黑料网大事记

Pipe Fishways for reconnecting fish passage in Australian rivers

Despite significant investment, fish conservation efforts fall often short due to barriers like weirs, dams, and culverts, that obstruct critical fish migration in rivers and freshwater systems. With tens of thousands of barriers in place, fishways are the most widely used mitigation strategy. However, no universal or 鈥渟ilver bullet鈥 fishway exists, and traditional designs are frequently costly. As a result, innovative and alternative fishway solutions are emerging.聽

To tackle this challenge, a multidisciplinary research team from the 黑料网大事记 Water Research Laboratory (WRL) in the School of Civil and Environmental Engineering, and the Centre for Ecosystem Science (CES) in the聽School of Biological, Earth & Environmental Sciences聽has been pioneering the development of pipe fishways. These systems are designed to provide cost-effective, adaptable, and reliable solutions for safe fish migration both upstream and downstream past barriers. Pipe fishways are scalable, retrofittable, require less water, quick to install, making them suitable for seasonal or emergency use. They also support the passage of a wide range of species, including smaller and weaker-swimming fish.聽

Our team combines expertise in hydraulic engineering and aquatic ecology, supported by state-of-the-art facilities for fish husbandry, hydraulic physical modelling, and dedicated fieldwork equipment with specialised technical support. Through rigorous experimentation, including live fish trials, hydrodynamic testing, and numerical modelling, we are developing innovative and evidence-based pipe fishways that can be deployed across a wide range of environments to restore connectivity in freshwater ecosystems.

Pipe Fishway designs

Our team has been developing a range of different pipe fishway designs tailored for a range of environmental and ecological needs:聽

  1. The Tube Fishway that lifts fish upstream across barriers with an unsteady surge mechanism
  2. A modified siphon fishway to enable volitional and bi-directional fish passage
  3. A cascading vortex pipe fishway which combines transport through pipes with swirling tanks for downstream passage. 聽

Progress to date

The Tube Fishway was our foundational pipe fishway and has been under continuous development since 2019. In controlled laboratory settings, the system has successfully lifted native Australian fish species over vertical heights of up to eight metres.

Temporary field trials at five diverse sites across New South Wales and Queensland have further demonstrated the Tube Fishway鈥檚 hydraulic performance and operational reliability under a variety of environmental conditions. To date, twelve fish species have been safely lifted with the Tube Fishway in lab and field trials.

The modified siphon fishway and cascading vortex pipe fishway have undergone initial hydraulic and fish testing in laboratory settings. Further research, including comprehensive field trials, is planned as the next step in their development.
Tube fishway installed downstream of Ewen Maddock Dam Queensland
A range of native Australian fish attracted and safely lifted with the Tube Fishway downstream of Ewen Maddock Dam, including longfin eel (Anguilla reinhardtii)

Underpinning research

The development and testing of innovative pipe fishways are underpinned by interdisciplinary research on fish attraction, passage and safety of fish. Under controlled laboratory conditions, systematic research has examined how factors such as attraction flow, pipe dimensions, entrance geometries, and lighting can be manipulated to encourage fish motivation to enter a piped entrance. These experiments have demonstrated that fish can be reliably guided into pipe fishways. These laboratory findings have been validated through field-based attraction trials, confirming their real-world ecological applicability.
Attraction tests of fish into pipes at Ourimbah Creek Weir and Manly Creek
Safe passage of silver perch (Bidyanus bidyanus) through a pipe contraction and 90 degree bend

Building on our fish attraction research, we further investigated the motivation of a range of native Australian fish species, such as silver perch (Bidyanus bidyanus) and golden perch (Macquaria ambigua), to voluntarily swim through a 3 m high pipe with hypobaric pressure gradient. This research underpins the fundamental biological operation of the siphon fishway.聽

To ensure that fish can be transported safely and without injury through pipe fishways, we systematically evaluated hydrodynamic conditions within key pipe components, including entrances, expansions, contractions, and bends.

This research integrated laboratory-based hydrodynamic measurements with Lagrangian pressure and acceleration sensors, live fish observations, and computational fluid dynamics (CFD) modelling. The combined approach provided unique insights into hydrodynamic thresholds that are biologically safe for fish, offering critical guidance for the design of fish-friendly pipe transport systems.
Silver perch (Bidyanus bidyanus) swimming up a 3m high pipe

  1. Conduct longer-term and larger-scale field trials of the Tube Fishway
  2. Implement field trials of siphon fishway and cascading vortex pipe fishway
  3. Systematically evaluate the efficiency of pipe fishways compared to more traditional fishways
  4. Undertake supplementary research on fish attraction and safety across a wider range of fish species, sizes and life-history stages
  5. Develop and test downstream passage solutions for barriers.聽

Cox, R X and Felder, S (2025) Injury-free transport of fish through closed conduit components. Journal of Ecohydraulics, 0(0), 1鈥16. 聽

Cox, R X, Senevirathna, L, Mulligan, S and Felder, S (2025) Particle tracking to assess safe fish transport through closed conduit components. Ecological Engineering, 218, 107677. 聽

Jeremy, Y, Martino, J, Felder, S, Kingsford, R T and Suthers, I M (2025) Tackling Fish Passage Problems: Conservation Implications of Fish Ascending Hypobaric Pressure Gradients in a Pipe. Aquatic Conservation: Marine and Freshwater Ecosystems, 35(1), e70050. 聽

Martino, J C, Suthers, I M, Kingsford, R T, Doyle, K E, Baumgartner, L J and Felder, S (2025) Pipe fishways: Opportunities and challenges for effective fish passage. Environmental Technology Reviews, 14(1), 471鈥487. 聽

Farzadkhoo, M, Jadraque, D, Kingsford, R T, Suthers, I M and Felder, S (2024) Entrance geometries of closed-conduit fishways to attract juvenile fishes. Ecological Engineering, 209, 107421. 聽

Cox, R X, Kingsford, R T, Suthers, I and Felder, S (2023) Fish Injury from Movements across Hydraulic Structures: A Review. Water, 15(10), Article 10. 聽

Farzadkhoo, M, Kingsford, R T, Suthers, I M and Felder, S (2023) Flow hydrodynamics drive effective fish attraction behaviour into slotted fishway entrances. Journal of Hydrodynamics, 35(4), 782鈥802. 聽

Farzadkhoo, M, Kingsford, R T, Suthers, I M, Geelan-Small, P, Harris, J H, Peirson, W and Felder, S (2022) Attracting juvenile fish into Tube Fishways 鈥 roles of transfer chamber diameter and flow velocity. Ecological Engineering, 176, 106544. 聽

Peirson, W L, Harris, J H, Suthers, I M, Farzadkhoo, M, Kingsford, R T and Felder, S (2022) Impacts on fish transported in tube fishways. Journal of Hydro-Environment Research, 42, 1鈥11. 聽

Peirson, W L, Harris, J H, Kingsford, R T, Mao, X and Felder, S (2021) Piping fish over dams. Journal of Hydro-Environment Research, 39, 71鈥80. 聽

Harris, J H, Peirson, W L, Mefford, B, Kingsford, R T and Felder, S (2019) Laboratory testing of an innovative tube fishway concept. Journal of Ecohydraulics, 5(1), 84鈥93.
Please contact:

Dr Stefan Felder聽| Associate Professor |聽s.felder@wrl.unsw.edu.au