2008 – Implementing upstream fish passage at an existing large dam: Hinze Dam trap and haul fishway

Steven O’Brien, Brent Mefford, John Harris

Abstract: The Hinze Dam Stage 3 Upgrade required ‘Waterway Barrier Works Approval’, including fish-passage assessments. The dam, sited in the Nerang River catchment, has relatively undisturbed riverine habitat upstream which, together with the reservoir’s recreational fishery, was a key driver for inclusion of a fishway. Low outflows from the dam and impacts of development on the river downstream contrast starkly with upstream environments.

The Hinze Dam Alliance (HDA) assessed that upstream transfer of fish will have significant environmental benefits but downstream passage, beyond that achieved during spill events, could not be justified.

Constraints at the site for upstream passage include unvarying 7.25ML/d releases from the reservoir and a distance of nearly 300m between the reservoir and the downstream river pool. HDA has developed an innovative trap-and-haul system to collect upstream-migrating fish near the spillway and transport them by tanker to upstream release areas. This system is the first of its kind designed for Australia. It provides flexibility to accommodate varying fish biomass, the ability to operate over a range of flows up to 20-year ARI events, facilities for data collection and removal of pest species, and capacity to manage predation with small-fish refuges during trapping and transfer and by releasing fish at several protected sites in the reservoir.

Keywords: fishway, trap and haul System, fish passage