On 20 April 1989 a letter was received from Mr Frank Harvey of the Australian Water Resources Advisory Council (AWRAC). He suggested that most of the high flow ratings for the Lachlan River at Forbes may not have taken into consideration substantial discharges from other floodways. In a later minute which was sent to the Tumut office he said that he would not be using this station because of this problem. An investigation was then required into checking our own historical data.

This report is a check of the data on the Forbes station. It outlines the problems with gauging these high flows and the associated problems of rating the river as well as the subsidiary channels. The report also outlines the need for a decision to be made regarding the collection of high flow data for the main channel only or the three channels.