Eurobodalla
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 Eurobodalla Shire is located near the south-eastern coast of New South Wales (NSW). The Shire covers 110 kilometres of coastline and lies within the Southern Rivers Catchment area. Eurobodalla Shire covers an area of 3,402 square kilometers but has a relatively small population of around 35,000 people. Approximately 80% of the Shire is either a national park or a state forest.
Insufficient data was available to assess changes to, or impacts on, many aspects of catchment quality over the current reporting period for the Eurobodalla. As a result, changes in erosion and groundwater quality are not reported.
Drought was potentially the most significant event impacting on catchment quality in Eurobodalla Shire over the current reporting period. The drought generally dates back to 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 in catchments across the Shire. 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 restrictions were in place for much of the current reporting period for metered water users across the Shire, but were lifted in mid 2007. Water restrictions are used to raise awareness and understanding of drought and encourage people to conserve and use water more efficiently, resulting in lower water consumption.
Where are the ‘Hot-Spots’?
Eurobodalla Shire manages Council owned land, Community Land and some of the Crown Reserves in the Shire (as Trust Manager on behalf of the NSW Department of Lands). However, large areas of Eurobodalla Shire are managed by Department of Environment and Climate Change, National Parks and Wildlife Service and State Forest of NSW.
’Hot spots’ in the Eurobodalla generally occur in the fragile coastal zone where much of the residential development is located. Development results in loss of habitat, and leads to increased extraction of water from rivers for domestic and residential use, increased urban stormwater volume and velocity, as well as increased sewage volumes which have an impact on creeks, coastal vegetation, dune structures and receiving water quality.
The Southern Rivers Catchment Management Authority identifies some of the key challenges facing catchments in the Eurobodalla region 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).
What has been done to address Catchment Quality?
Council carefully monitors any sewer surcharge incidents and has in place strict reporting protocols for managing these. Over the reporting period, Council included a precautionary category in its sewage surcharge reporting format. The new category ‘threatening major’ includes any surcharge that, although not obvious, may have entered a waterway or caused a health threat. Major cleaning of the site occurs immediately, but the consequence of any environmental influence is confirmed in the laboratory, with samples of the receiving waters being analysed and reported within 24 hours.
The analysis either confirms the incident as a ‘major’ or ‘minor’ incident, to allow correct reporting procedures to follow. As a precautionary measure the Environmental Health Officer immediately closes the beach. Once determined, major incident sites have the ‘sign-posted’ measure maintained for public awareness, while further recovery operations and sampling takes place. Minor incident have the ‘sign posting’ removed following receipt of the official result. This temporary period, between closing the beach with immediate ‘signage’ at the time of the incident and finding that contamination had not taken place, remains as a ‘beach closure’ in the reporting, but not as a major surcharge event on Council’s records.
Eurobodalla completed an Integrated Water Cycle Management Strategy in 2003, which supports Rainwater Tank rebates and identifies opportunities for sewage and stormwater capture and use in the Shire. Some major benefits of this strategy included:
- Utilisation of existing capacity in the Tomakin Sewage Treatment Plant;
- Reducing the volume of effluent discharged from the Batemans Bay outfall; and
- Implementing significant levels of effluent reuse from the Tomakin Sewage Treatment Plant.
Over the reporting period, a number of water project concepts were developed, including upgrades to Batemans Bay and Tomaga Sewage Treatment Plants. These projects include the concept design for the Batemans Bay Treatment Plant to be substantially improved to accommodate wet weather flow patterns and upgraded treatment processes. The Malua Bay catchment will be rerouted to the Tomakin Treatment Plant, removing approx 20% of the flow from the Batemans Bay plant. Sewage investigations were also conducted over the reporting period into the provision of sewer facilities to Wallaga Lake, Akolele, Tilba and Mystery Bay. Another major water project concept developed was the Moruya River pipeline and Deep Creek Water Treatment Plant to allow increased extraction of water for domestic use during high flow periods, which will have ecological benefits for the Moruya River.
Water conservation measures and restrictions were introduced for most of the reporting period, and were removed in mid 2007. Permanent water conservation measures are now in place.
The Shire also supported 36 community Landcare groups through the Eurobodalla Landcare Management Committee over the reporting period.. These groups undertook a high number of projects over the reporting period, many of which have an impact on catchment health. A significant number of projects that implement priorities contained in Estuary Management Plans and other strategic documents were also developed and implemented over the reporting period. These projects address a range of strategic catchment health issues aimed at improving estuary – and thereby catchment – health. The Eurobodalla Biodiversity Program was also run over the reporting period, providing incentives for environmental improvements on private land. Many of these projects target catchment health issues by undertaking works such as fencing of creeks to remove stock from waterways.
What does this mean for Council?
The catchment data supplied from Council and the Department of Water and Energy is lacking for many attributes within Eurobodalla. This means that only partial assessment of the catchment quality is 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.
Eurobodalla should undertake the following actions to ensure improved catchment quality:
- Continue to work closely with Southern Rivers Catchment Management Authority, to implement joint projects that deliver strategic catchment health outcomes in line with Catchment Action Plan priorities and ensure consistency in approaches to land and water management
- Continue to build effective and collaborative relationships with NSW State Government agencies to agree on strategic priorities, , share data, seek funding to implement strategic catchment improvement projects and make progress on evaluating catchment health and project effectiveness
- Continue to ensure impacts on ground and surface water quality are considered in landuse zoning, development applications, sewage and water supply treatment.
- Continue to support and encourage sustainable land use and water management in urban and rural communities and businesses.
- 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, and integrate these across Council operations including landuse planning and water planning.
- Continue to develop programs and projects to assist rural industries regarding sustainable practices and monitoring.
- Pursue opportunities for increased appropriate and controlled reuse of treated effluent from Council’s sewage treatment plants to reduce demand on potable water supplies
- Implement appropriate environmental monitoring programs to measure the effectiveness of Council's policies, strategies, projects and management activities.
References
Southern Rivers CMA (2008) Southern Rivers Catchment Management Authority, viewed at http://www.southern.cma.nsw.gov.au/index.html on 14 October 2008.
