Alluvium prepared detail designs for two cone fishways on the Maribyrnong River, at Garden Avenue and at Arundel Road, both near Keilor, Victoria. The fishways operate on a similar principal to vertical slot fishways, but have higher flow capacity and a smaller footprint as they can be set at a steeper grade.
The fishway at Garden Avenue has been constructed and is performing well, with good numbers of fish moving through the fishway. The design approach allowed an effective fishway to be provided at this popular public site with limited available space, and at an economical cost.
A particular challenge was catering for the range of flows and the arrangement of the fishway perpendicular to the river flow direction, and aligned under the existing roadway.
We undertook 2-D modelling of the fishway to establish suitable conditions. We also designed the chambers to self-flush in high flow events, and to remove structural cross-members under the road that could collect debris.