality in Cootamundra over the current reporting period. The drought 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. 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 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’?

Cootamundra discharges its treated effluent into the Muttama Creek. The outflows are monitored and tested to ensure that they stay within the guidelines of the NSW Department of Environment and Climate Change licenses. Over the reporting period, the pH levels exceeded the licence on two occasions and the total suspended solids once.

The plant also recycles the treated water and uses it to irrigate Mitchell Park; Albert Park Reserve; Jubilee Park; Clarke Oval Reserve; Fisher Park; Bradman Oval; Cameron Square Park; Nicholson Park; Country Club Oval; and three schools.

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

Strongly acidic soils occurred within both the Lachlan River and Murrumbidgee River catchments. In the Lachlan Catchment, the main ‘hot spot’ was within the Bland Creek subcatchment. The subcatchments of Muttama and Cunjegong Creeks were the areas with strongly acidic soils in the Murrumbidgee catchment. Impacts of acidic soils generally include increased erosion, siltation and salinity, and decreased crop yields, and poor performance of perennial pastures.

Lachlan Catchment Management Authority has identified some of the key challenges facing catchments in Cootamundra as:

the loss of native vegetation across the catchment and resulting land degradation. This is leading to stream and wetland sedimentation, increasing water turbidity, rising watertables and increased salinity levels in waters.
rapidly increasing dryland salinity and some irrigation salinity, associated with rising watertables.
the need for irrigation to remain viable. Irrigation was held to be necessary for agriculture in the river valley and a significant contributor to the catchment's prosperity.

reduce remaining significant point-source pollution, and urban and rural runoff where this is causing water quality problems-particularly turbidity and increased levels of nutrients (DECC:1, 2008).

Murrumbidgee Catchment Management Authority has identified some of the key challenges facing catchments in Cootamundra 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:2, 2008).

What has been done to address catchment quality?

In order to reduce the volume of effluent being discharged to Muttama Creek, Cootamundra has implemented a program to further reuse the effluent. This project is nearing completion with all playing fields presently receiving effluent, which also reduces the groundwater use in the Shire.

Other Cootamundra initiatives include:

Town tree management
Murrumbidgee water action plan - Phosphorus action campaign.
Entering of Voluntary Conservation Agreements with NPWS over Stockinbingal and Wallendbeen Cemeteries to conserve remnant vegetation.

Cootamundra Shire also promotes the NSW governments Rainwater Tank program to be used by residents to reduce potable water demand.

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 Cootamundra. 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.

Cootamundra should undertake the following actions to ensure environmental improvement in the catchment:

Continue to work closely with Lachlan 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:1 (2008) NSW Water Quality and River Flow Objectives: Lachlan River Community Comment on Objectives, Department of Environment and Climate Change viewed at http://www.environment.nsw.gov.au/ieo/Lachlan/report-01.htm on 15 October 2008.

DECC:2 (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 15 October 2008.

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Regional State of the Environment Report 2008