This report examines the impacts on flood levels and flow distributions of earthworks on the property of "Branglebar". It recommends corrective action to alleviate the impact of these works.

At present, the entire right bank floodplain of the Bogan River at this site is blocked to flood flows. This represents a width of about 10 km and includes a major flood runner, the Yangunyah Cowal. The effect of the blockage is to impound flood waters on the upstream property "Mulgawamna", and prevent the flow of beneficial flood waters onto downstream properties such as "Marra". Flood level increases of up to 0.3 m were experienced during the flood of April/May 1990, and very little Hoodwater made its way onto "Marra" during the February 1992 flood.

Two floodways are required to pass the right bank flood flows and maintain a near natural Hood flow distribution. Several floodway options ranging in width from 500 to 700 m have been considered to keep flood level increases to 0.1 m and flow velocities to 0.6 m/s. One particular option has been recommended for the far right side of the floodplain.