Junction of Bannockburn Creek with the Macintyre River showing sediment (sand) slug filling the river channel, August 2012. Credit: Scott Nichols
The Border Rivers Gwydir Catchment Management Authority (BRGCMA), now Local Land Services, engaged NSW Department of Primary Industries Fisheries (Fisheries NSW) to undertake an assessment of Bannockburn Creek and the Macintyre River in the area of a large sand sediment slug that is moving through the lower reaches of the Bannockburn Creek and into the Macintyre River.
This investigation builds on recommendations made by Soil Conservation Service in their Bannockburn Creek Catchment Assessment Report (June 2011), primarily the need for “assessment of strategic and sustainable removal of sediment” from the system. The aim of this study is to make an assessment of strategic and sustainable removal of sediment from Bannockburn Creek and the Macintyre River.
Properties through which Bannockburn Creek and the Macintyre River pass were inspected with the relevant landholder in late August 2012, identifying local issues, control points and potential sites for physical extraction of material.
It was concluded that the physical extraction of sand may provide potential ''breathing space" for identified reaches within the sediment slug, but that extraction should be implemented in conjunction with other activities such as instream rehabilitation works (e.g. installation of woody debris and reed beds) and works to control sediment input from the surrounding catchment (erosion control works).
Recommendations were made regarding preferred locations for sand extraction, the use of instream rehabilitation works and erosion control works, in addition to further assessments requires and likely legislative requirements that would need to be met prior to undertaking any of these activities.