Santos today welcomed the findings of the final stage of the Namoi Catchment Water Study, with the modelling predicting that there will be no harmful impact on water volumes available for existing land uses from development of the coal seam gas industry in the Gunnedah Basin.
The study modelled a wide variety of scenarios for the next 90 years, ranging from a continuation of the ‘status quo’ with no further resource development, through the most likely development scenario based on existing industry plans, to a number of highly improbable and hypothetical scenarios.
The extensive $4.5 million study, conducted in four stages over the past two and a half years, was designed to provide an understanding of groundwater and flows in the catchment area and to assess potential impacts of resources activities within the Namoi catchment.
Over the past 30 years, existing uses have caused a draw-down of nearly eight metres in some alluvial aquifers in the catchment based on NSW Office of Water monitoring data, compared to modelling which forecasts a maximum of 0.5m draw-down over the next 90 years from expected CSG production. This half-metre draw-down is within the existing annual variations in aquifer levels. (See graphs via link below.)
Alan Feely, Santos Manager for Environment and Water, said: “In the study, the scenario that reflects the most likely development of the CSG industry in the region, Scenario 2, shows that the draw-down in the alluvium from CSG activity is insignificant.”
“The study’s findings show that concerns about the impact of CSG on the volume and availability of water resources for agriculture and municipal usage are unfounded. It shows that the coal seam gas industry can co-exist with agriculture without damaging the water resources in the Namoi catchment.
“The effects of CSG in the surface water and alluvium are generally widely distributed and very low-intensity, likely to be unnoticeable among the seasonal and annual fluctuations resulting from rainfall and the extraction of water by other users,” Mr Feely said.
Even under the study’s Scenario 3, which far exceeds the CSG industry’s best case plans and which assumes the existence of coal and coal seam gas resources yet to be confirmed, the estimated impact of CSG activity is still insignificant. The extreme nature of this scenario is evidenced by its assumption that the Gunnedah Basin would host six hypothetical CSG developments, over and above the two envisaged under current business plans.
In commenting on the improbability of the study’s Scenario 3 or other even more extreme scenarios ever eventuating, Mr Feely said: “Santos has no foreseeable production proposals which extend beyond what is generally contemplated in Scenario 2. This means Santos will not seek to develop production projects beyond the scale of the proposed Narrabri and Bando developments in the next fifteen years at least. We will not apply to develop future areas unless the impact on groundwater can be proven to be both predictable and manageable.”
“Outside of Scenario 2, Santos is committed to only undertake limited exploration and appraisal activities, with the water information obtained from these studies made available to allow further refinement of the Namoi Groundwater Model.”
Mr Feely said Santos believed it would be helpful for the Independent Expert Scientific Committee to now review the study.
“Santos has always said its processes will be driven by science and we believe the Independent Committee has a role to play in assisting the community to interpret the results of the study and the impact of all land-uses on aquifer drawdown,” Mr Feely said
“Demonstrating the scientific rigour behind our activities has always been a key objective for us, that is why we have supported this study from the outset.
“While extracting the gas is very important for NSW future energy needs, it is equally important to protect the Namoi water resources, and Santos is committed to doing that,” Mr Feely said.