Fishways are designed to allow native migratory fish to pass through or around in-stream barriers like dams and weirs.

Each fishway is specifically designed for each site to cater for the inherent upstream and downstream operating water level ranges and the large differences in water levels that this can produce across a structure.

Rock ramp and vertical slot fishways work by creating a series of stepped pools that limit height difference so that fish are able to successfully move upstream between them.

Dams & Civil Unit, NSW Water Solutions, has developed an innovative form of tall-rock ridge type of rock-ramp fishway. The fishway uses precast reinforced concrete baffle units in place of difficult-to-source shape-specific natural rocks to create the fishway ridges that separate and control the step height (headloss) between the adjacent fishway pools.

The innovative baffle units:

• improve upstream fish passage by offering more consistent and reliable hydraulic performance
• can be applied to sites with a larger range of upstream water levels
• are faster and simpler to construct.

 Contact:

John Lenehan, Principal Engineer
Tel: (02) 9372 7819
Fax: (02) 9372 7999
Email: john.lenehan@services.nsw.gov.au