Buckenbowra Weir Removal - CAN-P_2620822

Goods or services supplied

The weir is approximately 1 metre high and comprises 2 rows of sheet metal piling core, loose rock filling, gabion basket scour protection and a concrete capping. A concrete and aluminium fishway is present on the western side of the structure adjacent to drop boards that can be used to lower water levels in the weir pool prior to initiation of works. An engineering assessment (obtained by the Principal) will determine if weir abutments will need to be removed or can remain and be made safe as part of these works. Unless abutments are retained, all weir components should be removed and disposed of appropriately. The structure has deteriorated, with scouring on the downstream side of the weir exposing the sheet metal piling and causing loss and deterioration of gabion rock baskets. Following removal of weir components, sediment present upstream of the weir will need to be regraded to meet downstream river bed levels on a low gradient to prevent erosion of the river bed. The site is accessible via Quart Pot Road on the eastern side of Buckenbowra River. The western side is not accessible. An intended process would be to set up erosion and sediment controls, slowly lower weir pool levels by sequential removal of drop boards. Working from the western bank back to the eastern bank to remove weir components, then regrading river bed across the weir location.