EXTENSIVE grazing is probably the best form of agriculture that can co-exist with ‘tight’ gas and coal seam gas production, according to a landmark report.
However, cropping and irrigated agriculture are more problematic.
“A balanced coexistence of mining and other forms of agriculture is possible, but requires careful management,” said the report, written by Dr John Williams, former chief of CSIRO Land and Water Division for the Australian Council of Environmental Deans and Directors.
“For this reason, good bioregional planning and assessment is an absolutely fundamental issue that requires priority attention.”
The report, which reviews the science of coal seam gas, was described by the magazine Irrigation Australia as probably the most independent, disinterested nationwide analysis yet undertaken of unconventional gas in Australia.
It focuses on Queensland and NSW.
Dr Williams said Queensland was the first state to pass legislation to protect the state’s strategic cropping land.
The aim was to strike a balance between agriculture, resources and urban development. “In NSW, a similar approach has been adopted,” he said.
Dr Williams made three key findings:
*The environmental risks are serious, particularly the potential impact on water resources.
*Unconventional gas is just another land use that needs to be regulated like all others and not be treated as a bogeyman.
*The potential economic benefits for regions and the state are also very real, but any social or economic costs tends to fall on local governments, community and individuals.
“Economic diversification leveraged off the energy boom is essential to the long-term wellbeing of regional communities,” Dr Williams said, particularly the need to increase local economic opportunities.
The report discusses the three ‘unconventional’ natural gases – coal seam gas (CSG), shale gas and tight gas – which can’t be extracted by conventional drilling into a pocket of gas trapped by rocks.
This is achieved by new extraction technology – hydraulic fracturing, or fraccing, which is changing the energy landscape. Fraccing involves pumping a fluid, mostly water and sand, under pressure into a coal seam or rock. This pressurised fluid opens up fractures in the coal or rock, allowing gas to move and come to the surface.
“The pressure required to fracture . ..without impacting on other aquifers requires careful management . . . and progressive monitoring and reporting,” Dr Williams said.
CSG or shale could put at risk the long-term function and value of vital renewable natural resources, he said.
These included water and aquatic ecosystems, biodiversity, landscape function and land used for food and forestry.
“These issues . .. are increasingly well understood by the gas industry peak bodies,” he said.
Dr Williams said potential CSG mining effects included direct clearing of bushland, fragmentation of native vegetation, spread of invasive species and increased fire risk.
Dewatering used in CSG could change the hydrology of wetlands and groundwater-dependent ecosystems.
However these impacts “are usually smaller than the historical impacts of land clearing for agriculture or urban development”. “Nevertheless, further loss of an already highly fragmented vegetation cover or reserves . . . can be a significant threatening process,” he said.
Wells for CSG extraction can be 200 to 750 metres apart in a grid pattern, and may be connected by roads, pipelines and compressor stations.
Dr Williams said unconventional gas projects would always be competing for land, water and infrastructure with other projects, agriculture and urban needs.
Only those uses should be allowed that enabled the landscape to maintain its function indefinitely.
“We argue that adoption of a knowledge-based, long-term regional strategic land-use planning approach for CSG (and other developments) regulation should help avoid perverse outcomes,” he said.
These developments should be treated no differently from any other industries competing for land, water and biodiversity resources.
Dr Williams said the capacity of regional landscapes should be clearly understood and developments should only be approved within those limits, together with the expected impacts.
“Our recommendations require a whole-of-system analysis, and . . . new methods and thinking such as cumulative risk assessment,” he said.