Concept design for water savings in Old Man Creek

Old Man Creek and Beavers Creek form an anabranch system to the Murrumbidgee River west of Wagga Wagga. Flows from the Murrumbidgee River into the anabranch system are regulated by an existing weir on Beavers Creek. Significant water savings can be achieved by limiting water losses within the Old Man Creek and Beavers Creek system. The project will require the upgrading of the existing regulating weir on Beavers Creek and the provision of fish passage at the weir.

Alluvium has been engaged to prepare the concept design for works related to the water savings project. This initially involves investigating options for the weir at Beavers Creek in regard to location and configuration. In a similar fashion we are examining options for fish passage, especially in the particular circumstances of a widely varying upstream and downstream water level that exists for this project.

Critical to the successful outcome is being able to deliver sufficient and timely flows to maintain the existing environment in the anabranch system, as well as meet irrigator requirements along Old Man Creek. To this end Alluvium’s first phase has been the preparation of a preliminary environmental assessment, in which the key ecological assets are identified, together with a broad description of the watering requirement to maintain the asset.

Critical issues in the design of the weir will be the management of woody debris that is transported along the waterway, and the provision of seasonal high flow events via the regulator gates.