Since European Settlement, Australia has been rapidly regulating the flows of rivers and streams, much to the peril of our native fish. Internationally, the need for fish to migrate within and between rivers has been recognised for over a century through the construction of fishways. In New South Wales (NSW), the first fishways were constructed in the early 1900’s with little success owing to poor designs, which were modelled for Northern Hemisphere Salmonids with advanced swimming and jumping capabilities. Unfortunately, it took until 1985 to realise just how poorly these early fishways were performing for Australian native fish and for suitable alternate designs to be developed.
By 2017, 135 “modern” fishways had been constructed in NSW including rock ramp, vertical slot, denil, and fish lock designs. However, no comprehensive review had been completed on the design, management, and maintenance of these fishways since they were constructed, with the last significant review of design principles in NSW occurring in 2000. Subsequently, the NSW Department of Primary Industries (Fisheries) undertook site inspections of these fishways to assess the relevance of the current designs guidelines with the aim to develop new, updated guidelines to assist the construction and operation of current and future fishways in NSW.
The aim of this presentation will be to detail the main findings of the fishway site inspections for rock-ramp, vertical slot, denil, and fish lock designs, with common faults and issues identified, and recommended solutions and guidelines being proposed. These findings will be used to develop a revised NSW Fish Passage Guidelines document that will aim to provide clarity and certainty to asset owners regarding operational and maintenance requirements, while also aiming to ensure that fishways are operating effectively to pass native Australian fish.