Abstract

Recent high gaugings obtained during the 2010 and 2012 flood events along the Murrumbidgee River reinforced the significant number of instances where high flow range ADCP measurements were found to have large negative differences from historical current meter measurements and/or historic rating tables. This level of change may have a significant impact on the rating curves at these sites with related impacts on flood forecasting, model calibrations, water accounting and long term water assessments. NOW needed to know whether these differences were due to a systemic difference between ADCP and current meter measurements, changes in stream controls or whether there were other factors impacting on the discharge measurements obtained. This paper outlines some of the issues and how they are being addressed.