A new study is looking at the costs and benefits of options for tackling problems associated with the Richmond River floodplain ‘backswamps’.
The swamps and other low-lying areas, in the Tuckean, Rocky Mouth Creek and Bungawalbin Creek systems, are the source of deoxygenated ‘blackwater’, which is responsible for fish kills and other ecological damage.
Richmond River County Council (RRCC) recently contracted environmental consultant GHD Pty Ltd to carry out a cost-benefit analysis of options for managing the swamps, which form an important part of the river’s floodplain.
GHD project manager Lisa King said the river was one of the most significant coastal drainage systems in northern New South Wales.
‘The Richmond River estuary, with its associated wetlands and waterways, supports a rich biodiversity and is a focal point for local commerce, including fishing, aquaculture, agriculture, tourism and recreation,’ Ms King said.
‘It is highly valued by the community, but it is under considerable pressure, due in large part to the impact the floodplain backswamps are having on water quality through episodic blackwater events and chronic acid-water problems.
‘This leads to fish kills, degraded local biodiversity and reduced water quality.’
Ms King said the recently gazetted Richmond River Estuary Coastal Zone Management Plan (CZMP) set out an overall planning process for the estuary.
Reinstatement of more natural flows and restoration of floodplain ecosystems were viewed as important steps towards improving water quality and the general health of the estuary.
‘A range of management options to deal with the backswamp problems has been developed through technical research and scientific trials, on the river and at other locations,’ Ms King said.
‘These include better groundwater management, wet pasture management, changes to flood-control infrastructure, modification and shallowing of drains and so on.’
Ms King said the CZMP identified several critical management actions for the estuary and floodplain.
‘One of these is that a cost-benefit analysis be undertaken of backswamps to identify management options and changes to current practice to reduce impacts on the estuary,’ she said.
‘The analysis is to evaluate the environmental, economic and social impacts from implementing different management options within the backswamp areas.
‘As several of these options will involve changes in land management or land use on private land, the study will identify the public impacts and private impacts of each option.’
Ms King said the study had started and a draft report, which would be open for public review, was scheduled to be completed in June.